Circular No. 40/2025/TT-BNNMT stipulates the分级制度和矿产资源储量；各类矿产勘探方法和工作量；矿产勘探项目方案和报告结果的样本及内容。

Regulations on classification of reserves and mineral resources; methods, volume of geological exploration work for each type of minerals; templates, contents of project proposals and reports on geological exploration results

Pursuant to the Law on Geology and Minerals No. 54/2024/QH15 dated November 29, 2024;

Pursuant to the Government Decree No. 193/2025/NĐ-CP dated July 2, 2025 detailing certain provisions and implementation measures of the Law on Geology and Minerals;

Pursuant to Decree No. 35/2025/NĐ-CP dated February 25, 2025 of the Government stipulating the functions, tasks, powers, and organizational structure of the Ministry of Agriculture and Rural Development;

At the proposal of the Director of the Vietnam Geological and Mineral Resources Administration;

The Minister of Agriculture and Rural Development issues this Circular regulating the classification of reserves and mineral resources; methods, volume of geological exploration work for each type of minerals; templates, contents of project proposals and reports on geological exploration results.

PART I

GENERAL PROVISIONS

Article 1. Scope of Regulation

This Circular regulates the classification of reserves and mineral resources; methods, volume of geological exploration work for each type of minerals (except seabed sediment minerals and marine sand); templates, contents of project proposals and reports on geological exploration results.

Article 2. Applicability

This Circular applies to state management agencies on geology and minerals; organizations and individuals granted permits for geological exploration of minerals; organizations and individuals implementing mineral exploration projects; other organizations and individuals related to mineral exploration activities.

Article 3. Explanation of Terms

In this Circular, the following terms are understood as follows:

1. Solid mineral resource is the quantity of solid minerals that have been surveyed and explored, meeting the minimum requirements for exploitation and utilization in whole or in part at present or in the future.

2. Determined solid mineral resource is the solid mineral resource that has been surveyed and explored, with its location, distribution area, shape, quantity, quality, and distinctive geological features identified with geological reliability from estimated to confirmed.

3. Predicted solid mineral resource is the solid mineral resource predicted in mineral surveys based on favorable geological premises and signs for mineral formation, or from individual works discovering minerals with geological reliability from speculative to inferred.

4. Solid mineral reserve is the portion of mineral resources that have been explored and expected to be exploitable under specific economic and technical conditions, yielding economic benefits at the time of evaluation.

5. Temporary criteria for calculating solid mineral reserves is a set of requirements regarding the quality of minerals and economic-technical conditions for mining. The parameters of temporary criteria for calculating reserves are limit values used to delineate industrial ore bodies and calculate reserves and resources.

6. Natural mineral water source is underground natural water formed and contained in a specific geological structure with favorable geological and hydrogeological characteristics for the formation, accumulation, and movement of water; it has a stable mineral composition and chemical, physical, microbiological properties, and original purity over time, meeting Vietnamese technical standards or foreign standards permitted for application in Vietnam.

7. Natural hot water source is underground natural water formed and contained in a specific geological structure with favorable geological and hydrogeological characteristics for the formation, accumulation, and movement of water; it has a temperature of 30°C or higher, meeting Vietnamese technical standards or foreign standards permitted for application in Vietnam.

8. Total mineralization degree is the total content of dissolved minerals (ions, molecules, compounds) in water, excluding gases.

9. Mineral water and natural hot water reserve is the portion of mineral water and natural hot water that has been explored and ensured to determine the certainty of existence conditions, stability of flow rate and quality over time, and the relationship between mineral water, hot water, and groundwater and surface water.

10. Estimated mineral water and natural hot water resource is the portion of mineral water and natural hot water that has been explored and preliminarily surveyed for exploitation and use to serve human life.

11. Solid mineral deposit is a natural accumulation of useful solid minerals with quantities and qualities meeting exploitation requirements under current technological and economic conditions.

12. Mineral water and natural hot water deposit are parts (strata, sections, areas, or aquifers) containing mineral water and natural hot water distributed below the ground with volumes and qualities ensuring reasonable use in the national economy.

13. Economically viable reserve is the portion of solid mineral reserves that have been definitely or reliably determined in terms of volume (volume) and quality, ensuring profitable exploitation and processing with a certain investment capital within a specified period.

14. Potentially economically viable resource is the portion of solid mineral resources that have been definitely or reliably determined in terms of volume (volume) and quality. Feasibility studies or pre-feasibility studies (Investment Project or Investment Report on Mining) prove that investing in the exploitation and processing of these solid mineral resources is not economically beneficial or cannot be exploited due to current technical, technological, environmental, and legal conditions; however, they may be economically viable in the future.

15. Unclearly economically viable resource is the portion of solid mineral resources identified or predicted based on basic geological survey results on mineral resources, surveys, and mineral exploration. Resource assessment mainly relies on geological parameters without conducting feasibility studies or pre-feasibility studies. Economic analysis is based solely on given economic-technical parameters or compared with similar mining enterprises' economic-technical indicators, thus unclear economic viability.

16. Technical and technological feasibility study is a detailed evaluation of the rationality of technology and the development potential of a mining project serving as a basis for investment decision-making. The basis for preparing a feasibility study report is the exploration work results.

17. Pre-feasibility study on technical and technological aspects are preliminary assessments of the project's development potential for mineral exploitation, serving as the basis for further consideration of future investment projects. The foundation for preparing a feasibility study report is the result of exploration with geological, technical, environmental, legal, and economic information collected up to the time of report preparation.

18. General Technical Study is an initial assessment of the project's development potential for mineral exploitation based on survey, investigation, and evaluation results of minerals, comparing economic-technical criteria with similar mines having the same geological structure and mining technical conditions. The goal of the general technical study is to identify investment opportunities.

19. Ore Factor is the ratio (in terms of thickness, area, volume) between ore and non-ore rock in cross-sections through the ore body or throughout the entire ore body. The industrial ore factor is the ratio (in terms of thickness, area, volume) between industrial-grade ore and non-ore rock (including non-industrial-grade ore) in cross-sections through the ore body or throughout the entire ore body.

20. Main Mineral is the mineral that, when mined and processed, provides the highest economic value among the combination of minerals/elements in the ore within the exploration area (mine) at the time of evaluation (determining reserves) and is determined in the exploration plan and the mineral exploration results report.

21. Accompanying Mineral is a mineral that can be mined together with the main mineral and has economic efficiency.

22. Laboratory-scale Research Technology Sample is a sample taken in a certain quantity for laboratory research to evaluate the ore's material composition, determine key economic-technical parameters, and propose a reasonable crushing, beneficiation, or production technology scheme for the primary component, accompanying valuable components (if any), or products according to the proposed use in the exploration plan.

23. Expanded Laboratory-scale Research Technology Sample (semi-industrial scale) is a sample taken in sufficient quantity for laboratory research, which may include small-scale actual production experiments to relatively thoroughly assess the ore's material composition parameters, key economic-technical parameters of the beneficiation stages, and propose a reasonable crushing, beneficiation, or production technology scheme for the primary component, accompanying valuable components, and use fields according to the exploration objectives.

24. Industrial-scale Research Technology Sample (pilot scale) is a large sample taken for actual production research to comprehensively and thoroughly assess the ore's material composition, fully determine all economic-technical parameters, and establish a reasonable crushing, beneficiation, or production technology scheme for the primary component, accompanying valuable components (if any), and products according to the proposed use in the exploration plan.

25. Block Stone is natural stone including igneous, sedimentary, and metamorphic rocks in solid blocks without cracks. Block Stone Used for Facing and Flooring (commonly referred to as facing stone) is solid stone blocks or processed into panels used for decoration, facing, and flooring according to standard sizes currently in effect. Block Stone Used for Artisanal Products (commonly referred to as artisanal stone) is solid stone blocks or processed and crafted into various artisanal products.

26. Ore Body, Mineral Body (hereinafter referred to as Ore Body) is a mineral accumulation distributed within a specific structural element or a set of geological structural elements, with dimensions and quality meeting current or near-future requirements for mining and processing.

Chapter II

CLASSIFICATION OF RESERVES AND MINERAL RESOURCES

Article 4. Requirements for Reserves and Mineral Resources

1. Reserves and solid mineral resources are calculated separately for each type of mineral based on the presence of minerals underground, excluding losses due to extraction and processing. For composite mineral deposits, reserves and mineral resources include both primary and accompanying minerals.

2. Reserves and solid mineral resources are calculated in units of volume or mass depending on the intended use.

3. The quality of solid mineral resources is determined in their natural state underground, without considering depletion due to extraction processes; according to the intended use and processing technology, taking into account the maximum recoverability and utilization of accompanying beneficial components.

Article 5. Criteria for Classifying Reserves and Mineral Resources

1. Classification of reserves and solid mineral resources is carried out based on the combination of three criteria: economic efficiency, technical feasibility assessment, and geological reliability, specifically:

a) Economic efficiency is divided into three levels: economically viable (indicated by the number 1), potential economic viability (indicated by the number 2), and unclear economic viability (indicated by the number 3);

b) Technical feasibility assessment is divided into three levels: feasible (indicated by the number 1), preliminary feasible (indicated by the number 2), and general assessment (indicated by the number 3);

c) Geological reliability is divided into four levels: certain (indicated by the number 1), reliable (indicated by the number 2), estimated (indicated by the number 3), and forecasted (indicated by the number 4). For the forecast level (indicated by the number 4), it is further divided into two sub-levels: inferred (indicated by the number 4a) and indicated (indicated by the number 4b).

2. The classification levels of reserves and solid mineral resources are determined according to the sequential numerical symbols for each level (economic efficiency, technical feasibility assessment, geological reliability) as specified in Clause 1 of this Article.

Article 6. Classification of Reserves and Mineral Resources

1. Solid mineral reserves are classified into three levels: 111, 121, and 122.

2. Solid mineral resources consist of defined solid mineral resources and forecasted solid mineral resources.

a) Defined solid mineral resources are classified into six levels, including economically viable resources with three levels 211, 221, 222, and resources with unclear economic viability with three levels 331, 332, 333;

b) Forecasted solid mineral resources are classified into two levels: 334a and 334b.

TABLE OF CLASSIFICATION OF RESERVES AND MINERAL RESOURCES

➀ - Feasibility Assessment of Technical and Technological Aspects.

➁ - Preliminary Feasibility Assessment of Technical and Technological Aspects.

➂ - General Assessment of Technical and Technological Aspects.

Article 7. Requirements for the Level of Assessment of Reserve and Resource Classes

1. Reserve Class 111

Reserve class 111 is delineated within the control range of exploration works and mining works. Reserve class 111 meets the following requirements:

a) Geological assessment level: the explored reserve volume ensures detailed information about the shape, size, position, and geological structure of the ore body; division and delineation of economically valuable mineral parts, layers, interbedded rock lenses, and non-compliant internal parts; clear determination of the quality and technological properties of the mineral; detailed study of geological hydrogeological, engineering geological conditions, and mining conditions, ensuring sufficient basis for mine design. Geological reliability of the reserve must be at least 80%;

b) Technical and technological feasibility assessment level: the mining project demonstrates that the extraction, beneficiation, and processing of minerals according to the selected technical and technological solution is reasonable, ensuring comprehensive, thorough, and economical use of mineral resources, environmental protection, and legality;

c) Economic efficiency: the mining project report or exploitation results confirm that the investment in mining and processing will yield economic benefits at the time of evaluation.

2. Reserve Class 121

Reserve class 121 is delineated within the control range of exploration works. Reserve class 121 meets the following requirements:

a) Geological assessment level: the geological assessment level of reserve class 121 is similar to that of reserve class 111. Geological reliability of the reserve must be at least 80%;

b) Technical and technological feasibility assessment level: the preliminary feasibility study report of the mining project or the technological sample research report confirms that the extraction and processing of minerals according to the selected technical and technological solution is reasonable, ensuring comprehensive, thorough, and economical use of mineral resources, environmental protection, and continued investment in the feasibility of the mining project;

c) Economic efficiency: the preliminary feasibility study report of the mining project or a comparison with similar operating mines under similar conditions confirms that continuing to invest in the feasibility study of the mining project will ensure economic benefits at the time of evaluation.

3. Reserve Class 122

Reserve class 122 is delineated within the control range of exploration works and extrapolation not exceeding half the basic exploration network grid based on the analysis of geological, geophysical, geochemical data or extrapolation from a higher-level reserve volume. Reserve class 122 meets the following requirements:

a) Level of geological assessment: the geological exploration results ensure that the basic characteristics of the mine's geological structure are clarified, the quantity, position, and shape of ore bodies are known, preliminary basic parameters such as size, shape, position, average thickness, and variation in thickness of the ore bodies, number and average size of layers, lenses, intercalations, and non-compliant parts within the ore bodies are delineated; the basic characteristics of the quality of mineral products and their beneficiation, processing, and recovery properties are clarified; the basic conditions of hydrogeological and engineering geology and other technical mining conditions are assessed; to prove or affirm the industrial potential of the mineral deposit, data from similar deposits currently being mined can be cited; the geological reliability of reserves must guarantee at least 50%;

b) Level of technical feasibility assessment: the level of technical feasibility assessment for reserve category 122 is similar to that of reserve category 121;

c) Economic efficiency: the level of economic efficiency assessment for reserve category 122 is similar to that of reserve category 121. The lower geological reliability of reserve category 122 compared to reserve category 121 may affect the risk level of the mining project;

4. Resource categories 211, 221, and 331;

Resource categories 211, 221, and 331 are delineated within the control range defined by exploration works;

a) Level of geological assessment: resource categories 211, 221, and 331 have a geological assessment level similar to reserve category 111. The geological reliability of resources must guarantee at least 80%;

b) Level of technical feasibility and economic efficiency assessment: resource category 211 represents the portion of resources that have been studied for feasibility in the mining project investment under technological, economic, environmental, and other conditions at the time of evaluation, indicating that mining and processing minerals from this resource source has economic potential; resource category 221 represents the portion of resources that have been preliminarily studied for feasibility in the mining project investment, indicating that mining and processing minerals from this resource source has economic potential; resource category 331 represents the general study on mining resources, thus it is unclear at the time of evaluation whether mining and processing minerals from this resource source will be economically viable or have economic potential;

5. Resource categories 222 and 332;

Resource categories 222 and 332 are delineated within the control range defined by exploration works and extrapolation limited by geological, geophysical, and geochemical data;

a) Level of geological assessment: these are portions of resources that have been explored with a geological assessment level similar to reserve category 122. The geological reliability of resources must guarantee at least 50%;

b) Level of technical feasibility and economic efficiency assessment: resource category 222 represents the portion of resources that have been preliminarily studied for feasibility in the mining project investment, indicating that mining and processing minerals from this resource source does not have economic viability at the time of evaluation but may become economically viable in the future; resource category 332 represents the general study on mining resources, thus it is unclear at the time of evaluation whether mining and processing minerals from this resource source will be economically viable or have economic potential;

6. Resource category 333;

Resource category 333 represents the portion of resources that have been generally evaluated and initially determined regarding the shape, position, and distribution of ore bodies delineated within favorable geological structures for mineral formation based on the processing and synthesis of geophysical, geochemical-mineralogical research results combined with some individual drilling and excavation works or extrapolation from adjacent areas with more detailed geological studies;

a) Level of geological assessment: resource category 333 represents the portion of resources that have been generally evaluated and initially determined regarding the shape, position, and distribution of ore bodies. The quality of minerals is determined based on samples taken from natural outcrops, geological works, or extrapolation from adjacent areas with more detailed geological studies. The geological reliability of the resource category must reach at least 20%;

b) Level of technical feasibility and economic efficiency assessment: resource category 333 represents the general study on mining resources, thus it is unclear at the time of evaluation whether mining and processing minerals from this resource source will be economically viable or have economic potential;

7. Forecasted solid mineral resources;

Forecasted solid mineral resources are inferred or estimated from favorable geological premises and indicators for mineral formation based on regional geological investigation data about mineral resources. Forecasted resources are delineated within the area of ore basins, ore zones, ore nodes, and ore fields, mineralization belts from geophysical, geochemical-mineralogical research results, natural outcrops, and excavation works. The quantity of forecasted resources is calculated using quantitative mineral generation prediction methods utilizing data from similar industrial value mineral deposits distributed in ore zones, nodes, etc. Depending on the level of basic geological investigation of mineral resources, forecasted resources are classified as follows:

a) Resource category 334a: this is the portion of solid mineral resources primarily inferred based on regional geological investigation data about mineral resources at scales of 1:50,000 - 1:25,000 (or larger), with favorable geological premises and indicators for ore formation. Additionally, resource category 334a can also be inferred from comparisons with deposits that have been and are being investigated, evaluated, and explored with similar geological contexts or extrapolation from adjacent areas with more detailed geological assessments.

b) Resource level 334b: is the portion of solid mineral resources primarily estimated during regional geological survey at scale 1:200,000 to 1:50,000, or estimated through comparison with similar geological contexts where mineral deposits have been discovered.

8. In cases where there is no feasibility study report or preliminary feasibility study report for the mineral exploitation project, the reserves levels 121 and 122 shall be determined based on the Appendix of the temporary index report for reserve calculation prepared by the Investor according to Model No. 03 of Appendix VI issued together with this Circular and submitted along with the mineral exploration result report.

Article 8. Classification of Reserves and Resources of Solid Mineral Deposits

For composite mineral deposits, the main valuable minerals and components are classified at the same reserve or resource level, while accompanying minerals/elements or valuable components are classified at the same level or lower levels depending on the degree of research, distribution characteristics, and recoverability.

Article 9. Relationship between Reserves and Resources of Solid Mineral Deposits

Between reserve levels 111, 121, 122 and resource levels 211, 221, 222, 331, and 332 can be converted when there are changes in economic factors, market conditions, mining technology, beneficiation technology, processing of minerals, environmental conditions, and related laws (according to Appendix I issued together with this Circular).

Chapter III

METHODS AND VOLUMES OF MINERAL EXPLORATION WORK FOR DIFFERENT TYPES OF SOLID MINERALS

WITH RESPECT TO EACH TYPE OF SOLID MINERAL

Article 10. Classification of Deposit Groups in Mineral Exploration

1. When classifying deposit groups in mineral exploration, the following bases shall be considered:

a) The shape, size, orientation of ore bodies, stability of thickness, variation in grade of major components, and complexity of geological structure of the deposit;

b) Quantitative indicators assessing the variation in thickness along workings, grade of ore bodies according to single samples (within the ore body boundaries), and geological mining conditions;

c) Specific arguments and evaluations for major ore bodies, which account for no less than 70% of the deposit's reserves. The classification of deposit groups in mineral exploration is proposed in the Mineral Exploration Plan and confirmed during the exploration process. Any changes require adjustments to the deposit group, exploration methods, and volumes as per actual developments at the deposit.

2. Deposit groups in mineral exploration are divided into the following categories:

a) Simple Mine Group (I);

b) Relatively Complex Mine Group (II);

c) Complex Mine Group (III);

d) Very complex deposit group (IV).

3. Conditions for classifying and determining deposit groups in mineral exploration:

a) Simple deposit group (I): includes large deposits or parts thereof with simple geological structures, consisting of false bedded ore bodies, horizontal or gently inclined beds; ore bodies have simple shapes, with an ore factor from 0.8 to 1.0; stable thickness, variation coefficient of thickness along workings not exceeding 40%; even distribution of major valuable components, variation coefficient of grade according to single samples not exceeding 40%;

b) Relatively complex deposit group (II): includes medium to large deposits or parts thereof with relatively complex geological structures, consisting of ore bodies with relatively simple to complex shapes; bedded, lens-shaped, etc.; relatively stable to unstable thickness of ore bodies, variation coefficient of thickness along workings from over 40% to 80%; distribution of major valuable components from relatively even to uneven, variation coefficient of grade according to single samples from over 40% to 100%, and an ore factor from 0.6 to 0.8;

c) Complex deposit group (III): includes small to medium deposits or parts thereof with complex geological structures, consisting of bedded, lens-shaped, chain of lenses, pod-shaped, columnar, tubular, etc.; very complex shapes of ore bodies, unstable thickness, variation coefficient of thickness along workings from over 80% to 100%; uneven distribution of major valuable components, variation coefficient of grade according to single samples from over 100% to 150%; an ore factor from 0.4 to 0.6;

d) Very complex deposit group (IV): includes small deposits or parts thereof with very complex geological structures, consisting of small to very small-sized vein, network of veins, lens, chain of lenses, pod-shaped, etc.; extremely complex shapes of ore bodies, very unstable thickness, variation coefficient of thickness along workings over 100%; extremely uneven distribution of major valuable components, variation coefficient of grade according to single samples over 150%; an ore factor below 0.4.

Article 11. Methods and volume of work for mineral exploration for each type of solid minerals

The methods and volume of work for mineral exploration for each type of mineral shall be determined based on:

1. Classification of mine groups in mineral exploration as prescribed in Article 10 of this Circular.

2. Meeting technical requirements for mineral exploration as stipulated from Article 12 to Article 25 of this Circular.

3. The network of exploration works for mineral exploration according to the orientation set out in Appendix II attached hereto.

Article 12. Principles for implementing mineral exploration work

1. Mineral exploration shall be carried out from general to detailed; from surface to deep underground, the network of mineral exploration works from sparse to dense, geological mapping at scales from 1:1,000 to 1:5,000 depending on the type of mineral and the distribution ratio of ore bodies within the area and as specified in the mineral exploration plan.

2. Collecting all information, data, geological, hydrogeological, engineering geological, environmental geological materials; mining conditions serving the evaluation, establishment of investment projects for mineral exploitation and mine design.

3. The sequence of mineral exploration shall be established based on compatibility with the complexity of geological structure, scale of reserves and economic value of the mine.

Article 13. Requirements for geodetic work

1. Coordinates of control grid points, measurement points of works, detailed measurement points in direct topographic surveying shall be measured and calculated from national coordinate origin points of Class "0", Class I, II, III in the VN2000 coordinate system, projection zone and central meridian specifically defined in the technical design. Heights of control grid points, measurement points of works, detailed measurement points in direct topographic surveying shall be measured and calculated from national height origin points of Class I, II, III and IV.

2. The exploration area must establish at least two levels of grids, a basic control grid and a mapping control grid. The basic control grid shall be connected to at least two national coordinate and height origin points. Surveying of the control grid may use static GNSS technology, electronic total stations, or other modern methods. Point density, measurement methods, accuracy shall comply with standards, technical regulations on direct topographic surveying for map creation and geographic base database currently in effect at the time of application.

3. Conduct topographic map drawing work at corresponding scales as required by exploration work. Topographic map scales from 1:1,000 to 1:5,000, depending on geological structure, ore body scale, and terrain complexity. Maps shall be established in accordance with National Technical Standards for Topographic Maps. Compilation of topographic maps shall comply with standards, technical regulations on content and symbols of topographic maps currently in effect at the time of application.

4. Determine the coordinates and heights of exploration work points, regional angle closure points. The basis for determination is the control grid points and electronic total stations, optical theodolites can be used for surveying. Measurement point accuracy shall not exceed 1/3 of the basic uniform height difference.

5. Digital data files and survey notebooks shall follow models in accordance with standards, technical regulations on direct topographic surveying for map creation and geographic base database currently in effect at the time of application.

Article 14. Requirements for Geological Survey Mapping

1. The geological survey mapping work for solid mineral exploration shall be carried out at a scale of 1:5,000 to 1:1,000, depending on the size of the ore body and the complexity of the mine's geological structure.

2. The geological map must clearly depict the specific characteristics of the mine's geological structure, the distribution features of igneous rock formations, sedimentary rocks, folds, tectonic fractures, metamorphic zones, mineralized zones, and ore bodies within the exploration area; it must provide a basis for evaluating the distribution features, formation conditions of the ore body, the relationship between the ore body and the surrounding rocks, and the surrounding geological structures.

Article 15. Requirements for Selection and Arrangement of Exploration Works

1. Selection of Exploration Works

a) In solid mineral exploration, various types of excavation works (strip trenches, ditches, shafts, adits) and drilling works shall be used. The selection and determination of exploration works shall be specified in the exploration project plan, consistent with the ore body's lying position, depth distribution, geological structure, shape, thickness, and the characteristics of the overburden layer, as well as the features of the ore body and the surrounding rock.

b) At each work site, detailed sampling shall be conducted to determine the quality and distribution characteristics of various minerals according to the project objectives and accompanying minerals (if any), weathering depth, structural features of the ore body's wall rock and pillar rock.

c) For mines with very complex geological structures, to clarify the lying position, shape, and internal structure of vein-type, seam-type, lens-type, chain-lens-type, pocket-type, column-type ore bodies, vertical seam adits or cross-seam adits shall be used, minimizing the use of drilling works.

d) Drilling works must meet the technical requirements stipulated in the current regulations governing the construction of drilling works for basic geological surveys, geological surveys on minerals, and mineral exploration.

đ) For ore bodies with large dip angles (≥ 55°), inclined drilling or horizontal drilling methods should be applied based on the topography of the mining area.

2. Arrangement of Exploration Works and Selection of Exploration Network Density

a) The arrangement of exploration works must ensure a comprehensive assessment of the geological structure's characteristics, shape, size, lying position, stability in thickness and quality of the ore body.

b) The network of solid mineral exploration works shall be oriented according to the provisions set forth in Appendix II attached hereto.

c) Exploration works, mining works, natural and artificial exposures within the exploration area shall be promptly, fully, and accurately described, mapped, and recorded in original documentation in accordance with the current regulations on collecting original data in solid mineral exploration, and shall be plotted on the actual geological map.

Article 16. Requirements for Sampling Work

1. When encountering ore bodies or mineralized zones containing ore in exploration works, detailed and systematic sampling shall be taken to delineate the ore body boundaries and assess the quality of the ore for its main components, accompanying components. The sampling positions shall be detailed on the original documentation.

2. The size of samples shall be based on the distribution characteristics of the material components inside the ore body, ensuring reliability and a full evaluation of the main components, accompanying components (if any), and harmful components.

3. Principles for Sampling

a) For works encountering ore bodies or mineralized zones containing ore, continuous sampling shall be taken to ensure sufficient basis for delineating the ore body boundaries and interbedded layers. The length of the channel sample shall be determined by the internal structure of the ore body, changes in material composition, structural and architectural features, and physical-mechanical properties of the ore.

b) The results of sampling for each type shall be presented through images.

c) Test samples for technological purposes must represent the chemical composition, mineralogical composition, physical-mechanical properties, particle size, and other properties suitable for the average composition of each type of ore and the main ore body in the mine.

d) Bulk weight samples shall be taken for a minimum of three samples for each type of natural ore. Along with each bulk weight sample, a minimum of three small bulk weight samples and moisture content samples shall be taken for analysis and comparison. The volume of the bulk weight sample ranges from 0.5 to 1 cubic meter. For hard or thin ore bodies, or deeply hidden ore bodies where bulk weight samples cannot be obtained, the bulk weight of the ore shall be determined by the average value of small bulk weight samples and moisture content. In this case, each ore body and type of ore shall have a minimum of five small bulk weight samples and moisture content samples taken.

Article 17. Requirements for Sample Processing Work

1. All samples must be processed before being sent for analysis reduction to particle sizes smaller than 01mm. Further processing and reduction shall be carried out according to a processing scheme suitable for each ore deposit.

2. The quality of sample processing is systematically checked at all stages and compliance with the sample processing scheme is verified. All basic chemical samples prior to analysis must be processed to a particle size of 0.074mm.

Article 18. Requirements for Sample Analysis Work

1. The results of sample analysis must ensure the determination of the content and form of existence of the main beneficial components and accompanying beneficial components (if any), harmful components.

a) The content of the main components and accompanying beneficial components, harmful components (if any) is determined through chemical analysis or other methods as prescribed and currently in effect at the time of application.

b) Basic chemical analysis samples analyze components according to each type of mineral and are specified in the exploration project content. Basic chemical analysis is conducted on 100% of the samples taken from the exploration site. Harmful components and other components are determined through group chemical analysis samples, at least 10%, but not less than 25 samples.

c) Group chemical analysis samples are selected from the stored analysis samples of basic chemical samples, ensuring representation of natural ore types or industrial ore grades. For group samples, in addition to the main components as stipulated in point b, Clause 1 of this Article, additional accompanying components (if any) and other harmful components are analyzed and specified in the exploration project content.

d) Mineral components, structural and architectural characteristics, and other physical properties of the ore are evaluated using petrographic, mineralogical, physical, chemical, and other analytical methods.

e) Technological sample research work: technological samples are studied at laboratory scale or expanded laboratory scale (semi-industrial). For new ores, difficult-to-treat ores, or ores without industrial production experience, there must be a separate evaluation program at expanded laboratory scale up to industrial scale. The quantity and number of technological samples are specified in the exploration project. The results of technological sample research must ensure the assessment of the ore's material composition, ore quality, determination of key economic-technical parameters of grinding and beneficiation processes, and proposal of reasonable grinding and beneficiation technology schemes for recovery of main components and accompanying beneficial components (if any). Harmful components and usage areas according to the exploration target; Additional exploration projects to upgrade reserves and explore deeper or expand within the mineral area where technological sample research has been conducted or in mines with similar quality and technological characteristics are ongoing, then the work of collecting and summarizing the results of technological sample research, beneficiation at the mine, and no requirement for taking and testing technological samples.

Article 19. Requirements for Sample Analysis Inspection Work

1. Sample analysis inspection work is regularly and systematically carried out.

2. Quality control of sample analysis results is implemented according to standards, specifications, and technical regulations on quality control of geological and mineral sample analysis results currently in effect at the time of application.

Article 20. Requirements for Hydrogeological and Engineering Geological Assessments

1. Requirements for hydrogeological assessment:

a) Collect meteorological and hydrological data of the exploration area for at least the last five years;

b) Evaluate and determine the main water-bearing layers, surface water flows and volumes that may cause flooding in the mine, particularly in the parts of the mine most susceptible to flooding, to address drainage and mine drying issues;

c) For water-bearing layers, determine their thickness, lithological composition, supply and drainage conditions, and the relationships between these layers, between surface water and groundwater, and other relevant hydrogeological parameters;

d) Study the chemical and microbiological components of water, assess its potential to corrode concrete and metals, the content of beneficial and harmful components in the water, and the impact of mine drainage on underground water usage facilities in the region, as well as the usability of water for domestic purposes. Recommend solutions related to water supply and drainage, and the degree of impact of mine drying on the surrounding environment.

2. Requirements for engineering geological assessment:

a) Determine the physical and mechanical properties of ore, surrounding rock, and overburden under natural and saturated water conditions; the engineering geological characteristics of soil and rock layers, their anisotropic nature, rock composition, fracturing, tectonic destruction, karst, weathering zone destruction phenomena, and dynamic engineering geological phenomena;

b) Evaluate the stability of mine structures and calculate basic parameters and the stability of mine structures;

c) All hydrogeological, engineering geological conditions, and other natural factors must be assessed to meet the basic requirements for investment project development and mine design. In cases where hydrogeological and engineering geological conditions are extremely complex, specialized investigation and evaluation projects are required. Hydrogeological and engineering geological assessment work shall be carried out in accordance with existing regulations at the time of application.

Article 21. Requirements for Geophysical Work

1. Depending on the type of mineral, geophysical work is selected to assist in determining the presence of ore bodies, mineralized zones within the mine, and exploration works. For areas with limited geological research, where the exploration target has not been determined, or where ore bodies are covered, appropriate ground geophysical methods should be chosen based on each type of mineral. For coal and metal mines, geophysical exploration and borehole geophysical methods should be selected.

2. The methods and volume of geophysical exploration work are detailed in the exploration plan suitable for each exploration target's characteristics.

Article 22. Requirements for Gas Content Assessment

For coal mines, radioactive minerals, mercury, arsenic, and other complex mineral types related to gas, gas content assessment work must be conducted.

1. Requirements for gas content assessment during mineral exploration:

a) Depending on the type of mineral, assess gas content both in the ore body and surrounding rock; collect comprehensive data on gas content from nearby operating mining works;

b) Determine the composition and source of mine gas;

c) Determine the distribution pattern of gases across area, depth of strata, and ore body orientation; geological factors influencing the distribution of mine gas;

d) Determine the impact of gases on future mineral extraction processes;

e) For coal, assess the level of gas richness as a basis for predicting mine gas emissions. When sufficient data is available, calculate the gas reserves in coal seams as an accompanying valuable mineral resource.

2. Tasks for gas content assessment:

a) Collect comprehensive and accurate data on natural gas content in the mine as a basis for investment construction project studies and mine exploitation design;

b) Determine the qualitative composition of natural gas and gas zones;

c) Determine the surface depth of gas zones and the natural gas content of major ore bodies in the mine;

d) Determine the influence of key geological factors on the distribution of gases in ore bodies and surrounding rocks, especially focusing on surrounding rock layers with high gas content;

e) Establish fundamental laws regarding changes in the depth of weathered gas zones, changes in gas content with depth, and the dependence of these laws on geological factors. The content and methods of mine gas research are specified in the project.

Article 23. Requirements for assessing the level of pollution and environmental impact in mineral exploration activities

During the implementation of the Mineral Exploration Project, the organizations and individuals conducting mineral exploration shall be responsible for performing the following tasks:

1. Collecting geological environment data to forecast and assess the main factors affecting the environment when implementing mineral exploration activities.

2. Evaluating geological accidents and negative impacts on the environment that may be caused by exploration activities, and proposing preventive and mitigation measures. The content and extent of environmental impact assessment during mineral exploration have been mentioned in the Mineral Exploration Project.

Article 24. Requirements for technical evaluation work related to mining conditions

1. Preliminarily evaluating the boundaries of the mining area, the slope angle of the layer's side, the slope angle of the pit edge, the coefficient and volume of overburden stripping for open-pit mining methods; preliminarily evaluating the rock pressure on the wall, pillar, and body of the ore for underground mining methods.

2. Calculating and forecasting the amount of rainwater, surface water, and groundwater flowing into the mine for open-pit mining; the total amount of water that can flow into the shaft for underground mining. Calculating and forecasting the stable slope angle of the pit edge for open-pit mining; the pressure of rock on the roof, walls, bottom, and well shaft for underground mining.

Article 25. Requirements for establishing digital exploration data and processing geological data

Original documents of mineral exploration work are established in digital form, fully reflecting the information according to the currently effective regulations at the time of application.

Article 26. Work on calculating reserves and solid mineral resources

1. The calculation of reserves and solid mineral resources is based on detailed reserve calculation criteria explained in the mineral exploration report for each mine. The explanation of temporary reserve calculation criteria for mineral resources is carried out according to the report attached to this Circular.

2. The method of calculating reserves and solid mineral resources is selected to ensure suitability with the structural characteristics of the ore body for each mine. Specialized software is applied for reserve calculation or verification.

3. Reserves and solid mineral resources are presented on the reserve calculation plan map; longitudinal section of the ore body for reserve calculation or block model at a scale of 1:2,000 to 1:1,000, depending on the scale, characteristics of the ore body, and 1:5,000 for mines with large exploration areas. The reserve calculation results are presented by each ore body, reserve grade, resource grade.

Article 27. Requirements for the highest reserve grade and the ratio of reserve grades

1. The highest reserve grade for Group I and II mines is Grade 121, and for Group III and IV mines is Grade 122; in cases where mines are being explored to supplement and upgrade mineral resources and reserves or to evaluate accompanying minerals, explore deeper and expand, the minimum exploration reserve grade required is Grade 122.

2. The ratio of Grades 121 and 122 is determined by the investor based on the geological characteristics of the mine, financial capacity, mining technical conditions, expected production capacity, and ensuring that the highest reserve grade accounts for at least 15% of the total mine reserves or sufficient for the first 3 to 5 years of exploitation design, and is reflected in the exploration project and the mineral exploration result report.

Article 28. Technical Requirements for Exploration of Certain Minerals

For minerals including: rare earths; primary gold; bauxite; copper; placer tin, placer gold, and placer titanium; coal; apatite; carbonate rock; clay rock; river sand and gravel; decorative stone and artistic stone, the requirements set forth from Article 10 to Article 27 shall be applied, and additional provisions shall be applied as stipulated in Appendix III attached hereto.

Chapter IV

CLASSIFICATION OF RESERVES, RESOURCES AND METHODS, VOLUMES OF EXPLORATION FOR NATURAL MINERAL WATER AND NATURAL HOT WATER

1. Natural mineral water and natural hot water sources shall be named according to their chemical composition (total mineralization, concentration of chemical elements, temperature, chemical compounds) and may also be named according to the administrative location where the natural mineral water and natural hot water sources are located.

2. In cases where natural mineral water and natural hot water sources have two (02) or more chemical element concentration indices, they shall be named according to the order specified in Appendix IV attached hereto. Example: natural mineral water with total mineralization ≥ 1500 mg/l and bromine concentration ≥ 5 mg/l shall be called highly mineralized, bromine natural mineral water.

Article 30. Classification of Natural Mineral Water and Natural Hot Water Mines Based on Exploration Results

1. The basis for classifying natural mineral water and natural hot water mines based on exploration results includes:

a) Complexity of geological structure and hydrogeological conditions;

b) Degree of uniformity of permeability of the host rocks and changes in hydrogeological or geothermal characteristics of the aquifers;

c) Characteristics of the water conveyance system and formation of mineral water reserves and hot water reserves.

2. Natural mineral water and natural hot water mines are divided into three (03) groups, including:

a) Simple mine group (referred to as Group I);

b) Complex mine group (referred to as Group II);

c) Very complex mine group (referred to as Group III).

3. Criteria for determining Group I:

a) Mines in the form of seams within pressurized groundwater basins;

b) Simple hydrogeological conditions;

c) Aquifer layers that are stable in position, thickness maintained, and permeability uniform;

d) No mixing of natural mineral water and natural hot water with non-mineral water or non-hot water;

đ) Factors such as total mineralization, concentration of chemical elements (trace elements), temperature, or chemical compounds accumulated and formed the source of water, with the main exploitable reserve being elastic static or natural dynamic reserve.

4. Criteria for determining Group II:

a) Part of mines in the form of seams within pressurized groundwater basins, intrusion-type mines, fissure-matrix type mines within geological structures related to deep tectonic destruction systems, as well as mines in the weathered crust of crystalline and metamorphic rocks with relatively uniform permeability;

b) Complex hydrogeological conditions;

c) Aquifer layers are cut by fault systems;

d) The boundary between natural mineral water and natural hot water and non-mineral water or non-hot water has a complex shape on maps and cross-sections of exploration areas. During exploitation, there may be infiltration of non-mineral water or non-hot water into the mineral water and hot water collection facilities;

đ) Factors such as total mineralization, concentration of chemical elements (trace elements), temperature, or chemical compounds accumulated and formed the source of water, with the exploitable reserve possibly being natural dynamic reserve and elastic static reserve.

5. Criteria for determining Group III:

a) Fissure-matrix type mines within geological structures and in crystalline and metamorphic rock blocks associated with the distribution of shallow fault systems, intrusion-type mines within near-surface groundwater layers, as well as mines in the weathered crust of metamorphic and crystalline rocks with strong directional permeability;

b) Very complex hydrogeological conditions;

c) Natural mineral water and natural hot water distributed locally within fault zones, often very heterogeneous in space, or in rocks with heterogeneous permeability and characterized by very limited distribution;

d) Hydrogeological or geothermal boundaries may change during exploitation; for small mines, this phenomenon may occur even during experimental phases. During exploitation, there may be infiltration of non-mineral water or non-hot water into the mineral water and hot water collection facilities;

đ) Factors such as total mineralization, concentration of chemical elements (trace elements), temperature, or chemical compounds accumulated and formed the source of water, with the main exploitable reserve being natural dynamic reserve.

Article 31. Protection of natural mineral water sources and natural hot water sources during exploration activities

1. Organizations and individuals exploring natural mineral water and natural hot water shall be responsible for establishing a protective zone around the water source during the organization and implementation of the exploration project.

2. The protective zone for natural mineral water and natural hot water sources is divided into two sanitary protection areas (strictly protected area and ecological protection area):

a) The strictly protected area is established right at the location where the water emerges, specifically within the range of the drilling holes or exploration wells. The range of the strictly protected area must not be less than five meters (05m), measured from the mouth of the drilling hole or exploration well.

b) The ecological protection area is adjacent to the strictly protected area. The range of the ecological protection area must not be less than ten meters (10m), measured from the outer edge of the strictly protected area.

3. Organizations and individuals exploring natural mineral water and natural hot water shall develop plans or measures to protect the water source within the protective zone; construct permanent or semi-permanent structures to protect the water source in the strictly protected area.

Article 32. Classification of Reserves and Estimated Resource Levels

1. Basis for classifying reserves and estimated resource levels:

a) Geological structure, hydrogeological and geothermal conditions of the deposit;

b) Water quality;

c) Mining conditions including: mining system, stability of flow rate and water level in drilling holes, corrosion, salt deposition level, and continuity in water extraction.

2. Natural mineral water and natural hot water reserves and estimated resources are classified into the following levels:

a) Reserve levels include: Class A exploitation reserve and Class B exploration reserve;

b) Estimated resource levels include: Class C1 estimated resource and Class C2 estimated resource.

3. The basis for evaluating the Class A exploitation reserve is the result of exploiting natural mineral water and natural hot water, which has confirmed the position, geological structure, and lithological composition of the water-bearing rock, changes in these factors across the area and cross-sections, and the permeability of the water-bearing rock.

4. The basis for evaluating the Class B exploration reserve is the result of exploring natural mineral water and natural hot water, which has confirmed the position, geological structure, and lithological composition of the water-bearing rock, permeability of the water-bearing rock, and supply conditions of the aquifer.

5. The basis for evaluating the Class C1 estimated resource is the result of exploring natural mineral water and natural hot water or basic geological survey results on minerals, which have relatively confirmed the position, geological structure, and lithological composition of the water-bearing rock, permeability of the water-bearing rock, and supply conditions of the aquifer or adjacent to the area with Class B reserves.

6. The basis for evaluating the Class C2 estimated resource is the result of basic geological surveys on minerals, determined through experiments in the aquifer at individual points, or inferred based on explored areas.

Article 33. Methods and Volume of Exploration for Evaluating Class A Exploitation Reserves

1. Requirements for geological and hydrogeological assessment:

a) Clearly determine the geological structure of the water-bearing layer, distribution and thickness of impermeable layers, and the hydrogeological role of fault zones;

b) Determine the pressure value of the aquifers; supply conditions of the aquifer and recovery capacity of the exploitation reserve;

c) Determine the boundaries of the aquifers, locations of water reservoirs and surface flows, hydraulic relationship between them and mineral water, hot water; distribution of drainage areas of mineral water, hot water on maps and cross-sections, including the supply area in simple deposits;

d) Determine the relationship between the aquifer and overlying and underlying layers; hydraulic relationship between mineral water, hot water and other aquifers' water and surface water;

đ) Monitor water dynamics for a minimum of five (05) hydrological years;

e) Identify the sources of the exploitation reserve and quantitatively evaluate those sources.

2. Requirements for assessing water quality.

Water quality is determined through accurate and comprehensive sampling and analysis of all chemical, physical, biological, and radioactive indicators; analytical and evaluation results ensure stable water quality over time within permissible limits; maximum deviation of indices of physical, chemical, biological, and radioactive components is ten percent (10%) compared to the average value of three initial analysis samples at the exploration stage.

3. Requirements for assessing water volume:

a) The Class A exploitation reserve is calculated and determined within the scope of mining works and by the total actual flow rate of the drilling holes for mining;

b) The Class A exploitation reserve is determined by the lowest daily flow rate of water emergence points according to monitoring data over multiple years (at least five (05) years), if extracted through self-flowing facilities or by the average flow rate of the respective springs.

Article 34. Methods and volume for assessing reserves at exploration level B

1. Requirements for geological and hydrogeological assessment

a) Determining the geological structure of the mineral water-bearing layer;

b) Determining the hydraulic relationship between natural mineral water, natural hot water, and water in other layers and surface water;

c) Approximately determining the source of formation of exploitable reserves of natural mineral water and natural hot water;

d) Monitoring water dynamics for a minimum of one (01) hydrological year.

2. Requirements for water quality assessment

a) Water quality is determined through accurate and comprehensive sampling and analysis of all chemical, physical, biological, and radioactive indicators; analytical results must clearly determine stable water quality within permissible limits over time; maximum deviation of indices for physical, chemical, biological, and radioactive components is twenty percent (20%) from the average value of three initial analysis samples during the exploration phase;

b) Before, during, and after each experimental water extraction; experimental exploitation water extraction requires comprehensive sampling and analysis, including: source water sample, trace element sample, chemical sample, microbiological sample, physical sample, radioactive sample.

3. Requirements for reserve assessment

a) Exploitable reserves of natural mineral water and natural hot water are typically assessed using hydraulic methods. For mines in Group I, a combined hydraulic and hydrodynamic method is used;

b) Exploration level B reserves are calculated based on the actual flow rate of individual wells (for single water collection structures) or the total flow rate of groups of wells (for group water collection structures). In cases where simultaneous testing is conducted through experimental water extraction or experimental exploitation water extraction achieving stable hydrodynamic, hydrometric, gas, and temperature dynamics, for Group I mines, continuous exploitation testing lasts a minimum of three (03) months; for Group II mines, a minimum of six (06) months; for Group III mines, a minimum of twelve (12) months;

c) For natural mineral water and natural hot water that naturally flows out on the ground surface, exploration level B reserves are calculated based on the minimum daily flow rate of water points during a one (01) year monitoring cycle. If exploitation is carried out through self-flow structures, calculation is based on the average flow rate of these points.

Article 35. Methods and volume for assessing estimated resources at level C1

1. Requirements for geological and hydrogeological assessment

a) Preliminary determination of the geological structure of the mineral water-bearing layer and the hydraulic relationship between natural mineral water, natural hot water, and water in other layers and surface water;

b) Sources of water formation are preliminarily determined based on comprehensive geological and hydrogeological data, or by analogy with currently operating or explored mines.

2. Requirements for water quality assessment

a) Water quality is determined through relatively accurate and comprehensive sampling and analysis of all chemical, physical, biological, and radioactive indicators to establish the principle feasibility of using natural mineral water and natural hot water according to requirements and objectives;

b) The potential change in water quality during exploitation is preliminarily assessed based on the analysis of comprehensive geological and hydrogeological conditions;

c) After each experimental water extraction, comprehensive sampling and analysis must be conducted, including: source water sample, trace element sample, chemical sample, biochemical sample, physical sample, radioactive sample to determine water quality.

3. Requirements for estimated resource assessment

a) Extrapolate twice the actual flow rate values of test wells for Group I mines, taking into account the allowable lowering of water levels. The extrapolation limit is justified based on stable water quality throughout the entire exploitation calculation period;

b) Actual flow rates of individual test wells or the total flow rate of interfering well groups are determined through experimental water extraction under stable hydrodynamic, hydrometric, gas, and temperature conditions for a minimum of one (01) month for Group II mines, and a minimum of three (03) months for Group III mines;

c) Actual flow rates of exploration wells not meeting the conditions for classification as level B reserves;

d) Minimum flow rates of water points are determined based on periodic measurements during the dry season with water quality ensuring compliance requirements throughout the rainy season.

Article 36. Method and volume of exploration to assess predicted resources at level C2

1. Requirements for geological and hydrogeological assessment

a) Preliminarily estimate the hydraulic relationship between natural mineral water, natural hot water, and water in other layers and surface water;

b) Sources of water formation are preliminarily evaluated based on geological and hydrogeological investigation materials or similar to already explored mines.

2. Requirements for water quality assessment

Water quality is determined through sampling and preliminary analysis for all chemical, physical, biological, and radioactive indicators, using samples taken from individual points within the aquifer layer or similar to areas that have been explored and assessed.

3. Requirements for estimated resource assessment

a) Predicted resources are calculated and determined within the scope of favorable rock formations and structures that have been investigated;

b) Predicted resources at level C2 are determined by the actual flow rate of a single well or the total flow rate of a group of short-term pumping wells under stable dynamic conditions, corresponding to all mine groups according to their complexity as follows: extrapolation within two (02) or three (03) times the actual flow rate for mine groups I and II at test wells; calculated flow rates of wells planned on areas adjacent to operational or explored water extraction facilities for mine group I;

c) Predicted resources at level C2 are based on the actual flow rate of exploration wells that do not meet the C1 level criteria;

d) Predicted resources at level C2 are based on the minimum natural flow rate of water outcrops determined by non-periodic measurement.

Article 37. Reserves of natural mineral water and natural hot water permitted for exploitation

The reserves of natural mineral water and natural hot water granted an Exploitation License are either class A exploitable reserves or class B exploration reserves.

Chapter V

MINERAL EXPLORATION PLAN; REPORT ON MINERAL EXPLORATION RESULTS, SUPPLEMENTARY EXPLORATION

Article 38. Content of the mineral exploration plan

1. The preparation of the mineral exploration plan is based on geological survey results regarding minerals, including: Survey materials, geological materials from previous stages serving as the basis for selecting the area and mineral objects to be explored or survey and sampling results to delineate the area for preparing the mineral exploration plan, carried out by organizations or individuals.

2. The mineral exploration plan includes: Explanatory section, appendices, and accompanying technical drawings.

3. The explanatory section of the mineral exploration plan contains main contents as stipulated in Clause 1 of Article 42 of the Law on Geology and Minerals.

Article 39. Content of supplementary exploration plan

1. Supplementary exploration is conducted to upgrade mineral resources and reserves or to determine accompanying mineral reserves (if any) within the mining area specified in the mining exploitation permit.

2. The preparation of the supplementary exploration plan to upgrade mineral resources and reserves is based on basic geological survey results regarding minerals, including: Survey materials, geological materials, exploration materials from previous stages; results of mining activities carried out by organizations or individuals engaged in mining, serving as the basis for selecting the area and objects for supplementary exploration to upgrade primary mineral reserves or to determine accompanying mineral reserves (if any).

3. The supplementary exploration plan to upgrade mineral resources and reserves includes: Explanatory section, appendices, and accompanying technical drawings.

4. The explanatory section of the supplementary exploration plan to upgrade mineral resources and reserves includes the following main contents:

a) Evaluation of current status and results of mineral exploitation in the supplementary exploration area;

b) Evaluation of the volume of exploration work already completed at the mine;

c) Methods and volume of exploration work suitable for determining reserves, quality of minerals, mining conditions, processing capacity, and utilization of the mineral objects to be supplemented;

d) Environmental protection measures during supplementary exploration;

đ) Method for calculating mineral reserves;

e) Organization and implementation schedule for the supplementary exploration plan;

g) Budget for supplementary exploration costs to upgrade mineral resources and reserves, prepared according to the unit prices of geological works and related unit prices prescribed by competent state management agencies;

f) Duration of the supplementary exploration plan to upgrade mineral resources and reserves.

Article 40. Contents of the report on mineral exploration results and supplementary exploration

1. The preparation of the report on mineral exploration results is based on the implementation results of the mineral exploration project attached to the Mineral Exploration Permit issued by the competent state management agency.

2. The preparation of the report on supplementary exploration results is based on the implementation results of the supplementary exploration project to upgrade mineral resources and reserves according to the approval document of the authority issuing the mining permit for that type of minerals.

3. The report on mineral exploration results and supplementary exploration includes: Explanatory notes, appendices, and technical drawings.

4. The explanatory section of the report on solid mineral exploration results and supplementary exploration includes the following main contents:

a) Geological characteristics of the area for mineral exploration and supplementary exploration;

b) Results of mineral exploration and supplementary exploration work: volume implemented, products of each method;

c) Quality and technological properties of the minerals;

d) Hydrogeological and engineering geological characteristics of the area for mineral exploration and supplementary exploration;

đ) Evaluation of mining conditions;

e) Indicators used to calculate mineral reserves, methods of calculating mineral reserves, and results of calculating mineral reserves.

5. The explanatory section of the report on geothermal water and natural mineral water exploration results includes the following main contents:

a) Geological characteristics of the area for geothermal water and natural mineral water exploration;

b) Results of geothermal water and natural mineral water exploration work;

c) Hydrogeological characteristics of the area for geothermal water and natural mineral water exploration;

d) Evaluation of the quality of geothermal water and natural mineral water at the exploration borehole;

đ) Results of calculating exploitable reserves of geothermal water and natural mineral water at the exploration borehole;

e) Recommendations on exploitation, processing, use, and protection of the quality of geothermal water and natural mineral water in the exploration area.

1. The mineral exploration project is prepared according to Template No. 01 of Appendix VI promulgated together with this Circular.

2. The supplementary exploration project to upgrade mineral resources and reserves is prepared according to Template No. 02 of Appendix VI promulgated together with this Circular.

3. The report on solid mineral exploration results and supplementary exploration for upgrading mineral resources and reserves in the application dossier for recognition of mineral exploration results and supplementary exploration is prepared according to Template No. 03 of Appendix VI promulgated together with this Circular.

4. The report on geothermal water and natural mineral water exploration results and supplementary exploration in the application dossier for recognition of exploration results and supplementary exploration is prepared according to Template No. 04 of Appendix VI promulgated together with this Circular.

Chapter VI

IMPLEMENTING PROVISIONS

Article 42. Effective Date

Article 1. This Circular takes effect from the date of issuance.

2. From the date this Circular takes effect, the following decisions and circulars shall cease to be effective:

a) Decision No. 25/2007/QĐ-BTNMT dated December 31, 2007, of the Minister of Natural Resources and Environment regarding coal exploration, classification of reserves, and resources;

b) Decision No. 26/2007/QĐ-BTNMT dated December 31, 2007, of the Minister of Natural Resources and Environment regarding carbonate rock exploration, classification of reserves, and resources;

c) Decision No. 27/2007/QĐ-BTNMT dated December 31, 2007, of the Minister of Natural Resources and Environment regarding bauxite mine exploration, classification of reserves, and resources;

d) Decision No. 14/2008/QĐ-BTNMT dated December 30, 2008, of the Minister of Natural Resources and Environment regarding tin, gold, and titanium sand mine exploration, classification of reserves, and resources;

đ) Circular No. 22/2009/TT-BTNMT dated November 11, 2009, of the Minister of Natural Resources and Environment regarding claystone mine exploration, classification of reserves, and resources;

e) Circular No. 33/2010/TT-BTNMT dated December 19, 2010, of the Minister of Natural Resources and Environment regarding iron ore mine exploration, classification of reserves, and resources;

g) Circular No. 52/2014/TT-BTNMT dated September 9, 2014, of the Minister of Natural Resources and Environment regarding classification of reserves and allocation of mineral water and geothermal water resources;

h) Circular No. 03/2015/TT-BTNMT dated February 13, 2015, of the Minister of Natural Resources and Environment regarding primary gold mine exploration, classification of reserves, and resource allocation;

i) Circular No. 04/2015/TT-BTNMT dated February 13, 2015, of the Minister of Natural Resources and Environment regarding lead and zinc mine exploration, classification of reserves, and resource allocation;

k) Circular No. 73/2015/TT-BTNMT dated December 28, 2015, of the Minister of Natural Resources and Environment regarding copper mine exploration, classification of reserves, and resources;

l) Circular No. 74/2015/TT-BTNMT dated December 28, 2015, of the Minister of Natural Resources and Environment regarding apatite mine exploration, classification of reserves, and resources;

m) Circular No. 01/2016/TT-BTNMT dated November 13, 2016, of the Minister of Natural Resources and Environment regarding technical guidelines for riverbed sand and gravel exploration and earth and stone material exploration for filling purposes;

n) Circular No. 45/2016/TT-BTNMT dated December 26, 2016, of the Minister of Natural Resources and Environment regarding mineral exploration project, mine closure, and sample activity report templates; document templates in the mining operation permit application dossier and reserve approval dossier; procedures and formalities for mine closure;

o) Circular No. 60/2017/TT-BTNMT dated December 8, 2017, of the Minister of Natural Resources and Environment regarding solid mineral resource classification and allocation;

p) Circular No. 05/2020/TT-BTNMT dated August 31, 2020, of the Minister of Natural Resources and Environment regarding technical guidelines for block stone exploration and reserve assessment for paving and decorative purposes.

q) Circular No. 02/2024/TT-BTNMT dated April 22, 2024, of the Minister of Natural Resources and Environment amending and supplementing certain articles of Circular No. 01/2016/TT-BTNMT dated January 13, 2016, of the Minister of Natural Resources and Environment on technical regulations for sand, gravel riverbed exploration and soil, rock material filling.

r) Article 7 on rare earth mineral exploration content and Chapter III on rare earth mineral exploration at Articles 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 and Appendix III, Appendix IV of Circular No. 21/2024/TT-BTNMT dated November 21, 2024, of the Minister of Natural Resources and Environment stipulating technical contents of geological survey, evaluation of natural resources and rare earth mineral exploration on land.

Article 43. Transitional Provisions

1. The exploration plan accompanying the mining exploration permit already issued by the competent authority; the supplementary exploration plan to upgrade the main mineral resource reserves or determine the accompanying mineral reserves (if any), issued before this Circular takes effect and still within the validity period of the permit shall continue to be implemented according to the provisions at the time of issuance of the exploration permit and supplementary mineral exploration.

2. The exploration plan for which the application for the mining exploration permit has been accepted, currently undergoing review but not yet approved for issuance of the mining exploration permit; the supplementary exploration plan to upgrade the main mineral resource reserves or determine the accompanying mineral reserves (if any) in the area permitted for mineral exploitation, accepted by the competent authority before this Circular takes effect, organizations and individuals have the right to choose to continue implementing according to the provisions at the time of submission of the application; the content of the review of the exploration plan, the supplementary exploration plan to upgrade the main mineral resource reserves or determine the accompanying mineral reserves (if any) and completion of the exploration plan after the review shall be carried out in accordance with the provisions of this Circular without having to prepare a new exploration plan.

3. The report on the results of mineral exploration, the report on the results of upgrading mineral reserves, which have been accepted for approval of mineral reserves and are currently under inspection, review, and submitted to the National Mineral Reserve Evaluation Council for approval, may continue to be implemented without having to prepare a new report on the results of mineral exploration or a report on the results of upgrading mineral reserves. The completion of the report on the results of mineral exploration, the report on the results of upgrading mineral reserves shall be carried out in accordance with the relevant provisions of this Circular.

Article 44. Implementation Organization

1. Ministries, ministerial-level agencies, agencies under the Government, Chairmen of Provincial People's Committees, and Municipal People's Committees directly under the Central Government are responsible for directing the implementation of this Circular.

2. Departments of Agriculture and Environment of provinces and municipalities directly under the Central Government are responsible for assisting the Chairmen of Provincial People's Committees and Municipal People's Committees directly under the Central Government in implementing this Circular at the local level.

3. Organizations and individuals related to this Circular are responsible for its enforcement. In the process of implementing this Circular, if there are difficulties or inconsistencies, organizations and individuals related to mineral exploration activities are responsible for reporting them to the Ministry of Agriculture and Rural Development through the Vietnam Geological Survey for timely resolution and handling in accordance with the regulations./.