Circular No. 42/2016/TT-BTNMT on technical regulations for assessing the potential of solid mineral resources in basic geological surveys of mineral resources

CIRCULAR

Technical regulations on assessing solid mineral resource potential on land

in basic geological surveys for minerals

Pursuant to the Law on Minerals No. 60/2010/QH12 dated November 17, 2010No. Decree No. 21/2013/NĐ-CP dated March 4, 2013 of the Government;

Pursuant to DecreeNo. concerning the functions of the Ministry of Natural Resources and Environment;June 2024;The Minister of Natural Resources and Environment promulgates this Circular on technical regulations for assessing solid mineral resource potential on land in basic geological surveys for minerals."b) In addition to the lists of public services issued according to the provisions of Clause 2, Article 4 of this Decree, specialized agencies under provincial People's Committees shall report to the provincial People's Committee for decision-making on amending, supplementing, or issuing the list of public services funded by the state budget within their jurisdiction and consistent with the local budget capacity within the approved budget by the Provincial People's Assembly, and send it to the Ministry of Finance and relevant ministries and sectors for supervision during implementation.""4. As of March 31, 2021, credit card issuers that issue cards with BINs issued by the State Bank of Vietnam must comply with the Domestic Chip Card Standard."onThe Director of the Office, Heads of Payment Department, Heads of units under the State Bank of Vietnam; credit institutions, foreign bank branches, payment switching organizations, electronic transaction settlement organizations are responsible for implementing this Circular.of the Government stipulating functions, tasks, powers, and organizational structure of the Ministry of Home Affairsu t, amended and supplemented by Decree No. 109/2025/NĐ-CP and Decree No. 193/2025/NĐ-CP This Circular stipulates the technical content of the work of assessing solid mineral resource potential on land in basic geological surveys for minerals as prescribed in Point b, Clause 1 and Clause 2, Article 22 of the Law on Minerals. The content of detailed geological mapping and design, layout of assessment tasks for minerals as prescribed in Circular No. 03/2011/TT-BTNMT dated January 29, 2011 of the Minister of Natural Resources and Environment does not fall within the scope of regulation of this Circular.uThis Circular applies to state management agencies for geology and minerals; organizations and individuals participating in implementing tasks to assess solid mineral resource potential on land and islands.

At the proposal of the Inspector General specialized agency under the People's Committee of the province/city.The terms used in this Circular shall be understood as follows:, amended and supplemented by Decree No. 109/2025/NĐ-CP and Decree No. 193/2025/NĐ-CPAssessment of solid mineral resource potential (hereinafter referred to as mineral assessment) is a basic geological survey activity for minerals according to types and groups of minerals on geological structures with favorable premises and signs, aiming to clarify the current status of resources, discover new minerals on the surface and underground as a basis for mineral management.

Mineralization zoneắn phầis a part of a geological structure where ore bodies or related mineralization manifestations such as thermal alteration zones, fracture concentration zones, fault zones showing mineralization are present. Number of employees and workers directly involved in the joint venture and association activities of the organization over the last 03 yearsMineral occurrence

PART I

GENERAL PROVISIONS

Article 1. Scope of Regulation

(ore occurrence) is a mineral discovery made during exploration that meets the quality requirements for exploitation at the current time but whose scale is not yet clear.

Article 2. Applicability

Mineral manifestation

Article 3. Explanation of Terms

is a natural aggregate of valuable minerals in the ground meeting the minimum quality requirements but whose scale and exploitable potential are not yet clear, or small resources that do not meet the current technological and economic requirements for exploitation.

1. Ore body (ore deposit) is a mineral accumulation distributed in a specific structural element or a combination of structural elements, having dimensions and mineral quality meeting the requirements for exploitation and processing at the current time or in the near future.

2. Mineral deposit (ore deposit) is a natural aggregate of ore bodies that have been assessed and explored, having resources, reserves, quality, and exploitation and processing conditions meeting the minimum economic efficiency requirements at the current time and in the near future.

3. Survey of the current status of a mine is to clarify the confirmed and reliable reserves, estimated resources, and evaluate the potential development of the mine.

4. Article 4. Principles and sequence of mineral assessment 1. Must proceed from preliminary to detailed, from surface to underground.

5. 2. Design and implementation of methods must comply with current technical regulations and sequential requirements. 3. Assess all types of minerals, including primary and associated minerals.

6. 4. Mineral assessment shall be carried out in the following sequence: (1) Develop a project proposal (Prepare a project proposal); (2) Implement the project (Implement the project); (3) Prepare a final report. (ore deposit) is a natural aggregate of mineral bodies that have been evaluated and explored, possessing resources, reserves, quality, exploitation conditions, and processing capabilities meeting the minimum economic efficiency requirements currently and in the near future.

7. Surveying the current status of a mine involves clarifying the current reserves, confirmed and reliable resources; estimated resources, and assessing the potential for mine development.

3. Prepare a final report.

1. Must proceed from preliminary to detailed stages, from surface to deeper levels.

2. Design and implement methods must comply with current technical regulations and maintain sequentiality.

3. Evaluate all types of minerals, including primary and associated minerals.

Article 4. Principles and sequence for evaluating minerals

Chapter II

TECHNICAL REGULATIONS

Article 5. Construction of the mineral assessment project

The construction work of the mineral assessment project includes the following main tasks:

1. Collecting and compiling all existing documents on infrastructure, geology, minerals, and related documents; evaluating the current status and reliability of these documents; assessing the effectiveness and limitations of the methods already implemented.

2. Conducting preliminary surveys of the area for the project; taking samples and analyzing them to supplement necessary geological and mineral documents; designing appropriate methods and procedures for implementation; determining the construction conditions for the project.

3. Determining the number of areas currently engaged in mineral activities that fall within the scope of the assessment. For mining activities, clearly define underground mining areas and open-pit mining areas.

4. Establishing the objectives to be achieved, including geological, mineral, and current status investigations (if applicable).

5. Anticipating the types of ore deposits that can be discovered and assessed. Identifying specific geological tasks of the project.

6. Designing a system of technical methods, specific requirements for each method, and determining the volume of each component of the project.

7. Anticipating resource evaluation criteria.

8. Determining the basis for preparing the budget estimate and drafting the project budget.

The mineral assessment project shall be prepared according to Model No. 1 issued together with this Circular.

Article 6. Implementation of the Mineral Assessment Project

The implementation of the mineral assessment project is divided into two stages: (1) preliminary assessment stage; (2) detailed assessment stage.

1. Preliminary Assessment Stage

a) Establishing a map of the current state of geological investigation, exploration, and mineral extraction, including the following types of work:

- Collecting, analyzing, processing, and compiling documents;

- Compiling and statistically summarizing remaining resources at mines that have been and are being exploited: it must clearly identify reserves, certain and reliable resources; estimated resources within the permitted boundaries, outside the permitted mining activity boundaries, within prohibited or temporarily prohibited mining areas (if applicable);

- Compiling, recording, and clarifying characteristics of ore deposits, material components, associated valuable components (including new discoveries during exploitation);

- Compiling, analyzing, and processing geological and mineral documents, supplementary surveys to ensure sufficient evidence of remaining resources and forecasts for future mine development;

- Supplementary survey work, document analysis, ore deposit types, and forecasts for future mine development in establishing a map of the current state of geological investigation, exploration, and mineral extraction at each corresponding mineral area, based on geological and mineral mapping at a scale of 1:10,000.

b) Preliminary Assessment

The preliminary assessment work of minerals includes the following main types of work:

- Establishing geological and mineral maps or diagrams at a scale of 1:25,000 or 1:10,000 depending on the complexity of the geological structure and mineral objects;

- Based on geological and mineral documents, mineral search indicators (geochemical anomalies, geophysical anomalies, distribution zones of mineralization), checking mineral discoveries and ore bodies at locations with search indicators through surface excavation works and/or drilling, combined with collecting old works' data encountering ores (if available). Each ore body must have at least one to two positions fully sampled for thickness;

- The topography used in the preliminary assessment stage is a topographic map at a scale of 1:10,000 national coordinate system (reduced or enlarged appropriately according to the investigation scale). Positioning survey points, structures, and structural lines using handheld GPS or by natural and artificial markers;

- Taking samples, processing, and analyzing various types of samples to clarify the composition and basic physical properties of minerals. At outcrops, drilling, and excavation works encountering minerals, channel samples must be taken, and at mineralized zones, point-channel or bulk samples must be taken;

- Conducting a preliminary assessment of minerals using a combination of reasonable methods to accurately define standards for assessing prospects in other areas and initially classify mineralization zones and ore bodies according to their prospectivity levels;

- Estimating resources for ore bodies based on thickness, length, depth, geological, geochemical, and geophysical indicators, calculation criteria directed according to guidelines and similar mineral deposits;

- Preparing a geological report as a basis for designing detailed assessments of ore bodies. In cases where information reports need to be prepared, they will be specified in the project.

2. Detailed Assessment Stage

The detailed assessment work of minerals includes the following main types of work:

a) Survey Work

Using a topographic map of the national coordinate system at the same scale or using a topographic map at the same scale supplemented and updated from a smaller-scale topographic map of the national coordinate system (depending on the type of mineral being assessed and designed in the project). When creating a new topographic map, it must comply with the current regulations of the Ministry of Natural Resources and Environment regarding the establishment of topographic maps. Positioning control grids, ends of main lines, intersections of main lines and cross-sections, completed structures, and mineral outcrops must be carried out using survey equipment with mean position errors as follows: Scale 1:10,000 = 10/2.0m; Scale 1:5,000 = 5/1.5m; Scale 1:2,000-1:1,000 = 2.5/1.0m.

b) Geological Work

- Detailed description of natural and artificial outcrops;

- Compiling geophysical and geochemical documents to create geological and mineral maps and sections at scales of 1:10,000 to 1:2,000 or larger depending on the complexity and size of the objects to be represented. On the maps and sections, geological factors affecting the formation, accumulation, distribution, and transformation of minerals, the morphology of ore bodies, and the distribution of different types of minerals must be shown. Determine ore bodies and mineral distribution patterns;

- Taking geochemical and heavy mineral samples along a network of lines to discover or predict hidden or covered ore bodies.

c) Geophysical Work

- Selecting a combination of geophysical methods suitable for each research object as well as the capabilities of each method;

- Implementing geophysical methods according to a network of perpendicular lines to the structural direction of the ore body and sequentially from shallow to deep research methods;

- Establishing geological-geophysical diagrams, charts, and models to determine the location, distribution scale, and degree of anomaly detected;

- Regularly comparing geophysical construction results with geological results to accurately identify the nature of anomalies;

- Requiring technical implementation and data processing of each geophysical method to comply with specialized technical regulations.

d) Hydrogeological and engineering geological work

Clarifying the characteristics of hydrogeology-engineering geology (hereinafter referred to as HGEG) of various rock types within the area of mineral resource evaluation, including:

- Collecting, studying, processing, and synthesizing existing documents;

- Preparing HGEG diagrams at the same scale as the mineral survey maps for the evaluated ore bodies;

- Pumping and testing water in some drill holes and trenches in the main aquifer and within the ore body according to specialized technical regulations;

- Conducting simple HGEG monitoring in all drill holes and wells;

- Collecting and analyzing surface water and groundwater samples in the main aquifer, within the ore body, and surrounding rock layers;

- Collecting and analyzing mechanical and physical rock samples surrounding and within the ore body.

đ) Construction work

Surface excavation and drilling along lines to monitor the ore body in terms of direction and depth. An ore body must have at least two excavation or drilling projects; sufficient control samples must be taken according to the designed project network. The evaluation line network needs to be arranged appropriately with the distribution characteristics and complexity level of the ore bodies, meeting the requirements of the resource grade specified in Appendix I issued together with this Circular.

e) Sampling work

- Collecting and analyzing various types of samples to:

+ Classify minerals based on composition and structural characteristics. Define the distribution range according to quality in defined resource blocks. Analysis must provide sufficient basis to assess the usability of minerals in different fields;

+ Determine the type of mineral and formation conditions;

+ Identify the chemical composition, quality of the mineral, specifically the chemical components, minerals, structural characteristics, existence form of valuable and harmful components; harmful components and factors for beneficiation processes, recovery rates of valuable components, concentrate quality (ore concentrate), tailings composition (tailings), and propose enrichment schemes. Preliminarily evaluate the beneficiation potential of the mineral by comparing with similar mines or taking and studying technical samples in the laboratory;

+ Determine quality parameters for resource estimation;

- Sampling and analysis work must ensure accuracy and representativeness. Trench samples must be taken according to the designed size suitable for each type of mineral and interbedded layers to have sufficient data to determine the distribution range of mineral types. Mechanized trench sampling methods (cutting, sawing) are encouraged. Laboratory technical samples must meet the requirement of representing the evaluated mineral;

- Sampling and analysis work must be checked and evaluated for reliability according to current regulations.

g) Estimating predicted resources grade 333 and forecasted resources grade 334a for ore bodies using one or several resource estimation criteria options. Resource criteria are established based on comparisons with explored or operating mines of similar scale, quality, and mining and processing conditions. Resource determination must be calculated using at least two different methods for comparison and reliability assessment (encouraging the use of specialized software). For accompanying valuable minerals, depending on their variation compared to the main mineral and their content, they may be determined at the same grade or reduced by one grade.

h) Preliminary economic assessment of the identified mineral resources based on: social demand, market; infrastructure, forecasted resources, mineral quality, mining and processing capabilities and methods; the impact of mining activities on the ecological environment.

Article 7. Preparation of the Final Report on the Mineral Assessment Project

The final report on the project must reflect the results achieved according to the contents stipulated in Articles 5 and 6 of this Circular, including the following main tasks:

1. Processing and compiling all types of project materials for the mineral assessment.

2. Establishing complete and consistent documentation, including drawings and descriptions, ensuring accurate representation of geological and mineral conditions within the assessed area.

3. Calculating mineral resources with appropriate reliability as prescribed.

4. Determining the distribution patterns of ore deposits.

5. Identifying areas with exploration potential for recommendation.

The final report on the project shall be prepared according to Model No. 2 issued together with this Circular.

Article 8. Products of the Mineral Assessment Project

1. Main products include: the Project Description, drawings, appendices, and original documents. These documents must be established in accordance with the provisions of Circular No. 03/2011/TT-BTNMT dated January 29, 2011, issued by the Minister of Natural Resources and Environment regarding the content of detailed geological and mineral maps and the design and arrangement of mineral assessment tasks. Original documents shall be established in accordance with current regulations.

2. Forms of Mineral Assessment Documentation

a) Types of drawing, appendix, and oral report documentation in mineral assessment must be presented in paper and/or digital form, complying with current specifications.

b) The system of geological and mineral symbols used shall comply with the provisions of Circular No. 23/2012/TT-BTNMT dated December 28, 2012, issued by the Minister of Natural Resources and Environment on the National Technical Regulations for Detailed Geological and Mineral Maps at a scale of 1:50,000 for land areas.

Article 9. Quality Control of the Project Implementation

1. The entity directly implementing the project shall conduct inspections and evaluations of the quality of all project components.

2. The state management agency for minerals shall conduct overall inspections and evaluations of the quality of all project components.

Chapter III

IMPLEMENTING PROVISIONS

Article 10. Effective Date

1. This Circular takes effect from February 10, 2017.

2. Repeal Decision No. 35/2001/QĐ-BCN dated June 20, 2001, issued by the Minister of Industry on the issuance of the Regulation on Assessing the Potential of Solid Mineral Resources in Basic Geological Surveys on Mineral Resources from the date this Circular takes effect.

Article 11. Implementation Organization

1. The Director of the Vietnam General Department of Geology and Minerals shall be responsible for guiding, monitoring, and inspecting the implementation of this Circular.

2. Units under the Ministry of Natural Resources and Environment and related organizations and individuals shall be responsible for implementing this Circular.

3. During the implementation of this Circular, if difficulties or obstacles arise, relevant organizations and individuals shall promptly report to the Ministry of Natural Resources and Environment for consideration and resolution.