Circular No. 33/2010/TT-BTNMT on exploration, classification of reserves and resources of iron ore deposits

CIRCULAR

Provisions on exploration, classification of reserves and resources of iron ore deposits

_________________________

MINISTER OF NATURAL RESOURCES AND ENVIRONMENT

Pursuant to Decree No. 25/2008/NĐ-CP dated March 4, 2008 of the Government stipulating the functions, tasks, powers, and organizational structure of the Ministry of Natural Resources and Environment; Decree No. 89/2010/NĐ-CP dated August 16, 2010 of the Government amending and supplementing Article 3 of Decree No. 25/2008/NĐ-CP dated March 4, 2008 of the Government stipulating the functions, tasks, powers, and organizational structure of the Ministry of Natural Resources and Environment;

Pursuant to Decree No. 160/2005/NĐ-CP dated December 27, 2005 of the Government detailing and guiding the implementation of the Law on Minerals and the Law Amending and Supplementing Certain Provisions of the Law on Minerals;

Considering the proposal of the Director of the Office of the Mineral Reserve Evaluation Council and the Director General of the Legal Department,

c) Enterprises may be granted permission for no more than one block out of the total three dual-frequency blocks (FDD) B

PART I

GENERAL PROVISIONS

Article 1. Scope of application

This Circular stipulates requirements for the work of exploration, classification of reserves and resources of iron ore deposits.

Article 2. Applicability

This Circular applies to state management agencies for mineral resources; organizations conducting basic geological surveys on minerals; organizations and individuals conducting surveys, exploration, exploitation of minerals; and other related organizations and individuals.

Chapter II

CLASSIFICATION OF RESERVES AND RESOURCES OF IRON ORE DEPOSITS

Article 3. Classification of reserves and resources of iron ore deposits

1. Resources of iron ore deposits are classified into two groups

a) Determined resource group;

b) Predicted resource group.

2. The determined resource group is divided into two types: reserves and resources.

Article 4. Classification of reserves and resources of iron ore deposits

1. Basis for classifying reserves and resources of iron ore deposits

a) Degree of geological research, including: certain, reliable, estimated, and predicted;

b) Degree of investment construction project study for mine works, including: investment construction project report for mine works (feasibility study), investment construction project report for mine works (pre-feasibility study), and general study;

c) Degree of economic efficiency, including: economically viable, potential economic viability, and unclear economic viability.

2. Classification of reserves and resources of iron ore deposits

a) Determined resources of iron ore deposits are classified into three reserve levels: 111, 121, and 122, and six resource levels: 211, 221, 222, 331, 332, and 333;

b) Predicted resources of iron ore deposits are classified into two levels: 334a and 334b.

3. Coding of reserve and resource levels of iron ore deposits is as follows:

a) The first digit indicates the degree of economic viability: number 1 - economically viable; number 2 - potential economic viability; number 3 - unclear economic viability;

b) The second digit indicates the degree of investment construction project study for mine works: number 1 - has an investment construction project report for mine works; number 2 - has a feasibility study report for mine works; number 3 - general study;

c) The third digit indicates the degree of reliability of geological research: number 1 - certain; number 2 - reliable; number 3 - estimated; number 4 - predicted.

Article 5. Requirements for the degree of research and delineation of level 111 reserves

1. Degree of geological research

a) Must accurately determine the morphology, size, orientation, pattern of shape variation, and internal structure of the iron ore body and the presence of fractures causing displacement of the ore;

b) Must accurately divide the iron ore body into natural forms and types with distinct characteristics, clarifying the quantity, distribution area, and size of non-ore rock layers or those not meeting the reserve calculation criteria; the spatial position of each form and type of iron ore must be accurately defined;

c) The quality of iron ore must be confirmed with certainty and must meet the reserve calculation criteria specified for each calculation block; the technological properties of iron ore in the deposit must be studied to the extent that different natural ore types and industrial (technological) types requiring separate extraction and processing can be identified. Test data must ensure sufficient information to design a comprehensive processing technology flowchart for recovering valuable components in the ore;

d) Hydrogeological, engineering geological, and mining conditions must be thoroughly researched to accurately calculate the amount of water inflow into the mining works; all technical mining conditions such as thickness, volume, physical-mechanical properties of ore and overburden rock must be fully studied, and dynamic engineering geological phenomena must be clarified;

e) The reliability of the reserve must guarantee at least 80%.

b) The determined reserve level is economically viable based on research of investment construction project reports or meets the reserve calculation criteria in the exploration result report.

The boundaries of level 111 reserves are delineated within the range of exploration works cutting through the ore body, provided that the distance between the works ensures only one delineation option for the ore body and intercalated rock layers with a density of works as prescribed in the annex to this Circular.

3. Degree of investment construction project study for mine works;

a) An investment construction project for mine works has been established;

b) Preliminary selection of reasonable technical and technological solutions for iron ore extraction and processing has been made;

c) The reserve level area does not lie within prohibited or temporarily prohibited mineral activity zones; Iron ore extraction and processing activities within the reserve level boundaries have a negligible impact on the surrounding ecological environment or appropriate measures to mitigate the impact have been selected;

d) A post-mining environmental restoration plan has been selected.

4. Degree of economic efficiency

The results of the investment construction project study demonstrate that iron ore extraction and processing at the deposit is economically viable at the time of evaluation.

Article 6. Requirements for the level of research and delineation of reserves at level 121

1. The level of geological research shall be carried out in accordance with the provisions of Clause 1, Article 5 of this Circular.

2. The delineation of reserve boundaries shall be carried out in accordance with the provisions of Clause 2, Article 5 of this Circular.

3. Level of investment construction project research

a) A feasibility study for the construction of mining projects has been established or temporary reserve calculation criteria have been recognized by the Mineral Reserve Evaluation Council;

b) Preliminary selection of appropriate technical and technological solutions for iron ore extraction and processing has been conducted;

c) The reserve level area does not fall within prohibited or temporarily prohibited mineral activity zones; preliminary assessment of iron ore extraction and processing activities within the reserve boundary's impact on the surrounding ecological environment and selection of measures to mitigate such impacts have been made;

d) A preliminary plan for post-mining environmental restoration has been established.

4. Degree of economic efficiency

The feasibility study for the construction of mining projects has proven or compared with currently operating mines with similar geological conditions, demonstrating that iron ore extraction and processing at the mine is economically viable at the time of evaluation.

Article 7. Requirements for the level of research and delineation of reserves at level 122

1. Degree of geological research

a) Basic conditions of the ore body's location and shape, as well as the presence of faults displacing the ore, must be determined;

b) All major natural forms and types of iron ore must be fully identified. However, detailed spatial distribution may not yet be defined;

c) The average thickness of the ore body must be determined, and the number of interbedded rock layers within the ore body that do not meet reserve calculation criteria need not be precisely delineated in space;

d) The quality of iron ore must be reliably confirmed and meet reserve calculation criteria for each block; different industrial types and grades of iron ore must be classified, but their detailed spatial distribution need not be precisely delineated; technological properties of iron ore must be studied sufficiently to allow the determination of a general ore processing flow sheet for the recovery of valuable components;

đ) Hydrogeological, engineering geological characteristics, and mining technical conditions must be studied sufficiently to determine the number of water-bearing strata and their water richness, estimate the amount of water likely to flow through mining works, and determine the volume of overburden, although their detailed spatial distribution across the mine area need not be specified;

e) The reliability of the reserves must ensure a minimum of 50%.

b) The determined reserve level is economically viable based on research of investment construction project reports or meets the reserve calculation criteria in the exploration result report.

Reserve boundaries must be delineated within the scope of exploration works and detailed sampling results. For mines with non-complex geological structures, where thickness and quality are relatively stable, extrapolation based on geological and geophysical data from ore-intersecting works or higher-level reserve boundaries is permitted. The extrapolation distance must not exceed half the distance between exploration works already defined for this reserve level.

3. The level of investment construction project research and economic efficiency shall be carried out in accordance with the provisions of Clause 3 and Clause 4, Article 6 of this Circular.

Article 8. Requirements for the level of geological research and delineation of resource grades 211, 221, and 331

1. Level of geological research and delineation of resource boundaries

The level of geological research and delineation of resource boundaries for grades 211, 221, and 331 shall be carried out in accordance with Clause 1 and Clause 2 of Article 5 of this Circular.

2. Level of investment construction project research and economic efficiency

a) Resource grade 211

An investment construction project has been established to prove that under technological, socio-economic, environmental, and other conditions at the time of evaluation, mining and processing iron ore from this resource does not yet have economic efficiency. However, in the future, it may become economically viable due to scientific progress, changes in socio-economic and environmental conditions, and laws.

b) Resource grade 221

A preliminary investment construction project report has been established to prove that under technological, socio-economic, environmental, and other conditions at the time of evaluation, mining and processing iron ore with the recovery of industrial value components in the ore from this resource does not yet have economic efficiency. However, in the future, it may become economically viable due to scientific progress, changes in socio-economic and environmental conditions, and laws.

c) Resource grade 331

Investment construction project research has not been conducted, and it has not been determined whether mining and processing iron ore with the recovery of industrial value components in the ore from this resource has economic efficiency or potential economic efficiency at the time of evaluation. However, geological research results have confirmed the certain existence of this resource.

Article 9. Requirements for the level of geological research and delineation of resource grades 222 and 332

1. Level of geological research and delineation of resource boundaries

The level of geological research and delineation of resource boundaries for grades 222 and 332 shall be carried out in accordance with Clause 1 and Clause 2 of Article 7 of this Circular.

2. Level of investment construction project research and economic efficiency

a) Resource grade 222

The level of investment construction project research and economic efficiency shall be carried out in accordance with Point b, Clause 2 of Article 8 of this Circular.

b) Resource grade 332

Investment construction project research has not been conducted, and it has not been determined whether mining and processing iron ore with the recovery of industrial value components in the ore from this resource has economic efficiency or potential economic efficiency at the time of evaluation. However, geological research results have confirmed the reliability of this resource.

Article 10. Requirements for the level of geological research and delineation of resource grade 333

1. Level of geological research and delineation of resource boundaries

a) Must determine the basic characteristics of the shape, position, and distribution of iron ore bodies;

b) Must preliminarily determine the thickness, structure, and stability of the iron ore body;

c) The quality of iron ore must be preliminarily determined based on sampling results from natural exposures, cleared sites, trenches, shafts, drilling, or extrapolating from adjacent areas with more detailed geological research;

d) Natural factors determining mining conditions do not necessarily require detailed research, mainly being initially understood and compared with nearby areas that have been more thoroughly researched.

2. Delineation of resource boundaries

The boundary of resource grade 333 is delineated within the scope of exploration works meeting resource calculation criteria and can be extrapolated according to the boundaries of geological structures and favorable rock systems for ore formation based on geophysical data combined with some drilling, excavation works, or from the boundaries of higher-grade reserves and resources.

3. Level of investment construction project research and economic efficiency

Investment construction project research has not been conducted, and it has not been determined whether mining and processing iron ore from this resource has economic efficiency or potential economic efficiency at the time of evaluation.

Article 11. Level of study and delineation of Class 334a mineral resources

1. Level of geological research and delineation of resource boundaries

a) Must establish signs of iron ore deposits and geological conditions favorable for the formation of iron ore deposits;

b) The location, thickness, and quality of iron ore deposits are determined based on sampling results from outcrops or inferred from similar studied mines or outcrops with similar geological conditions.

2. Delineation of resource boundaries

Class 334a mineral resources are primarily inferred based on basic geological investigation materials about mineral resources at a scale of 1:25000 – 1:50000, based on geological signs for the formation of iron ore or inferred from detailed studies of similar mines with similar geological conditions.

3. Level of investment construction project research and economic efficiency

For this class of mineral resources, there is no requirement for data on investment construction project research and economic efficiency assessment.

Article 12. Requirements for level of study and delineation of Class 334b mineral resources

1. Level of geological research and delineation of resource boundaries

a) Must establish premises of iron ore deposits and geological conditions favorable for the formation of iron ore deposits;

b) The location, thickness, and quality of iron ore deposits are determined based on sampling results from outcrops or inferred from similar studied mines or outcrops with similar geological conditions.

2. Delineation of resource boundaries

Class 334b mineral resources are primarily inferred based on basic regional geological investigation materials about mineral resources at a scale of 1:50000 – 1:200000, based on favorable geological conditions for the formation of iron ore or inferred from detailed studies of similar mines with similar geological conditions.

3. Level of investment construction project research and economic efficiency.

For this class of mineral resources, there is no requirement for data on investment construction project research and economic efficiency assessment.

Chapter III

CLASSIFICATION OF PROSPECTING MINES

Article 13. Basis for classification of prospecting mines

1. Based on the shape, size of iron ore bodies, complexity of mine geological structure, stability of thickness, quality, and internal structure of iron ore bodies.

2. Quantitative indicators to evaluate the degree of variation in classification criteria.

3. Based on argumentation and specific evaluation of the main area of iron ore bodies, which accounts for not less than 70% of the mine's reserves.

Article 14. Classification of prospecting mines

1. Simple mine group (I)

2. Complex mine group (II)

3. Very complex mine group (III).

Article 15. Conditions for classification of prospecting mines

1. Simple mine group (I)

Includes mines or mining areas with simple geological structures, flat or gently inclined seam-type ore bodies, an ore product grade factor greater than 0.8, and simple shapes, a perimeter variation factor less than 1.4; stable thickness, a thickness variation factor not exceeding 40%; even distribution of major beneficial and harmful components, a component content variation factor not exceeding 40%.

2. Complex mine group (II)

Includes mines or mining areas with complex geological structures, large lens-shaped or seam-type ore bodies; various lens, pocket, column, pipe shapes; an ore product grade factor ranging from 0.6 to 0.8, and complex shapes; a perimeter variation factor ranging from 1.4 to 1.8; unstable thickness, a thickness variation factor ranging from over 40% to 100%; uneven distribution of major beneficial and harmful components, a component content variation factor ranging from over 40% to 100%.

3. Very complex mine group (III)

Includes mines or mining areas with very complex geological structures, small to medium-sized lens, vein-column ore bodies, an ore product grade factor below 0.6, and very complex shapes, a perimeter variation factor greater than 1.8; highly unstable thickness, a thickness variation factor over 100%; highly uneven distribution of major beneficial and harmful components, a component content variation factor over 100%.

Chapter IV

REQUIREMENTS FOR PROSPECTING WORK ON IRON ORE MINES

Article 16. General requirements for iron ore exploration work

1. Basic investigation, surveying, and exploration of iron ore must comply with the sequential principles of geological investigation steps concerning mineral resources.

2. All necessary and reliable geological data and mining operation information must be collected to serve the study of investment construction projects for mines; delineate areas and depths with the greatest potential for exploitation.

3. The task of iron ore exploration work is to determine in detail the structural characteristics of the mine's geology, origin, distribution features, shape, and lying conditions of the ore body; it must assess reserves, resources, and quality and technological properties of the iron ore; conduct detailed assessments of hydrogeological, engineering geological conditions, and mining conditions; investigate clearly accompanying minerals and useful components within the mine and their extraction potential; evaluate the volume of overburden and factors affecting the ecological environment.

4. Exploration of iron ore must be carried out throughout the entire area and depth where the ore body exists within the permitted exploration boundaries.

Article 17. Requirements for topographic basis and geodetic work

1. Mine topography must be accurately surveyed at a scale of 1:5000 - 1:1000 depending on size, terrain complexity, and intended use. Topographic maps must be established according to current regulations on geodetic work in mineral exploration.

2. All exploration works must determine coordinates and elevations and must relate to the National Coordinate Network according to current geodetic regulations.

Article 18. Requirements for exploration techniques

1. Geological research work

Must clarify the structural characteristics of the mine's geology, origin, lying conditions, size, and shape, internal structure, sharpness features, distribution of different types and styles of ores, characteristics of changes and relationships between the ore body and surrounding rocks, folds, and tectonic destructions; must establish a mine geological map at a scale of 1:5000 - 1:1000 depending on the size and geological complexity of the mine, along with appropriate cross-sections and stratigraphic columns; must have a regional geological map at a scale of 1:25000 - 1:10000.

2. Exploration works

a) In iron ore exploration, drilling and excavation works can be used. Selected exploration works must be suitable for the lying conditions, distribution depth, geological structure, shape, thickness, and characteristics of the overburden layer of the iron ore body;

b) Outcrops and upper parts of ore bodies or mineralized zones must be studied using excavation works and shallow drill holes combined with applying geophysical, geochemical methods, and detailed sampling;

c) Deep iron ore exploration mainly uses drilling combined with maximum surface geophysical research methods and drill holes when the ore body depth is not large, shallow drill holes combined with excavation. In mines with very complex geological structures, underground excavation works must be carried out in representative sections of the ore body to clarify lying conditions, shape, internal structure, material composition, types, and styles of ores, and technological sampling;

d. For drill holes, the highest possible core recovery rate must be achieved. The core sampling ratio must not be less than 70% per drill run. To enhance the reliability of drilling works, borehole geophysical methods must be used;

đ) For vertical drill holes deeper than 200m, azimuth and inclination angles must be measured and checked every 20-50m. Measurement results must be considered when constructing geological cross-sections, plans, and calculating ore body thickness;

To cut through steeply dipping ore bodies, the most appropriate method is inclined drilling;

e) All exploration works must penetrate the full thickness of the iron ore body within the exploration boundary range.

3. Requirements for the layout of exploration works

a) Exploration works must be arranged in a network that allows comprehensive research of the structural characteristics, morphology, size, lying conditions, stability degree, and quality of the iron ore body thickness;

b) The orientation density of iron ore exploration works should refer to the Appendix of this Circular;

c) Exploration documentation

All exploration works, mining works, natural and artificial exposures in the mine must be promptly, fully, and accurately described, geologically mapped, and original documentation prepared according to current regulations on preparing original documentation in mineral exploration and plotted on actual documentation maps.

Article 19. Requirements for sample collection and processing work

1. Sample Collection Work

a) All exploration works, as well as mining works, must be described in detail, and samples from ore-bearing works must be collected for quality research. The results of sample collection must be recorded in original documents and must be cross-checked with geological descriptions;

b) Sampling methods must be based on the specific geological characteristics of the mine, ensuring the highest reliability and economic efficiency. When multiple sampling methods are used, they must be compared in terms of reliability and completeness of results;

c) Sample collection at exploration works must be carried out under the following conditions:

The sampling network must be stable, and the density of the sampling network must be determined by the geological conditions of the ore body. Samples must be taken along the direction of the most variable mineralization, continuously throughout the thickness of the ore body.

Natural forms of ores and host rocks containing mineralization must be sampled separately using channel samples. The length of channel samples must be determined by the internal structure of the ore body, changes in material composition, structural features, architecture, mechanical properties, and other characteristics of the ore. In areas where core recovery rates vary significantly, separate sampling must be conducted.

d) The quality of sampling by each method must be systematically checked to evaluate reliability and completeness of results.

The reliability of core drilling sampling must be checked by taking samples from half of the remaining core.

đ) Technological test samples must be representative, meaning that the samples must have chemical composition, mineralogical content, mechanical properties, particle size, and other characteristics consistent with the average composition of each type or grade of iron ore or the entire deposit.

e) Large bulk samples must be taken in quantities of 3-5 samples for each natural form of ore and for layers not meeting internal ore body standards. Along with each large bulk sample, additional 3-4 small bulk samples and room humidity samples must be taken for checking and comparison. The volume of large bulk samples ranges from 0.5 to 1m³.

For dense ores, the ore weight is primarily determined by small bulk samples and verified by large bulk samples. For loose, highly fractured, and porous ores, the ore weight is determined by large bulk samples. Moisture content must also be determined alongside the weight.

2. Sample Processing Work

Processing and reducing analytical samples must be carried out according to established processing schemes for each mine. The accuracy of the processing scheme and reduction factor k must be verified using data from similar mines or mining documentation. The sample processing scheme is formulated according to the formula Q = kd, where the factor k is set to 0.05 when ore quality is stable, 0.1 when ore quality is unstable, or when harmful impurities in the ore approach the permissible limit of the standard. The quality of sample processing must be systematically checked at all stages, interpreting the reduction factor k and compliance with the processing scheme. All basic chemical samples before analysis must be processed to a particle size of 0.074mm.²Article 20. Requirements for Analysis and Sample Inspection Work

1. Sample Analysis Work

a) The chemical composition of iron ore must be thoroughly studied to ensure reliable assessment of ore quality, clarify harmful impurities and accompanying beneficial components. Their concentrations in the ore are determined through sample analysis using chemical, physical, and other methods prescribed by state standards;

b) Research on accompanying components in the ore is carried out according to specific regulations;

c) Basic chemical samples of unenriched ore must be analyzed for T.Fe, Mn, and harmful components affecting the quality requirements of commercial ore; other components are determined by group samples;

d) Basic chemical samples of enriched ore, in addition to the requirements specified in Point c Clause 1 of this Article, must determine beneficial and harmful components in concentrate;

đ) Group samples must represent all natural forms of ore or technological types and grades of them;

The procedure for combining basic chemical samples into group samples, their distribution, and total weight must ensure uniform representation of basic ore types regarding accompanying components, harmful impurities, and clarifying their variation patterns along strike and dip directions of the ore body;

To clarify the degree of oxidation of primary ore and determine the boundaries of the oxidized zone, phase analysis must be performed;

e) The mineralogical composition, structural features, architectural characteristics, and other physical properties of the ore must be studied using petrographic, mineralogical, physical, chemical, and other analytical methods.

a) The technological properties of ore are studied at laboratory and semi-industrial scales. For easily enrichable ores, when industrial processing experience exists, laboratory sample testing results can be used as a basis;

2. Technological sample research work

b) Technological samples must be taken to characterize all types of ore discovered in the mine;

It is necessary to study the technological properties of industrially classified ore types to the extent required for selecting reasonable ore processing schemes and determining enrichment criteria;

c) Semi-industrial technological trials are conducted by the mining exploitation investment organization, with agreement from the mining design organization;

d) The potential for using tailings water and waste rock obtained in the ore processing scheme must be investigated, and recommendations for cleaning industrial water flows must be provided.

3. Sample Inspection Work

a) The reliability of chemical analysis results must be evaluated through internal, external, arbitration, or standard sample analysis;

b) Inspection analysis work must be carried out regularly and systematically. Inspection is performed on key chemical components specified in reserve calculation standards;

c) External inspection samples are parts of internally inspected samples. Both internal and external inspection samples must represent all types of ore and concentration levels according to each basic analysis round.

c) The sample used for external testing analysis is the retained portion of the sample that has been subject to internal testing analysis. External and internal testing samples must be representative of all types of ore and levels of concentration for each basic analysis period;

d) When dividing the grade levels, attention must be paid to the grade levels of the criteria for estimating reserves. The number of samples for testing is 5% of the total number of basic samples. In cases where the number of basic samples is small, the requirement for the number of testing samples shall not be less than 30 samples for each grade level or conducting a 100% sample analysis of the basic samples;

đ) In cases where external testing analysis detects systematic errors in the basic analysis, arbitration analysis must be conducted at a laboratory with higher analytical capabilities. The arbitration analysis sample is the retained sample from the basic analysis sample, except that the remaining part of the analyzed sample may be used. The arbitration analysis sample must have been subjected to external testing analysis. The number of arbitration testing samples is 30-40 samples for each grade level with systematic errors. If arbitration analysis detects systematic errors in the basic analysis, the cause must be clarified and measures taken to correct them, deciding whether to re-analyze the grade level with systematic errors or allow the use of adjustment factors. Testing procedures that differ must be accepted by the Mineral Reserve Evaluation Council;

e) The sampling procedure for testing, the number of testing samples, the method of testing analysis, and the handling of testing analysis data must comply with current regulations;

Article 21. Requirements for evaluating associated minerals and useful components;

1. Samples and analyses of mineralogical, chemical, and physical-mechanical properties of overburden and interbedded rocks must be taken from the early stages of exploration to detect and recover associated minerals and useful components;

2. The evaluation of associated minerals and useful components must be carried out according to specific provisions;

Article 22. Requirements for studying iron ore quality;

a) Determine natural ore types, industrial (technological) categories and grades for selection and processing separately;

b) For each industrial (technological) category of ore already classified, it is necessary to determine:

A reasonable enrichment process diagram (gravity separation, magnetic separation, combined gravity and classification spiral separation, roasting and magnetic separation...);

Basic technological parameters of enrichment (yield of concentrate, quality of concentrate, recovery rate of Fe in concentrate);

An appropriate fine grinding method and equipment;

The necessity of preliminary pelletizing;

Characteristics of metallurgical processing for enriched ores (blast furnace smelting, matte production, non-coking);

c) For accompanying components, their existence forms and distribution in the processed concentrate products must be clarified, as well as establishing conditions, feasibility, and economic efficiency of their recovery;

Article 23. Requirements for hydrogeological and engineering geological research work;

1. Hydrogeological research work;

a) Hydrogeological research must clarify the degree of water saturation of the mine, identify potential water sources that can flow into mining operations. For each aquifer layer, thickness, lithology, type of collector, supply conditions, relationship with other aquifers and surface water, static water level, and other parameters must be determined. Research on the chemical and microbiological composition of mine water, study the corrosiveness of water to concrete, metals, polymers, determine the content of beneficial and harmful compounds in water. Evaluate the possibility of using water for supply or recovery of useful components, as well as assess the impact of these waters on ongoing underground water extraction works in the mining area. Assess the impact of mine drainage on the surrounding environment and propose protective measures for other structures affected by groundwater;

b) If the mining area has operating mines with similar hydrogeological conditions to the area under investigation, the data on water saturation levels, engineering geological conditions, and dry mining methods applied in these mines should be utilized;

2. Engineering geological research work;

a) Engineering geological research must clarify the physical-mechanical properties of ore, surrounding rock, and overburden, determine characteristics of stability in natural and water-saturated environments, and other technical conditions related to mine design;

b) If there are active mine shafts or workings within the mining area with similar engineering geological conditions, data on engineering geological conditions of these shafts and workings can be used to evaluate the characteristics of the exploration area.

Article 24. Requirements for assessing the level of pollution and environmental impact

1. Data on natural geography and geological environment must be collected to forecast and assess the main factors affecting the environment. For mines where it has been determined that there is natural gas storage (Methane, CO2, etc.), the variation laws of gas content and composition must be studied over area and depth. Factors affecting human health (toxic gases, radiation, geothermal conditions, etc.) must be identified.₂2. Geological disasters and negative impacts on the environment caused by iron ore exploration activities must be evaluated, and preventive and mitigation measures must be implemented. The content and extent of the environmental impact assessment must be included in the exploration project.

Article 25. Requirements for technical research on mine exploitation conditions

1. Preliminary boundaries of the mining area, slope angles of the seam face, final slope angles of the open-pit, stripping ratio, volume of overburden, location of waste disposal sites, and initial evaluation of rock pressure on walls, pillars, and ore body must be determined.

2. Areas without industrial iron ore for construction of production facilities and residential areas, and waste disposal sites must be identified. Measures to protect underground space, prevent environmental contamination, and land reclamation must be proposed. To address land reclamation issues, the thickness of planting soil layers, agricultural studies, toxicity of rocks, and vegetation development potential must be determined.

Article 26. Work on calculating reserves and resources of iron ore

1. Calculation of reserves and resources of iron ore must be based on reserve calculation criteria recognized by the Reserve Evaluation Council for each specific mine or according to the requirements of the investor considering current technical standards. Basic quality requirements for ore according to processing technology and mining technical conditions must be clearly defined in the reserve calculation criteria.

2. Reserves are calculated as existing underground quantities not including losses during extraction, and are expressed in units of thousands of tons.

3. In addition to reserves and resources of iron ore, the volume of overburden and non-compliant rocks within the reserve calculation range must also be calculated.

4. Reserves and resources of iron ore are presented on topographic maps at scales of 1:1000 to 1:5000 depending on the scale and terrain characteristics. Methods for calculating reserves and resources of iron ore must be selected to suit the specific geological features of each mine.

Article 27. Requirements for the highest grade of reserves and the proportion of different grades of reserves

1. Highest grade of reserves

a) For Group I and II mines, the highest grade of reserves to be explored is Grade 121;

b) For Group III mines, the highest grade of reserves to be explored is Grade 122.

2. Proportion of different grades of reserves

The quantity and reasonable proportion between Grades 121 and 122 are determined by the investor based on the geological characteristics of the mine, financial capacity, mining technical conditions, designed mining capacity, but must ensure that the proportion of Grade 121 reserves out of the total of Grades 121 and 122 is not less than 10%, and this must be reflected in the exploration project.

Article 28. Content and presentation form of documents in the exploration report of iron ore mines

The content and presentation form of documents in the exploration report of iron ore mines shall be carried out in accordance with the Regulations on procedures, formalities for approval, review, examination, and approval of mineral reserves in the mineral exploration report issued together with Decision No. 14/2006/QĐ-BTNMT dated September 8, 2006, of the Minister of Natural Resources and Environment.

The content and format of the documents in the report on iron ore exploration shall be carried out in accordance with the provisions on the procedures, formalities for submission, review, examination, and approval of mineral reserves in the mineral exploration report issued together with Decision No. 14/2006/QD-BTNMT dated September 8, 2006, of the Minister of Natural Resources and Environment.

Chapter V

IMPLEMENTING PROVISIONS

Article 29. Conversion of Iron Ore Deposit Grades and Resource Grades

Clause 1. The deposit grades and resource grades of iron ore deposits classified according to previous regulations must be converted to deposit grades and resource grades as prescribed in this Circular.

Clause 2. The work of conversion and preparation of reports on the results of converting deposit grades and resource grades of iron ore deposits shall be carried out in accordance with the Provisions on Classification of Solid Mineral Reserves and Resources issued together with Decision No. 06/2006/QĐ-BTNMT dated June 7, 2006 of the Minister of Natural Resources and Environment.

Article 30. Effectiveness and Responsibility for Enforcement

Clause 1. This Circular takes effect from January 28, 2011.

Clause 2. The Office of the Mineral Reserve Evaluation Council is responsible for organizing monitoring, guidance, inspection of the implementation of this Circular.

Clause 3. The Inspectorate of the Ministry of Natural Resources and Environment has the responsibility to coordinate with relevant units to inspect, check, detect violations, and promptly handle them within its authority or recommend competent authorities to handle violations stipulated in this Circular.

Clause 4. During the implementation of this Circular, if difficulties or obstacles arise, ministries, sectors, localities, organizations, and individuals shall promptly reflect them to the Ministry of Natural Resources and Environment for consideration and resolution./.