Decision No. 41/2002/QĐ-BCN on the issuance of regulations on inspection and acceptance of the volume of excavated earth and rock and coal production at open-pit mines.

Pursuant to …;

Regarding the issuance of Regulations on inspection and acceptance of the volume of overburden removed and coal production at open-pit mines

collect the volume of overburden and coal production at open-pit mines

 

THE MINISTER OF INDUSTRY

Pursuant to Decree No. 74/CP dated November 1, 1995 of the Government on the functions, tasks, powers, and organizational structure of the Ministry of Industry;

Considering the proposal of the General Director of Vietnam Coal Corporation at Proposal No. 02/TTr-ĐCTĐ dated April 9, 2002 regarding the approval of Regulations on inspection and acceptance of the volume of overburden removed and coal production at open-pit mines, in accordance with the recommendation of the Head of the Planning and Investment Department,

 

DECISION:

Article 1. These Regulations on inspection and acceptance of the volume of overburden removed and coal production at open-pit mines are hereby issued together with this Decision.

Article 2. This Decision shall take effect fifteen days from the date of signature and replace Decision No. 6/ĐTKT1 dated August 10, 1972 of the Ministry of Electricity and Coal on the issuance of Regulations on inspection and acceptance of the volume of overburden removed and coal production at open-pit mines.

Article 3. The Heads of the Ministry's Office, the Inspectorate, the Heads of Departments and Bureaus under the Ministry, Vietnam Coal Corporation, and the Heads of related agencies and units are responsible for implementing this Decision./.

 

REGULATIONS

On inspection and acceptance of the volume of overburden removed and coal production at open-pit mines

(issued together with Decision number 41/2002/QĐ-BCNdated April 10 2002 of AND Industry)

 

PART I

GENERAL PROVISIONS

Article 1.

1.These Regulations apply to enterprises that exploit coal using open-pit methods or those currently in the construction phase preparing for open-pit coal exploitation.

2. The inspection and acceptance of the volume of overburden removed and coal production at mud coal mines shall be carried out according to separate regulations.

Article 2.The inspection and acceptance of the volume of overburden removed and coal production at open-pit mines must be determined through measurement methods. Measurement data are the official figures for calculating coal production and the volume of overburden removed.

The enterprise's General Director must organize monitoring and inspecting the volume of overburden removed through statistical methods. Statistical data can only be used for quick reporting and provisional allocation of work volumes when measurements are made earlier or later than the reporting period or used as a ratio to allocate measured volumes to construction machines when the difference is less than the measurement. + 5%.

Statistical data cannot be used to calculate actual coal production and the volume of overburden removed.

In cases where overburden removal cannot be measured (overburden volume during mining affecting transportation routes, drainage channels, requiring excavation; silt volume from pit dredging), it is permissible to use delivery records based on train car diagrams to determine the volume of overburden removed. In such cases, the total volume of overburden removed in a year must be less than 10,000 cubic meters.³If the volume exceeds 10,000 cubic meters³ or other special cases, the enterprise must develop an acceptance plan to be approved by the competent authority before implementation.

Unit of measurement for overburden removed: cubic meters.³.

Article 3.Raw coal production (hereinafter referred to as coal production) is determined by two methods:

1. Based on weighing data or coal delivery records based on train car diagrams.

2. Based on monthly, quarterly, and annual measurement data for each seam, layer, and work site as determined by the Geology Department.

Weighing data can be used as the actual performance data for the period. If there are no clear scales, walls, or pillars of the coal seam, it is permissible to use the measurement data from the Geology Department as the actual performance data for the period.

If there are no scales, complex geological conditions, and the volume of coal extracted cannot be accurately determined, it is permissible to use delivery records based on train car diagrams; in this case, the volume of coal extracted for the entire work site must be less than 10,000 tons per year.

Unit of measurement for coal production: tons.

Article 4.Quarterly, the enterprise's General Director must organize measurements and inventory checks of coal stock to adjust coal extraction; accurately determine the volume of coal between production and consumption stages.

Annually, the enterprise's General Director must organize a review of the train car diagrams and specific coal delivery weights (hereinafter referred to as raw coal weight). Inspections must be conducted in both rainy and dry seasons.

Every eight months, the raw coal weight of the seam being mined must be re-determined.

Article 5.Inspection and measurement of coal production and overburden volume at mines must be conducted at least once a month for each machine and layer, either five days before or after the end of the month.

Coal production and overburden volume measured early or late in the month may use statistical data from train car diagrams to add or subtract from the measurement results. Statistical data from train car diagrams for early or late measurements must be recorded in tracking sheets and ledgers accurately.

Coal production and overburden volume measured early or late in the previous period must be recorded fully to be added or subtracted from the measurement results of the following period.

Measurements must be conducted immediately after the excavator has completed work on a layer or moved to another location. Measurement work must not be delayed until the end of the month. If the volume of overburden removed is less than 10,000 cubic meters per month, it is permissible to update measurements on a quarterly basis.³/ Monthly measurements shall be allowed to update periodically on a quarterly cycle.

Article 6.Materials used to calculate actual coal production and overburden volume include:

1. End-of-quarter completion maps signed by the Surveyor-in-Charge and the Geologist-in-Charge; bearing the seal and signature of the enterprise's General Director and approved by the competent authority.

2. Design plans or technical solutions approved by the competent authority.

3. Annual planning maps approved by the competent authority or authorized to the enterprise. Quarterly plans must align with the approved annual limits.

4. Adjustment maps due to changes in the annual plan or production issues such as landslides, changes in seam conditions, or other reasons approved by the competent authority or authorized to the enterprise.

Article 7.

1. All coal production within the planned period must be inspected and accepted. If production exceeds the plan limit, it must be reviewed and analyzed according to Clause 4, Article 6 of these Regulations.

2. Coal production must be calculated separately for each seam, layer, and work site.

Article 8.Documents, maps, and calculations for checking coal production volume and overburdenquantity must be accurately constructed in accordance with technical regulations,reflecting the true situation of mining operations and the current state of themine.

Strictly prohibit erasing, altering documents, data, maps, calculation drawingsfor overburden quantity, coal production volume, and related materials.

Annually, the General Director of the enterprise must organize the calculationand inspection of overburden quantity and coal production volume, analyze andcompare with the technical design approved by the competent authority. After theinspection, the results of the calculations must be reported to the competentmanagement authority and relevant state management agencies for supervision.

Article 9.The time for measuring, inspecting, and accepting coal production volume andoverburden quantity shall be carried out according to the following provisions.

Quarterly, enterprises must conduct inspections and acceptance of coalproduction volume and overburden quantity implemented at each work site and forall mines.

Annually, the competent management authority must organize regular inspectionsand sign off on the acceptance maps of the results regarding coal productionvolume and overburden quantity implemented by subordinate enterprises.

Chapter II.

CLASSIFICATION OF OVERBURDEN

Article 10Overburden includes two types: overburden within planned limits and overburden outside planned limits.

Overburden is divided into two types: overburden within plan limits andoverburden outside plan limits.

Article 11.Overburden within plan limits is included in the actual overburden quantity,while overburden outside plan limits is not included in the actual overburdenquantity during the planning period.

1. Overburden from coal seam walls, pillars, inter-seam rock, and surface coverwithin the design and technical plan limits approved by the competent authorityand disposed of in designated waste dumps.

2. The following types of overburden are considered overburden within planlimits:

a) Overburden from thin and small coal seams not listed in the geological reportat the beginning of the year, which are excavated and transported to designatedwaste dumps during mining. In this case, the extracted coal is counted towards themine's production volume but not included in the actual overburden quantity.

b) Overburden generated due to changes in geological conditions, where theposition of coal seam walls and pillars rises or falls compared to the originalposition, necessitating adjustments to the layer limit.

c) Overburden outside the annual plan limit but within the mandatory removalrange due to landslides affecting production, transportation routes, drainagechannels, layers, and mining areas within the required limits.

For overburden specified in points a, b, and c of Clause 2 of this Article, timelyupdates and geodetic and geological documentation must be prepared along with adetailed explanation submitted to the competent authority for approval beforeexcavation and removal.

If the adjusted overburden quantity is less than 10% of the plan based on thework site and less than 5% of the total mine volume, the enterprise may approveits own adjustment plan. If the enterprise has only one work site, it may adjustless than 5% of the planned overburden quantity.

If the adjusted overburden quantity exceeds 10% of the plan based on the worksite and 5% of the total mine plan, the enterprise may only excavate and removeafter completing geodetic and geological documentation and obtaining approvalfrom the competent authority.

When landslide earth requires treatment outside the design, the excavation planmust be approved by the competent authority.

3. Overburden from coal seam walls and pillars may be disposed within thetechnical boundary of the mine (if stipulated in the design or annual plan),approved by the competent authority.

When overburden is transported from one layer to another within the technicalboundary as a transportation method, it can be counted once in the overburdenquantity of the reflecting layer. Subsequent overburden quantities must be recordedseparately and only used to calculate transportation costs.

Overburden previously allowed to be temporarily disposed within the technicalboundary but must be removed to the designated dump according to the miningplan cannot be included in the overburden factor of the work site. This type ofoverburden must be recorded separately like soft soil, low density material, andnon-drilled, non-blasted material.

Article 12. Overburden outside plan limits refers to overburden not defined in Article 11 ofthis Regulation.

Article 13.Overburden within plan limits of the year is simultaneously included in theoverburden quantity of the year.

If overburden is excavated outside the annual plan limit but within the designtechnical boundary of the mine, it can be included in the actual overburdenquantity when the mining plan allows excavation up to that limit.

If a mine completes its annual plan in all layers, it may exceed the limit andcarry forward to the next year's plan. Such plans must be approved by thecompetent authority.

Article 14.The limits for calculating overburden within and outside the plan are as follows:

1. At mechanized mining sites:

a) The actual position of layers within the plan may deviate by a sawtooth patternfrom the limit by + 5 meters, measured from the bottom of the layer.

b) The actual position of the final layer of the site may deviate by a sawtoothpattern from the technical boundary by + 2 meters, measured from the bottom of the layer.

c) The actual position of roads may deviate maximally from the design or plan by + 4 meters, measured from the center of the road.

d) The actual height of the layer may not deviate from the designed or plannedheight by more than + 1.5 meters.

2. For semi-mechanized and manual mining sites:

a) The actual position of layers within the plan may deviate by a sawtooth patternfrom the limit by + 3 meters, measured from the bottom of the layer.

b) The actual position of the final layer of the site may deviate by a sawtoothpattern from the technical boundary by + 1 meter, measured from the bottom of the layer.

If the deviation exceeds the above provisions, overburden calculated from theplanned limit position is considered overburden outside the limit.

c) The actual position of roads may deviate maximally from the design or plan by + 3 meters, measured from the center of the road.

d) The actual height of the layer may not deviate from the designed or plannedheight by more than + 1 meter.

Chapter III

MEASUREMENT AND CALCULATION TECHNICAL BASIS

Article 15.The coordinate and elevation basis for measuring and inspecting overburdenquantity and coal production volume must be within the common coordinate andelevation system of the entire mine.

All stations for topographic survey equipment must be triangular points,intersection points, or ridge vertices with relative closure errors not exceeding1/5000.

The main point can only be transferred to a secondary point with a maximumdistance of 80 meters for maps at a scale of 1/500 and 100 meters for maps at ascale of 1/1000 when measured using a delta theodolite or other instruments ofequivalent accuracy. For electronic total stations, measurements may be takenaccording to the capabilities of the instrument but must ensure accuracy. It isstrictly prohibited to measure from one secondary point to another secondarypoint.

Article 16.The height of the instrument placement point must be determined by geometricleveling and must be consistent with the height system of the entire mine. Thesurveying error of geometric leveling of the instrument placement points shallnot exceed the value + 50mm L (L is the length of the leveling route measured in kilometers).

In special cases, the height of the instrument placement points may bedetermined by trigonometric leveling, but the height must be transferred from twodirections and must be measured in both forward and reverse directions of thetelescope. The difference in height calculated in both forward and reversedirections shall not exceed + 0.01 m/100m, with the length of the measuring edge < 1500 m.

Article 17.Topographic surveys of layers are conducted using theodolites, and the pointsmust be placed accurately at characteristic positions of the layer such as theedge of the layer, the base of the layer, and the slope of the layer.

At locations with complex terrain, when conducting surveys to check coalproduction and overburden stripping at various layers, detailed topographicprofile diagrams and the positions of the points must be drawn.

Only tapes with absolute values less than 50 should be used to measure detailstopography when using a Delta theodolite and measuring at angles less than 30degrees.⁰ Whenusing a Theo 20 theodolite and other instruments of equivalent accuracy.

Foroptical theodolites, the density of topographic points is specified according tothe table below.

For electronic total stations, the distance from the instrument to the prismfor measurement is allowed according to the capability of the instrument butmust ensure the length measurement error < + 0.2 m; the height measurement error of detailed points < + 0.05 m. The measurement distance must ensure that the measurer can observe theentire surface of the terrain being measured.

Article 18.Maps and cross-sections for calculating coal production and overburdenstripping must be constructed on rigid drawing paper with minimal shrinkage,kept flat without folding or rolling.

On cross-sections, coordinate axes and contour lines spaced 20 meters apartmust be drawn, along with annual plan limits and technical design limits toanalyze volume. Cross-sections need to be arranged fixedly in accordance with thelayer lines.

Article 19.The edge error of each square coordinate grid with a side length of 100 mm onrigid drawing paper shall not exceed + 0.2 mm.

The permissible error when positioning points on the map is defined as follows:

For instrument placement points including main and secondary points, it must besmaller than + 0.3 mm.

For topographic points, it must be smaller than + 0.5 mm in length and +15 minutes in angle.

When drawing maps, a measuring ruler with a radius of no less than 10 cm and anaccuracy of no more than 15 minutes must be used.

Article 20.Maps for calculating mine volumes (overburden and coal production) must complywith the following provisions:

1.Map Scale:

a)For planned overburden stripping sites > 300,000 m³/year, the map scale is 1/1000.

b)For planned overburden removal sites < 300,000 m³/year, the map scale is 1/500.

2.Maps for calculating overburden and coal production volumes must be updated atleast once a year. All documentation and maps for calculating mine volumes mustbe stored and archived according to current regulations. The mine surveyor isresponsible before the competent authority for the quality and reliability ofthese stored documents.

Article 21. When calculating coal production and overburden stripping, depending on theactual situation of the site, one of the three methods may be used: verticalsection method (profile diagram) or horizontal section method (plan diagram),method using computer software for calculation.

The use of computer software for calculation must be approved in writing by thecompetent management authority.

Article 22.When using the vertical section method, the use of profile diagrams forcalculating mine volumes must comply with the following provisions:

1.For maps at a scale of 1/1000:

a)The scale of the profile diagrams:

Horizontal scale 1/1000.

Vertical scale 1/1000.

b)The maximum distance between profile diagrams is 20 meters.

2.For maps at a scale of 1/500.

a)The scale of the profile diagrams is:

Horizontal scale 1/500.

Vertical scale 1/500.

b)The maximum distance between profile diagrams is 10 meters.

AT In areas where the layer bends or has complex topography, additional auxiliarysections must be established for calculation.

3.When calculating volume, if the ratio of the cross-sectional areas of twoadjacent sections (S small/S large) <2/3, then the formula for calculating the approximate volume between the twosections must be used as follows:

The volumes of the initial and final mining blocks, basic geometric shapes,are determined by necessary dimensions and calculated according to theguidelines in Appendix I.

Article 23.When calculating coal production and overburden stripping using the horizontalsection method on the map, the end-of-month and end-of-next-month miningconditions must be represented by different colored lines. Calculations must beconducted separately for each area, each layer, and each machine.

The haulage road used for calculations must be taken as the average throughthe face and pillar haulage roads at the end of the previous month and the endof the next month.

AT For long layers, the height difference between the floor and roof of the layerwhere production is calculated shall not exceed 2 meters; if it exceeds, thearea must be divided to ensure the height difference is less than 2 meters.

The actual height of the layer (H) is the difference in the average height ofall points on the floor and roof of the layer within the production calculationarea, as stipulated in Clause 3 of Article 22 of this Regulation.

Article 24.To calculate the area on a cross-section or plan, a planimeter, dividing simpleshapes or programs on handheld calculators or computers may be used. Aplanimeter is only used for calculating areas larger than 4 cm²on the map. Before using a planimeter, the machine and its coefficient for eachmap scale must be checked. Each area must be measured at least twice, and thedifference between the two measurements shall not exceed three units of themachine.

When using the division of simple shapes on the profile diagram (triangles,squares, rectangles, parallelograms, and other shapes) to calculate the area, theheight of the layer is determined by the difference in height between the roofand floor of the layer. Rulers shall not be used to determine the height of thelayer.

Article 25.When converting from volume V to mass Q of raw coal, use the following formula:

Article 24_{a) C} : V_{a) C} x g _{a) C}

Where:

Article 24_{a) C}represents the mass of raw coal extracted (tons) .

V_{a) C}represents the volume of raw coal implemented (m³) determined by the following formula:

V_{a) C} = V_TS + V_{- Office of the President of the State}

g _{a) C} represents the specific volume of raw coal (tons/m³) determined as follows:

c) The Reorganization Enterprise Fund at the state-owned holding corporation level is centralized in a separate account of the state-owned holding corporation, managed by the Board of Directors, to support the reorganization and ownership conversion of enterprises under the state-owned holding corporation as stipulated in Article 2 of this Decision and is responsible for settling accounts with the Ministry

V_TSrepresents the volume of clean coal (m³).

V_{- Office of the President of the State}represents the volume of interbedded rock (m³).

g _TS represents the specific volume of clean coal (T/m³).

g _{- Office of the President of the State} represents the specific weight of interbedded rock (T/m³).

The determination of the specific weight of clean coal and the specific weight ofinterbedded rock is carried out by the Geology Department according to Article 30of this Regulation.

The permissible thickness of interbedded rock allowed to be mixed with raw coaldepends on the design and plan approved by the competent management authority.

Article 26.Mines must have separate production quantity calculation books for coal andoverburden for each work site. Calculations and explanations must be clear andaccurate for each layer, each machine, and the entire work site. Productionquantity calculation books for coal and overburden must be systematically storedand fully maintained throughout the existence of the mine. The person calculatingand the person checking must sign, and the Chief Surveyor and Chief Geologistmust confirm after inspection.

Chapter VI

IMPLEMENTATION

Article 27.The use of data on mine volume is specified as follows:

1Quarterly, enterprises base on the monthly acceptance figures of their subordinatemines to adjust the monthly overburden volume and settle accounts for thequarter.

2At year-end, the competent management authority bases on the acceptance figuresand annual reports of subordinate enterprises to review and confirm thecompliance with the overburden removal and coal production plans and relatedtargets for the enterprises.

The competent management authority is responsible for inspecting and guiding theimplementation of overburden removal and coal mining according to the annualplan; handling issues arising related to coal production and overburden removalas stipulated. When necessary, they must organize direct inspections of coalproduction and overburden removal data of enterprises and their subordinate mines.

Article 28.

1.At the end of each quarter, enterprises must calculate and check the quarterly coalproduction and overburden volume. The coal production and overburden volume ofthe last month of the quarter is the total quarterly volume minus the combinedvolume of the first two months.

2There must be at least one person responsible for calculating and one personresponsible for checking the data on coal and overburden. Official acceptance andreporting data must exclude errors detected by the checker.

3The permissible error when conducting checks on overburden removal acceptancefigures and coal production using geodetic methods shall be carried out accordingto Section 5-34 of the Technical Regulations for Mine Geodesy in Coal Mines 18TCN-01-97.

If the difference between the enterprise's report and the inspection result does notexceed the permissible error, the reported number can be retained; if it is larger,a recheck is required, and the final official figure will be that of the lastinspection by the competent management authority.

Article 29. The Mine Geodesy Department is responsible for:

1Surveying, calculating, and inspecting the overburden volume of each machine,each layer, each work site, and the total volume of the entire mine, organizingstockpile surveys at coal storage areas.

2Providing up-to-date maps promptly to the Geology and Mining EngineeringDepartments..

Article 30.The Mine Geology Department is responsible for:

1Calculating coal production for each seam, each layer, each work site, and theentire mine.

2Annually, determining calculation parameters such as the specific weight of coal,permissible specific weight of interbedded rock to be mined together, monthlycalculating the actual ratio of interbedded rock in each layer according to thefollowing regulations:

a)During the monthly update period, the Geology Department must cooperate withthe Geodesy Department to accurately determine the exposed faces and pillars ofcoal seams, geological factors such as faults, seam dip angles, geologicalmovements, and other factors at the layer face; accurately survey exploration andmining works such as drill holes, exploration wells, trenches, and othergeological works.

b)Accurately determine conversion factors: loose bulk density of coal, loose bulkdensity of rock. Every six months, organize the determination of the specificweight of raw coal and interbedded rock by sampling at the seam.

Article 31.The Mining Engineering Department is responsible for:

1Organizing the preparation and approval of monthly, quarterly, and annual plans;coordinating with the Geodesy Department to ensure the accuracy of planningmaps and implementation maps at the same scale as stipulated in Article 20 ofthis Regulation.

2Cooperating with the Geodesy and Geology Departments to determine the finalimplementation plan, calculate, analyze, and explain volumes and qualitiesoutside the plan.

3Cooperating with the Geodesy and Geology Departments to determine rock hardnessparameters, the proportion of rock requiring blasting, specific weight of coal,rock, transport capacity, and other relevant parameters.

Article 32.

1The enterprise director is responsible for the timeliness and accuracy ofacceptance data, maps, and implementation reports of mine volume before thecompetent management authority and related state management agencies.

If the enterprise has not reached an agreement with the inspection and acceptancefigures of the competent management authority, the enterprise has the right toappeal in writing to a higher-level management authority for verification.

During the time the competent authorities are reviewing, temporarily adopt theenterprise's acceptance figures and the decision of the highest-level managementauthority as the final decision.

2The head of the direct superior agency of the enterprise is responsible to thestate agency for organizing and directing subordinate enterprises and units toacceptance and report mine volume annually and is responsible for compiling andreporting data and materials to the competent state management agencies asstipulated.

Chapter V

IMPLEMENTING PROVISIONS

Article 33.Organizations and individuals violating this Regulation will be subject todisciplinary action, administrative fines, or criminal prosecution depending onthe severity, and if damage is caused, compensation must be provided according tothe law.

Article 34. In the course of implementation, if there are difficulties, related units shouldreport to the Ministry of Industry for research and supplementation or amendment./.