Coal reserves of the mine field. The accepted method of calculating stocks

Coal reserves of the mine field. The accepted method of calculating stocks

Reserves of solid mineral deposits are calculated mainly by the method of geological and operational blocks or by the method of sections. Other calculation methods were not adequate to the intelligence systems used, are characterized by cumbersome geometric constructions and increased variance of the average calculation parameters, complicate the justification and application of conditions.

The method of geological blocks is universal for calculating the reserves of flat bodies of minerals, explored both geometrically correct and incorrect network. With this method, counting blocks with the same geological conditions are allocated, i.e. within the counting block there should be: approximately the same angles of incidence, power, ash content, volume weights, and there should also be no discontinuous violations within the blocks of high accuracy of counting reserves (categories A and B).

The method of operational blocks is used to calculate the reserves of flat bodies explored and dissected by mining workings and wells into parts equivalent in shape and size to operational blocks.

The method of sections is used to calculate the reserves of isometric, tube-shaped and complex-shaped bodies of minerals, mainly explored by drilling or mining-drilling systems, which make it possible to build sections. They can be vertical and horizontal.

The calculation of coal reserves in this work was carried out in the boundaries of the mine field indicated by the task by the method of geological blocks.

The accuracy of the calculation of reserves depends on the size of the exploration network and is classified as categories of reserves A, B, C1, allocated during the exploration of mineral deposits in order to prepare it for industrial development.

To perform this work, we take the ratio of stock categories: A ≥ 20%, B ≥ 30% and C1 ≤ 50%. We will take the exploration network to identify the category of reserves A equal to 250x400 m, i.e. the distance between the exploration lines is 400 m, and the distance between the wells on the exploration lines is 250 m. The size of the exploration network of category B reserves is taken to be 2 times larger than for category A, and to identify category C1, the least reliable of the industrial, twice as large as for category B.

Due to the fact that the development of coal seams begins from the upper horizons, the counting blocks of the most reliable reserves (category A) are located closest to the exits, reaching 23% of the total number of reserves in the boundaries of the mine field designated by the task.

Category B blocks should be placed at the level of the average depth horizons, immediately below the boundary of category A blocks, so that when the front of clean-up mining approaches, by thickening the network of exploration wells, the reserves of category B should be transferred to A, in order to continue the front of mining operations to a depth of 31%.

Counting blocks of category C1 are allocated at the deepest horizons below the lower boundary of the block of category B to the lower boundary of the mine field (5 C1, 6 C1), in the border with counting blocks of high categories (A and B) in the zone of coal seams under sediment (7 C1, 8 C1, 10 C1) and tectonic disturbances (9 C1, 11 C1).

 


Preparation of initial data for calculating coal reserves

The main parameters when calculating coal reserves by the method of geological blocks are:

- block area;

- estimated reservoir capacity for wells, taking into account ash content;

-average counting power by counting unit;

- volumetric weight of coal.

The areas of the blocks on the plan are simple in configuration, so we define them as the sum of the areas of elementary geometric shapes. The true area of the counting block taken for calculating coal reserves is determined by the formula:

Sist=Spl*seca,

where, Sist is the true estimated area of the block, m2,

Spl – the area of the counting block on the plan, m2,

Seca is the value of the secance of the average angle of incidence of the formation in the contour of the counting block.

The average estimated capacity of the coal seam according to the counting block is defined as the arithmetic average for the wells included in the contour of the counting block.

The volumetric weight of coal is assumed to be equal to 1.4 t / m3.

 


Coal reserves of the mine field

 

Coal reserves are determined by the formula

Q = Sist*msr*d,

Where Q is coal reserves, t;

       Sist – the true area of the block, m2,

       msr – average estimated reservoir capacity, m;

       d is the volume weight of coal, t/m3.

 


The results of the calculation are summarized in a table.

 

 Block No.

Sпл

secα

Sист

mср

V

d

Q

% of total inventory

1А

1100000

1,022340

1124575

2,27

2552785

1,4

3573899

23

2А

1800000

1,040299

1872539

2,39

4475368

1,4

6265515

3В

1540000

1,022340

1574405

2,27

3573899

1,4

5003459

31

4В

2400000

1,040299

2496719

2,39

5967158

1,4

8354021

5С1

1600000

1,035276

1656442

2,27

3760123

1,4

7896259

46

6С1

2400000

1,035276

2484663

2,39

5938345

1,4

8313682

7С1

212000

1,018717

215968

2,27

490247

1,4

686346

8С1

288750

1,030613

297590

2,27

675529

1,4

945741

9С1

304500

1,035276

315242

2,27

715598

1,4

1001838

10С1

168000

1,040299

174770

2,39

417701

1,4

584781

11С1

136500

1,045690

142737

2,39

341141

1,4

477598

Итого

43103139

100

List of used literature:

Dissertation work of the Master of Geology and Mineral Exploration, Head of the Department of State Supervision in the Coal Industry No. 4 of the Ministry of Emergency Situations of the Republic of Kazakhstan for the Karaganda region I.E. Mausymbaeva.

Supervisor: Candidate of Technical Sciences Filimonov E.N.