In the CGS system, tonnage in metric tons is calculated by multiplying the specific gravity of the economic mineral by the total volume in cubic meters. In FPS, the total volume in cubic feet should be divided by the tonnage ratio. The tonnage ratio is the number of cubic feet per ton of ore. The tonnage coefficient can be calculated using the formula: 2240 / 62.5Xg cubic feet, where g is the specific gravity of the ore.
The total reserves in the area can be found by dividing the volume by the tonnage ratio. Weight calculations should be taken into account due to the presence of pore spaces, cracks and cavities in the ore bodies.
To assess the reserves, the first step is to plan to divide the mineral deposit into a series of ore reserve blocks. On planning paper, each hole or hole is a unit.
For each block, it is necessary to calculate the area of influence. The volume can be obtained by multiplying the area by the true width of the ore body. Relationships of deposits determine the method of calculating the area.
Total tonnage can be calculated by adding tonnage to individual blocks. The middle class (A) is determined by the formula:
T1A1 + T2A2 + T3A3 ... T10A10 / T1 + T2 + T3 ... T10
If there are 10 ore reserves in the deposit, then each tonnage is taken as T1, T2, T3, and the estimates are presented as A1, A2, A3.
Basically there are two ways to find a block area as 1. Geometric and 2. Graphic.
The area added method, the extended area method, the triangle method and the polygon method fall into the first category. In the latter category there is an isochoric mapping method, the strata contours, the cross-section method.
Before using any method, mineralized areas must be differentiated on the basis of geological knowledge in the area, such as ore continuity, structural features, height, etc.
If the borehole holes or holes are drilled in a grid, the effective area method is highly advisable. In this method, the area of influence and, consequently, the weights in the central pits or holes are two and four times the sides and corner pits. All blocks have an equal area of influence in the extended area method. The methods of triangles and polygons are mainly applicable to the non-network pattern of sample points.
