Determination of mining boundary of open pit in China

Rational determination of mining boundary is one of the key problems in the design of open pit mine, which directly affects the main technical and economic indexes of mine. Comprehensive analysis of factors such as natural, economic and technical organization. Stone mine to determine the mining realm, we must first solve the problem of the first mining area, and then determine the optimal state.

The two shows that there is a direct relationship between the economic stripping ratio and waste rate. Block rate is high, the economic stripping ratio is high, and vice versa. Different conditions of deposit, waste rate changes greatly, so the economic stripping ratio also has great changes. Another impact of economic reasonable stripping mining is an important factor price is blocks and blocks of varieties and specifications of the relevant, varieties, specifications high price is high.

Four, the lowest rate of economic blocks

General open pit mine economic benefits, in addition to the nature of the rock itself and the corresponding mining technology, the main decision in stripping ratio. So the main factor in determining the value of mining and mining is the stripping ratio. In the face of stone mining, in addition to stripping ratio, there is a major and reasonable determination of the mining boundary is one of the key issues in the design of open pit, directly affect the main technical and economic indicators of mine. Comprehensive analysis of factors such as natural, economic and technical organization. Stone mine to determine the mining realm, we must first solve the problem of the first mining area, and then determine the optimal state.

First, select the main principles of first mining area

In general, the mining of the face stone mine is smaller in size and the level of mining is not needed in the whole mining area. Therefore, to determine the mining realm, is the first choice of the first mining area. The main principle of choice is:

The exploration degree is higher, the reserve is more reliable;

Sufficient reserves, to ensure that the appropriate length of service in the mine;

Have better mining conditions;

The stripping ratio is small, high waste rate;

The rational development of the whole deposit is not affected.

Two, determine the main principles of mining realm

1) to ensure that there is a certain profit;

2) make full use of resources, minimize the loss of reserves;

3) mine service life;

4) to ensure the safety of production;

5) does not affect the need to protect the buildings, structures, rivers, railways, highways, etc..

Three, the manager of reasonable stripping ratio calculation method

In order to guarantee a certain amount of profits in the stone mine, the stripping ratio is not larger than the economic and reasonable stripping ratio.

At present, our country facing stone mines are open pit mining, so in the calculation of economic reasonable stripping ratio, do not use and underground mining comparative cost or profit method, and ensure that the method of obtaining the necessary minimum profit, the profit method.

No broken ore comprehensive utilization of waste rate factors.

The same number of ore mining, block rate is high, the product blocks more, better economic benefits. There are obvious economic benefits directly affect the rate of visible blocks facing stone mines. Therefore, from the point of view of economy, the lower bounds on blocks rate have certain requirements, can not meet the requirements can not guarantee to obtain the necessary profits, there is no exploitation value. The minimum necessary profit shall be guaranteed to pay taxes and to repay the investment loans and interest.

The lowest rate of economic blocks can be calculated to determine:

Broken ore is not comprehensive utilization

Minimum economic blocks rate and production stripping ratio has a direct relationship, production stripping ratio, minimum economic blocks rate is high and mining, production stripping mining is smaller than the minimum economic blocks rate is low, both of which showed a linear relationship. Therefore, evaluation, selection and determination of the mining area or block, in addition to the ore properties and other technical conditions must also pay attention to the stripping rate ratio and blocks of two parameters.

Under general conditions, production stripping production ratio at about 0.3 m3 / m3, the lowest economic blocks of granite mine rate for 15-25%; marble mine for 20-30%. If the variety is good, the price is high, there are more exports, the lowest rate of economic blocks can be appropriately reduced.