Types of mines

4. Mining methods

According to the different stope management methods in the ore recovery process, the mining methods of non-coal mining mines can be divided into four categories:

(1) Open stope mining method is characterized by the fact that in the mining process, the goaf mainly relies on temporary or permanent residual pillars to support, and the goaf is always empty, which is generally used when the ore and surrounding rock are stable.

(2) The caving mining method is characterized by the planned use of the overlying rock layer of the caving ore body and the rocks of the upper and lower wall to fill the goaf with the ore extraction to control the ground pressure in the mining area. Generally, it is used under the condition that the surrounding rock of the ore body is unstable and the surface allows subsidence.

(3) The filling mining method is characterized by the support of the goaf by the filling material within the goaf during mining. This method can effectively maintain the gob, the stability of the surrounding rock is not high, but the production cost is high. It is mainly used for mining high ore value, sufficient filling materials, the surface does not allow subsidence and the geological conditions are particularly complex.

(4) The retention mining method is characterized by the temporary retention of part of the mined ore in the goaf during the mining process, so as to support the goaf with pillars and maintain sufficient mining space. Generally, the ore is stable, and is not easy to oxidize, bond and spontaneous combustion, and the surrounding rock of the ore body is moderately stable.

5. Current status

1. Small scale of mine investment and low mining capacity

The main body of mine investment is not enough to understand the scale of stone mine investment, do not have the investment consciousness of scale mine, performance in the mine construction has no long-term plan, geological work blank, mining plan is not clear, mining methods are backward, mining equipment and lifting equipment is simple, the annual mining volume is only a few hundred cubic meters, at most thousands of cubic meters, mining production has no plan at all. Not to mention mass production.

There is no threshold limit on the scale of investment in the stone mining industry, resulting in the proliferation of small mines across the country. Small-scale mines are often in a major stone producing area in large numbers, scattered, large ore bodies are divided into small ore bodies, complete stone deposits are divided into seven and a half, mining riddled with holes, the destruction and waste of resources is very serious.

Due to the small area of mining activities (the smallest is several hundred square meters), adjacent mines affect each other, resulting in frequent conflicts between mining enterprises, casualties occur from time to time, increasing the difficulty of mining management.

2. Insufficient emphasis on technology

Prior to this, because there is no technical threshold for stone mines in China, the genetic types and geological structures of stone deposits are diverse, and the investment subjects of mining enterprises are mostly individual or private enterprises, unwilling to spend money on geological exploration and mining design, subjectively believing that stone mining is blasting stone, there is no higher technical content in it. The weight of science and technology in quarrying activities is despised, so that the actual problems encountered in the mining process are at a loss.

Although this kind of mine in the capital investment side is larger than the previous situation, but in the overall mining plan of the mine, the determination of mining force method, the rational purchase of mining equipment are lack of unified guiding ideology, lack of scientific basis.

There are many mines with an investment scale of more than 10 million yuan, or even tens of millions of investment. Due to unclear geological conditions, unclear occurrence and occurrence conditions of ore bodies, lack of reasonable economic and technical evaluation of mines, lack of mining design scheme, mine investment has great blindness and great risks. The determination of the first mining area, the layout of the mining face, stripping and slagging, transportation and stacking sites are not clearly designed, and the whole mining area is very disorderly. Due to the uncertainty of the first mining area, the mining production has great blindness, and even the thickness of the fracture zone and regolith is not clear. Once the mining progresses to the expected depth in the mind, the thought will be shaken, and even stop working in this mining face, and find another site to start over. A shot to change a place, always stay on the surface of the mining area, all the surface of the mining area have been mined again without finding a lot of further mining, wasting a lot of manpower, financial and material resources, as well as precious time. What is more terrible is that so much power has been invested, and there is no clear route, because the activities carried out in the front lack purpose, the corresponding data lack reference value, and can not produce great guiding significance for the future work.