(I) Evaluation: The cement filling mining method is a new technology developed in the past ten years. The cementation filling method is effective for preventing rock movement and surface subsidence, improving the recovery rate of the pillar recovery and reducing the depletion rate, and ensuring a poor work safety. It is a mining method with a promising future. Some of the problems that exist are temporary, and will gradually be resolved with the development of science and technology.
(2) Scope of application
(1) mining precious metals, rare metals, non-ferrous metals bonanza.
(2) Mining non-ferrous metal rich ore bodies with spontaneous combustion hazard to facilitate the prevention of internal combustion.
(3) Mining of rich ore at the same time in the open and underground.
(4) Priority is given to the rich mining area in the mining bed, and as far as possible to protect the upper part of the mining, mining and mining.
(5) Mining rich ore in riverbed or underwater.
(6) Mining security pillars in advance. (well method)
(7) The surface requires special protection. (in the absence of rich ore bodies)
(3) Problems existing
(1) High filling cost – the cost of cementing filling is 20 yuan/ m3 or more. The ratio of filling costs to the direct cost of mining is:
Filling method | domestic | foreign |
Cementation | 35 to 50% | 50% |
Hydraulic | 15 to 25% | 5% |
Reasons for high cost: 1 More expensive cement is used. (3 per meter is filled with 150 ~ 350kg cement compound, filling in cost, the cost of more than 40% cement.
2 The use of high-cost compressed air conveying cement material.
(2) Segregation of cement - The cause of cement segregation is that the water is too large, and the water is large and the concentration is small during transportation. Most mines use a concentration of 40% to 50% (weight concentration). The solution is to add the right amount of flocculant. According to the experimental research of Dongda Mining Department, it is believed that the use of "polyacrylamide" flocculant can greatly improve the phenomenon of cement body segregation. In production, 0.2 ‰ of this flocculant can be put into every 100 g of cement mortar. The use of this flocculant only increases the mining cost by 0.45 yuan/m 3 , which is 1.5 to 3.0% of the total cost.
(The concentration of Jiaojia metal in the test can reach more than 60%, and it is good to grasp it, it is possible to reach 70%.)
(3) The problem of uncoordinated mining and charging – from the actual situation of the mine, the filling cannot meet the requirements of mining. It directly affects the improvement of production capacity of the stope. (The average daily production is only 45 to 50 tons). The transport method and filling process of the filling should be studied.
(4) The contradiction between cement filling and hydraulic filling - At present, China uses cement filling method mining room, and hydraulic filling method mining column. At the beginning of the production, the cement filling work is large, and the hydraulic filling work is large in the later stage. Very unbalanced, complicating the filling system and technical management. If only cementation is used, the cost is too high.
(5) The pillars and conditions of the mining are improved, but the pillars in the mining stage are still very complicated. If the concrete bottom column is slow, it will affect the completion of the production task.
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