Study And Application Of The Mining Methods For Inclined Fractured Phosphate Orebody With Medium Thickness

Kaiyang phosphorus mine is classified into Sinian marine sedimentary deposits, in which, the phosphate ore bodies are medium thickness inclined. This kind of layered phosphate strata are mainly composed by dolomite, phosphate rock, clay rocks and rock composition of the transition between them. Over the years, open-stope method and caving mining method are mostly used for such ore body at home and abroad. Both methods not only bring high loss and dilution rate but also lead to mountain avalanche, collapse of mined areas and other major engineering disasters. At the same time, phosphogypsum which produced by the phosphorous chemical is a strong acid, which would pollute the environment seriously if it is accumulated on the earth surface. Through theoretical analysis,laboratory experiments and engineering site condition consideration, the five types of mining methods for such medium thickness inclined fractured phosphate ore body are proposed. with unascertained mathematical theory which adopted the optimized among the five mining methods, continuous sub-pillar of phosphogypsum filling mining method is optimized as the best option. According to the recovery characteristics of the optimesed mining method, support pattern and parameters for the cut up the hill within the slope roof are chosed. The maximun mining stope span is calculated as 25m for the representative rock conditions of ore body. In allusion to the difficult problems of fine grain grad of phosphogypsum, slow dehydration, long maintenance cycle, long cycle time of stope mining and lower production ability, a rapid filling dehydration system is proposed to solve the problems of 1000 gypsum cement dehydration,easy to run pulp and slurry leakage. And for the serious loss of triangle ore of thick inclined ore body, long arm installed machine is used to achieve the recovery of the triangle ore at the bottom of the stope. The continuous sub-pillar filling method is successfully applied to the Maluping part of Kaiyang Mine with features of safety, high efficiency, low dilution loss and low operating cost. And this mining method has enabled large-scale industrial use of phosphorus and perfect with efficient and safe mining and low dilution loss, promoting sustainable development of phosphate chemical industry.