Study and choice of parameters for a system of mine working by horizontal layers in a descending order with a suspension support system and filling of the worked-out space

Abstract

Crushability of the ore in the kinetics equation is defined by the characteristic time for crushing, T, which is needed to reduce the coarse-class content in the mill by e (e is the natural--logarithm base). It is also defined by the index m, which determines the form of the dependence. The mathematical model permits the prediction of mill productivity in relation to its operating regime and the composition of its mineral mixture.1. 25 3.LITERATURE CITED E. I. Shemyakin, V. I. Revnivtsev, N. N. Faddeenkov, and A. S. Petrov, "One approach to an est~m-te of energy consumption while breaking up ore," 0bogashch. Rud., No. 6, 158 (1981). C. E. Andreev, "The content of the coarse class in a mill determines its productivity," Obogashch. Rud., No. 2, 38 (1962 Thick steep beds with faults are usually worked by a system of sublevel caving, which is characterized by a high loss of coal, high fire hazard, prolonged development working, and impossible mechanization of stoping work.The possibility of working such disrupted areas with a rising order is limited by the instability of overhanging coal beds that create hazardous conditions for work at the stone face. For that reason, attempts have been made to work thick steep beds by decending horizontal layers with pne,---tic filling of worked-out space [i]. But low cost-effectlveness systems due to the absence of ways and means for mechanized coal excavat:ion or support of near-face space led to abandonment of this principle.Research and development is now underway to create a system for working of thick steep seams by horizontal layers in descending order with a solidifying fillitng of the workedout space [2,3]. An important aspect of this process is creating a stable ceiling of the solidifying filler. Tests at Nogradskaya mine of Prokop'evskugol' Ente]--prlses show tl~at, under unfavorable mining and geologic conditions, the layer of solldlfy~tng can collapse, and individual fall-outs can occur when the filling mass is not formed properly.This necessitates installing an additional support for the artific:lal ceiling.Foreign experience with a system of horizontal layers of working i~n descending order with solidifying material used to fill the worked-out space also conf~s the need for supporting the artificial ceiling to prevent the collapse of blocks and foz'matlon of fall-outs. For additional support, a raft of beams and metal net is used, resting on stakes or bang,nfrom rods fixed in the overhead layer [4]. In the latter case, this additional support does not limit the choice of the height of the horizontal strip and allows cCntlnuous excavation of the underlying sea,, by stoplng and tunneling machines. The introduct:ion of additional support, however, increases the labor costs of development working and z~akes the utillty of this process questlonable in areas outside of structures requiring spec:lal protection. For that reason, and also in view of the fact that the mines of the Prokep'~vsk-Kiselev deposit lack an adequate material base for development working with a solldi...