1、翻译部分英文原文STUDY ON TOP CAVING COAL MINING PARAMETERThis paper is divided into 5 parts, the first is intrduction, the second is three kinds of technical mode of top caving coal, generally mining in low-pitched thick coal seam, the third is study on top caving coal law under conditions of top caving coa
2、l, the fourth is optimizing parameter of caving coal, the fifth is conclusion. The nucleus part of the article is the fourth aim at caving interval, increase the recovery rate, the ratio of coal and send out top coal being theorically analysed. Computer simulation offer to yield of working face ever
3、yday, getting across one drawing per two reamer is better.Part 1: Intrduction.Part 2: Three kinds of technical mode of top caving coal generally mining in low-pitched thick coal seam. The paper predict developing history、foreground、advantages and comingshorts as well as a few kinds of modes of top c
4、aving coal in our country, and introduce mode of Yangquan、Micun、Wulan.Part 3: Study on top coal mining drawing law on drawing top coal, and study on moving process of coal and rock at drawing opning position of. When high of top drawing body take turns less than、equal to、more than x0, accordingly, c
5、oal and rock border come into being mobile funnel、desendent funnel、cracked funnel, see fig1:Movement of top coal:Top coal take advantage of rock press fragmentate, at first under the forward dirction of working face press, and dead weight of coal, crack change big, top coal disintegrate, at last, dr
6、awing behind support tangent, the shape of coal drawing is approximate rotating ellipsoid.According to move of top coal, provide caculate method of ellipsiod and put forward method of reduce refuse content:(1) Choose reasonable caving interval, when caving step interval is short, refuse content is s
7、erious, recovery is lower.(2) Shaft along two neibour orifice approximate equal to short shaft.(3) Especial thick coal seam first mine top coal seam, then mine bottom seam.(4) Rock in coal seam, suggest casting away sub-level caving.Fig-1 Relationship between tundish and drawing bodyIn the same way,
8、 analying ground pressure of top caving coal working face. Through the observation to the rock press of the 73-17 working face, we preliminarily mastered the appearance rules of the rock press of the comprehensive mechanized working face. It may have the important meaning and reference values for th
9、e deep coal mining in Nantun coal mine.The nucleus part of the article is optimizing top caving parameters and computer simulation analyse, aiming at caving interval, increasing the recovery rate, caving coal mode being theorically analysed, carrying out calculating methods of numerical value, build
10、ing up methods and steps of determin nature and fix quantity. The developing process of top coal drawing body and top-coal drawing law with different drawing intervals and opening intervals. It shows that the shape of coal drawing is approximate rotating ellipsoid and it is very difficult to drawing
11、 the triangle so as to improve coal drawing ratio and reduce refuse content, a new approach was put forward to optimixe technology parameters and study coal drawing law with this method, on the basic of statistics and analysis of a lot of the actual material coming from the fully mechanized and cave
12、d face, the production system of this mining face is systematically analyzed furthermore. A computer simulation model about this mining face has been estanlished and simulate the fully mechanized and vaved face on the spot. When caving step interval is small, rock in the behind of the mining hollow
13、area will get drawing opening poison earlier than the upper coal do, the drawing opening poison will be shutt off as soon as the rock is seen, a part of top coal will be remained inside mining hollow area; If the drawing step interval is too big, upper rock near support get to the orifice ealier tha
14、n hind coal do, a part of coal in the mining hollow area will be remained inside, becoming triangle loss. The reasonable drawing step interval will make coal-rock face dropping averagely, the triangle loss is smallest and the refuse content is lowest. Draw conclusion:(1) Reasonable drawing step inte
15、rvals would infect rate of refuse content and recovery rate, reasonable drawing step interval make the coal-rock face droping averagely.(2) When average thickness of seam is 6 meters, the mining and caving rate is 1:1. The way which cave once per one reamer is advocateted, while two side of working
16、face are in hollow area, adopting the way of caving once per two reame.(3) Caving coal interval is as interger mutiple as web of winning machine, commonly use drawing top coal once per reamer, or once per two reamer、once per three reamer, for winning machine of cylinder type, caving coal interval chang between 0.51.5m and 0.61.8m, low mining and caving coal and thickness of coal seam is less than 8m, usually use drawing top
