Research On Steep Thick Seam Upper-coal’s Comprehensive Weaken Technology Based On SCA

The steeply inclined thick coal seam is hard to extract.and the geological environment ofUrumqi coal region is complex,Coal seam angle (45~87°)and thickness(over30m)are all large.The high level fully-mechanized caving (15~27m) of steeply inclined thick coal seam withspecial geological structure which has caused a series of problems which contain the complexregular pattern of rock pressure,low caving rate of high level upper-coal, wall falingl and rooffalling of roadway,working face Hydrogen sulfide and other harmful gas emission and so on.At present, the methods for top coal weaking are hydraulic fracturing and pre-blasting methodThe drawbacks of hydraulic fracturing is waterflooding cycle too long,and the limit range ishard to regulation; pre-blasting method is easily lead to The roadway destruction and thederived dynamic disaster. Both achieve the top coal breaking effective and improve thecavability on roadway instability regulation,it’s crucial for promote pre weaking progress tostudy a kind of general adaptation coal breaking agen for extremely steep coal seam, reducethe use amount of explosives in the mine,So the study of upper-coal weakening has significantmeaning for steep thick coal seam.This thesis is aim of the steep thick seam group upper-coal weaken which mining byShenhua Xinjiang Energy Co.Ltd.By laboratory experiment, top coal weakening effectexperiment of alkaline matrix, numerical simulation and analysis on coal pore pressure anddynamic rupture process,and engineeringfield test,etc, appling the existing mature theory andexperience of upper-coal’s weaken, Proposed and implemented a comprehensive weakeningmethod based on deep hole blasting in advance with static cracking agent, on this basis,Through the loose circle monitoring instrument, optical borehole TV,and geological radarcomprehensive analysis the construction area, compared comprehensively to the constructioneffect,verify and analysis the construction result.The study shows that using the comprehensive SCA weaking method of lime water-surface active agent, The situation of upper-coal caving has materially changed,theinner frcture initiation and expansion of upper-coal has accelerated, the gas overflow channelalso Expand and increased, Neutraling hydrogen sulfide, the efficiency for safety andproduction caving be improved.The study can be use for reference on efficient mining,disaster prevention andenvironmental protection of thick coal seam.