pitch seam meaning in Chinese

松脂裂纹

The conventional methods for mining such seams including the longwall blasting and block caving suffer form the drawbacks of being low in recovery , high in labor intensity and low in efficiency . after shifting to the use of the fully - mechanized extraction system by the zhaogezhuang branch mining industry co . of kailuan ( group ) co . , the mining of the pitching seams has met with remarkbable social and economic result
针对大倾角煤层长壁炮采、落垛等采煤方法,存在回采率较低、员工劳动强度大、高产高效受限及安全等诸多问题,开滦(集团)赵各庄矿业分公司在探讨大倾角煤层采煤工艺的改革及实践大倾角煤层综合机械化采煤过程中,取得了较好的社会经济效益。