常見例句The top coal broken mechanism and reasonable determination of caving coal heigh in caving coal faces are expounded. 主要闡述了放頂煤工作面頂煤破碎機理及放煤高度的合理確定;It is key problem to raise the top coal recovery rate of the fully mechanized sublevel caving mining. 提高頂煤放出率是綜放開采的一個重大課題,預注水弱化頂煤是解決這一問題的有效方法之一。Practices have proved that quick advancing techniqe is applicable in isolated unmined area Comprehensive top coal caving face. 實踐證明,孤島綜放工作面快速推進技術是可行的。The caving of hard top coal of 4-2# coal seam in Tongchuan Jiaoping Coal Mining Area seriously impacts the production efficiency of the mine. 銅川焦坪礦區(qū)4-2%23煤層堅硬頂煤垮落破碎難題是嚴重影響礦井生產(chǎn)效益的"瓶頸"。This article introduced applications,observation and research's actuality and developing trend of fully mechanized top coal caving mining under water. 介紹放頂煤開采技術在水體下采煤領域中的應用情況、觀測研究現(xiàn)狀及其發(fā)展趨勢。In 1997, the Xingtai Mine succeeded in using bolting &boltmesh supporting tech. in coal roadway(supporting the top coal along the bottom). 1997年,邢臺礦在全煤(沿底托頂煤)巷道采用錨桿加錨索的支護技術獲得成功。 返回 top-coal