This method with a simple production system,is of lower cost But problems such as methods of tunnel support and feedback and expanding roadway,and designs of ratio of extraction to reservation,should be still studied in the extraction through tunnel.

Discussion on sectional mining,technical feasibility and economic rationality of steep side expansion of Guangou quarry is made and some issues to be noted are proposed due to the problems existing in the design and mining of the quarry,such as large stripping volume in the initial mining stage and voriation in stripping ratio during mining.

Feasibility study of side slope extension in Nanfen Iron Ore Mine;