关键词: 地下转露天开采, 资源条件, 资源回收率, 经济效益

Abstract: Based on the dominance of open pit mining，the conditions of resources which adapt to transferring from underground into open pit mining are analyzed.Comparing with the underground mining，open pit mining owns the advantages of high recovery ratio of resource，large production capacity，low production cost，high operation safety level，well operation environment，and so on.The factors of resource recovery ratio，operation safety，and economic benefits and the secondary recovery of resources are the reason for transferring from underground into open pit mining.Among these，the enlargement of production capacity，the decrease of production cost in open pit，the increase of ore price，and lower stripping ratio which brought by lower cutoff grade are the main one of transferring from underground into open pit mining to increase economic benefits.The secondary recovery from the residual minerals with open pit mining can fully make use of mineral resources which are lost by underground mining.There are three mining forms，mainly including of ore pillars recovery，filling recovery，and open pit mining which destroyed the minerals.

Key words: Transferring from underground into open pit mining, Conditions of resource, Recovery ratio of resource, Economic benefits