制造水泥,85%的原料是石灰石。全国年需要量约9000万吨。充分利用现有水泥矿山资源,延长矿山使用年限,节约用矿,避免浪费,这比新建接替矿山可以节省投资,降低成本,加速资金周转,在经济上具有重要意义。现就有关的几个技术问题提出一些个人的看法。一、关干凹型露天开采水泥石灰石矿山,可不可以、应不应该把凹型露天开采也列为开拓方式之一?我认为,在进行经济比较的前提下,对有些矿来说是可 Make cement, 85% of the raw material is limestone. National annual demand of about 90 million tons. Making full use of the existing cement and mines resources, extending the useful life of the mines, saving the mines and avoiding waste, it is economically significant than saving the mines to replace the mines newly, reducing costs and speeding up capital turnover. Here are some personal technical opinions on the issue. First, the dry hollow cement mining limestone mines, is it possible, should not be concave open pit mining as one way to open up? I think, in the context of economic comparison, for some mines is