前言七○砂的旧砂能否回用,是使用石灰石砂作造型材料的关键问题之一。因为旧砂能不能回用,不但影响成本,而且由于新、旧砂的吞吐量增大,必将加重运输、废砂处理等一系列的负担。因此旧砂的回用问题,深为大家重视。旧砂分:水爆砂(水爆池中存砂),块砂(落砂机的块砂)和背砂三种。水爆砂和块砂主要用作面砂。为了衡量旧砂回用的可能性和是否有回用价值,我们在旧砂的回收率、耐碾性和保存性三个方面作了一些试验。试验部分 Preface 70 sand sand can reuse, is the use of limestone sand molding material for one of the key issues. Because the old sand can not be reused, not only affect the cost, but also because of new, old sand increased throughput, will certainly increase the transport, waste sand treatment and a series of burdens. Therefore, the reuse of old sand, deep for everyone attention. Old sand points: water blasting sand (water bursting pool in the sand), block sand (sand machine block sand) and the back of the sand three. Water blasting sand and block sand is mainly used as surface sand. In order to measure the possibility of reuse of used sand and whether there is reuse value, we have done some experiments on the recovery of old sand, sanding resistance and conservation of three aspects. Experimental part