德意志民主共和国的有色金属資源不太多,一般是小、貧和薄的矿体。限于采矿的条件,劳动生产率較低,貧化率較高。自1950年开始首先在埃伦弗利德斯多夫錫选矿厂引进了重介质选矿法,以后在銅矿和鎢矿进行了推广。劳动生产率提高了,全員劳动生产率提高一倍以上。由于采用重介质选矿預先富集,大大地节約了磨矿以后的設备,如培西特斯格留鎢选矿 The non-ferrous metals resources of the German Democratic Republic are not too large, generally small, poor and thin ore bodies. Limited to mining conditions, labor productivity is low and the rate of depletion is high. Since 1950, the heavy-medium beneficiation process was first introduced at the Ellen Friedensdorf Tin Concentrator and was later promoted at copper and tungsten mines. The productivity of labor has risen, and the total labor productivity has more than doubled. Due to the pre-enrichment with heavy medium beneficiation, the equipment after grinding is greatly saved, for example,