Optimum Process Flow Sheet for Copper Scrap Recycling

1.黑铜的还原方法及氧化精炼用碳作还原剂时，追求高的铜回收率比追求高的铜纯度更好。以铁和铁碳合金为还原剂，用Cu_2O-15mass%SiO_2渣对碳还原得到的黑铜进行氧化精炼，获得纯度大于99.9%的铜。因此，这是一个足够高的纯度和获得的铜可以直接返回到火法冶金回收过程。硫化法在最佳条件下，锡、铅、锌、钴易硫化，硅、铬、铝不易硫化。铜的浓度非常高。除铁之外的所有杂质元素的总和约为1.3质量%，这是可接受的足够低的。因此，采用硫化法可以从Cu_2 O基废渣中回收高品位硫化铜，并将其投入铜冶炼厂.酸浸法的最佳工艺条件为：在343 K下，用4NH_2SO_4搅拌浸出细粒Cu_2 O基废渣。

1. Reduction Method and Oxidative Refining of Black CopperWhen carbon is used as reductant, it is better to seek a high recovery ratio of copper rather than a high purity of copper. Iron and Fe-C alloy were also examined as a reductant.From the black copper obtained by carbon reduction, over 99.9% purity of copper was obtained by oxidative refining with Cu_2O-15mass%SiO_2 slag. Thus, that is a high enough purity and the obtained copper can be returned directly to the pyrometallurgical recycling process.2. Sulfurization MethodIn the optimum condition, tin, lead, zinc and cobalt were easily sulfurized, while silicon, chromium and aluminum were difficult to sulfurize. The concentration of copper was very high. The summation of all the impurity elements, except for iron, was about 1.3 mass% and this is acceptably low enough. Therefore, high-grade copper sulfide can be recovered from used Cu_2O-based slag by the sulfurization method and it is possible to charge this material into a copper smelter.3. Acid Leaching MethodThe optimum condition for this method is that fine-grained used Cu_2O-based slag is leached in 4N H_2SO_4 solution with stirring at 343 K.