Copper Enrichment from Copper contained Iron Scrap by Liquid Phase Separation of the Fe-Cu-P System

在日本，焚化炉或焚化炉底灰熔炼炉产生的金属残渣数量有所增加。金属残渣中含有铜、银、金等贵重金属。金属渣的主要成分是铜、磷、硅和铁的余物。传统铜冶炼厂铜含量为5% ~ 20%，且铜含量过低，难以回收有价金属，因此研究了一种利用熔融金属体系相分离技术来提升有价金属的新方法。虽然铁和铜的二元熔体在所有成分中都是可混溶的，但在二元熔体中加入碳或磷会导致铁相和铜相之间的相分离。吸收贵金属的铜相在传统铜冶炼厂中精炼是可行的。介绍了铜的相分离、铜的回收和有价金属的分配比例的基本情况。根据质量平衡反应和本研究获得的铜在铁中的溶解度以及铁在铜相中的溶解度，计算了含铁、含铜焚烧废渣中铜的回收率。假设铜相中的铜全部回收，铁相中溶解的铜损失，则铜回收率与残渣中铜品位对应，如图8所示。采用Cu-Fe-P体系相分离回收铜时，含铜10%和30%的金属渣中铜的回收率分别为35%和80%。另一方面，Cu-Fe-P-C体系相分离对含铜10%和30%的金属渣中铜的回收率分别为50%和90%。银、金、钯、铂、铑的分布比例见表2。金、银、钯富集于铜相中，而铑则主要分布于铁相中而非铜相中。铂相对分布于两相。

Amount of metal residue from incinerators or melting furnaces of incinerator bottom ash has been increased in Japan. The metal residue contains valuable metals such as copper, silver and gold. Main components of the metal residue are copper, phosphorus, silicon and iron of the remainder. Copper content is 5 to 20% and too low to recover the valuable metals in a conventional copper smelter, so a new approach to upgrading the valuable metals with phase separation in molten metal system was researched. Whereas the binary melt of iron and copper is miscible over all composition, the addition of carbon or phosphorus to the binary melt leads to phase separation between an iron phase and a copper phase. The copper phase absorbing the precious metals is feasible for refining in a conventional copper smelter. Fundamental information about the phase separation, recovery of copper and distribution ratio of the valuable metals are presented.Based on the mass-balance reaction and the solubility of copper in iron and iron in copper phases obtained in this study, copper recovery from the incineration metal residue containing iron and copper was calculated. Assuming that all copper in copper phase is recovered, and the copper dissolved in iron phase is loss, copper recovery is represented against copper grade in residue as shown in Fig. 8. When copper recovery by applying the phase separation of Cu-Fe-P system is carried out, copper recoveries from metal residues containing 10 and 30% copper are 35 and 80%, respectively. On the other hand, cooper recoveries with the phase separation of Cu-Fe-P-C system are 50 and 90% from metal residues containing 10 and 30% copper, respectively.The distribution ratios of silver, gold, palladium, platinum and rhodium are listed in Table II. We can recognize the gold, silver and palladium are enriched in copper phase, on the contrary rhodium is more distributed to iron phase than to copper. Platinum is comparatively distributed to both phases.