A METHOD OF PURIFYING NON-FERROUS METAL MELTS FROM FOREIGN ELEMENTS

摘要

In a method of purifying melts, substantially comprising non-ferrous metals, preferably copper and lead, from impurities in the form of not-readily separable elements, such as cobalt, nickel, lead, bismuth, antimony and arsenic, there is injected into the melt at least one solid reactant with the aid of a carrier gas. During the process of injection the melt is maintained under strong turbulence. The carrier gas and the solid reactant are selected so that there is formed with the impurifying element or elements a product whose melting point is higher than the temperature prevailing in the melt, which has a density different from that of said melt. The resultant product is then separated from the melt. The melt may, for example, comprise copper, and the impurifying elements may be nickel and/or cobalt, and the reactant silica, which forms a solid product with nickel and/or cobalt. Suitably, the melt can also contain an oxidant, such as iron (III) oxide or copper oxide. The melt may also comprise crude lead and the impurifying elements antimony and/or arsenic. In this case the oxidant may be lead oxide, which may also function as the solid reactant for forming a solid product. Other combinations are also conceivable.