Optimizing Melting Temperatures for High-purity Copper Recovery from Scrap Sources

Abstract

Recycled copper is essential to meet the increasing global demand for this material. This study aims to optimize the purity of copper extracted from scrap metals. Under ambient conditions and without altering pressure levels, fire-refining experiments were conducted on three samples copper scrap. These samples were melted at temperatures ranging from 1363 K to 1453 K with an increment of 283 K. By exploiting the volatility of certain impurities (Zn, Ar and P) and the oxidation of others within the slag, this process significantly improved copper purity. The experimental results showed that the highest copper concentrations and the lowest impurities were obtained at 1393 K for all three samples, which were consistently confirmed by other experiments conducted at 1388 K and 1398 K. A pre-treatment consisting of washing, drying and heating applied to one of these samples had considerably improved the copper concentration of this sample. The copper obtained from treated sample reached a purity of 99.952.wt %, an increase of 0.02% compared to the untreated sample. With this purity and thermal conductivity reaching 338 W.m-1.K-1, this copper will have a wide range of industrial applications. Specifically, it can be used in the manufacture of industrial boilers where corrosion resistance and excellent thermal conductivity are required.