Sustainable Developments in the Nickel Recovery Process

The conventional practice for controlling impurities and excess copper in the electrolyte at the copper refinery is to bleed a certain volume of electrolyte from the tankhouse and treat this bleed solution in a copper-removal circuit, i.e., deposit out or liberator cells. The decopperized electrolyte is then fed to the nickel sulfate plant, where crystallized nickel sulfate and black acid are produced from the evaporators. Aiming at sustainable developments, a new process to recover the nickel, was innovated and commercialized to eliminate the production of black acid and to cut the elevated energy cost at the FMI–El Paso Operations. This new environmentally friendly process is narratively described, viz., advanced decopperization, efficient recovery of sulfuric acid, effective removal of arsenic, antimony, and bismuth impurities, and economical recovery of nickel carbonate. Significant sustainable developments in the brown field, especially focusing on saving energy consumption and reduction of carbon dioxide (CO2), are also rationally discussed in this paper.