Ferronickel Generation from Nickel Sulfide Concentrates by Metallic Iron Addition: Optimization of the Nickel Extraction Process

Nickel sulfide concentrates are critical materials for the production of metallic nickel. The disadvantages associated with the conventional nickel extraction process are the considerable amounts of sulfur dioxide emissions in the smelting process and the complex Ni refining steps to produce a marketable product. The authors proposed a novel thermal treatment method for nickel sulfide concentrates with minimal SO2 emissions and have increased the ferronickel particle size through a two-stage heat treatment process. Heating the materials at 1223 K followed by slow cooling to 973 to 1073 K produced large ferronickel particles of d80 = 500 μm and Ni extraction of approximately 97 pct.