The process analysis of converting ferronickel into high nickel matte

Sulfurization smelting is a effective process for the transformation of ferronickel into low nickel matte, with subsequent conversion through oxygen blowing and converting enabling the production of high nickel matte. This study involved the initial mixing and smelting of ferronickel, SiO₂, pyrite, and coke, followed by the blending of the resulting low nickel matte with SiO₂ during oxygen blowing at elevated temperatures, with an emphasis on optimizing both stages of the process. The research revealed that in the first stage, when 50 g of pyrite, 27 g of SiO₂, and 3 g of coke were added, and the smelting was carried out at a temperature of 1425℃ for 2.5 h, over 99 % of the nickel was successfully converted from ferronickel into low nickel matte, with a nickel content exceeding 35 % and sulfur content of around 17 %, while the slag nickel content was as low as 0.4 %. In the second stage, with a conversion time of 8 h, 23 g of SiO₂ addition, and a converting temperature of 1300℃, over 96 % of the nickel was transformed into high-grade matte with a nickel content exceeding 75 % and sulfur content of 18 %. These findings provide valuable insights for the utilization of ferronickel in the production of nickel sulfate to meet the demands of the burgeoning lithium battery industry.