Preparation of Nickel Matte from Laterite Nickel Ore Using Pyrite as the Sulfurization Agent
摘要
With the depletion of high-quality nickel sulfide ore resources, the reliance on laterite nickel ore as a primary raw material for nickel production has increased. The pyrometallurgical process for laterite nickel ore mainly yields ferronickel, which is used predominantly in stainless steel production and falls short of the needs of the burgeoning new energy sector. Consequently, there is an urgent need to develop a new process for producing nickel matte through sulphidizing smelting of laterite nickel ore. The study examines the impact of various parameters, including the sulfurizing agent, reducing agent, flux, and the proportion of ore, on the slag liquidus temperature and nickel and cobalt recovery ratios. The findings reveal that when maintaining the original system with a m(SiO2)/m(MgO) ratio of 1.2, the slag composition remains outside the liquid phase region when altering the CaO content. Increasing the CaO content expands the m(SiO2)/m(MgO) value range for the slag composition within the liquid phase region. Optimized conditions show that with an m(SiO2)/m(MgO) ratio of 2.5, 10 pct CaO addition, 6.5 pct sulfiding agent addition, 4 pct reducing agent addition, pO2 at 10−9 atm, and an SO2 gas flow rate of 4 mL/min, the nickel and cobalt recovery ratios reach 98.72 and 81.92 pct, respectively. Most of the iron transitions to the slag phase, with 79.80 pct entering the slag and 20.20 pct remaining in the nickel matte. The resulting nickel matte contains 19.41 pct Ni, 0.84 pct Co, and 28.39 pct S, primarily comprising nickel-iron, nickel matte, and iron matte phases.