Abstract:The metallurgical industry has high coal consumption and large carbon emissions. Biomass, as a renewable carbon source with zero carbon emissions throughout its entire life cycle, has enormous potential in replacing coal. In the metallurgical industry, biomass has received certain research and attention, but currently, more attention is paid to its fuel properties, and mainly concentrated in the steel industry. Nickel is an important strategic metal, currently mainly sourced from nickel laterite ore. Rotary kiln pre-reduction - electric furnace smelting is one of its important smelting methods. In this paper, rice husk char was selected as reductant in the smelting process of nickel laterite ore containing 1.45% nickel and 24.5% iron, with Shenmu semi-coke as the control group. Simulating actual progress, the effects of holding time, holding temperature, and reductant ratio were discussed, and the differences in reducing effect between the two reductants were compared. The experiment was conducted in the QSX-12-17 muffle furnace. About 130 g of nickel laterite ore and a preset ratio of reductant were mixed evenly, covered, and placed in the muffle furnace. The furnace was heated according to the preset heating program. After natural cooling, the crucible was smashed to separate the slag and alloy for detection and analysis. Overall, as the amount of reductant increases, the nickel content in the alloys decreases while the iron content increases, and both recovery rates show an upward trend; The increase in holding temperature and holding time led to an increase in nickel content and recovery rate. The nickel-iron alloys exhibit obvious segregation in each operating condition. The main compositions of the slag are magnesium olivine, enstatite, and pyroxene. Considering the content and recovery rate of nickel and iron, the optimal parameters for the reduction smelting process have been determined as follows: The ratio of fixed carbon mass of reductant to the sum of oxygen mass of NiO and Fe2O3 in laterite nickel ore is 0.339 kg/kg (corresponding to 5% usage of Shenmu semicoke and 6.38% usage of biochar). The melting parameters are set at 1 550 ℃ for 60 minutes, and the alloys, which are reduced by using rice husk charcoal and Shenmu semi coke, each contains iron of 85.98% and 87.31% respectively, and nickel of 12.47% and 11.26% respectively. The corresponding recovery rates are 95.18% and 97.00% for nickel, and 77.76% and 64.67% for iron. The alloys contain almost no manganese and chromium, and contain cobalt of 0.47% and 0.37% respectively. The recovery rates of cobalt are 40.8% and 37.9% respectively for each reductant.