Preparation of ferronickel from nickel laterite via coal-based reduction followed by magnetic separation
来源期刊：International Journal of Minerals Metallurgy and Materials2018年第7期
论文作者：Lun-wei Wang Xue-ming Lü Zhi-xiong You Xue-wei Lü Chen-guang Bai
文章页码：744 - 751
摘 要：The sticking phenomenon between molten slag and refractory is one of the crucial problems when preparing ferronickel from laterite ore using rotary hearth furnace or rotary kiln processes. This study aims to ameliorate sticking problems by using silicon dioxide（SiO2） to adjust the melting degree of the briquette during reduction roasting. Thermodynamic analysis indicates that the melting temperature of the slag gradually increases with an increase in the SiO2 proportion（SiO2/（SiO2 + Al2 O3 + Mg O） mass ratio）. Experimental validations also prove that the briquette retains its original shape when the SiO2 proportion is greater than 75 wt%, and sticking problems are avoided during reduction. A ferronickel product with 8.33 wt% Ni and 84.71 wt% Fe was prepared via reductive roasting at 1500°C for 90 min with a SiO2 proportion of 75 wt% and a C/O molar ratio of 1.0 followed by dry magnetic separation; the corresponding recoveries of Ni and Fe reached 75.70% and 77.97%, respectively. The microstructure and phase transformation of reduced briquette reveals that the aggregation and growth of ferronickel particles were not significantly affected after adding SiO2 to the reduction process.
Lun-wei Wang1，Xue-ming Lü1，Zhi-xiong You1，Xue-wei Lü1，Chen-guang Bai1
1. College of Materials Science and Engineering, Chongqing University
摘 要：The sticking phenomenon between molten slag and refractory is one of the crucial problems when preparing ferronickel from laterite ore using rotary hearth furnace or rotary kiln processes. This study aims to ameliorate sticking problems by using silicon dioxide（SiO2） to adjust the melting degree of the briquette during reduction roasting. Thermodynamic analysis indicates that the melting temperature of the slag gradually increases with an increase in the SiO2 proportion（SiO2/（SiO2 + Al2 O3 + Mg O） mass ratio）. Experimental validations also prove that the briquette retains its original shape when the SiO2 proportion is greater than 75 wt%, and sticking problems are avoided during reduction. A ferronickel product with 8.33 wt% Ni and 84.71 wt% Fe was prepared via reductive roasting at 1500°C for 90 min with a SiO2 proportion of 75 wt% and a C/O molar ratio of 1.0 followed by dry magnetic separation; the corresponding recoveries of Ni and Fe reached 75.70% and 77.97%, respectively. The microstructure and phase transformation of reduced briquette reveals that the aggregation and growth of ferronickel particles were not significantly affected after adding SiO2 to the reduction process.
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