红土镍矿高温硫化熔炼镍锍

Production of nickel matte through high-temperature sulphidizing smelting from laterite nickel ore

本文通过热力学分析,揭示了红土镍矿硫化熔炼低镍锍过程物相演变规律,阐明了硫化熔炼过程机理。结果表明:在一定硫化熔炼条件下,红土镍矿中镍氧化物转变历程为NiO→Ni→Ni_(3)S_(2),钴氧化物转变历程为CoO→Co→Co_(9)S_(8),铁氧化物转变途径为Fe_(2)O_(3)→Fe_(3)O_(4)→FeO→FeS或Fe_(2)O_(3)→Fe_(3)O_(4)→FeO→Fe→FeS;金属与S亲和力强弱顺序为Ni≈Fe>Co;金属与O亲和力强弱顺序为Fe>Co>Ni。由理论计算可知:在硫化熔炼过程中,当硫磺添加量为矿料质量的2%、碳添加量为矿料质量的4%时,产出镍锍品位为21.45%,镍、钴回收率分别为99.43%、87.58%,硫直接利用率为62.68%。目前,红土镍矿高温硫化熔炼镍锍,已初步实现工业应用,与常规RKEF技术相比,过程绿色低碳,是具有里程碑意义的技术变革。

The phase evolution of producing nickel matte via sulphidizing smelting from laterite nickel ore was revealed by thermodynamic analysis,and the mechanism of sulphidizing smelting was elucidated.The results show that,under certain sulphidizing smelting conditions,the transformation course of nickel oxide in laterite ore is NiO→Ni→Ni_(3)S_(2),the transformation course of cobalt oxide is CoO→Co→Co9S8,and the transformation path of iron oxide is Fe_(2)O_(3)→Fe_(3)O_(4)→FeO→FeS or Fe_(2)O_(3)→Fe_(3)O_(4)→FeO→Fe→FeS.The strength order of affinity between metal and S is Ni≈Fe>Co.The strength order of affinity between metal and O is Fe>Co>Ni.According to the theoretical calculation,when the sulfur content is 2%of the ore mass and the carbon content is 4%of the ore mass,the nickel grade is 21.45%,the recovery of nickel and cobalt are 99.43%and 87.58%,respectively,and the direct utilization rate of sulfur is 62.68%.At present,the technology of producing nickel matte via high-temperature sulphidizing smelting from laterite nickel ore has been preliminarily applied in industry.Compared with conventional RKEF technology,the process is a green and low carbon,which is a milestone technical change.