Red mud is a waste product of alumina production and has an adverse effect on environment. About 90 million tonnes of red mud are produced annually throughout the world and little is recycled for useful applications. The world nickel reserves consist of approximately 30% sulphide ores and 70% oxide ores. Despite the relative abundance of oxide ores, 55% of nickel and nickel alloys produced today are derived from sulphide ores. However, with the production of nickel and its alloys from low-grade oxide ores becoming increasingly important, a major concern is high sulphur level in the resultant alloy. For this reason, desulphurization of the ferronickel becomes an important consideration. In the present study, experiments were conducted to determine if red mud could be used as a major ingredient of custom designed fluxes for the desulphurization of ferronickel alloy. Factors investigated included desulphurization rates, contact angle measurements and flux-refractory interactions.

Red mud is a waste product of alumina production and has an adverse effect on environment. About 90 million tonnes of red mud are produced annually throughout the world and little is recycled for useful applications. The world nickel reserves consist of approximately 30% sulphide ores and 70% oxide ores. Despite the relative abundance of oxide ores, 55% of nickel and nickel alloys produced today are derived from sulphide ores. However, with the production of nickel and its alloys from low-grade oxide ores becoming increasingly important, a major concern is high sulphur level in the resultant alloy. For this reason, desulphurization of the ferronickel becomes an important consideration. In the present study, experiments were conducted to determine if red mud could be used as a major ingredient of custom designed fluxes for the desulphurization of ferronickel alloy. Factors investigated included desulphurization rates, contact angle measurements and flux-refractory interactions.

A produção de ferroníquel está intimamente ligada à indústria siderúrgica. Todas as operações pirometalúrgicas pertencentes à rota de processo (calcinação, redução e refino) visam o melhor aproveitamento energético e a menor quantidade de impurezas no produto final. A etapa de refino pirometalúrgico produz escória rica em ferro e níquel, que normalmente é processada para recuperação destes metais e reinserção no processo, na própria etapa de refino ou no forno de redução, dependendo da quantidade de impurezas. Ensaios realizados com a escória granulada da Mineração Morro Azul mostram que é possível recuperá-los por processos físicos, de maneira similar à existente no local, porém com resultados superiores, mediante algumas alterações propostas para o circuito. / Ferronickel production is intimately connected to the steel industry. All pyrometallurgical operations which comprise the process route (calcining, smelting, refining) aim at better energetic usage and smaller amount of impurities in the final product. The pyrometallurgical refining stage produces slag rich in iron and nickel, which is usually further processed for metal recovery and reinsertion back into the process, in the refining or smelting stages, depending on the amount of impurities. A series of tests carried out on the Mineração Morro Azul granulated refining slag shows that it is possible to recover the metallic particles through physical processing, similarly to the existing facility, but with improved results due to some alterations proposed for the circuit.

A produção de ferroníquel está intimamente ligada à indústria siderúrgica. Todas as operações pirometalúrgicas pertencentes à rota de processo (calcinação, redução e refino) visam o melhor aproveitamento energético e a menor quantidade de impurezas no produto final. A etapa de refino pirometalúrgico produz escória rica em ferro e níquel, que normalmente é processada para recuperação destes metais e reinserção no processo, na própria etapa de refino ou no forno de redução, dependendo da quantidade de impurezas. Ensaios realizados com a escória granulada da Mineração Morro Azul mostram que é possível recuperá-los por processos físicos, de maneira similar à existente no local, porém com resultados superiores, mediante algumas alterações propostas para o circuito. / Ferronickel production is intimately connected to the steel industry. All pyrometallurgical operations which comprise the process route (calcining, smelting, refining) aim at better energetic usage and smaller amount of impurities in the final product. The pyrometallurgical refining stage produces slag rich in iron and nickel, which is usually further processed for metal recovery and reinsertion back into the process, in the refining or smelting stages, depending on the amount of impurities. A series of tests carried out on the Mineração Morro Azul granulated refining slag shows that it is possible to recover the metallic particles through physical processing, similarly to the existing facility, but with improved results due to some alterations proposed for the circuit.