INFLUÊNCIA DO MÓDULO DO SILICATO DE SÓDIO NA FLOTAÇÃO DE MINÉRIO DE FERRO: ESTUDOS FUNDAMENTAIS
INFLUENCE OF SODIUM SILICATE MODULUS ON IRON ORE FLOTATION: FUNDAMENTAL STUDIES
Renato Souza Arantes, Tamires Fonseca Souza, Rosa Malena Fernandes Lima
Resumo
Este artigo apresenta a influência do módulo do silicato de sódio sobre as flotabilidades e cargas superficiais da hematita e do quartzo com oleato de sódio. Baseado nos resultados dos ensaios de microflotação, efetuados em pH 7, foi observado que as flotabilidades da hematita foram maiores do que as flotabilidades do quartzo para todas as concentrações de silicato de sódio testadas independentemente do módulo do reagente. Os valores de potencial zeta da hematita tornaram-se negativos para valores de pH menores do que o ponto isoelétrico do mineral (pH 7,2) e cargas negativas maiores para valores de pH acima do seu ponto isoelétrico, o que sugere a precipitação de SiO2amorfa e adsorção de espécies aniônicas presentes na solução sobre a superfície do mineral, especialmente para valores de pH acima de 10. No caso do quartzo, não foi verificada influência significativa do módulo do reagente tanto nas flotabilidades quanto nos valores de potencial zeta.
Palavras-chave
Abstract
The influence of sodium silicate modulus on the floatabilities and surface charges of hematite and quartz with sodium oleate is presented herein. Based on microflotation test results, performed at pH 7, it was observed that the floatabilities of hematite were higher than the floatabilities of quartz for all concentrations of sodium silicate tested, independent of reagent modus. The values of zeta potential of hematite become negative for pH values smaller than the mineral isoelectric point (7.2) and have bigger negative charges for pH values above its isolectric point, which suggests precipitation of SiO2amorphous and adsorption of anionic specimens present in solution on the mineral surface, especially for values of pH above 10. In the case of quartz, we were unable to verify a significant influence of the reagent modulus on floatabilities and values of the zeta potential.
Keywords
Referências
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