Flotação aniônica de minério de ferro
AUTOR(ES)
Débora Rosa Nascimento
DATA DE PUBLICAÇÃO
2010
RESUMO
The increasing demand for iron ore by the consumer market provides the exploitation and concentration of marginal ores (low Fe and high contents of SiO2 and other impurities). However, for the production of poor and complexes ore concentrates within the specifications of the market it is necessary to search new processing routes among them can highlight the direct anionic flotation of iron minerals. In this work, there are studies about anionic flotation of iron ore using sodium oleate as collector. In the first phase, were conducted studies about interference of depressants metasilicate, hexametaphosphate and fluorsilicate of sodium, dextrin white and corn starch in flotability of hematite and quartz with sodium oleate at doses of 50 mg/L for hematite and 70 mg/L for quartz at pH 7. In these studies, it was found that sodium hexametaphosphate did not lead to selective separation between the two minerals, and the conditioning with sodium metasilicate in the dosage of 1 mg/L, pH 9, were obtained flotability of 82 and 32% , respectively, for hematite and quartz. The previous activation of minerals with MnCl2 (dosage of 5 mg/L) and subsequent conditioning with sodium metasilicate (dosage of 100 mg/L) and oleic acid (dosage of 50 mg/L) resulted in 73% and 15% of flotability of quartz and hematite. At pH 7, the Mn predominant species in solution are Mn2+ and MnOH+, which is adsorbed on the surface of quartz making it positive, which allowed the adsorption of oleate on the surface. This effect was not observed for the hematite, whose isoelectric point was 7.8. In direct flotation tests, using the depressor fluorsilicate of sodium, made with the sample of iron ore from Mina Fábrica Nova, were obtained rougher concentrates with Fe content of 46.7% and 28.8% SiO2 and the metasilicate of sodium, using the same sample, the levels obtained were 49.3 and 25.3% Fe and SiO2, respectively. In the case of reverse flotation of gangue silicates with previous activation with MnCl2 resulted in worse results than those obtained in the direct flotation of the ore from Fábrica Nova.
ASSUNTO(S)
flotação Íons minérios de ferro reagentes para flotação tratamento de minerios
