Sistemas de reagentes surfatantes na flotação catiônica reversa de minério de ferro

• Ano de defesa: 2004
• Autor(a) principal: Ronney Rogerio Rodrigues Silva
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: flotação catiônica; minério de ferro; Minérios de ferro; Metalurgia
• Link de acesso: http://hdl.handle.net/1843/BUOS-8DHJZ3

Frother usage in cationic iron ore flotation still is scarcely employed in current applications and, consequently, the mechanisms involved directly on the synergic interaction between frother and cationic collector are not well established. In some cases, a collector-frother blend depicts a similar or enhanced performance than the collector alone, hence a decrease in the concentration of the collector is possible. To corroborate the interaction of collector and frother tests were performed on microflotation (EMDEE) and bench flotation scales. Reagents used included a cationic collector of the class of the alkyl alcoxy-propane amine (etheramine) and several surfactants (mostly frothers) dosed in different ratios together with the etheramine. Structural compatibility amongst surfactants (collector- frother) involved in the system appears to be of paramount importance for the end result. Some frother can evendeteriorate flotation performance whilst others enhance both recovery and selectivity. The size of the hydrocarbon chain affects flotation performance. For a given frother /collector blend, flotation shows best results when the hydrocarbon chain is larger than or equal to the collector hydrocarbon chain. Solubility of the frother also appears to be of great importance. For higher concentrations of the collector-frother solution a smaller solubility of the frother and, consequently, a less intense interaction between collector and frother in comparison tosolutions prepared al lower concentrations. The dosage rate of the collector- frother blend also showed fundamental importance. Atlarger dosages, the ratio of amine replacement by frother could be higher than at smaller dosages.Performance evaluation parameters were selectivity index (IS), mass yield (RM), iron recovery (RFe) and separation efficiency (ES). All are affected by the type of surfactant, by the ratio of replacement used and by the interaction between these two factors.Industrial application potential of a collector/frother blend is shown technically and economically feasible. Important gains can be reached as for most the frother tested the blend will present a lowering in cost and, for some of the frother mixed with the collector the blend showed better flotation performance for the same dosage of the collector alone.