Size-dependent kinetics of iron ore reverse flotation

Abstract

Flotation experiments under pH 10.5 were performed using quartz/hematite artificial mixtures. The influence of particle size and monoamine unit consumption on the kinetic parameter was analyzed, in a fundamental level. The coarse quartz class was between 212 µm and 600 µm and the fine class was between 74 µm and 212 µm. Hematite particles were graded between 32 µm and 74 µm. Consumption of corn starch was 700 g/t. Consumption of monoamine was 80, 100, and 120 g/t. The first order kinetic model had better fit when compared to the rectangular one, although the correlation coefficient was higher than 0.950 in all cases. The iron recovery to the froth overflow was higher in the presence of coarse quartz and with high amine dosage (maximum value of 0.0307 s⁻¹). The analysis of the surface areas available to the collector adsorption proved to be a good tool for the understanding of such complex phenomena. There is a competition between quartz and hematite surfaces for collector adsorption, which is damped by collector excess. This competition can explain the difference in the flotation kinetic parameter. Hematite flotation behavior was dependent on the presence of fine or coarse quartz.

Keywords:

• Flotation
• quartz
• hematite
• Garcia–Zuñiga model
• Klimpel model

Additional information

Funding

The authors thanks to Brazilian Council for Technological and Scientific Development (Conselho Nacional de Desenvolvimento Científico e Tecnológico), Foundation for Research Support of the State of Minas Gerais (FAPEMIG) and Brazilian Federal Agency for Support and Evaluation of Graduate Education (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) for their financial support.