Effect of negative and positive Bias on improvement of coals using column flotation

Juan Barraza¹; Juan Guerrero¹; Irineu Brum²; Carlos Sampaio²

¹ Universidad del Valle, Cali, Colombia; ² Universidad Federal do Rio Grande do Sul, Porto Alegre, Brasil

Baixar PDF doi:10.20906/CPS/CBCM2017-0020

Resumo

Two coals from Copelmi colliery (Brazil) and Cerrejon colliery (Colombia) were floated using negative and positive bias in a 5 cm diameter conventional flotation column. Flotation parameter investigated included air velocity in the range 0.6 to 1.5 cm/s. For all runs, a pulp concentration of 8 % w/w, a commercial frother Aerofroth 65 (AF65) and collector kerosene were used. Results showed that, in general, ash content of floats was lower than that of the parent coals. The lowest ash recovery was obtained using positive bias at the range 3.6-7.8% for the Brazilian coal, whereas 4.9-13.3% for the Colombian coal. The highest mass yield for the Brazilian coal (32.3%) and for the Colombian coal (60.9%) was obtained with a negative bias at an air velocity of 0.6 cm/s.

Palavras-chave: negative bias ; positive bias ; column flotation ; coal