The Process of Flotation

What characterizes the process of flotation of ultrafine gold is the high dispersion of the necessary pulp for the flotation. To obtain this high dispersion, there is the need of the eventual use of dispersants and a very low percentage of solids during the flotation (maximum of 5% to 10%).

The reactives used (collectors, foamers, activators, etc.) are usually used for the flotation of free gold. Evidently for other different minerals of those of Salamangone, new associations of reactors will have to be investigated.

The time of collecting in the rougher is of the order of the 10 minutes, having no need of another stage of flotation in the case of Salamangone.

Due to the low percentage of solids, the volumes of the cells of flotation and of equipment are proportionately very large, which took the PMC – Mining Novo Astro to try to develop equipment which better the economy of the project. Cells in columns and conventional cells were tested, being that the disenvolvement of the conventional cells was very superior, which was to be expected due to the type of foam formed. Being thus, the possibility of cells in columns was discarded.

For the tenors of rejection of gravimetry, varying from 1 to 3 g/t of gold, recuperation of 80%/90% were obtained for the enriching in the order of 10 times, and 75%/80% for the enriching in the order of 20 times.