Optimisation of spodumene
Results of investigations into the optimum conditions for concentration of
spodumene by anionic froth flotation are presented. Parameters investigated
include: collector dosage; cell rotor velocity; feed pH, conditioning
period, temperature, solids content, and reprocessing steps required to
yield an optimum product. Results are based upon sequential testing of
various values for each parameter while maintaining all others constant.
These show that optimum conditions are attained with: the pulp at a pH of
7.5 to 9.8, 18% solids, 15oC and a 10min conditioning
period; a cell rotor velocity of 1040rpm; and that an oleic acid
concentration of 1.4kg/t as a collector is adequate. It was also found that
under these operating conditions, no significant increase in grade could be
achieved with more than two passes through cleaner cells. Analysis of these
tests indicates that a product with an optimum lithia content and a
calculated recovery of 96.24% may be achieved by the cleaning the rougher
concentrate twice in conventional sub-aeration flotation cells.