JOHANNESBURG (miningweekly.com) – Successful removal of coarse waste is beneficial in that it reduces power requirements in the milling circuit, lowers water needs, and increases platinum group metal (PGM) feed grades.
With preconcentration, a head grade of, for example, 2 g/t can be as much as doubled to 4 g/t, resulting in PGMs being valuably increased in the circuit. Mintek’s studies show that upfront preconcentration is viable but mineralogy dependent.
Sometimes it works, sometimes it doesn't work, but if it works, there's value in it, because then it reduces capital expenditure and operational expenditure of plants.
Mining benefits include being able to lower the cutoff grade, which increases the reserves and also provides flexibility in the mining methods, Mintek physical separation head Gertrude Marape pointed out during Mintek’s PGM Day covered by Mining Weekly. (Also watch attached Creamer Media video.)
Displayed was a PGM grade of 1.7 g/t being uplifted to 4.8 g/t through dense medium separation (DMS), at PGMs losses to DMS floats at around 0.4 g/t.
