Silver(I) Recovery by Ion Flotation Process from Aqueous Solutions in Cells with Spargers

Abstract

Extractive metallurgy has recently turned its attention to waste treatment for the recovery of precious metals through innovative metallurgical processes, such as ion flotation. This work studied the influence of several chemical and physical factors, such as the concentration of xanthate [x], frother agent [e], dithiophosphate [xl], pH, superficial gas velocity Jg, percentage of gas holdup Eg, bubble diameter (Db) calculated with the drift flux model, and the type of sparger, in the efficiency of silver(I) recovery by the ion flotation technique in sub-aerated cells. The results obtained indicate a 90.7% v/v recovery of silver(I) under conditions of 3.77 × 10−4 M [x], 1.25 × 10−4 M [e], Jg 0.5 cm/s, Jl 0.19 cm/s, Eg of 4.1% v/v, and Optimal Db of 0.11 cm, with a rigid bubble generator, achieving an apparent flotation kinetics of 4.16 1/min. The use of combinations [x]–[xl] achieve a silver(I) recovery of 86.9% with a Jg of 1.0 cm/s. The best recovery efficiencies achieved 93% w/w silver(I) are with pH 8.0, [e] of 1.25 × 10−4, Jl of 0.19 (cm/s) and a rigid sparger compared to a flexible one.