Studies on selective flotation of smithsonite from silicate minerals using mercaptans and one stage desliming

Abstract

The separation of oxide zinc mineral from silicate minerals in smithsonite mineral, associated silicate minerals and oxide zinc ore samples was assessed using methyl mercaptan (CH₃SH), ethyl mercaptan (C₂H₅SH) and hexyl mercaptan (C₆H₁₃SH; HM) as collectors. The optimal flotation conditions were defined through Hallimond tube, contact angle and batch flotation and the results were applied to a natural Angooran oxide zinc ore. The microflotation and artificial mixture flotation results showed a maximum of 78% flotation recovery using HM. Selective flotation of oxide zinc ore was also accomplished by using an HM collector at pH 9. The flotation recovery was 55% without desliming. When the initial feed was deslimed before bench scale flotation tests, the recovery increased from 55 to 75% with 22·5% zinc content in the concentrate. When methyl mercaptan or ethyl mercaptan was used, lower zinc recoveries and grades compared to HM flotation were achieved.