ENHANCING THE FLOTABILITY OF GOLD-BEARING ORES BY A MIXTURE OF COLLECTORS

摘要

The flotation efficiency of gold ores depends on the quality of the collectors and their ratio which were used. Among the collectors are two most important and widely used groups: xanthates and dithiophosphates. The tests results of dialkyl dithiophosphates (Hostaflots L of Clariant GmbH, Germany) and potassium butyl xanthate ((PBX) (Clariant GmbH, Germany)) for gold-bearing ores flotation as well as their ratios are discussed in this paper. In order to determine the efficiency of dialkyl dithiophosphates for the flotation of gold ores, the following collectors were tested. They are dithiophosphoric acid diethylester – Hostaflot LET, dithiophosphoric acid diisobutyl ester – Hostaflot LIB and secondary butyl – Hostaflot LSB, either alone or in combination with potassium butyl xanthate (PBX). The tests results were compared with a standard collector, PBX. The best results of gravity tailings flotation were obtained using a mixture of (LET + LIB):PBX in a (1 + 1):1 ratio. The gold recovery to the flotation concentrate was 49.1 per cent. The gold losses with flotation tailings were 8.0 per cent. When the standard collector, PBX, was used, the gold recovery was 47.8 per cent. Gold losses with flotation tailings were 9.8 per cent. This study shows that gravity tailings flotation using a mixture of LET + LIB + PBX in 1:1:1 ratio is more effective than using PBX alone. Gold recovery to the flotation concentrate using gravity/ flotation technology was 92.0 per cent, ie it was 1.8 better than using PBX. The tests results showed the applicability of dialkyl dithiophosphates (Hostaflots LET and LIB) combined with xanthates (PBX) for use in the flotation of ores containing fine gold or submicroscopic gold locked in the sulfide fraction.