Evaluating the performance of new collectors on feed to Nkana Concentrator's flotation circuit

Nkana Concentrator of Zambia Consolidated Copper Mines (ZCCM) treats copper -cobalt sulphide ore using a bulk flotation and segregation flotation flows heet to produce separate copper and cobalt concentrates. Recently, in an effort to increase mineral recovery as well as improve copp er/cobalt separation, various alternative collectors have been considered a s replacement for Sodium Ethyl Xanthate (SEX) which has been used for more than 30 years. Three such collectors that were evaluated are Senkol 26, a X anthic ester, Senkol 45, a blend of alkyl dithiophosphate and Xanthates and Senkol 700 a thionocarbomate type, which were supplied by SENMIN of South Africa. In this work a series of laboratory testworks were conducted on Nkana Conce ntrator feed materials from four different sources namely, Mindola, Chibulu ma, South Ore Body (S.O.B.) and Central shafts to compare the performance o f these collectors against the existing SEX collector Parameters considered in the evaluation were grade-recovery relationships and copper/cobalt kine tics at different collector dosages. Release analysis techniques were also employed to determine the theoretical maximum recovery of copper and cobalt for each of the collectors. It was found that the existing collector SEX showed superior flotation perf ormance as compared to the three Senkol collectors. SEX responded better th an Senkol collectors at bath bulk and segregation stages of flotation. Howe ver, the Senkol collectors, particularly Senkol 45 and Senkol 700 gave very fast flotation kinetics at all dose rates during bulk flotation. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.