Metallurgical improvement of a lead/copper flotation stage by pulp potential control

This paper presents the metallurgical improvement obtained as a result of i n-plant tests performed to study the selective flotation of the galena and chalcopyrite contained in a fine-grained complex ore of pyritic matrix, gro und in a reducing environment, and conditioned with a mixture of non-conven tional collectors (i.e., different from xanthates) by increasing the pulp p otential (Eh) to around 0.3 V using hydrogen peroxide. The results showed t he recovery (i.e., floatability) of galena and chalcopyrite presented a max imum near 0.32 and 0.27 V, respectively. Compared to these minerals, the re covery of accompanying sphalerite and pyrite was marginal. The recovery of silver, gold, sphalerite and pyrite behaved in a similar manner to that of chalcopyrite suggesting these species reached the concentrate locked to the floated chalcopyrite particles rather than independently. (C) 2000 Elsevie r Science B.V. All rights reserved.