Thiosulfate leaching of silver from a solid residue after pressure leaching of industrial copper sulfides flotation concentrates

Hydrometallurgical recovery of silver from a solid residue after pressure leaching of a flotation copper concentrate from the Lubin Concentrator (KGHM Polska Miedz S.A.) was investigated. Thiosulphate leaching was examined with regard to the highest possible leaching efficiency and optimization process parameters. The effect of thiosulfate ions concentration within the range from 0.25 to 1.00 mol/dm3 at a constant ammonia concentration, and ammonia concentration within the range from 0.40 to 1.00 mol/dm3 at a constant thiosulfate concentration on leaching recovery of selected metals were examined. Moreover, the effect of copper(II) ions addition on silver leaching was studied. It was shown that the leaching recovery of silver increased with increasing thiosulfate and ammonia concentration. At the highest thiosulfate ions concentration, the observed silver leaching recovery was 60%. The best results were obtained at an ammonia concentration of 0.80 mol/dm3, where the leaching recovery of Ag reached 75%. It was established that addition of Cu(II) did not affect silver leaching. Nearly 100% efficiency of thioslulohate silver leaching was achieved by pretreatment of the solid residue after pressure leaching with NaOH solutions

Recovery of cobalt and nickel by atmospheric leaching of flotation sulfide concentrate from lubin concentrator

An experimental study on leaching of cobalt and nickel from a Lubin (Poland) sulfide flotation copper concentrate with oxygenated sulphuric acid solution in the presence of iron(III) sulfate is presented. The effect of temperature, iron(III) concentration, initial sulphuric acid concentration, oxygen flow rate and chloride ions addition on cobalt and nickel leaching were examined. The obtained results show, that enhancing investigated leaching parameters increases both the rate and leaching recovery of nickel and cobalt. The effect of iron(III) ions concentration is particularly significant. Additionally, a significant correlation between copper and nickel/cobalt leaching recovery was observed. Due to the fine dissemination of nickel and cobalt, they were leached remarkably faster when copper leaching recovery exceeded 90%

Solvent extraction of zinc(II) from ammonia leaching solution by LIX 54-100, LIX 84 i and TOA

Commercial extractants LIX 54 -100, LIX 84 I and TOA were used to recover zinc(II) from ammonia solutions. The effect of extractant and ammonia concentration, contact time and reextraction were studied. It was found that extraction of zinc depended on the ammonia, ammonium sulphate and extractant concentration but did not depend on the contact time. The McCabe-Thiele distribution isotherm for LIX 54-100 showed that 95% of zinc(II) ions can be recovered in four stages of extraction. Reextraction of Zn(II) ions from the loaded organic phase showed that the metal can be removed almost completely using sulphuric acid