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Recovery of silver and lead by means of chloride leaching of solid residue after atmospheric leaching of the copper concentrate from the KGHM Lubin Concentrator (Poland) was investigated. The effect of leaching temperature, chloride concentration, Fe(III) and oxygen presence, solid-to-liquid ratio and feed preleaching with NaOH on the silver and lead recovery was analysed. Chloride leaching appeared to be very effective for recovery of lead, whereas satisfactory recovery of silver was observed after chemical pretreatment of the leaching feed with alkali solution of NaOH in order to liberate Ag entrapped in the jarosite structure. It was found that to achieve the satisfactory recovery of Ag and Pb leaching had to be performed in acidified 4 M chloride concentration at temperature of 90 degrees C. The presence of oxidants, that is O2 and iron(III) ions, was beneficial in the initial stage of the process. The maximum recovery of Ag and Pb was found for the solid-to-liquid ratio of 1:10 after 10 hours leaching. (Authors.), Recovery of silver and lead by means of chloride leaching of solid residue after atmospheric leaching of the copper concentrate from the KGHM Lubin Concentrator (Poland) was investigated. The effect of leaching temperature, chloride concentration, Fe(III) and oxygen presence, solid-to-liquid ratio and feed preleaching with NaOH on the silver and lead recovery was analysed. Chloride leaching appeared to be very effective for recovery of lead, whereas satisfactory recovery of silver was observed after chemical pretreatment of the leaching feed with alkali solution of NaOH in order to liberate Ag entrapped in the jarosite structure. It was found that to achieve the satisfactory recovery of Ag and Pb leaching had to be performed in acidified 4 M chloride concentration at temperature of 90 degrees C. The presence of oxidants, that is O2 and iron(III) ions, was beneficial in the initial stage of the process. The maximum recovery of Ag and Pb was found for the solid-to-liquid ratio of 1:10 after 10 hours leaching. (Authors.)

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 optimisation process parameters. The effect of thiosulphate 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 thiosulphate 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 thiosulphate and ammonia concentration. At the highest thiosulphate 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 thiosulphate silver leaching was achieved by pretreatment of the solid residue after pressure leaching with NaOH solutions., 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 optimisation process parameters. The effect of thiosulphate 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 thiosulphate 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 thiosulphate and ammonia concentration. At the highest thiosulphate 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 thiosulphate silver leaching was achieved by pretreatment of the solid residue after pressure leaching with NaOH solutions.

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. (Authors.), 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. (Authors.)

The atmospheric leaching was studied of copper sulphide concentrate from the Lubin concentrator in Poland using oxygenated aqueous H2SO4 in the presence of Fe(III). The results showed that the leaching process has to be preceded by controlled, non-oxidative decomposition of acid-consuming carbonate components in order to further liberate finely disseminated metal-bearing minerals. Atmospheric leaching appeared to be a very efficient process for recovering Cu, Zn, Co and Ni from the concentrate due to the favourable mineralogical composition and the fine size of the leached particles. Maximum recoveries of 95% Cu, 90% Zn, 40% Ni and 50% Co were obtained after leaching for 5-7 hours at 90 degrees C in oxygenated solutions containing 20-30 g/dm3 of Fe(III). The solid leaching residue can be further processed by flotation or chloride leaching to recover Ag, Pb and precious metals., The atmospheric leaching was studied of copper sulphide concentrate from the Lubin concentrator in Poland using oxygenated aqueous H2SO4 in the presence of Fe(III). The results showed that the leaching process has to be preceded by controlled, non-oxidative decomposition of acid-consuming carbonate components in order to further liberate finely disseminated metal-bearing minerals. Atmospheric leaching appeared to be a very efficient process for recovering Cu, Zn, Co and Ni from the concentrate due to the favourable mineralogical composition and the fine size of the leached particles. Maximum recoveries of 95% Cu, 90% Zn, 40% Ni and 50% Co were obtained after leaching for 5-7 hours at 90 degrees C in oxygenated solutions containing 20-30 g/dm3 of Fe(III). The solid leaching residue can be further processed by flotation or chloride leaching to recover Ag, Pb and precious metals.