بازيابي مس، نيكل وكبالت از محلول هاي رقيق پايه سولفاتي به روش ترسيب شيميايي

چكيده انگليسي :

96 Recovery of Cu Ni and Co from Low Grade Sulfate Solutions using Chemical Precipitation Ali Tariverdilu tariverdilu@chmail ir Date of Submission 2015 25 07 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisors Hamid Zilouei hzilouei@cc iut ac ir Ali Ahmadi a ahmadi@cc iut ac irAbstractBecause of the depletion of high grade mineral resources with simple mineralogical composition and theincreasing demand for strategic base metals such as Cu Ni and Co the production of these metals fromcomplex and low grade ores and mine tailings is increasingly risen Hydrometallurgical processes includingleaching purification and precipitation have a high potential for the treatment of these resources Inaddition to economic benefits the extraction of metals from tailings reduces the environmental issues Theionic precipitation method is one of the important and applicable methods in concentration and purificationof complex solutions Among various metal precipitation techniques sulfide and hydroxide precipitation areone of the most intrestiong methods to remove impurities The main purpose of this study is the cumulativerecovery of Cu Ni and Co from sulfate based dilute solutions similar to bioleaching conditions using ionicprecipitation In this research sulfidic and hydroxidic precipitations were used to concentrate the solutions In the first phase the effect of three factors pH temperature and molar ratio of sulfide to metals using thecentral composite design to recovery of Cu Ni and Co from solutions containing Fe Mg and Ca wasstudied To determine the optimal conditions for recovery of mentioned metals 17 tests were performed Analysis of variance ANOVA with the high level of confidence 95 was used for the analysis ofresponses obtained for each metal in order to obtain the best model for each metal The parameters of pH sulfide to metals molar ratio and interaction of these factors as well as interaction of increased values of pHwith sulfide to metals molar ratio was significant in Cu recovery Statistical optimization of results for Cushowed that maximum recovery of Cu is obtained when pH and sulfide to metal molar ratio is 8 and 0 97 respectively For recovery of Ni and Co however just the effect of pH and interaction of increased valuesof pH and temperature were significant Also statistical optimization suggests maximum recovery of 82 4 at pH 8 and 60 for Ni and 73 7 at pH 8 and 30 for Co In the case of simultaneous precipitation of Niand Co from low grade solutions due to relatively high concentration of Ni as well as simply operatingconditions hydroxide precipitation were used to recovery of Ni and Co These solutions were obtainedfrom leaching of a lateritic low grade ore which Ni Co and Mg composition in this solutions were 2 9 0 12and 26 g L respectively For selective recovery of Ni and Co the Fe and Al content of leach liquor wasprecipitated at pH 3 5 90 and 2 h initially Thereafter the Ni and Co contents of solution obtained fromFe and Al precipitation step was precipitated at pH 7 7 5 50 and 1 5 h Results of the first hydroxideprecipitation stage indicate that the removal of Fe and Al was selective so that just 6 4 Ni and 2 6 Cowere removed in this step Analysis of precipitate produced from second hydroxide precipitation stagerevealed presence of 36 77 Ni and 2 63 Co in it Keywords Low grade ores sulfide precipitation hydroxide precipitation centralcomposite design

تاري وردي لو، علي

بازيابي مس، نيكل وكبالت از محلول هاي رقيق پايه سولفاتي به روش ترسيب شيميايي

منابع كم عيار , ترسيب سولفيدي , ترسيب هيدروكسيدي , روش مركب مركزي