Comprehensive Recovery Of Polymetal In Low-grade Copper-cobalt Ore

Mineral resources are important strategic resource reserve to industrial society.China is abundant in the species of mineral resources,which enjoys a reputation as “the Kingdom of Non-ferrous Metals”,and is the world's largest non-ferrous metal producer and consumer so far.But because of the continuous development,high-grade metallurgical mineral resources are increasing scarce,resulting in inadequate reserve resources.Nowadays,Chinese non-ferrous metal raw materials rely on imports heavily.It is of great significance to strengthen the comprehensive utilization of low-grade and polymetal mineral resources.In the study,the Low-grade copper-cobalt ore provided by a certain mine was taken as the basic research object.The study mainly targeted Copper,Cobalt and Nickle composition in the ore.We aimed to achieve the separation,enrichment and recovery of Cu,Co and Ni,and to develope a practical process line.The main contents and conclusions are as follows:?1?We investigated the roasting and leaching conditions by single factor experiment to find the best sulfation roasting-acid leaching technological conditions of copper&cobalt ore preliminary.When sodium sulfate as copper-cobalt ore roasting additive,the optimum roasting and leaching conditions was as follows: sodium sulfate?Mass fraction 6%?;solid grinding and mixing;the best firing temperature?500 ??;constant temperature time?20 min?;solid/liquid ratio?1:3?;sulfuric acid concentration?5%?;leaching time?150 min?;leaching temperature?80 ??.The leaching rate of copper and cobalt could reach more than 90% when nickel was more than 70% at the same time.With sodium sulfite as the roasting additive,the optimum experiment conditions fixed at: sodium sulfite?2%?;solid grinding and mixing;the best calcination temperature?500 ??;constant temperature time?40 min?;S/L?1:3?;sulfuric acid concentration?10%?;leaching time?250 min?;leaching temperature?80??.At this stage,copper and cobalt leaching rate could achieve more than 90% individually;nickel leaching rate obtained 70%.?2?We systematically explored the separation and recovery of copper in acid leachate.The optimum extraction conditions of copper from acid leachate were studied,including the concentration of CP180,extraction time,acidity of liquid phase,oscillation rate,organic and liquid ratio.Other parameters on extraction and stripping were also determined.The experimental results showed the basic conditions were as follows:15% CP180 extractant extracted 4.40 g/L copper in simulated solution;room temperature;p H=1.5;O/A=1:1;extraction time for 10 min.Two stage counter-current extraction rate was up to more than 99.5% while one stage extraction rate achieved 96%.At stripping stage,the optimum stripping conditions was as follows: 2 mol/L sulfuric acid at room temperature,compared with phase ratio 1:1,time=4 min.One stage stripping rate was above 90%,while two stage counter-current stripping rate was over 99%.The separation of copper ion and organic phase won't affect the reuse of the extractant.?3?The new synergetic extraction system,CP180-P507-kerosene,was used to study the separation and recovery of copper.We carried out a series of study in order to determine the maximum interference concentration of Fe³⁺,Co²⁺,Ni²⁺ and Zn²⁺ in liquid phase by the new synergetic extraction system.The experiment obtained that the system was consisted of 15% CP180 + 0.03% P507 + kerosene.The extraction rate was increased by two percentage points compared with the extraction of CP180 single extractant.Copper extraction rate could be more than 99.9%.The maximum interference multiple of Zn²⁺,Ni²⁺,Fe³⁺,Co²⁺ to Cu²⁺ were 2.5,2.0,2.0,3.0 respectively.Finally,more than 99.5% of Cu²⁺ was stripped after three-stage counter-current stripping at A/O ratio of 3:1 and we got a 14 g/L copper-rich solution.?4?The Zn²⁺ and Fe³⁺ in simulation solution were extracted by P204 before the separation of Ni²⁺ and Co²⁺.The optimum technological parameters of the separation of Ni²⁺ and Co²⁺ by Versatic10-Lix984-Na OH-kerosene extraction system were studied systematically.The experimental results showed as follows: under the conditions of organic saponification rate of 75%,p H=2.5,10% Versatic 10,O/A=1:1 and extraction time of 10 min,Versatic 10 could almost completely extract Ni²⁺ and Co²⁺.The cobalt & nickel separation was successfully achieved in the stripping stage by adding Lix984 in the extraction system.The consist of synergetic extraction system was determined to be 10% Versatic 10-1% Lix984-Na OH-kerosene.Under the conditions of 1.0 mol/L H2SO4 and stripping time 50 s,the recovery rate of cobalt could reach more than 95% and the concentration of cobalt was about twice before in the liquid phase.This stage achieved the separation of nickel and cobalt.