P204+P507 Collaborative Extraction Separation Process And Mechanism Of Manganese,Copper,Zinc And Magnesium From Cobalt Leaching Solution

Cobalt is known as"industrial monosodium glutamate"and"industrial teeth",which is a very scarce small metal resource,it is an important non-ferrous metal,and it is one of the strategic resources that plays an important role in the development of the national economy.In recent years,with the increase in the demand for cobalt resources in the new energy industry,the scale of the cobalt industry has been stimulated.At present,the cobalt leachate mainly adopts the step-by-step extraction and separation process,but the system has many extraction stages,a large amount of ammonia nitrogen wastewater and other problems,and the annual demand for cobalt is much greater than the production volume,so it is of great significance to study cobalt and manganese elements cheap,environmentally friendly and a large number of purification and separation technologies.In view of the above problems,the synergistic extractant P204+P507 was used to study the extraction and separation of metal ions containing cobalt,manganese,copper,zinc,magnesium and other metal ions,explore the optimal process of extraction and separation of the collaborative system,and analyze the mechanism of the extraction process.In this paper,the extraction and separation properties of cobalt and manganese,copper,zinc and magnesium in the leachate were first studied using（P204+P507）synergistic extractant,and the effects of extractant ratio,extractant concentration,extraction equilibrium p H,organic saponification rate,extraction comparison and other factors on the extraction performance of metal ions were explored.The optimal extraction process conditions for the experiment were as follows:compound extractant concentration of 35%（P204:P507=4:1）,sulfonated kerosene with diluent of 65%,organic saponification rate of 50%,extraction compared O/A=2,extraction time 10 min,aqueous equilibrium p H=3.57,single-stage extraction rates of zinc,manganese and copper were 99.97%and 88.42%,respectively,87.18%,the extraction rate of cobalt at this time is only 17.42%.The optimal process conditions of the washing process are more than 99%of the cobalt can be washed down by using 1.5 mol/L sulfuric acid compared with O/A=20 and washing twice,and the cobalt is enriched to 50.47 g/L in one washing solution;The concentration of cobalt in the secondary wash solution reached 44.15 g/L.The washing rate of other elements is only less than 10%.Using 3 mol/L of sulfuric acid,manganese can be enriched to 71.71 g/L,copper 8.89 g/L,and zinc 1.1 g/L in one backwash compared with O/A=20.Zinc enrichment to 8.18 g/L can be achieved in secondary back-extraction.In the study of extraction mechanism,the extract formed by extractant P204/P507 in the extraction of cobalt,manganese,copper,zinc and magnesium is composed of MA₂ and ML₂,and the extraction mechanism is cation exchange reaction.The synergistic system extraction process requires one P204 and one P507 molecule for each M²⁺extraction,and releases 2H⁺into the aqueous phase.P204 extracts cobalt and manganese.The reaction process of zinc and magnesium is endothermic reaction,and the reaction process of copper extraction is exothermic reaction.The synergistic system of P507 system and P204+P507 extracts cobalt,zinc and magnesium as endothermic reaction,and extracts manganese and copper as exothermic reaction.In the infrared spectroscopic analysis of the extracts of each system,the P=O double bond in the extractant participated in coordination,the H⁺on the P-OH bond and the metal ion cation exchange,and part of the P204 and P507 polymerization to form a composite form of dimeric hydrogen bond in the synergistic extraction system,the dimer hydrogen bond redshift indicated that the hydrogen bond broke and cation exchange reaction occurred in the extractant.