| In the carbon slurry/carbon leaching gold extraction process,the recycling efficiency of gold-loaded activated carbon determines the production capacity,cost and economic benefits.This paper takes the carbon leaching system of a gold mine in Inner Mongolia as the specific research object,and studies in detail the behavior characteristics of fresh activated carbon through adsorption,desorption-electrolysis,activation and regeneration,in order to optimize the relevant process parameters or indicate the optimization direction.Through comparative analysis of the specific surface area,pore structure,iodine value and other indicators of activated carbon in different links,it is found that it is agitated and abraded during adsorption to reduce the appearance of wrinkles;the surface of the lean carbon after desorption is rougher,and the surface of the lean carbon after desorption is rougher.The base metal oxides are washed away,and then heated to regenerate to remove volatile pollutants,thereby unclogging the pores and even forming new active sites.So far,the microscopic basis for the recycling of activated carbon has been proved.Through laboratory adsorption tests and thermodynamic analysis,it is believed that the adsorption of cyano-gold complex anions by activated carbon is an exothermic physical process,so strengthening heat dissipation and controlling the amount of lime used will help gold adsorption.The adsorption test also showed that the amount of gold adsorption was positively correlated with the ionic strength of the solution,while it was negatively correlated with p H at high ionic strength,and positively correlated with p H at low ionic strength,and it was analyzed by XPS analysis,solution chemistry calculation,and zeta potential analysis.the reason.Therefore,in the actual production of high ionic strength slurry,the amount of lime should be reduced as much as possible under the premise of ensuring safety to improve the efficiency of gold adsorption.The laboratory batch desorption test shows that the process is most in line with the overall reaction kinetics,and the effect of the single cycle period is the most significant,shortening from 8h to 2h can greatly increase the desorption rate and desorption speed;mix in the desorption solution 0.5% Na CN can increase the desorption rate,but it is not helpful to continue to increase to 1%;and the electrolysis efficiency is characterized by the desorption liquid replacement rate here.Increasing the replacement rate will help increase the desorption rate,and it has a shorter effect in the long-term test.Significant in the cycle.This shows that in actual production,when the electrolysis efficiency is kept within a certain range,the circulation speed of the lean solution should be accelerated,which can effectively improve the desorption efficiency.Using ultrasonic pickling-microwave activation technology to regenerate activated carbon,and comparing with traditional thermal regeneration methods,it is found that the adsorption performance of microwave activated regenerated carbon at 600°C after ultrasonic pickling is the best,with a gold capacity of 15.64g/kg.It is 2.37 times that of Xintan.Among them,the microwave temperature has a greater impact on the adsorption of regenerated carbon,and the effect of ultrasonic pickling has little effect.Considering operating costs and maintenance,it is better to use a 600°C microwave activation process,with a gold capacity of 14.81g/kg,which is 2.25 times that of new carbon.Research shows that the exploration of the technical feasibility of microwave activation and desorption of lean carbon should be accelerated,which can greatly improve the efficiency of recycling.Finally,by improving the desorption efficiency and regeneration activation effect of goldloaded activated carbon,the production cost of the enterprise can be reduced,the economic benefit can be maximized,and the optimization of the beneficiation process of other mining enterprises can be provided as a reference. |
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