The Effect Of Impurity Ions On Microfluidic Extraction Of Copper And Indium Extraction

Copper has been widely used in the field of electrical and electronic industries,and with the development of science and technology,it has been being developed new applications.Scattered metal indium has also widely used in computer,national defense,nuclear industry,modern information industry and other high-tech fields,which has an important strategic position.The extraction of low grade copper resources and indium mainly depends on hydrometallurgy.While solvent extraction is an essential part in the process.The conventional solvent extraction process,mixer-settler,is facing some problems such as low efficiency,easy emulsification and co-extraction.Thus,a microfluidic extraction technology is proposed.In this study about the extraction and separation effect of copper and nickel or copper and cobalt from sulfate solution,using LIX984N as extraction agent,the effect of extractant concentration,initial pH and contact time on the separation effect was studied in separating funnel and double "Y" type micro-chip extraction process respectively.It was found that under these conditions that the concentration of extractant was 15%,the initial pH was 2.5,the extraction rate of copper was more than 97%when the contact time was not less than 50s in separating funnel;compared with that of the separating funnel extraction process,the contact time just need 1.95s in micro-chip extraction process.In the "Y" type micro-chip extraction process,the mass transfer of copper was 10 times as bigger as that of nickel,while which was 2 times in separating funnel.In addition,the total volumetric mass transfer coefficient of copper was 15 times as bigger as that of the separating funnel.According to the Response Surface Methodology,it was found that the volume flow rate and the concentration of extractant had the greatest effect on the extraction rate of copper and cobalt at pH value between 2 and 3 in the "Y" type micro-chip extraction process.When the volume flow rate was 0.035mL min-1,the extractant concentration was 17.36%,the initial pH value was 2.5,the highest extraction rate of copper and the lowest extraction rate of cobalt could be obtained simultaneously.Under these optimum conditions,the actual extraction rate of copper reached 96.73%,and the relative error with the predicted value was only 0.13%;the actual cobalt extraction rate was 2.41%,and the relative error with the predictive value was 1.2%,indicating that the response surface methodology could obtain accurate and effective process optimization parameters.In addition,compared with the literature about the extraction separation of copper and cobalt with LIX984N,in microchip extraction process,the single-stage extraction rate was higher,and the balance time was shorter.The effects of extractant concentration,initial pH and contact time on the extraction and separation of indium in separating funnel and capillary were discussed in the study of extraction and separation of indium,iron,zinc,aluminum and magnesium.The results showed that the optimum experimental conditions in separating funnel was that the value of pH was 0.7,concentration of extractant was 20%;the contact time was 120s,the oscillation frequency was 300rpm;the optimum experimental conditions in capillary was that the value of pH was 0.7,extraction concentration was 30%and the contact time was 60s.The research found that iron ions could be extracted into the organic phase by D2EHPA in conventional extraction,while in the micro fluid extraction,the co-extraction rate of iron and indium was lower than that of conventional extraction.Under the best experimental conditions,the separation coefficient of indium and impurity ions in the process of capillary extraction was higher than that of separating funnel extraction.The separation coefficient of indium and iron increased from 276 in separating funnel extraction to 18720 in capillary extraction.The separation coefficient of indium and zinc increased from 70118 to 266373,the separation coefficient of indium and aluminum increased from 4987 to 41955,and the separation coefficient of indium and magnesium increased from 2918 to 11809.