Research On The Separation Behavior Of Cu、Zn、Cd、Co In Cu-Cd Residues

In this study, the XRD analysis of the copper-cadmium residue produced by Inner Mongolia Zinc Plant have been conducted, the results showed that Cadmium existsmainly in the state of cadmiym sulfate, and zinc and cobalt exists mainly in the forms of sulfate and oxide, the form of copper is a little complicated, consist of copper metal, copper of cuprous oxide and copper sulfate. To explore the extraction and separation methods of Cu-Cd residues, using Leaching-Extraction of copper using LX973-cobalt removal using naphthol-extraction of zinc and cadmium using P204. The results show that:(1) Using water leaching-acid leaching combined leaching on Cu-Cd residues, when using water leaching, copper has been barely leaching, the leaching rate of zinc,cadmium and cobalt were5.13%,68.29%,48.10%; When using acid leaching, liquid-solid ratio was3:1, concentration of sulfuric acid was21.68g/L, concentration of additive A was189.5g/L, leaching tenprature was30℃, leaching time was60mins, the leaching rate of copper, zinc, cadmium and cobalt were43.50%,92.86%,30.28%,50.35%, the pH of liduid was2.80. The total leaching rate of copper, zinc, cadmium and cobalt were43.51%,98.00%,98.56%,98.45%.(2) Extraction of copper with30%LIX973-Kerosene system from acid leaching liquid was investigated, copper content in acid leaching liquid was22.72g/L, and the concentration of zinc was higher, when O/A ratio was1.9:1. The leaching rate of copper was higher at99.74%, copper and other metals can separated effectively.(3) Stripping copper with sulfuric liquid, which contained Cu2+35g/L, H2SO4180g/L, and the O/A radio was1:1, the stripping rate of copper was49.30%, the residul copper was only6.54g/L in the loaded organic phase, the results is very closed to the organic phase stripping isotherm point. The effect of stripping is very good.(4) The optimal condition of cobalt removal using beta-naphthol:the amount of beta-naphthol was1.6times of its theoretical amount, naphthol/nitrite ratio was1:0.6, the temperature of reaction was35℃, mixing time was1h. Remove cobalt ratio was close to100%, the test achieve the purpose of depth cobalt removal.(5) Extraction of zinc with30%P204-Kerosene system from solution after remove cobalt, which contains Zn68.26g/L, concentration of cadmium in aqueous phase is essentially no change. P204was priority extracted zinc. Joining Calcium oxide and additives B can reduced the acidity of extraction of zinc. It was better when additive B. To adopt90g/L H2SO4stripping of zinc, zinc stripping rate reached96.99%. The organic phase containing Zn2+was only0.5g/L after stripping.