Disposing Waste Water From Cuprous Chloride Production By Using Extraction And Ion Exchange

Cuprous chloride has been used widely for its specific physicochemical characteristics. In the process of preparing cuprous chloride, a great deal of waste water can be leaved, which contains copper with the mass concentration of 2～3g/L. At present few methods have been developed for disposing such waste water and these methods have various problems. In order to find a new disposing method, which is economically feasible and has simple process but with high efficiency of copper recycling, we calculated and investigated the particle structure and the solution feature of such waste water by using coordinate bond theory and thermodynamic theory, and further experimentally studied the waste water by using ion- exchange and extraction.Through investigating the particle structure and solution feature, our observations are: The main forms of the copper particle in the waste water are CuSO_4(aq), Cu²⁺,CuCl⁺, CuCl₂^- and CuCl₃^2-; As temperature rises, the distribution coefficients of CuCl₂^- and CuCl⁺ increase, but the distribution coefficients of CuCl₃^2- and Cu²⁺ decrease; As pH rises, the distribution coefficient of CuSO_4(aq) increases, but the distribution coefficients of Cu²⁺ and CuCl⁺ decrease; In the solution the stability is high for the complexes of Cu(I) but is low for the complexes of Cu(â…¡). The main forms of the copper particle in the solution are CuSO_4(aq), Cu²⁺ and CuCl⁺ after the solution is aerated.Through the experiment with 201×7OH^- strong-base anion exchange resin and 732Na strong-acid cation exchange resin to dispose the waste water, we obatin the following results: The efficiency of both cation exchange reaction and the anion exchange reaction can be enhanced as the pH is deduced by adding the concentrated hydrochloric acid; If the pH is deduced by in adding the concentrated sulfuric acid, only the efficiency of the cation exchange reaction can be enhanced, while the efficiency of the anion exchange reaction is decreased; The efficiency of both cation exchange reaction and the anion exchange reaction can be enhanced by adding NaCl and Na₂SO₄ to the solution; A high temperature is conducive to the cation exchange reaction but not to the anion exchange reaction; The disposing can be significantly improved with the method of multi-stage exchange. According to our calculations, the concentration of copper could meet the first national effluent standard if we first perform the forth-order anion exchange reaction and then perform the forth-order cation exchange reaction.Through the experiment by using 8-hydroxyquinoline and rhodamine b, we obatin the follwing results: Adding the concentrated sulfuric acid to decrease pH can enhance the efficiency of rhodamine b extraction reaction, but not conducive to the 8-hydroxyquinoline extraction reaction; A high temperature is conducive to the 8-hydroxyquinoline extraction reaction but not to the rhodamine b extraction reaction; A significant improvement can be achieved with the method of the ordered extraction, i.e., using 8- hydroxyquinoline first and then rhodamine b. According to our calculations, the concentration of copper can meet the first national standard of effluent if we first perform the forth-order rhodamine b extraction reaction and then the fifth-order 8- hydroxyquinoline extraction reaction.Cu(â… )can be oxidized to Cu(â…¡) in the waste water by aerating the solution. After the solution is aerated, both cation exchange reaction and 8- hydroxyquinoline extraction reaction can be improved in the solution. The cation exchange reaction can be improved by decreasing pH while the 8- hydroxyquinoline extraction reaction can be improved by increasing pH in solution. A rising temperature is conducive to both cation exchange reaction and 8- hydroxyquinoline extraction reaction. According to our calculations, the concentration of copper can meet the first national standard of effluent with the method of performing the fifth-order cation exchange reaction or the fifth-order 8- hydroxyquinoline extraction reaction.