Cuprous Chloride Was Prepared From Copper Plating Wastewater And Improve Its Antioxidant Activity

Nowadays,4 billion cubic meters electroplating wastewater,containing a lot of copper ions were released in china every year.It's not only the waste of resources,but also the environment pollution will be caused if the copper ions couldn't be reused.In this paper,cuprous chloride was prepared by sulfite reduction.Bluestone was obtained from the treatment of copper-containing electroplating wastewater.At the same time,the influences of various factors and improvement of anti-oxidization of cuprous chloride have been studied during preparation.According to experiment,the optimum technics of preparation cuprous chloride are: n(CuSO₄):n(Na₂SO₃):n(NaCl)=1:1.33:1.6,temperature of reaction is 60 centigrade,pH value is 3.5.Under this condition,recycling rate of cuprous chloride is beyond 97 percent, pure cuprous chloride is up to 98 percent;scale-up experiment was shown:sodium sulfite content controls in 0.85～1.1 times the amount of copper sulfate,and other conditions remain.Purity of cuprous chloride is up to 98 percent;productive rate is more than 80 percent.Study on anti-oxidization of cuprous chloride was shown:Because of the existence of water,cuprous chloride oxidation reaction rapidly occurred in air or steam and oxidation reaction did not happen under ultraviolet radiation or blast drying.By organic surface coating on cuprous chloride,I found citric acid and thiourea can improve the anti-oxidization of cuprous chloride.The technics of cover treatment:the content of citric acid is 4 percent,reaction times is 4～8 hours;the content of thiourea is 2 percent,reaction times is 2～6 hours;Both of reaction temperature are room temperature.The coated cuprous chloride is characterized by means ofXRD,IR,TG-DSC.The IR results demonstrate that citric acid carboxyl and hydroxyl can react on surface of CuCl and citric acid carboxyl absorb on surface of CuCl;electroneutral ligand of thiourea modify the Cu⁺ surface of CuCl through Cu-S coordination bonding and it coats the surface of CuCl;TG-DSC demonstrates that citric acid coating on CuCl has distinct exothermic reaction at temperature of 366.9℃and lose 2.74%weight,which shows organic matter coating on CuCl decompose at 366.9℃around,thiourea coating on CuCl has distinct exothermic reaction at temperature of 392.2℃and lose 1.13%weight,which shows organic matter coating on CuCl decompose at 392.2℃around;XRD analysis was shown that drawing into thiourea and citric acid did not have obvious impact on the chemical composition of CuCl.