Processing Research Of Recovery Silver From Silver Electroplating Wastewater By Ion Exchange

[Ag (CN)2]-(aq) is mainly composition of silver plating wastewater from a electroplating factory in Shenzhen. Now,we need to recovery of silver from the silver plating wastewater. Because of cyanide complex and anion exchange resin has a strong affinity, using anion exchange resin to treat with wastewater which contain silver,so as to achieve the purpose of the recovery of silver. But now there are some problems in using ion exchange resin to recovery silver from plating wastewater. Firstly, there are certain toxicity in the cyanide complex wastewater. It often need to change the pH to get high of adsorption and desorption in the process of ion exchange, at the same time it may release HCN which is toxic substances; What’s more, it is need to elute and regenerate after silver complex exchange resin. If we intend to achieve good elution effect, needing to choose suitable eluent, because the resin not exchange NaOH or NaCl like common anion exchange resin.This article related experiments in response to these problems, choose201x7, D261, D301R, D301G to do resin filter static experiment, D261has most saturated absorption, the value is73.5mg Ag/g wet resin, chosen as the best resin. D261dynamic experimental method for the determination of the adsorption capacity of dynamic saturation:80.3mg Ag/g wet resin. Depending on the flow rate D261resin adsorption curves and temperature affect the results of the experiment, select1.5mL/min flow rate, ambient temperature as the optimum conditions.Eluent selection experiment, using NaOH, H2SO4+SC (NH2)2, H2SO4+SC (NH2)2+(CH3)2CO different groups to do experiment of desorption. NaOH desorption rate is low, between10～15%; H2SO4+SC(NH2)2desorption rate is high, between85-89%; H2SO4+SC(NH2)2+(CH3)2CO desorption rate is maximum, between90～93%;5%H2SO4solution+20%SC (NH2)2of (CH3)2CO to1:1mixed for optimal, maximum of desorption rate is93.1%.Processing technology of recovery of silver from wastewater by ion exchange, The main technique flow:water quality analysis, resin selection, resin adsorption, resin desorption and regeneration, postprocessing. Choosing the appropriate reinforcing method according to water quality analysis.the resin selection accoding to the physical and chemical properties of aim ion and resin’s scharacteristic.providing the optimal technological condition parameter for adsorption and desorption by small experimental and pilot test.postprocessing mainly include extracting silver and the treatment of wastewater.