Study And Engineering Application On Electroplating Wastewater With De-nickeling By Cyclone Electrowinning Technology

This topic combined with the general situation of Huizhou Environmental Electroplating industrial Park,researches the nickel-containing wastewater treatment process,raises questions,and explores solutions.In combination with issues such as the lack of reasonable utilization of the electroplating wastewater containing nickel,the advanced cyclone electrowinning technology was used to extract nickel from electroplating wastewater containing nickel.The feasibility of the cyclone electrolysis technology was explored,and the factors influencing the electrolytic nickel extraction experiment were investigated to find the best electrolysis conditions.At the same time,The topic also explored the enrichment effect of NDA-36 resin on nickel concentrates,then researched and improved the cyclone electrowinning pilot plant.For the electroplating wastewater containing nickel of the wastewater treatment plant of the Huizhou Environmental Electroplating industrial Park,a new two-stage de-nickeling and copper removal process using cyclone electrowinning technology was designed.The first stage of electrolysis removes copper impurities from electroplating wastewater containing nickel,and the second stage electrolytically extracts nickel from the decoppered liquid,thereby reducing the doping of copper and other impurities in the nickel product and improving the purity of the nickel product.The effect of circulating flow rate,current density,temperature,and p H on the copper removal and nickel extraction experiments was investigated by single factor and orthogonal experiments,and explored the optimal parameter combination of de-nickeling and copper removal process.The best parameters for determining the first stage of electrolysis removes copper impurities were as follows: initial temperature 50?,circulating flow 800 L/h,and current density 450 A/m~2.The best parameters for nickel extraction in the second phase were: initial temperature 30?,circulating flow 800 L/h,current density 500 A/m~2,and p H 2.5~3.The topic explored the secondary enhancement of concentration of electroplating wastewater containing nickel with NDA-36 resin.The results of single factor static adsorption experiments showed that NDA-36 resin had the best adsorption effect on Cu2+ at a temperature of 40? and p H 3,and the best adsorption effect on Ni2+ at a temperature of 40? and p H 5.The experimental data was fitted by Langmuir isotherm equation.It was concluded that the maximum saturated adsorption capacity of NDA-36 resin to Cu2+ and Ni2+ was 125.25mg/g and 66.32mg/g,and they both were preferential absorption.The results of dynamic adsorption and regeneration experiments show that NDA-36 resin has good dynamic adsorption performance for Cu2+ and Ni2+,especially the adsorption of Cu2+.Regeneration experiment increased the maximum concentration of the regenerated solution of Cu2+ and Ni2+ to 2.5-fold and 1.75-fold respectively of the initial concentration,the enrichment effect was significant,and the both metal ions basically reached the recovery rate of 100%.The cyclone electrowinning de-nickeling equipment has been improved and a nickel-on-copper integrated online extraction system has been designed,including two nickel ion exchange columns,a cyclone electrowinning pilot plant,a diffusion dialysis unit,and a copper-nickel online monitoring and p H control system.