Cyanide Solution Using Ion Exchange Resin Processing

This paper deals with the methods to recover cyanide and valuable metallic elementsfrom cyanide-containing wastewater by ion-exchange resin. Two kinds of anion resins,namely D301 and 201×7 were selected, with which effective adsorption was abtained fromthe waste cyanide water. The factors relating to the adsorption process such as themaximun CN~- amount adsorbed by resin, the consumption of resin, the velocity of fluid andpH value of waste feeding cyanide solution were tested in the experiment, also the functionof ion-transfer reagent was studied. In addition, the desorption condition of loading resinwas explored. Then a method was proposed to deal with cyanide-bearing water, whichapplys two different resins in one process and then desorbs them respectively. The resultsshow that after the two-step adsorption, the concentration of Cu, Zn and Ni ions are below0.36mg/L, 0.47mg/L, 0.50mg/L respectively, which coincide with the standards ofdischarging; And 99.88 percent of CN~- in cyanide water was absorbed by resin. During theprocess of desorption, the desorption rates of Cu, Zn and Ni reach to 70% and those of CN~-and Au reaches to 80%. The process not only effectively recovers the toxic cynide,decreases and controls the pollution, but also selectively recycles the valuable metallicelements in the wastewater. It also improves the economic profit and the ratio of resourceutilization. It is a double-profits technology between environmental and economic benefits.In addition, the principle of ion-exchange in resin was studied.