Study On Treatment Process Of Mother Liquor In Sodium Chlorate Industry

The sludge produced in chlorate industry contains certain of Cr6+which is harmful to the environment. The NF and ion exchange resin get more attention for their good performance of treating wastewater. So far, there is little study using the combination of NF and ion exchange resin for the treatment of mother liquor of sodium chlorate. In this paper, the possibilities of combination of strongly ion exchange resin and NF for the treatment of mother liquor of sodium chlorate are investigated. The main study was to have knowledge of the effect of operation parameters on the results.In the adsorption experiment of strongly ion exchange resin, the effect of pH value, exchange time, the initial concentration of Cr6+and the temperature on exchange capacity was investigated. When pH is between2to4, it will do a favor to the exchange capacity. Along with the advancement of exchange time, ion exchange capacity is more and more big. And after a period of time, the exchange capacity achieves balancement. The ion exchange capacity will become bigger with temperature, the operation temperature is usually about40℃.In the NF experiment, the effect of working pressure, initial concentration of sodium sulfate, time and flow capacity on the membrane flux and removal rate of sodium sulfate was studied. Membrane flux increases continuously with working pressure build-up and the removal of sodium sulfate increases when the working pressure becomes higher. Membrane flux increases with feeding flow but the removal rate of sodium sulfate remains almost constant with the change of flow capacity when the flow capacity is between10to30L·min-1. The content of sodium sulfate made the removal rate decline among95%to98%, and also made the membrane flux decline. The membrane flux and removal rate of sodium sulfate dropped with time.The combination of strongly ion exchange resin and NF for the treatment of mother liquor of sodium chlorate will work well which was proposed in this paper. Cr6+which was adsorbed will reused in electrolyzing Process and the penetration liquor will be used in salt dissolving section. The technological process for crystallization mother liquor provides a certain theoretical basis for industrialization.