硫酸钠和氯化钠高盐废水分盐工艺研究

Study on salt separation technology of sodium sulfate and sodium chloride high salt wastewater

为回收利用高盐废水中的大量硫酸钠和氯化钠,实现盐类的资源化利用,满足环保形势需要,研究高盐废水的分盐处理工艺势在必行。介绍了含硫酸钠和氯化钠高盐废水的4种分离工艺,即高温硝低温盐法、热蒸—冷冻—热蒸法、纳滤—两步热蒸法、纳滤—热蒸—冷冻/热蒸法。这4种工艺均可实现结晶盐的资源化,固废减量化,水全部回收利用;结晶盐氯化钠和硫酸钠可满足工业级盐回用或出售。

In order to recycle a large number of sodium sulfate and sodium chloride in high salt wastewater to and realize the utilization of salt resources meet the needs of environmental protection,it is imperative to study the salt separation treatment process of high salt wastewater.Four separation processes of high salt wastewater containing sodium sulfate and sodium chloride were introduced,which are high-temperature nitrate and lowtemperature salt method,hot steaming-freezing-hot steaming method,nanofiltration-two step hot steaming method,nanofiltration-hot steaming-freeze/hot steaming method.These four processes can realize the resource of crystallized salt,the reduction of solid waste and the recycling of all water;crystalline salt sodium chloride and sodium sulfate can be reused or sold as industrial grade salt.