废水除氯产物氯氧化铋的干法再生研究

Study on Dry Regeneration of Bismuth Oxychloride Obtained from the Removal of Chloride Ions Contained in Wastewater

针对常规氧化铋除氯法得到的除氯产物氯氧化铋(BiOCl)在湿法循环再生中需大量使用碱性药剂,且只能得到低附加值氯化钠盐的问题,探究BiOCl干法再生的可行性。研究不同煅烧温度对除氯产物BiOCl再生产物结构、形貌和纯度的影响,并对最佳再生产物的除氯性能进行测试。结果表明:BiOCl经不同温度煅烧后,在坩埚剩余产物中主要出现Bi_(2)O_(3)和Bi_(24)O_(31)Cl_(10),在冷阱收集产物中主要含有BiCl_(3)、Bi_(2)O_(3)和BiOCl;当煅烧温度为800℃时,BiCl3的产量最高,达到63.5%,颗粒尺寸达到纳米级。利用800℃煅烧坩埚剩余产物为除氯剂,对含氯废水的除氯效率可达90.5%。因此,BiOCl的干法再生不但可得到高附加值的含氯产品,还能获得高的循环除氯效率。

In the recycling process of the bismuth oxychloride(BiOCl),a chloride removal product obtained by the traditional bismuth oxide chloride removal method,a large number of alkaline agents are required,and only the low value-added sodium chloride salt is obtained.To solve these problems,the feasibility of BiOCl by the dry regeneration is explored.The effects of different calcination temperatures on the structure,morphology,and purity of the products regenerated from BiOCl are studied,and the chloride removal performance of the optimum product is tested.The results show that,after the calcination treatments of BiOCl with different temperatures,the crystal phases of Bi_(2)O_(3)and Bi_(24)O_(31)Cl_(10)are mainly appeared in the remaining products in the crucible,and the products collected in the cold trap mainly contained BiCl3,Bi_(2)O_(3)and BiOCl.When the calcination temperature is 800℃,the yield of BiCl3 is highest,reaching 63.5%,and its particle sizes reach the nanometer level.We used the remaining product in the 800℃calcined crucible as the antichlor,and the chloride removal efficiency could reach 90.5%.Therefore,the dry regeneration of BiOCl cannot only obtain the high value-added chloride-containing products,but also achieve high circulating chloride removal efficiency.