氟化钙诱导结晶处理除氟再生废液试验研究

Experimental Study on the Treatment of Defluorinated Regenerated Waste Liquid by Induced Crystallization with Calcium Fluoride

为了解决矿井水吸附过滤除氟过程中产生的除氟再生废液二次污染和氟化钙回收利用等问题,该文提出了氟化钙诱导结晶流化床处理工艺,进行了静动态诱导结晶除氟试验,考察了初始氟浓度、石灰占总钙摩尔比、钙氟比、晶种粒径、pH值和反应时间等多种因素对除氟效果的影响,分析了氟化钙诱导结晶除氟机理。结果表明:在进水流量<20 L/h,初始氟浓度500~1500 mg/L条件下,当石灰占总钙摩尔比约为60%、钙氟比约为0.9,氟化钙晶种平均粒径约为100~130μm、pH值为8~9和反应时间约为1.0~1.2 h时,试验出水氟浓度约为12.5~15.0 mg/L,氟化钙泥渣含水率约为28%~31%,易于后续达标处理和回收利用。

In order to solve the problems of secondary pollution and recycling of calcium fluoride of defluorinated regenerated waste liquid in the process of adsorption and filtration for mine water,the fluidized bed process of induced crystallization with calcium fluoride was used,the static and dynamic defluorination experimental was carried out.The effects of the initial fluoride concentration,the lime to total calcium molar ratio,the calcium fluoride ratio,the seed size,the pH value and the reaction time on the effect of fluoride removal were investigated.The mechanism of calcium fluoride induced crystallization was analyzed.The results showed that the effluent fluorine concentration was about 12.5~15.0 mg/L,the moisture content of calcium fluoride sludge was 28%~31%under the conditions that the inlet flow is less than 20 L/h,the initial fluorine concentration is 500~1500 mg/L,the ratio of lime to the total calcium is about 60%,the ratio of calcium to fluorine is about 0.9,the average grain size is about 100~130μm,the pH value is 8~9 and the reaction time is about 1.0~1.2 h.It is easy to follow up the standard processing and recycling.