从转底炉烟尘中高效回收钾和钠

Efficient Recovery of Potassium and Sodium from Dust of Rotary Hearth Furnace

针对转底炉烟尘,提出加热水浸高效回收钾、钠工艺。考察了水浸时各因素对钾、钠回收的影响,同时对有害元素氟、铊的浸出情况进行了分析。结果表明,在水浸温度80℃、液固比6、时间1 h、搅拌转速500 r/min的条件下,钾、钠的浸出率在99%以上,锌、氟、铊的浸出率分别为10.03%、18.35%、81.89%。水浸液净化沉锌优化条件为:温度40℃、时间60 min、搅拌转速350 r/min、Na_(2)CO_(3)用量12 g/L、水浸液pH=8.37,此时净化液中锌含量为0.3 mg/L,锌脱除率99.99%,杂质钙、镁含量分别为5.72 mg/L、1.3 mg/L。净化液蒸发结晶制备氯化钾,产品符合国家标准(GB 6549—2011)中工业氯化钾优等品标准。

Aiming at the dust of rotary hearth furnace,a high efficient recovery process of potassium and sodium by heating and water leaching was proposed.The effects of various factors on the recovery of potassium and sodium during water leaching were investigated,and the leaching conditions of harmful elements fluoride and thallium were analyzed.The results show that under the conditions of water leaching temperature of 80℃,liquid-solid ratio of 6,time of one hour and stirring speed of 500 r/min,the leaching rate of potassium and sodium is both above 99%,and the leaching rate of zinc,fluorine and thallium is 10.03%,18.35%and 81.89%,respectively.The optimal conditions for zinc deposition from water leaching solution are as follows:the temperature is 40℃,the time is 60 min,the stirring speed is 350 r/min,the dosage of Na_(2)CO_(3)is 12 g/L,and the pH value of the solution is 8.37.At this condition,the zinc content in the purification solution is 0.3 mg/L with the zinc removal rate of 99.99%,and the contents of impurity calcium and magnesium are 5.72 mg/L and 1.3 mg/L,respectively.The purified solution was evaporated and crystallized to prepare potassium chloride,and the product meets the national standard(GB 6549—2011)for industrial potassium chloride superior product standard.