洗涤工序对氯化钾质量和收率的影响

Influence of washing working procedure on quality and yield of potassium chloride

为了提高钾资源循环利用率,常用加工车间排出的尾液与老卤按比例兑卤生产低钠光卤石矿。此矿中硫酸钙、细盐含量较高,影响滤饼的洗涤效果,导致氯化钾产品的质量和收率低下。对等量滤饼在不同的组成、洗涤时间、洗涤水量和洗涤浓度下进行洗涤实验,结果表明：在洗涤水温为15℃时,控制滤饼指标中氯化钠的质量分数为10%~11%,硫酸钙质量分数小于2%,含湿量小于15%,并在1倍理论水量下洗涤6 min时,洗涤液浓度在47%左右,既满足离心脱水对浓度的要求,也使产品中氯化钾的质量分数和收率大幅增加,分别在93%和90%以上,洗涤效果最佳。

In order to improve recycling rate of potassium resources,tail washings discharged from the processing workshop was used to mix with old brine in proportion to produce low-sodium carnallite ore.Due to the higher contents of calcium sulfate and fine salt in this ore,the washing effect of filter cake was affected which led to low quality and yield of potassium chloride product.Washing experiments with the same quantity of filter cake under the different conditions,such as different compositions of filter cake,washing times,and amounts and concentrations of washing water,were carried out.Experiment results showed that the washing concentration was about 47% when temperature of washing water was 15 ℃,controlling the mass fraction of sodium chloride in filter cake at 10%~11%,mass fraction of calcium sulfate less than 2%,moisture content lower than 15% and doubled theoretical amounts of water for washing 6 min.Not only concentration requirement of centrifugal dewatering was met,but also mass fraction and yield of potassium chloride in the product were about 93% and 90% respectively,and washing effect was the best.