沸石法苦卤提钾工艺研究

以改性斜发沸石为离子交换剂,采用离子交换技术,做了以氯化钠溶液为洗脱剂的苦卤提钾工艺研究。单柱实验表明,洗脱温度越高、洗脱剂浓度越大以及适当流速时有利于钾富集。吸附采用模拟移动床流程,进料顺序为“低段溶液-苦卤”,钾平均吸附率可达95%以上;洗脱采用固定床流程,进料顺序为“高段溶液-中段溶液-低段吸后溶液-25%（质量分数）NaCl溶液”,得到氯化钾平均质量浓度为35.39 g/L的富钾卤水,较苦卤钾浓度提高2.7倍。在钾富集同时,苦卤中的镁、硫酸根等杂质离子亦得到了有效去除,为实现苦卤高效节能提钾奠定了基础。

Process of potassium extraction from bittern with modified clinoptilolite

Based on ion exchange technology,the potassium extraction technology from bittern was studied.The modified clinoptilolite and sodium chloride solution were respectively as ion exchanger and eluent.The single-column experiments showed higher elution temperature,higher concentration of eluent and appropriate flow rate were beneficial to potassium enrichment.The adsorption adopted the simulated moving bed process,which feeding order was low concentration solution and bittern in turn.The average adsorption rate of potassium ion was above 95%.The elution adopted fixed bed process,which feeding order was high concentration solution,middle concentration solution,low concentration solution after adsorption and sodium chloride solution of 25%（mass fraction）.Average mass concentration of potassium chloride in the potassium-rich brine was 35.39 g/L,which rose 2.7 times higher than the bittern.At the same time of potassium enrichment,the impurities had been effectively removed in bittern,such as magnesium ion and sulfate ion.This research lays a foundation for high efficiency and energy saving on potassium ion extraction of bittern.