Abstract:

The new process of producing potassium nitrate was investigated via ion exchange technology. In the process, sodium nitrate was regarded as eluent, and the process parameters of extracting potassium were studied. The influence of eluent concentration and temperature on elution effect were explored. The results showed that high temperature and concentration of the eluent (sodium nitrate) were beneficial for adsorption. When the raw material was brine and the temperature was 80℃ and the mass percent of sodium nitrate was 46%, the potassium ion concentration after enrichment increased from 0.84g/L to 15.95g/L. Meanwhile, when the raw material was exchanged for bittern, high temperature was also beneficial for adsorption effect, the potassium ion concentration after enrichment increased from 8.93g/L to 23.34g/L under the same elution condition. It showed that the method was suitable for low potassium brine and high potassium bittern. The higher potassium concentration is, the higher saturated adsorption capacity and concentration of potassium can be obtained in the potassium-enrichment brine. This study provides the new way for potassium nitrate production industrialization in the future.

Key words: zeolite, brine, ion-exchange, potassium-enrichment

摘要：

采用离子交换技术，研究了以硝酸钠为洗脱剂，富集生产硝酸钾的新工艺。主要研究了沸石法富集卤水/苦卤中钾离子的过程工艺参数，考察了洗脱剂浓度和洗脱温度对洗脱效果的影响。结果表明：在原料为卤水、采用硝酸钠溶液作为洗脱剂的洗脱实验中，高温、高浓度的洗脱剂有利于沸石柱的洗脱，当温度为80℃、硝酸钠溶液质量分数为46%时，富集后的钾离子浓度由原料浓度的0.84g/L提高到15.95g/L；改变原料的浓度，在原料为苦卤、硝酸钠溶液作为洗脱剂的洗脱过程中，高温同样有利于沸石柱的洗脱，当温度为80℃、硝酸钠溶液质量分数为46%时，富集后的钾离子浓度由原料的8.93g/L提高到23.34g/L；表明该方法适用于低钾卤水和高钾苦卤，且原料中钾离子浓度越高，饱和吸附量越高，所得富钾卤水中钾离子浓度越高。该研究为未来硝酸钾的生产工业化提供了新思路。

关键词: 沸石, 卤水, 离子交换, 钾富集