钠硝石矿中硝酸钠水溶浸取过程研究

Research on leaching process of sodium nitrate from nitratine using water

对钠硝石矿中硝酸钠水溶浸取过程进行了研究。为了提高浸取液中硝酸钠的质量分数,选择不同浸取时间、不同固液质量比进行了水溶液浸取实验。实验结果表明:钠硝石矿水溶液浸取速度较快,不同固液质量比条件下均在10 min内达到平衡;相同时间条件下,固液质量比以1.0为宜。硝酸钠的浸取率达90%。25℃下,选取钠硝石矿与浸取液固液质量比为1.0,浸取时间为10 min,经6次重复后,浸取液中各种盐的浓度与首次浸取液相比:硝酸钠质量分数由5.54%增加到29.58%;氯化钠质量分数由12.03%减少到11.89%;硫酸钠质量分数由3.22%降低到1.87%。结合相图分析,提出了实际生产中采取分级喷淋方式浸出硝酸钠的方案。

Leaching process of sodium nitrate from nitratine using water was studied. In order to increase the mass fraction of sodium nitrate in leaching solution, different extracting times and liquid-solid mass ratios were selected to carry out the leaching experiments. Tests results indicated that leaching speed of nitratine was rather fast, balances were all achieved within 10 min under the different liquid-solid mass ratios;under the same time condition, liquid-solid mass ratio of 1.0 would be appropriate. Leaching rate of sodium nitrate could reach 90%. Under the conditons of 25 ℃ ,liquid-solid mass ratio of 1.0 and leaching time of 10 min,extractable liquid was repeated 6 times to do the leaching,the mass fraction of sodium nitrate in leaching sloution increased from 5.54% to 29.58% ,while the mass fraction of sodium chloride reduced from 12.03% to 11.89% and the mass fraction sodium sulfate reduced from 3.22% to 1.87% comparing with those in the initial leaching solution. With the aid of phase diagram, a method of grading spray was proposed for leaching sodium nitrate in real production.