利用农药含钾废渣制备氯化钾

利用热解及钙盐沉淀法对农药含钾废渣进行处理,制得高纯度的KCl.通过管式炉反应器对农药含钾废渣中有机物的去除进行了研究,探讨了升温速率、热解终温、终温保持时间及空气流量对热解过程的影响,并对钙盐沉淀法除氟过程的溶液pH及m(Ca2+)∶m(F-)进行了确定.实验结果表明:当升温速率为20℃/min、热解终温为600℃、终温保持时间为90 min、空气流量为3.0m3/min时,废渣中的有机物完全分解;钙盐沉淀法除氟的最佳条件为溶液pH 8,m(Ca2+)∶m(F-)=3.0,氟离子的去除率达到98％;最终得到KCl的产率为70.6％,产品纯度为98.2％,符合国家Ⅰ级优等品标准.

Preparation of Potassium Chloride from Potassium-containing Residue in Pesticide Production

Potassium chloride with high purity was prepared from potassium-containing residue in pesticide production by pyrolysis and calcium precipitation processes.In a tube furnace reactor,the removal of organic compounds in the residue was studied,the factors affecting the pyrolysis process were discussed,and the solution pH and m(Ca2+)∶m(F-) in the calcium salt precipitation process for fluorine removal were determined.The experimental results show that:When the heating rate is 20 ℃/min,the final pyrolysis temperature is 600 ℃,the final isothermal period is 90 min and the air flow rate is 3.0 m3/min,the organic compounds in the residue are decomposed completely;Under the optimum conditions of solution pH 8 and m(Ca2+)∶m(F-)= 3.0 in calcium salt precipitation,the removal rate of fluoride ions can reach 98%.The final yield and purity of potassium chloride are 70.6% and 98.2% respectively,which can meet the superior grade of national standards.