KOH-KF亚熔盐法活化含钾岩石制备W沸石

Synthesis of zeolite W from potassic ores activated by KOH-KF sub-molten salt

针对含钾岩石的综合利用,以KOH-KF为活化助剂,进行了亚熔盐法活化含钾岩石制备W沸石的研究。采用X射线衍射(XRD)确定了活化产物的组成。实验结果表明,适宜的活化条件为:KF和KOH量比n(KF)/n(KOH)为0.05,KOH和含钾岩石质量比m(KOH)/m(potassic ores)为3,KOH质量分数为70%,反应时间为6 h,反应温度为190℃。向上述适宜活化条件下获得的液固混合产物中按照一定比例补加KOH、气相SiO_(2)和H_(2)O,采用水热法合成了W沸石。制得的W沸石经钠改型后在模拟海水中的提钾量(K+)为48.39 mg×g^(-1)。合成沸石的母液经浓缩后被再次用于含钾岩石活化,有利于实现资源节约和工业化应用。

Potassic ores were activated by a sub-molten salt method using KOH-KF as the activating agent to prepare zeolite W.The composition of activated products was determined by X-ray diffraction(XRD).The experimental results show that the suitable activation conditions are n(KF)/n(KOH)=0.05,m(KOH)/m(potassic ores)=3,KOH mass fraction=70%,reaction time=6 h and reaction temperature=190℃.KOH,fumed silica and H_(2)O were added to the resulted liquid-solid mixture and zeolite W was synthesized by a hydrothermal method.The zeolite W modified by sodium exhibits potassium extraction capacity of 48.39 mg×g^(-1) from simulated seawater.The mother liquor of synthesized zeolite was concentrated and reused for the activation of potassic ores,which is helpful for energy conservation and industrial application.