高浓度氯化钠循环传质钠化钙基蒙脱石

Na-Ca Exchange onto Ca-montmorillonite in High Concentration Sodium Chloride Solution by a Circulation Mass Transfer Method

采用氯化钠为钠钙交换剂，在其浓度较高情况下通过循环传质交换钙基蒙脱石层间钙离子达到钠化目的。研究了钠钙交换过程中影响蒙脱石可交换钠ENa^＋的因素，确定了交换条件：氯化钠最小浓度CNaCl为3％；矿浆浓度在高盐强电解质中可提高到25％；钠钙交换时间大于45min，包括15min以上的搅拌时间；将蒙脱石加入到配制好的盐溶液中将显著提高钠化效率。在以上条件下得到的钠基蒙脱石碱性系数均大于1，吸水膨胀优良，膨胀容为原土的6-9倍。建立了母液循环次数与氯化钠初始浓度、钙基蒙脱石使用量以及其层间可交换钙E1／2Ca^2＋的数学模型。

A circulation mass transfer method was used to prepare Na-montmorillonite by exchanging Ca with Na onto Ca-montmorillonite in high concentration sodium chloride solution. The influences of factors on ENa＋ were investigated. Alkaline coefficient above 1 of Na-montmorillonite with excellent water swelling property was obtained under these conditions： the minimum concentration of NaCl was 3 % （mass）; the concentration of slurry could reach to 25%; time for Na-Ca exchanging was more than 45 min including 15 min stirring time; NaCl should be added into deionized water before montmorillonite. A mathematical model was established which was between circulation times of mother liquor and concentration of initial sodium chloride, quantity of Ca-bentonite, cation exchanging Ca^2＋ E1/2Ca^2＋.