从氯碱盐泥中浸出钙镁的试验研究

针对某氯碱生产过程中产生的盐泥, 为从其中回收钙镁, 制备纳米氢氧化镁和纳米碳酸钙, 对氯碱盐泥进行了盐酸浸出试验研究。结果表明: 采用盐酸浸出, 浸出时间15 min, 温度为60 ℃, 酸度2 mol/L, 液固比5∶1, 搅拌速率500 r/min, 钙镁总浸出率可达到98%以上, 所得钙镁富液中, Ca²⁺、Mg²⁺ 、Al³⁺、Fe³⁺离子浓度为分别为0.63、0.25、0.05、0.022 mol/L, pH=0.5。

Experimental Study on Leaching Calcium and Magnesium from Chlor-alkali Salt Slurry

In order to effectively recover calcium and magnesium in the salt slurry generated during chlor-alkali production, which can be used for the preparation of nanometer magnesium hydroxide and nano calcium carbonate, an experimental study was conducted on hydrochloric acid leaching of the chlor-alkali salt slurry. In the experiment, such kind of chlor-alkali salt slurry was leached with hydrochloric acid at a temperature of 60 ℃, with the liquid-solid ratio of 5∶1, the acidity of 2.0 mol/L, with a stirring speed of 500 r/min, resulting in the total leaching rate of calcium and magnesium up to more than 98% after 15-min leaching time, and the concentration of Ca²⁺, Mg²⁺, Al³⁺ and Fe³⁺ in the calcium-magnesium rich solution with pH of 0.5 reaching 0.63, 0.25, 0.05 and 0.022 mol/L, respectively.