联碱碳化塔洗水制备轻质碳酸钙

为了回收联碱厂碳化塔洗水中的CO32--、HCO3-,减少污染物排放,采用复分解法,以碳化塔洗水为原料与饱和氢氧化钙溶液反应制备轻质碳酸钙.通过正交试验和单因素试验探讨了碳化塔洗水滴加速率、反应温度、搅拌速率、添加剂对产物粒径的影响;通过SEM、XRD分析了产物形貌及性质.试验结果表明,在碳化塔洗水以3 mL/min的速率滴加、反应温度为15℃、搅拌速率为700 r/min、op-10的投加量为Ca（OH）2溶液质量分数的0.1％的最佳反应条件下,得到的产物粒径为0.3 ～ 1.0 μm,颗粒分散均匀,粒度分布较窄,晶型为四方形片块状轻质碳酸钙.以碳化塔洗水为原料与饱和氢氧化钙溶液反应制备轻质碳酸钙,为联碱厂废水的处理及资源综合利用提供了新途径.

Preparation of light calcium carbonate using cleaning water of carbonation tower in integrated soda plant

For the purpose of reclaiming CO32 and HCO3 from cleaning water ot camonauon tower m rote grated soda plant and reducing pollutant emission, double decomposition method was adopted to prepare light calcium carbonate through the reaction of cleaning water of carbonation tower and saturated calcium hydroxide solution. The influences of dropping velocity, reaction temperature, stirring speed and additive on product particle size were discussed through orthogonal test and single factor experiment; besides, the morphology and properties of the product were analyzed using SEM and XRD. The results of the test showed that, under the optimal condi tion that, the dropping speed of cleaning water of carbonation tower was 3 mL/min, the reaction temperature was 15 ℃, the stirring speed was 700 r/min, the dosage of op10 was 0.1% of the mass fraction of the Ca（OH）2 solu tion, the product was massive light calcium carbonate with a crystal structure of square piece, which had uniform particle dispersion and narrow particle size distribution with particle size of 0.3 1.0 . Therefore, the method of using cleaning water of carbonation tower as raw material to prepare light calcium carbonate through the reac tion of it with saturated calcium hydroxide solution was proposed, which provided a new approach for the treat ment and resources comprehensive utilization of the wastewater in integrated soda plant.