脱硫石膏湿法转化制备碳酸钙及硫酸铵

Preparation of Calcium Carbonate and Ammonium Sulfate by Wet Conversion of Desulfurization Gypsum

为了对冶金脱硫石膏进行综合利用,本文提出了一种新颖的脱硫石膏化学转化法,通过铵盐循环的方式,以廉价的碳酸氢铵为原料,将脱硫石膏转化为高质量的碳酸钙产品,同时获得硫酸铵。该方法的反应条件温和,在全溶液状态下进行转化,无高温煅烧和尾气排放,钙元素和硫元素可完全分离而获得纯净的碳酸钙和硫酸铵产品。实验结果表明,在反应温度为65℃、反应时间为2.5h的条件下,脱硫石膏的转化率达到67%以上。将转化后的碳酸钙与氯化铵共同加热至沸腾,可回收碳酸铵。反应完成后进行固液分离,将回收的碳酸铵与分离液体进一步反应,可得到转化率在97%以上、纯度在98%以上的碳酸钙。

In order to comprehensive utilization of metallurgical desulfurization gypsum,a novel chemical conversion method of desulfurization gypsum was proposed in this paper.Through ammonium salt circulation,desulfurization gypsum solid waste was convered into high-quality calcium carbonate products,while obtained ammonium sulfate.The reaction conditions of this method were mild,and the conversion was carried out in a fully solution state without high-temperature calcination or exhaust emissions.Calcium and sulfur elements could be completely separated to obtain pure calcium carbonate and ammonium sulfate products.The experimental results showed that when the reaction temperature was 65℃and the reaction time was 2.5h,the conversion rate of desulfurization gypsum was over 67%.The converted calcium carbonate was heated and boiled with ammonium chloride to recover ammonium carbonate.After the reaction was completed,solid-liquid separation was carried out to further react the recovered ammonium carbonate with the separated liquid.Calcium carbonate with a conversion rate of over 97%and a purity of over 98%was obtained.