钛石膏综合利用及硫钙分离新工艺研究

为了解决钛石膏综合利用问题，提出一种温和的湿化学法转化法，采取铵盐循环的方式实现以低价碳酸氢铵为原料、使钛石膏固废转化为高质量碳酸钙产品，同时获得硫酸铵和富铁渣。试验结果表明，钛石膏与碳酸氢铵的质量比为1∶1、反应温度为65 ℃、反应时间为1.25 h条件下，钛石膏的转化率可以达到95%以上，将转化后的碳酸钙和铁渣等与氯化铵加热沸腾反应并回收碳酸铵，将反应完成后的固液分离，利用回收的碳酸铵与分离液体进一步反应可得纯度高达98%以上的碳酸钙和含铁量高达61%以上的铁渣。

Study on new process of comprehensive utilization and separation of sulfur and calcium of titanium gypsum

In order to solve the problem of comprehensive utilization of titanium gypsum，a mild wet chemical conversion method was put forward.Using low-price ammonium bicarbonate as raw material，titanium gypsum solid waste was converted into high-quality calcium carbonate products，and ammonium sulfate and iron-rich slag were obtained at the same time.The test results showed that under the conditions of mass ratio of titanigypsum to ammonium bicarbonate of 1∶1，reaction temperature of 65 ℃ and reaction time of 1.25 h，the conversion rate of titanigypsum could reach more than 95%.The converted solid calcium carbonate and iron slag were heated and boiled with NH₄Cl to recover ammonium carbonate，and the solid-liquid separation after the reaction was completed.Further reaction of the recovered ammonium carbonate with the separation liquid could obtain calcium carbonate with purity of more than 98% and iron slag with iron content of more than 61%.