关键词: 钛石膏, 钛白粉, 碳酸氢铵, 硫酸钙, 碳酸钙, 铁渣

Abstract:

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%.

Key words: titanium gypsum, titanium dioxide, ammonium bicarbonate, calcium sulfate, calcium carbonate, iron slag