Recovery of titania from high titanium slag by roasting method using concentrated sulfuric acid

By means of energy-dispersive X-ray spectroscopy（EDX） and scanning electron microscope（SEM）analysis,the phase structure characteristics of high titanium slag were analyzed.Through the single factor and the orthogonal experiment methods,the effects of material particle size,mass ratio of acid to ore,roasting temperature,and roasting time on the acidolysis ratio of TiO2during the process of roasting high titanium slag with concentrated sulfuric acid were systematically investigated.The results show that the sequence of each factor affecting the acidolysis ratio of TiO2 is:mass ratio of acid to ore,roasting time,and roasting temperature.The optimum technological conditions are obtained as mass ratio of acid to ore of 2.1,roasting temperature of 310 ℃,roasting time of 75 min,and material particle size of 45-53 μm.The acidolysis ratio of TiO2 is over 96%under the optimum conditions.The roasting process is proved to be significant in the exploitation and utilization of high titanium slag.The advantages of the proposed roasting process are of high efficiency,low power consumption,and minimum pollution.