Study On Preparation Of Rich Titanium Material From Titanium Slag

Panxi area in China is rich in titanium resources. The grade of TiO2in Titanium slag which is obtained by electric furnace smelting of the ilmenite concentrate after ore dressing is lower, but the content of calcium and magnesium is higher. So it cannot be used directly as raw material to produce titanium dioxide through chlorination process and titanium sponge. Therefore, it will be of great significance that researching and producing rich titanium material in the high grade by removing impurities of titanium slag.In this paper, the electic furnace melting slag in Panzhihua of Sichuan Provice was selected as the research object, the technological process of producing of high grade rich titanium material was explored, the process of adding NH4H2PO4for activation of roasting-dilute phosphoric acid leaching and then adding NaOH for activation of roasting-water leaching-dilute phosphoric acid leaching was proposed. The best process parameters were obtained, rich titanium material in the higher grade were obtained by exploring each technology process and combining the related theory. And the rich titanium material can be met the requirements of producing titanium dioxide through chlorination process.In this paper, modification of titanium slag was studied in the first. Then the effect of dosage of additives and heat treatment conditions on the phase structure and enrichment of titanium slag was explored. According to the results, NH4H2PO4was an ideal modifying agent, and the optimum condition of experiments had been abtained:NH4H3PO4/mass ratio of titanium slag was0.3, roasting temperature was1300℃, roasting time was2h.The leaching process conditions were optimized in the acid leaching experiment of the amount of modified titanium slag. According to the results, when phosphoric acid concentration was20%, leaching temperature was60℃, the ratio of liquid to solid was10:1(mL/g) and the leaching time was2h, TiO2grade could reach74.99%and the total content of CaO+MgO was1.17%by using phosphoric acid as the leaching liquid during leaching.Kinetic model of leaching process was studied, and the result showed that the leaching process was controlled by internal diffusion. The dynamic equation was and according to the Arrhenius formula, the apparent activation energy of calcium, magnesium, aluminum, iron in the processes was18.66kJ·mol-1、22.52kJ·mol-1、17.65kJ·mol-1、20.67kJ·mol-1respectively. The dynamic equation of leaching process was:The roasting and leaching processes were studied in the experiment which silicate was used for removing impurity. The optimum condition of roasting and water leaching technology of titanium NaOH/mass ratio of titanium slag was0.3, roasting temperature was400℃, roasting time was4h; leaching temperature was90℃, the ratio of liquid to solid was10:1(mL/g), leaching time was4h. The TiO2grade of rich titanium material was93.2%, and the recovery was93.6%after acid leaching.Further exploration should be made for the selection and preparation of additives used in rich titanium slag granulating.