The utilization of titanium-bearing blast furnace slag (TiO2 about 23 wt%) is an urgent problem to be solved. The selective crystallization and carbonization by methane process is a novel method to extract the titanium in the slag. In this study, the thermodynamic calculation results showed that the increase in basicity was beneficial for the crystallization of perovskite in the TiO2–CaO–SiO2 ternary slag, which contributes to the enrichment of titanium. In the following carbonization process, it was also found that the addition of Fe2O3 and CH4N2O was beneficial for the synthesis of Ti(N,C,O). The reasons were Fe2O3 could catalyze the decomposition of methane to generate the active carbon, and CH4N2O acted as the pore-forming material which resulted in the specific surface area of solid powder increasing, namely increasing the contact chance of methane with powders.
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Thanks are given to the financial supports from the National Natural Science Foundation of China (51674053, 51604046), National Key R&D Program of China (2018YFC1900500), Fundamental and Frontier Research Project of Chongqing (cstc2017jcyjAX0322), Graduate Scientific Research and Innovation Foundation of Chongqing (CYB19003), Undergraduate Scientific Research and Innovation Foundation of Chongqing (S201910611297), and Young Elite Scientists Sponsorship Program by CAST (2018QNRC001).
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