Titanium is exceptional value to industry, military and consumer applications due to the attractive combination of properties exhibited by metallic titanium and its alloys. The Kroll reduction reaction is a complex heterogeneous exothermic reaction with the possibility of the formation of TiCl2 and TiCl3 as reaction intermediates. Chlorine impurity has been a significant technical challenge in titanium production ever since the inception of the Kroll processes themselves. In this investigation, an attempt was made to check the influence factors of titanium sponge structure, raw materials, times of distillation and vacuum distillation process parameters on chorine impurity scavenging. The results indicate that the decrease of Ti sponge porosity increased the difficulty of chloride impurities removing. Chlorine content increased rapidly from 0.012 to 0.121% when the system pressure grew from 0.1 to 12 Pa in the vacuum distillation process. The chlorine content in titanium sponge was also increased with the increase of NaCl, MgCl2 and CaCl2 impurities in Mg reductant.
Chlorine impurity Titanium sponge Vacuum distillation Kroll process
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This work was supported in part by National Science Foundation of China (No. 51874156), Transfer Payment Program of Sichuan Province of China (No. 2017GZYZF0039) and the Scientific Research Item of Panzhihua City (No. 2017CY-G-5). The encouragement of academician Dai Yongnian is greatly appreciated.
Nagesh CR, Kumar GB, Saha B, Gokhale AA (2017) Titanium sponge production and processing for aerospace applications. Aerospace materials and material technologies. Springer, Singapore, pp 73–89CrossRefGoogle Scholar
Dehghan-Manshadi A, Bermingham MJ, Dargusch MS, StJohn DH, Qian M (2017) Metal injection moulding of titanium and titanium alloys: challenges and recent development. Powder Technol 319:289–301CrossRefGoogle Scholar
Jiao H, Tian D, Wang S, Zhu J, Jiao S (2017) Direct preparation of titanium alloys from ti-bearing blast furnace slag. J Electrochem Soc 164(7):D511–D516CrossRefGoogle Scholar
Ono K, Suzuki RO (2002) A new concept for producing Ti sponge: calciothermic reduction. JOM 54(2):59–61CrossRefGoogle Scholar
Zhang W, Zhu Z, Cheng CY (2011) A literature review of titanium metallurgical processes. Hydrometallurgy 108(3–4):177–188CrossRefGoogle Scholar
Low RJ, Qian M, Schaffer GB (2012) Sintering of titanium with yttrium oxide additions for the scavenging of chlorine impurities. Metall Mater Trans A 43(13):5271–5278CrossRefGoogle Scholar
Fan Z, Niu HJ, Cantor B, Miodownik AP, Saito T (1997) Effect of Cl on microstructure and mechanical properties of in situ Ti/TiB MMCs produced by a blended elemental powder metallurgy method. J Microsc 185(2):157–167CrossRefGoogle Scholar
Gao F, Nie Z, Yang D, Sun B, Liu Y, Gong X, Wang Z (2018) Environmental impacts analysis of titanium sponge production using Kroll process in China. J Clean Prod 174:771–779CrossRefGoogle Scholar
Zhang Y, Deng J, Jiang W, Mei Q, Liu D (2018) Application of vacuum distillation in refining crude lead. Vacuum 148:140–148CrossRefGoogle Scholar
Liang L, Dachun L, Heli W, Kaihua L, Juhai D, Wenlong J (2018) Removal of chloride impurities from titanium sponge by vacuum distillation. Vacuum 152:166–172CrossRefGoogle Scholar