(1. 昆明理工大學 真空冶金國家工程實驗室，昆明 650093；
2. 昆明理工大學 云南省復(fù)雜有色金屬資源清潔利用國家重點實驗室，昆明 650093；
3. 昆明理工大學 云南省有色金屬真空冶金重點實驗室，昆明 650093；
4. 昆明理工大學 冶金與能源工程學院，昆明 650093)
摘 要: 通過熱力學計算以及XRD、SEM和EDS等測試手段，研究TiO2鈣熱還原制備鈦粉過程中鈦酸鈣 (CaTiO3)的形成原因。熱力學計算表明：當溫度高于800 K時，添加劑CaCl2水解產(chǎn)物CaO與TiO2生成CaTiO3的反應(yīng)以及還原副產(chǎn)物CaO與TiO2生成CaTiO3的反應(yīng)均滿足反應(yīng)發(fā)生的熱力學條件。實驗研究表明：CaTiO3的生成主要是由添加劑CaCl2水解生成的CaO與TiO2燒結(jié)反應(yīng)所致，CaTiO3的量隨著CaCl2添加量的增加而增加，且CaTiO3更容易被還原為金屬鈦。當CaCl2與TiO2的質(zhì)量比約為1:4時、在1 273 K下還原時間為6 h時，反應(yīng)過程中的CaTiO3被完全還原為金屬鈦粉，該粉末具有不規(guī)則外形，顆粒粒徑為8~15 μm。經(jīng)EDS分析，金屬鈦粉中鈦的質(zhì)量分數(shù)達到99.55%。
關(guān)鍵字: 鈦；二氧化鈦；氯化鈣；鈦酸鈣；鈣熱還原
（1. National Engineering Laboratory for Vacuum Metallurgy,
Kunming University of Science and Technology, Kunming 650093, China;
2. State Key Laboratory Breeding Base of Complex Nonferrous Metal Resources Clear Utilization in Yunnan Province,
Kunming University of Science and Technology, Kunming 650093, China;
3. Key Laboratory for Nonferrous Metals Vacuum Metallurgy of Yunnan Province,
Kunming University of Science and Technology, Kunming 650093, China;
4. Faculty of Metallurgy and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China）
Abstract:The formation cause of perovskite calcium titanate (CaTiO3) in calciothermic reduction process of titanium dioxide to prepare the titanium powders was investigated by thermodynamic calculation, XRD, SEM and EDS. Thermodynamic calculations indicate that the reactions of CaO hydrolyzed from the additive of CaCl2 to form CaTiO3 and the reduction by-product of CaO reacted with TiO2 to form CaTiO3 at the temperature beyond 800 K, satisfy the thermodynamic reaction conditions. The experimental results demonstrate that CaO is produced by the hydrolysis of CaCl2, and the large amount of CaTiO3 is generated in the sintering reaction of CaO with TiO2. Furthermore, with increasing the amount of CaCl2, CaTiO3 increases and is easily reduced to titanium. When the mass ratio of CaCl2 to TiO2 is about 1:4, the reduction temperature is 1 273 K and the reduction time is 6 h, CaTiO3 is completely reduced to titanium with irregular shape and particle size of 8−15 μm, and the mass fraction of titanium powder is 99.55% by EDS analysis.
Key words: titanium; titanium dioxide; calcium chloride; perovskite calcium titanate; calciothermic reducation
