Research and Development of Continuous Production of Titanium from the Oxide by means of Combination of Calciothermic Reduction and Electrolysis in Molten Calcium Chloride

建立了一种由氧化钛直接生产金属钛的新工艺。在传统的Kroll工艺中不使用任何瞬态化合物，如TiCl_4。这一过程包括(A)溶解在熔盐中的钙的钙热还原和(B)副产物CaO的电解。将这两个基本步骤组合成一个单一的浴槽，实验证实了这是一个工业应用的过程。分别进行了(A)大规模熔融氯化钙钙热还原实验和(B)熔融盐电解CaO制Ca回收实验两项基础实验，以寻找收率、杂质、离子传递热对流、合适的坩埚材料和电极的空间布置。先后规划(A)和(B)的组合进行大规模连续生产，并进行施工确认。氧含量仅为500ppm的钛可以在(A)中形成，达到平衡。在所谓的OS工艺(A)+(B)中，得到的钛在阳极被CO/CO_2中引入的碳污染。而采用ZrO_2固体电解质膜可以去除这种污染。OS法可直接从铌、Ta、V、Zr和Cr的氧化物中制备铌、Ta、V、Zr和Cr，是一种适用于工业节能的新生产方法。

A new process is established to produce metallic titanium from its oxide directly. This does not use any transient, compound such as TiCl_4 in the conventional Kroll process. This process consists of (A) calciothermic reduction by calcium dissolved in molten salt, and of (B) electrolysis of the by-product CaO. Combination of these two elemental steps into a single bath was confirmed experimentally as an industrial applicable process.Two fundamental experiments, (A) calciothermic reduction in large scale molten calcium chloride and (B) molten salt electrolysis of CaO to produce Ca for recycling, were conducted separately in order to find the yield, impurities, ionic transfer thermal convection, suitable crucible materials, and space arrangement of electrodes. Successively the combination of (A) and (B) was planed for continuous production in large scale, and constructed for confirmation.Titanium containing only 500 ppm oxygen could be formed in (A), which arrived at the equilibrium. In so-called OS process, (A)+(B), the obtained titanium was contaminated with carbon which was introduced from the evolved gas, CO/CO_2,at the anode. This contamination was, however, removed by using the membrane of ZrO_2 solid electrolyte. OS process could be applied for production of Nb, Ta, V, Zr and Cr directly from their oxides, and this was proposed as a new production method applicable in the industry for energy-saving.