Continuous Reduction Process of Titanium Chloride by Magnesium

开发了一种熔盐连续还原生产金属钛的工艺。作为常规工艺的原料，氯化钛和镁由于密度不同而分成两个熔层。将氯化钛气体吹入较低的熔盐中，并由较高的镁还原。钛沉淀在堆积在容器底部的盐中，从熔盐中提取出来。盐的组成从KCI、氯化钠和氯化锂中选择，以分离熔盐和还原剂。致密的氧化镁适合作为坩埚材料。所得粉末比Kroll法制备的钛粉细小约1/10。还原机理主要是熔盐中溶解的镁还原，镁层中的还原是相加的。考虑到这一机理，提出了一种不与金属镁直接接触吹炼氯化钛的新工艺。产率在80%以上，但所得颗粒细小，分离效果好，难以与盐分离。第一种解决方案是采用液体旋流等冷凝工艺。过量的还原剂附着在钛颗粒上，促进了钛颗粒的粘结。第二种解决方案是分两步减少。在第一步中，通过分解部分形成的钛粉在熔盐中形成较低的氯化钛。在第二步，这些高浓度的氯化物被镁还原。该方案易于连续操作，较粗的颗粒易于回收，类似地还原了Nb和Ta的氯化物，得到了它们的纯金属粉末。其细小的晶粒度适用于紧凑型大容量冷凝器。

A process to produce titanium metal in the molten salt was developed for continuous reduction. Titanium chloride and magnesium, which are used as raw materials for the conventional process, are separated into the two molten layers because of density difference. Titanium chloride gas is blown into the lower molten salt, and reduced by the upper magnesium. Titanium settled in the salt piles up on the vessel bottom, and it is extracted from the molten salt.The salt composition was chosen from KCI, NaCl and LiCl, to separate the molten salt and the reductant. The dense MgO was suitable for the crucible material. The obtained powder was about 1/10 finer than the titanium particle by the Kroll method. The main mechanism of reduction was the reduction by magnesium dissolved in the molten salt, and the reduction in the magnesium layer was additive. Considering this mechanism clarified here, a new technique that titanium chloride is blown without any direct contact with metallic magnesium was proposed. The yield was over 80%.On the other hand, the obtained particles were so small and well isolated that the separation from the salt became difficult. First solution was to adapt the condensification process such as liquid cyclone. The excess reductant adhered to titanium particles and enhanced the corsening. The second solution was to take a two-stepwise reduction. In the first step, the lower titanium chlorides are formed in the molten salt by resolving a part of formed titanium powder. In the second step, these highly concentrated chlorides are reduced by magnesium. This proposal are easily operated continuously, and the coarser particles were recovered easily.Similarly niobium and tantalum chlorides were reduced and their pure metallic powders were obtained. Their fine grain size was suitable for compact large capacity condensers.