高纯钛的生产与应用

联系西北有色金属研究院高纯钛生产实际,叙述了碘法,熔盐电解法,电子束熔炼法,电子束区域熔炼法等传统高纯钛生产方法的进展及应用现状,指出每一单一的传统精炼方法都日益不能满足电子工业对高纯钛纯度的要求,而目前比较经济的方法是将多种单一方法组合起来形成复合工艺,如熔盐电解-电子束熔炼法,电子束熔炼-电子束区域熔炼法。并介绍了很有发展前途的固相电解、激光精炼新工艺和高纯钛在半导体器件和高真空设备中的应用状况。     

LiCl-KCl熔盐中电解还原钛铁矿的研究

在LiCl-KCl熔盐中,采用熔盐电解法还原钛铁矿,研究了电解时间、槽电压及电解温度对还原钛铁矿的影响,探讨了在熔盐中钛铁矿电解脱氧的机理。结果表明,钛铁矿还原优先生成铁,钛氧化物由高价到低价逐步还原,而未得到金属钛及其合金,说明在LiCl-KCl熔盐中,TiO的脱氧还原是钛铁矿熔盐电解生成金属钛及其合金的反应限制性步骤。     

熔盐电解制备钛及钛合金研究进展

熔盐直接电解钛氧化物制备金属钛及其合金的机理至今仍是研究热点,目前主要存在两种解释：一是阴极氧化物得到电子,氧离子化后进入溶液,进而在阳极以气体的形态放出,而钛留在阴极;另外,熔盐中的Ca^2＋在阴极得到电子后生成金属钙,金属钙进一步还原钛氧化物得到金属钛。本文主要就近年来围绕两种机理展开的研究进行归纳总结,并在文献和实验的基础上通过能斯特方程计算推导钒钛磁铁矿直接熔盐电解制备钛合金的可行性,为实现经济、简洁的钛合金生产提供借鉴。     

Contactless electrochemical reduction of titanium (II) chloride by aluminum

Because of the strong affinity between aluminum and titanium, it has not been possible to produce pure titanium by direct aluminothermic reduction of titanium chlorides. Described in this article is a new process for contactless reduction of titanium dichloride by aluminum in which titanium dichloride and the reductant (aluminum or aluminum alloy) were physically separated, but electrochemically connected through molten NaCl and an external circuit. Titanium dichloride was spontaneously reduced to metal by a cathodic reaction with the simultaneous discharge of chlorine ions into the melt. At the anode, metal aluminum was oxidized to form aluminum chloride dissolved in the molten salt. The electrons were transferred between the electrodes through the external circuit. The concentration of aluminum in titanium produced at 1223 and 1273 K varied from values below the detection limit of the X-ray fluorescence analysis (0.01 mass pct) to 4.5 mass pct. The average contamination was 0.76 mass pct Al. When an aluminum-nickel alloy was used as the reductant, nickel was not detected in the titanium obtained by reduction. This observation suggests that aluminum scrap may be used as a cheap reductant in this contactless electrochemical process.     

Titanium powder prepared by magnesiothermic reduction of Ti2+ in molten salt

A process to produce titanium powder from Ti²⁺ in the molten salt was confirmed experimentally. It consists of two steps. In the first step, titanium (IV) chloride gas dissolves in the molten salt as the titanium (II) chloride by reacting chemically with the metallic titanium or magnesium. In the second step, this molten salt is exposed to the metallic reductant Mg for the final reduction to the metallic Ti powder. Experimentally, the feed of TiCl₄ gas and the subsequent reaction with Ti prepared the molten salt containing 5 to 10 mass pct Ti²⁺. By Mg reduction of this salt, the well-isolated fine Ti particles were recovered. The powder morphology and particle size depended on the Ti²⁺ concentration, reduction temperature, time, and concentration of the by-product MgCl₂. The stirring by argon gas bubbling effectively grew the fine and round particles to a few tens of microns in size.     

氯化渣冶炼技术开发与生产实践

通过对攀枝花钛精矿冶炼熔盐氯化渣技术难点的分析,在25.5MVA大型钛渣电炉上开展了熔盐氯化渣的技术开发,成功生产出满足海绵钛生产的专用钛渣。     

A Model to Simulate Titanium Behavior in the Iron Blast Furnace Hearth

The erosion of hearth refractory is a major limitation to the campaign life of a blast furnace. Titanium from titania addition in the burden or tuyere injection can react with carbon and nitrogen in molten pig iron to form titanium carbonitride, giving the so-called titanium-rich scaffold or buildup on the hearth surface, to protect the hearth from subsequent erosion. In the current article, a mathematical model based on computational fluid dynamics is proposed to simulate the behavior of solid particles in the liquid iron. The model considers the fluid/solid particle flow through a packed bed, conjugated heat transfer, species transport, and thermodynamic of key chemical reactions. A region of high solid concentration is predicted at the hearth bottom surface. Regions of solid formation and dissolution can be identified, which depend on the local temperature and chemical equilibrium. The sensitivity to the key model parameters for the solid phase is analyzed. The model provides an insight into the fundamental mechanism of solid particle formation, and it may form a basic model for subsequent development to study the formation of titanium scaffold in the blast furnace hearth.     

铯源型钢水液面自动控制系统的应用和优化

介绍了RAM型Cs-137钢水液面自动控制系统在成渝钒钛科技有限公司炼钢厂l^#连铸机上的应用,并结合连铸机的实际情况对该系统进行了优化,为炼钢厂的品种钢开发及降成本工作和RAM型Cs-137钢水液面自动控制系统在炼钢厂的推广打下了坚实的基础。     

Selective Removal of Iron from Low-Grade Ti Ore by Reacting with Calcium Chloride

Metallurgical and Materials Transactions B - Recently, titanium metal production by molten salt electrolysis using CaCl2 as molten salt and TiO2 or rutile (94 to 96 pct TiO2) as feedstock...     

Density measurements of the lithium fluoride/lithium sulfide eutectic at high temperature

A straightforward and reliable method to determine densities of molten salts at high temperatures was de-veloped by Janz and Lorenz several years ago.^[1] This method was followed in order to determine the density of the LiF/Li₂S eutectic^[2] over the temperature range of 1176 to 1355 K in which the eutectic is liquid. The rel-ative lack of data for this eutectic is surprising given its potential usefulness in the study of advanced batteries'31 and electrowinning of metals from molten sulfides.^[41] The method is based on the fact that a solid piece of metal of known volume suspended from a pan balance into a molten salt will weigh less than if it were sus-pended in air at the same temperature. This difference in weight measured in grams will be equal to the buoyant force of the liquid at that temperature. The density of the salt bath can then readily be determined by dividing this difference by the volume of the solid piece of metal that is immersed in the bath. The procedure can be re-peated to give density values over a range of temperatures.     

CaCl2-CaF2-CaO熔盐体系的粘度研究

利用钙热还原反应冶炼钛、锆、铈等稀有金属时,熔盐黏度增大往往导致搅拌困难、耗能增大、甚至反应减缓等问题。为探明影响CaCl_2熔盐黏度的因素,采用旋转柱体法测定了在1 073～1 373K不同成分熔盐黏度随温度变化的情况,根据试验结果绘制了CaCl_2、CaCl_2-CaF_2、CaCl_2-CaO和CaCl_2-CaF_2-CaO四种熔盐体系的黏度—温度曲线。结果表明,在测试温度范围内,熔盐黏度大多在2.0～10.0mPa·s,四种熔盐体系的黏度都随温度的降低而增大;同样温度条件下加入CaF_2后使熔盐黏度减小,加入CaO使熔盐黏度增大。     

连续化制钛方法（2）

主要论述了一种连续化电解具有导电性的熔融钛渣之类的含钛混合氧化物熔液，从而制取金属钛或钛合金的专利方法，并对该方法的技术可能性和经济性进行了分析和评价。     

Thermodynamic properties of titanium and iron in molten silicon

Titanium and iron in silicon are known as harmful “lifetime killer” impurities, which shorten the lifetime of excited carriers in silicon solar cell and disturb power generation. Therefore, the removal of titanium and iron is one of the most important topics for the production of solar grade silicon. Thermodynamic properties of titanium and iron in molten silicon were determined at 1723 K by equilibrating molten silicon-titanium alloys or molten silicon-iron alloys with molten lead, which has a limited mutual solubility for both alloys. The activity coefficients of infinite dilution, self-interaction coefficients of titanium and iron in molten silicon, and the Gibbs energy change of mixing for silicon-titanium and silicon-iron at 1723 K relative to pure liquid silicon, titanium, and iron were determined.     

Inclusion evolution after calcium addition in Ti-bearing Al-kill steel

In current article, experiments with different calcium addition were carried out in an Al₂O₃ crucible at 1873?K to investigate the variation of inclusion in Ti-bearing Al-kill Steel. It was found that calcium significantly influenced the morphology, composition distribution and size of oxide inclusions in Ti-bearing Al-kill Steel. Liquid oxide inclusions were modified promptly after calcium addition. Meanwhile, calcium could also modify solid titanium aluminate inclusions to spherical ones similarly, but there were a number of multilayer inclusions in molten steel at the initial stage. Different calcium treatment level should be adopted in different titanium content steel production process. As for the production practice, to achieve the full liquid inclusions in molten steel, the amount of calcium and titanium should be controlled simultaneously during the production process.     

拜耳法生产氧化铝熔盐加热系统开停车模式优化及回盐液位计算

导出了管道化溶出熔盐加热系统熔盐体积的计算公式、不同温度下熔盐密度的计算公式、盐槽液位计算迭代式,给出了回盐温度对盐槽液位的定量影响,提出了一系列预防熔盐堵管的措施。改进后的开停车模式,相对经济、可靠。     

Titanium powder production by TiCl4 gas injection into magnesium through molten salts

A process to produce titanium powder continuously is proposed and its applicability is examined experimentally. The method is based on the chemical reaction in the conventional Kroll reduction process; however, TiCl₄ gas is injected into molten salt on which a molten magnesium layer is floated as the reductant. Bubbles of gaseous TiCl₄ can be reacted at the lower surface of the liquid Mg layer, while TiCl₄ gas reacts on the upper surface in the Kroll process. The fine Ti particles produced in this study were well separated from magnesium and could be recovered from the bottom of the molten salts. The particles were small and fine enough for use in powder metallurgy, while congregated lumps of about 20 μm in size are obtained by the Kroll process. The composition of molten salts and an operation temperature above 1073 K did not affect the morphology of the Ti particles, if suitable material for the reaction vessel was chosen.     

海绵钛生产过程的能耗分析及新技术的提出

对传统的镁热还原法和TiCl4熔盐电解法生产海绵钛工艺流程中的能源分配及消耗情况进行了总结分析，重点提出了一种在熔融CaCl2体系中直接电解还原TiO2制取海绵钛的低能耗，无污染绿色新工艺。     

熔盐氯化法海绵钛生产技术的应用与改进

熔盐氯化法海绵钛生产技术包括熔盐氯化-铝粉除钒-还原和蒸馏-氯化镁电解。本文概述了我国海绵钛生产现状,对熔盐氯化法海绵钛生产技术进行了介绍和评价,指出其工艺中的不足,并提出了一些建议。     

HRB500E抗震钢筋中钛化物析出热力学分析

 钢液凝固过程中钛化物在液相、固相的存在形态对固相组织的性能有着重要的影响,其第二相析出起到细化晶粒的作用。为分析HRB500E抗震钢筋钢中TiN、TiC、Ti(C,N)析出物的析出规律,对TiN、TiC、Ti(C,N)析出物进行热力学计算。结果表明,TiN、TiC在钢液成分均质状态下难以析出,TiC_0.19N_0.81在温度为1 843 K时析出;在凝固过程中,由于Ti、N在凝固前沿富集,TiN在凝固过程中具备析出的热力学条件,析出温度为1 745 K;在固相奥氏体中,TiN和TiC粒子具备析出热力学条件,TiC析出温度比TiN的低,铁素体中有TiC的析出。     

含稀土铁尾矿回收与利用的研究进展

以含稀土铁尾矿的资源回收与利用为对象,综述了含稀土铁尾矿中稀土、铌的回收工艺。研究表明:MgO固氟-NH4Cl焙烧法提取稀土,可使稀土回收率达85%以上,是一种绿色的稀土提取工艺;碱金属亚熔盐液相法回收尾矿中铌的工艺使难处理铌矿的分解率和回收率都在95%以上,具有广阔的应用前景;同时也综述了二氧化钛、锌的回收工艺。