Titanium Metal Production Research Articles

Investigations on reduction of ilmenite ore with different sources of carbon

It is crucial to understand the relative impact of different reductants on ilmenite ore from the same source, since different reductants may have different levels of impact on the reduction of the ore. Such a study will throw light on the nature and mechanism of reduction and help in devising suitable industrial processes for the production of TiO2 and titanium metal. Reduction of ilmenite with graphite and coke has been investigated in the temperature range 1273–1423 K. Iron was the only phase produced in the ore after reduction at 1173 K, when coke was used as the reducing agent. Significant reduction occurred at 1273 K and above. At 1273 K, Fe3C and rutile were formed by reduction. At higher temperatures, lower oxides of titanium were also formed by reduction. The process was controlled by diffusion at 1373 K and by reaction at the phase boundary at 1423 K, when coke was used as the reducing agent. The reduction process was controlled by nucleation at 1373 K and by reaction at the phase boundary at 1423 K, when graphite was used as the reducing agent. The rate of reduction decreased at 1423 K compared to that at 1373 K in the case of both reductants. Graphite was less effective as a reducing agent at 1273 K but more effective compared to coke at 1423 K. Whereas reduction of TiO2 to lower oxides occurred at shorter time intervals when graphite was used as the reductant, this reaction occurred only after longer reduction periods when coke was used for reduction.

A literature review of titanium metallurgical processes

Various titanium metallurgical processes have been reviewed and compared for titanium dioxide and titanium metal, mainly focusing on the future development of hydrometallurgical processes. It is recognised that ilmenite is becoming increasingly important due to the rapid depletion of natural rutile. Many processes are commercially used or proposed to upgrade ilmenite to synthetic rutile. Most of these processes involve a combination of pyrometallurgy and hydrometallurgy and are generally expensive. The commercialised thermo-chemical chloride processes such as Kroll and Hunter processes are batch operations and need higher grade natural rutile or upgraded synthetic rutile and slag as the feed and the involvement of cost sensitive chlorination and thermo steps. Many improvements for the thermo-chemical processes have been made, but they hold little potential for significant cost reductions beyond current technology. The development of the electro-chemical processes for direct reduction of TiO 2 and electro-slag as feed material and in-situ electrolysis has achieved some success. However, some challenging issues such as redox cycling, feeding, kinetics, control heat balance have to be resolved before scaling-up to commercial applications. Direct hydrometallurgical leach processes are advantageous in processing abundant ilmenite ores, low energy consumption and produce sufficiently high quality of pigment grade TiO 2 products for a wide range of applications and major demand. Novel BHP Billiton sulphate processes have been developed to improve leaching strategies, separation of metals by solvent extraction, reduced wastes and recycling acids, and very promising for commercial applications in future. Direct chloride leaching processes have been investigated intensively, featuring purification by solvent extraction and reclaiming HCl by hydrolysis or pyrohydrolysis. Caustic leach with high selectivity and titanium dioxide nano-technology has also been developed. Further development of direct leaching ilmenite coupled with solvent extraction for titanium pigment and metal production, is recommended.

Nano-Scaled Particles of Titanium Dioxide Convert Benign Mouse Fibrosarcoma Cells into Aggressive Tumor Cells

Nanoparticles are prevalent in both commercial and medicinal products; however, the contribution of nanomaterials to carcinogenesis remains unclear. We therefore examined the effects of nano-sized titanium dioxide (TiO(2)) on poorly tumorigenic and nonmetastatic QR-32 fibrosarcoma cells. We found that mice that were cotransplanted subcutaneously with QR-32 cells and nano-sized TiO(2), either uncoated (TiO(2)-1, hydrophilic) or coated with stearic acid (TiO(2)-2, hydrophobic), did not form tumors. However, QR-32 cells became tumorigenic after injection into sites previously implanted with TiO(2)-1, but not TiO(2)-2, and these developing tumors acquired metastatic phenotypes. No differences were observed either histologically or in inflammatory cytokine mRNA expression between TiO(2)-1 and TiO(2)-2 treatments. However, TiO(2)-2, but not TiO(2)-1, generated high levels of reactive oxygen species (ROS) in cell-free conditions. Although both TiO(2)-1 and TiO(2)-2 resulted in intracellular ROS formation, TiO(2)-2 elicited a stronger response, resulting in cytotoxicity to the QR-32 cells. Moreover, TiO(2)-2, but not TiO(2)-1, led to the development of nuclear interstices and multinucleate cells. Cells that survived the TiO(2) toxicity acquired a tumorigenic phenotype. TiO(2)-induced ROS formation and its related cell injury were inhibited by the addition of antioxidant N-acetyl-l-cysteine. These results indicate that nano-sized TiO(2) has the potential to convert benign tumor cells into malignant ones through the generation of ROS in the target cells.

Approaches to the Design and Processing of Novel Titanium Alloys

The range of commercial titanium alloys available is currently extremely restricted, with one alloy (Ti-6Al-4V), and derivatives of it, accounting for a very large proportion of all applications. High performance alloys are costly to fabricate and limited to low-volume applications that can sustain the cost. With the emergence of new processing technologies that promise to reduce significantly the cost of production of titanium metal, especially in powder form, there is an emerging imperative for cost-effective near net shape powder processing techniques to permit the benefit of reduced metal cost to be passed on to higher-volume applications. Equally, there is a need for the design and development of new alloys that are intrinsically low-cost and lend themselves to fabrication by novel cost-effective net shape processing. The approaches that might be used to select, design and process both conventional alloys and novel alloy systems will be reviewed, with a focus on innovation in design of low-cost alloys amenable to new processing paths and increasingly tolerant of variability in composition.

Production of titanium and titanium alloys by electrochemical reduction of oxide precursors

The direct reduction of titanium oxides has been investigated at several research organisations worldwide in search of a replacement for the current method of titanium metal production: the Kroll process. By cathodically polarising oxide feedstock of varying composition, both commercial purity titanium and titanium alloys have been produced, including the shape memory alloy Ni–Ti and novel compositions such as Ti–W. The reduction pathway has shown to be via a series of lower oxides and titanate species, with critical ramifications for process optimisation. Research continues on improving the process current efficiency and development of a suitable inert anode material.

The potential applications for titanium metal powder and their life cycle impacts

It has been predicted that new processes being developed for titanium metal production as well as new fabrication techniques will see the cost of fabricated titanium fall by as much as 50%. Potential applications for lower-cost titanium powder are examined in this paper, with cookware, being identified as a possible lead product. The potential environmental benefits of using this material in place of competing materials such as stainless of competing materials such as stainless steel in chemical process equipment and automotive exhausts are also illustrated, based on a life-cycle approach.

Development of Inert Anode Materials for Electrowinning in Calcium Chloride Melts

The electroreduction of solid titanium dioxide in a calcium chloride melt is an attractive method for the production of titanium metal. Several groups have proposed versions of this route, but no commercial process yet exists. In laboratory studies, consumable carbon anodes are used, and these can give rise to a number of cell design and operational issues. The replacement of the carbon anode with an inert anode offers numerous benefits that include: elimination of carbon dioxide emissions; more efficient cell operation and reduced electrode costs. We have evaluated a wide range of candidate inert anode materials, including metals, alloys and conductive ceramics. The studies examined the chemical stability of these materials in a calcium chloride-based melt, and also performance in laboratory-scale electrolysis tests. All metals and alloys tested were either dissolved in the melt and/or formed a thick, highly resistive crust. A conductive ceramic, chromium titanate, was the best-performed candidate and gave an acceptable cell voltage during a 24 h electrolysis test. This work was undertaken as part of the CSIRO Light Metals Flagship.

Mechanism of titanium sponge formation in the kroll reduction reactor

The Kroll process of magnesium reduction of titanium tetrachloride is used the world over the production of titanium metal in the form of sponge. Although the process has been in practice for the last five decades, there is no clear understanding of the reaction mechanism and sponge formation. The present study involved reduction experiments in a 2000 kg titanium sponge-capacity prototype reactor to develop a better understanding of TiCl4 reduction of magnesium with respect to the process parameters. Experiments were also conducted in two smaller experimental reactors to study the temperature evolution during the process as a function of the TiCl4 feed rate. Based on the results of all these experiments, a model has been proposed for the mechanism of sponge formation in the Kroll process.

Chloride metallurgy: PGM recovery and titanium dioxide production

This paper examines in detail the thermodynamics and application of chloride metallurgy for the extraction of precious metals, such as gold and silver, and platinum-group metals. The advantages with regard to the solubilities of metal ion species and their reduction potentials in chloride media are discussed with examples. The use of chloride media for the extraction of platinum-group metals from spent autocatalysts and for the production of high-purity pigment-grade TiO2 and titanium metal from ilmenite feed stocks is discussed in the case studies provided.

BHP Billiton commits US$1.1B for Atlantis development

Various titanium metallurgical processes have been reviewed and compared for titanium dioxide and titanium metal, mainly focusing on the future development of hydrometallurgical processes. It is recognised that ilmenite is becoming increasingly important due to the rapid depletion of natural rutile. Many processes are commercially used or proposed to upgrade ilmenite to synthetic rutile. Most of these processes involve a combination of pyrometallurgy and hydrometallurgy and are generally expensive.The commercialised thermo-chemical chloride processes such as Kroll and Hunter processes are batch operations and need higher grade natural rutile or upgraded synthetic rutile and slag as the feed and the involvement of cost sensitive chlorination and thermo steps. Many improvements for the thermo-chemical processes have been made, but they hold little potential for significant cost reductions beyond current technology. The development of the electro-chemical processes for direct reduction of TiO2 and electro-slag as feed material and in-situ electrolysis has achieved some success. However, some challenging issues such as redox cycling, feeding, kinetics, control heat balance have to be resolved before scaling-up to commercial applications.Direct hydrometallurgical leach processes are advantageous in processing abundant ilmenite ores, low energy consumption and produce sufficiently high quality of pigment grade TiO2 products for a wide range of applications and major demand. Novel BHP Billiton sulphate processes have been developed to improve leaching strategies, separation of metals by solvent extraction, reduced wastes and recycling acids, and very promising for commercial applications in future. Direct chloride leaching processes have been investigated intensively, featuring purification by solvent extraction and reclaiming HCl by hydrolysis or pyrohydrolysis. Caustic leach with high selectivity and titanium dioxide nano-technology has also been developed. Further development of direct leaching ilmenite coupled with solvent extraction for titanium pigment and metal production, is recommended.

Utilisation of Salts from Inland Saline Water Sources

Processing of saline water to produce industrial minerals with large volume applications is considered one way to attack the salinity problem in the Murray-Darling Basin. We propose that saline water in the Basin be treated to produce industrial mineral salts such as sodium chloride, magnesium sulphate, and magnesium chloride. The magnesium-rich bittern fraction of the saline waters may be processed further to value-added products such as magnesium hydroxide, Sorel cement, or spinel refractories. Sorel cement could be consumed in large quantities in the Basin as construction material and may be used to seal new interception scheme lakes, although the stability of the Sorel cement in aqueous environment remains to be investigated.The processing of mineral sands can be linked with treatment of saline water in an integrated and cost-effective manner that aims to remove salt from the Basin. The sodium chloride fraction can be used to produce chemicals such as chlorine, hydrochloric acid and sodium hydroxide that can be used in the processing of zircon. Direct chlorination of ilmenite could consume the equivalent of about 1.4 tonnes of sodium chloride for each tonne of ilmenite treated if no chlorine was recycled. Chlorination of synthetic rutile (about 90% TiO2) could consume the equivalent of about 0.3 tonnes of sodium chloride for each tonne of titania pigment produced. Work in CSIRO Minerals has produced low radioactivity zirconia from a Murray Basin zircon by caustic soda decomposition followed by concentrated hydrochloric acid leaching.In addition, it is proposed that desalination plants be established across the Basin to recover fresh water, heat, and electricity from saline water. These plants will obtain heat and electricity from solar power generation schemes with storage of power in solar ponds and molten salts.Integrated saline water and mineral sands mining industry in the Basin may ultimately lead to new technology for Australia such as titanium metal production. Titanium metal produced from TiO2 pigment may be used in building desalination plants across the Basin to recover fresh water from saline waters.

Titanium Resources of the Commonwealth of Independent States

The raw material base of the titanium industries of the Commonwealth of Independent States (CIS) is assessed, with a focus on the geology and mineralogy of producing and prospective deposits and prevailing end-use patterns in CIS and the world as a whole. Upon the break-up of the USSR, Ukraine was the only supplier of titanium ore for the titanium industries of the FSU, which are located in Russia, Kazakhstan, and Ukraine. Efforts of Russia and Kazakhstan to explore and develop their own titanium ore deposits are described, as are the uses of different titanium raw materials (e.g., ilmenite, rutile) in titanium metal and pigment production. FSU producers, now significant participants in world titanium markets, are expected to continue exports of titanium metal because of depressed domestic demand and still relatively low (but growing) levels of titanium consumption in pigment production.

Abnormalities of pulmonary function and pleural disease among titanium metal production workers.

The authors conducted a cross-sectional survey of respiratory disease among 209 titanium metal production workers. Work in areas where there was exposure to titanium tetrachloride and titanium dioxide particulates was associated with reductions in ventilatory capacity. Pleural disease (plaques and diffuse thickening) was present in the chest radiographs of 17% of the subjects and was associated with the duration of work in titanium manufacturing. It was also associated with past asbestos exposure. After control for asbestos exposure, it remained associated with titanium manufacturing. The findings are consistent with the hypothesis that titanium tetrachloride and titanium dioxide particulates may be associated with a reduction in ventilatory capacity and that the overall process of titanium manufacturing may be associated with unexpected pleural disease.

Development of Technology for Large Scale Production of Titanium Sponge

Intensive investigations on the development of titanium metal production technology had been carried out during 1965-1975 at the Bhabha Atomic Research Centre, Bombay and at the Nuclear Fuel Complex, Hyderabad. The Defence Metallurgical Research Laboratory, Hyderabad has set up a 'Titanium Sponge Experimental Facility' with a capacity to produce 100 tonnes of sponge per annum in 2000 kg batches by the Kroll's process with a view to optimising technology for large scale production. The paper presents an outline of the experimental facility and discusses the

Synthesis of magnetite using ilmenite under hydrothermal conditions

Ilmenite (FeTiO3) is mainly used as a raw material for the production of titanium dioxide (TiO2) pigment and titanium metal. The TiO2 content in natural ilmenite varies from 42 to 54%, and the other main chemical constituents are the oxides of iron. The methods adopted [1] for the production of TiO2 were mainly based on digestion of ilmenite with inorganic acids or treatment with hot gases (e.g. Cl2, H2S, I2 etc.) at elevated temperatures. In these processes the iron is removed as the corresponding salts of acid or the gases. The iron salts formed in most of the methods do not have any commercial value and discarding of these iron compounds causes pollution problems.

Chemical engineering aspects of titanium metal production

Chemical engineering aspects of titanium metal production