Pyrometallurgical processing of high-titaniferous ores.

The future development of Ural mineral and raw materials base of steel industry is considerably stipulated by the development of deposits of titanium-magnetite ores, the reserves of which are accounted for near 77% of iron ores of Urals. It was shown, that the content of titanium dioxide as well as harmful impurities in the titanium-magnetite have the decisive meaning for selection of processing technology of them for extraction out of them vanadium and other useful components. Technological schemes of the titanium-magnetite enrichment and industrial methods of titanium-magnetite concentrates processing considered. Examples of titanium-magnetite processing by coke-BF and coke-less schemes given. The problems of blast furnace melting of titanium-magnetite ores highlighted. Main problems relate to formation of refractory compounds in a form of carbo-nitrides during reduction of titanium and infusible masses in blast furnace hearth. It was shown, that intensification if carbides precipitation is stipulated by increase of intensity of titanium reduction at increased temperatures of a heat products and requires the BF heat to be run at minimal acceptable temperature mode. Technological solutions, necessary to implement in blast furnace for iron ore raw materials with increased content of titanium processing were presented, including increase of basicity of slag from 1.2 to 1.25-1.30, increase of pressure at the blast furnace top from 1.8 to 2.2 atm, decrease of silicon content in hot metal from 0.1 to 0.05%, application of manganese-containing additives. It was noted, that theoretically the blast furnace melting of titanium-magnetite is possible at titanium dioxide content in slag up to 40% when application of the abovementioned technological solutions, silicon content in hot metal to 0.01% and very stable heat conditions of a blast furnace. The actuality of titanium and its pigmental dioxide production increase was noted. Possibilities of development of Medvedevskoje and Kopanskoje deposits of high-titaniferous ores in Chelyabinsk region with extraction not only iron and vanadium but also titanium considered.

The fragmented nature of the titanium metal value chain

SYNOPSIS This study investigates the fragmented nature of the global and local titanium metal value chains. South Africa has the fourth most abundant titanium reserves in the world. However, South Africa mainly exports titanium ore and imports value-added titanium products, which impacts the potential to derive more economic benefit from this resource. For South Africa to benefit from its titanium reserves, an understanding of the current fragmented nature of the global titanium value chain would assist in entering the global titanium industry. Information on the global and South African titanium value chains was collected by means of a desktop study. It was found that the leading countries operating within both the upstream and the downstream titanium industry are the USA, China, Japan, Russia, and Kazakhstan. The key drivers that caused fragmentation were identified as technology, markets, production costs, and the availability of titanium mineral reserves. An important outcome of this study is the identification of the local need for a technological foundation in support of downstream titanium processing to market-competitive titanium mill and powder products. Keywords: fragmentation, titanium, titanium value chain.

Kinetics of Evaporation of Alloying Elements under Vacuum: Application to Ti alloys in Electron Beam Melting

Vacuum metallurgical processes such as the electron beam melting are highly conducive to volatilization. In titanium processing, it concerns the alloying elements which show a high vapor pressure with respect to titanium matrix, such as Al. Two different experimental approaches using a laboratory electron beam furnace have been developed for the estimation of volatilization rate and activity coefficient of Al in Ti64. The first innovative method is based on the deposition rate of Al on Si wafers located at different angles θ above the liquid bath. We found that a deposition according to a cos2(π/2−θ) law describes well the experimental distribution of the weight of the deposition layer. The second approach relies on the depletion of aluminum in the liquid pool at two separate times of the volatilization process. Both approaches provide values of the Al activity coefficient at T=1, 860 °C in a fairly narrow range [0.044–0.0495], in good agreement with the range reported in the literature. Furthermore numerical simulation of the Al behavior in the liquid pool reveals (in the specific case of electron beam button melting) a weak transport resistance in the surface boundary layer.

Preparation of Titanium Alloy Parts by Powder Compact Extrusion of a Powder Mixture and Scaled up Manufacture

Blended Elemental Powder Metallurgy (BE-PM) is a very attractive method for producing titanium alloys, which can be near-net shape formed with compositional freedom. However, a minimization of oxygen pick-up during processing into manufactured parts is a big challenge for powder metallurgy of titanium alloys. In this paper, different approaches for preparing titanium alloy parts by powder compact extrusion with 0.05-0.1wt.% of oxygen pick-up during manufacturing are discussed. The starting materials were a powder mixture of HDH titanium powder, other elemental powders and a master alloy powder. Different titanium alloys and composites, such as Ti-6Al-4V, Ti-4Al-4Sn-4Mo-0.5Si, Ti-5Al-5V-5Mo-3Cr, and Ti-5Al-5V-5Mo-3Cr-5vol%TiB, with different profiles such as round and rectangular bars, a wedge profile, wire and tubes have been successfully manufactured on a laboratory and pilot-plant scale. Furthermore, a possible route for scaling up the titanium processing capabilities in the University of Waikato has also been discussed.