Synthetic rutile producers

Synthetic Rutile. In contrast to ilmenite, only a small number of rutile deposits can be mined economically, and the price of natural rutile is therefore high. Consequently, many different processes have been developed to remove the iron from ilmenite concentrates without changing the grain size of the mineral because this is highly suitable for the subsequent fluidized-bed chlorination process. All industrial processes involve reduction of Fe3+ with carbon or hydrogen, sometimes after preliminary activation of the ilmenite by oxidation. Depending on the reducing conditions, either Fe2 + is formed in an activated ilmenite lattice, or metallic iron is produced. 

Another possible method of increasing the TiOz content of ilmenite is by partial chlorination of the iron in the presence of carbon. This is operated on a large scale by several companies [2.24], [2.25], The most important companies which are producing synthetic rutile are located in Australia (Renison Goldfields Consolidated, Tiwest, Westralian Sands), United States (Kerr-McGee Synthetic Rutile), India (Ke-vala Minerals and Metals Ltd., DCW Ltd., Bene-Chlor Chemicals Ltd.), and Malaysia (Hitox). In 1994 production of synthetic rutile was about 0.6 x 106 t of contained TiOz. 

Synthetic rutile raw material is produced from ilmenite by reducing the iron oxides and leaching out the metallic iron with hydrochloric or sulfuric acids. In both processes, the objective is to increase the amount of Ti02 in the raw materials. 

In the chloride process natural rutile ore or synthetic rutile with a Ti02-content of up to 96% is chlorinated in a fluidized bed reactor with oil-coke and chlorine. The raw TiCl4 produced is mixed with reducing agents to convert impurities, such as vanadium oxychloride, to lower valency state vanadium compounds. The titanium tetrachloride formed is then distilled yielding titanium tetrachloride in... 

Titanium is produced by chlorination of rutile (Ti02, 95%), synthetic rutile prepared from ilmenite or titanium slug of a high content with cokes at 1000 C to give crude TiCU, which is then purified by distillation and by reduction of the purified TiCU with Mg at about 900 °C under argon atmosphere (Kroll process), or by two step reduction with sodium metal (Hunter process) [2-5]. 

Synthetic rutile is made from titanium-rich sands, which are primarily of Australian origin. Synthetic Ti02 is produced by either the sulfate or the chloride process. The sulfate process is older and is becoming less common. In the United States, it has been deemed environmentally unfriendly and has been almost completely phased out. The sulfate process is primarily used to produce synthetic anatase. The chloride process is used for making both anatase and rutile. 

As in the case of ilmenite, the largest producers are in Australia, the Republic of South Africa and Sierra Leone. There is not enough natural rutile to meet demand, and it is therefore gradually being replaced by the synthetic variety. In 1994 the world wide production of rutile was about 0.5 x 106 t of contained Ti02. Compositions of typical rutile concentrates are given in Table 14. 

The chloride process utilizes the treatment of rutile (natural or synthetic) with chlorine gas and coke to produce titanium tetrachloride (TiC14). The titanium tetrachloride is distilled to remove impurities and then reacted with oxygen or air in a flame at about 1500°C to produce chlorine and very fine particle titanium dioxide. The chlorine is recycled (Fig. 1). 

This dye exists in nature in three crystalline forms—anatase, brookite, and rutile—however, only one is used as an additive). It possesses an intense white color, is resistant to sunlight, oxidation, pH, and the presence of microbes. Only the synthetically produced titanium dioxide can be used as a food additive. This dye cannot be dissolved in all solvents. The allowed quantity of dye in foods is up to 1% and can be used in confectionery products in the formation of white parts as well as a background. Finally, it can be used in the production of pills and cosmetics. 

The demand for TiO is much greater than the annual rutile production from mining, so synthetic TiO is produced in a large scale from ihnenite and titaniferous slag. 

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