Ilmenite beneficiation

The resultant slag, a complex mixture of titanates, may contain 70—85% Ti02- The slag route is particularly useful when ilmenite is closely associated with haematite, from which it cannot economically be separated mechanically. Because the iron content of the slag is low, its use reduces the quantity of iron sulfate in the Hquid effluent of sulfate process plants. Slag used as a feedstock for TiCl production must be low in magnesium and calcium. A variety of other ilmenite beneficiation or synthetic mtile processes have been pursued, primarily to provide alternative chloride process feedstocks. Low grade ilmenite... 

Table 5.11 Different metallurgical process options for ilmenite beneficiation.

Wendell Dunn A family of chlorine beneficiation processes based on selective chlorination of ores in a fluidized bed. Developed by W. E. Dunn of Chlorine Technology in Australia in the 1970s, primarily for beneficiating ilmenite. The first such commercial ilmenite beneficiation plant, completed in 1991, was that of Bene-Chlor Chemicals Private, Madras. 

Woodall-Duckham Also called the Babcock W-D process. A process for recovering hydrochloric acid and metal oxides from spent metal chloride solutions, such as those obtained from metal pickling and ilmenite beneficiation. The liquor is first concentrated by evaporation, and then atomized in a heated spray-tower. Water evaporates from the droplets in the upper part of the tower, and chlorides are converted to oxides in the hotter, lower part. Developed by Woodall-Duckham in the 1960s by 1992, over 150 installations were in use worldwide. Now offered by Babcock Woodall-Duckham, United Kingdom. 

EARS [Enhanced acid regeneration system] A process for recovering hydrochloric acid from the ERMS ilmenite beneficiation process. It may be used also for recovering waste pickle liquor. The acid liquor containing ferrous chloride is evaporated at low temperature to form iron chloride pellets, which are fed to a pyrohydrolysis reactor. This generates hydrochloric acid and iron oxide pellets, which can be used for steel production or disposed of as inert landfill. Developed by E. A. Walpole at the University of Newcastle, Australia, from the early 1990s and piloted by Austpac Gold (now Austpac Resources). 

In a reducing atmosphere, some of the metallic compounds are reduced to metals and others to the lower oxides. Since subsequent leaching is an oxidation step, the dissolution medium reacts more rapidly with the reduced metal than with the lower oxides, thus giving a certain degree of selectivity. The 100,000-ton/year ilmenite beneficiation plant of Benilite Corporation of America (Cl5) for the production of a feed for chloride-process titanium dioxide plants employs a partial reduction of iron oxides prior to leaching with hydrochloric acid. 

Gilman, S.K. Taylor, R.K.A. (2001) The Future of ilmenite beneficiation technologies. In Heavy Mineral Conference 2001, Melbourne Australia. 

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