This technology was developed in the early 1960s in Western Australia by a joint initiative between industry and government. The process was named after Robert Gordon Becher, who invented, developed and introduced the technique to the Western Australian Mineral Sands industry. The process was patented in 1961.
Oxidation involves heating the ilmenite in a rotary kiln with air to convert all of the iron in the ilmenite grains to iron(III) oxide:
- 4 FeTiO3 (s) + O2 (g) → 2 Fe2O3·TiO2 (s) + 2 TiO2 (s)
This allows for use of a wide range of ilmenite materials with varying Fe(II) and Fe(III) content to be used in the next step.
Reduction is performed in a rotary kiln with pseudobrookite (Fe2O3.TiO2), coal and sulfur, then heated to a temperature greater than 1200 °C. The iron oxide in the mineral grains is reduced to metallic iron to produce reduced ilmenite:
- Fe2O3·TiO2 (s) + 3 CO (g) → 2 Fe (s) + TiO2 (s) + 3 CO2 (g)
Once the Reduced Ilmenite has cooled it is separated from the char by screening, then continues to the next step of the process.
Aeration involves the removal of the metallic iron created in the last step by "rusting" it out. This is achieved in large tanks that contain 1% ammonium chloride solution with air being pumped through the tank. The tank is being continuously agitated, and the iron will rust and precipitate out of solution, away from the titanium dioxide portion in the form of a slime.
- 4 Fe (s) + 3 O2 (g) → 2Fe2O3
The finer iron oxide is then separated from the larger particles of synthetic rutile.
- "SGS Metallurgical Services - Mineral Sands".
- "Rutile and ilmenite - Australian production and potential profile".
- "Australian Atlas of Mineral Resources Mineral Sands Fact Sheet".
- "ATSE Clunies Ross Foundation Medal Awards - 1992".
- "Murdoch University Titanium".
- "Chamber of Minerals and Energy Western Australia - Mineral Sands Factsheet".
- "WIPO-WO/1994/003647) TREATMENT OF TITANIFEROUS MATERIALS".