Becher process: Difference between revisions
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=== Acid Leach === |
=== Acid Leach === |
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Once the majority of the Iron Oxide has been removed the remainder of the Iron Oxide is leached away using 0.5M Sulphuric Acid. |
Once the majority of the Iron Oxide has been removed the remainder of the Iron Oxide is leached away using 0.5M Sulphuric Acid<ref>{{cite web|url=http://www.wipo.int/pctdb/en/wo.jsp?WO=1994%2F03647&IA=WO1994%2F03647&DISPLAY=DESC| title=WIPO-WO/1994/003647) TREATMENT OF TITANIFEROUS MATERIALS }}</ref>. |
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==References== |
==References== |
Revision as of 08:00, 9 March 2008
The Becher Process is an industrial process used to upgrade ilmenite to synthetic rutile.[1].
The mineral, ilmenite contains 55-65% titanium as TiO2, the rest being iron oxide. The Becher process removes the iron oxide, leaving a residue of synthetic rutile, which is more than 90% TiO2.[2].
History
This technology was developed in the early 1960s in Western Australia[3] by a joint initiative between industry and government. The process was named after Robert Becher, who invented, developed and introduced the technique to the Western Australian Mineral Sands industry.[4] The process was patented in 1961.[citation needed]
Process
The Becher Process is suitable for weathered ilmenite that has low concentrations of chromium and magnesium.[5] There are four steps involved in removing the iron portion of the ilmentite:
Oxidation
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
Reduction is performed in a rotary kiln with pseudobrookite (Fe2O3.TiO2), coal and sulfur, then heated to a temperature greater than 1200 °C.[6] 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) + 2 TiO2 (s) + 3 CO2 (g)
Aeration
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.
Acid Leach
Once the majority of the Iron Oxide has been removed the remainder of the Iron Oxide is leached away using 0.5M Sulphuric Acid[7].
References
- ^ "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" (PDF).
- ^ "Chamber of Minerals and Energy Western Australia - Mineral Sands Factsheet" (PDF).
- ^ "WIPO-WO/1994/003647) TREATMENT OF TITANIFEROUS MATERIALS".