Titanium Ores
Titanium is the world's ninth most abundant element, being five times less abundant than iron but one hundred times more abundant than copper.
In nature, titanium occurs in complex oxides, usually in combination with iron and also with the alkaline earth elements. These impurities color the ores from buff to black and they are therefore far removed from the requirements of a clean white titanium dioxide pigment.
The original commercial ore, first used by the sulfate process is ilmenite. This occurs mainly as a black sand: in Australia, South Africa, India, the USA and Malaysia, and also as a hard rock deposit: in Canada, Norway and the USA. Ilmenite typically contains 45-65% TiO2 with iron making up the majority of the remainder. This may be used directly in the sulfate process or beneficiated to yield a product containing around 92% TiO2 with the iron available as a usable by-product.
The second most available ore is the buff colored mineral rutile, which contains around 95% TiO2 with smaller amounts of iron and other impurities. Rutile sands are mostly found in Australia, Sierra Leone and South Africa. The chloride manufacturing process for TiO2 requires this type of high purity ore, or may use beneficiated materials.
These are produced either by acid leaching of the iron and other impurities or via a slagging process to separate molten iron, producing a titania-rich slag which is then solidified and ground to the desired particle size. This beneficiation process allows fine ore sand to be converted to a more desirable, coarser TiO2 feedstock with iron produced as a by-product.
Figure 10.0 shows the composition of ilmenite, mineral rutile, beneficiated ores and other, non-commercial ores.
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