The components of mineral sands deposits all have high specific gravity (greater than 2.85 g/cm3) and are often referred to as heavy minerals (HM). Other HM minerals found within mineral sands deposits can include leucoxene, magnetite, chromite, garnet, staurolite, kyanite, sillimanite, pyroxene, monazite and cassiterite. Valuable minerals within mineral sand deposits are sometimes grouped together under the term valuable heavy minerals (VHM) to distinguish them from the other (trash) heavy minerals.
The proportions of the minerals found in specific deposits are a function of mineral provenance and the age of the deposit, with a number of less resistant minerals weathering over time. The other major minerals found in the deposits are quartz and clay minerals. The latter is usually formed by various in situ alteration mechanisms.
- Generally, ilmenite is the predominant valuable heavy mineral (VHM) found within mineral sand deposits. The percentage of ilmenite within the HM assemblage can range from 40 to over 90 per cent. The proportion of the other valuable minerals (rutile, zircon and leucoxene) within deposits vary considerably. However, these minerals seldom occur individually in percentages of above 20 per cent of the HM assemblage. Few exceptions, such as Iluka’s Jacinth and Ambrosia deposits in South Australia, are known to occur.
TiO2 Content of Titanium Dioxide Products