Ilmenite, rutile and zircon are the three heavy minerals mined from the sand mines at Sibelco’s North Stradbroke Island Operation in Queensland, Australia. The heavy minerals extracted account for 1% of the total sand. The remaining 99% is used in post mining rehabilitation.
Ilmenite is blended and processed to create titanium dioxide, a high quality white pigment which is ultraviolet (UV), water and chemically resistant while also being non-toxic.
More than half of all titanium dioxide pigment is used in the production of paints (household, industrial and automotive etc.) as it reflects the sun’s harmful UV rays and protects paint from peeling. Titanium dioxide is also an important ingredient in the manufacturing of sunscreen, cosmetics, plastics, ink, paper, toothpaste and some foods such as flour and icing sugar to improve their brightness.
Rutile is used in three major applications: titanium dioxide pigment, flux core welding wire and titanium metal production.
Rutile, when processed into titanium dioxide pigment, can be used in the same products as ilmenite. Rutile is sometimes the preferred source for titanium dioxide pigment as it provides the most efficient product with the least waste in manufacture.
Flux core welding wire is the preferred welding consumable for pressure vessels, petrochemical piping, and heavy-equipment manufacturing, as flux core wire stabilises the electric arc ensuring a superior joint.
Rutile can also be converted into titanium sponge, which is then processed into titanium metal. Titanium metal’s unique properties include its high strength-to-weight ratio, high melting point and resistance to corrosion. This makes rutile a preferred metal in the aerospace industry for manufacturing aircraft frames and jet engines. It is also commonly used to produce top quality sporting equipment, pacemakers, artificial limbs, surgical equipment, spectacle frames and watches. When Titanium metal is mixed with other metals such as iron, manganese and aluminium, it forms alloys which are both temperature and corrosion resistant meaning they have a wide array of uses in difficult environments.
More than 50% of all zircon is used in the ceramics industry due to zircon’s ability to impart opacity, (whiteness and brightness) and to create glazes on products such as tiles, sanitary-ware (baths, sinks and toilets) and crockery. Zircon is a hard and tough material as it maintains its physical and chemical composition when subjected to high temperatures and corrosive environments. It is an extremely good foundry and refractory material, used in refractory bricks, especially in furnaces for steel and glass making.
Zircon is used:
- to block X-ray emissions in cathode ray tubes (CRT) found in computers and television monitors.
- to produce biomedical devices such as hip and knee replacements, rechargeable light weight batteries, television screens, fuses and toothpaste.
- as a foundry sand for specialist investment casting or high-precision casting.
Zircon alloy is used as the housing for fuel rods in nuclear power stations, due to its low thermal neutron absorption.