Ownership: Tiwest Pty Ltd (100%) – (50/50 Joint Venture between Tronox Limited and Exxaro Resources).
At Tiwest’s Cooljarloo Mine, 170 kilometres north of Perth in WA, heavy mineral concentrates are produced from dredging and dry mining operations. The Tiwest Joint Venture is Australia's largest pigment producer.
At December 31 2009 the Cooljarloo mine had proven probable reserves of 110,300,000 tonnes grading 2.700 per cent for 2,978,100t of contained heavy mineral sands.
Its measured, indicated and inferred resources were at 228,800,000 grading 2.399 per cent for 5,489,400t of contained heavy mineral sands.
The operations include mining and dry separation of titanium minerals and zircon, upgrading of ilmenite into synthetic rutile and production of titanium dioxide pigment.
The raw materials for Tiwest's titanium minerals business come from ancient shoreline deposits in the Lancelin to Gingin area. Grains of valuable heavy minerals were deposited on ancient shorelines thousands of years ago, where the action of waves and wind formed 'belts' of minerals called strand lines.
Today, Tiwest produces more than 700,000t of heavy mineral concentrate per year using a dredging operation and dry mining techniques. The dredging operation uses two large floating dredges in a purpose-built pond to pump slurried ore to a floating concentrator which recovers heavy minerals from the sand and clay using a series of gravity spirals. The dry mine uses earthmoving equipment to extract ore located above the water table, feeding it to a land-based concentrator for separation using a hopper and conveyor system.
The resultant heavy mineral concentrate is transported to the dry separation plant at Chandala. The dry separation plant has a capacity to process 720,000tpa of heavy mineral concentrate and after separating via a complex series of electrostatic, magnetic and gravity processes can produce up to 450,000tpa of ilmenite, 30,000tpa of rutile, 80,000tpa of zircon and 15,000tpa of leucoxene.
The synthetic rutile plant is also located at Chandala. The improved Becher process is used to upgrade ilmenite from 62 per cent titanium dioxide content to synthetic rutile of 93 per cent titanium dioxide content. The plant’s current nameplate capacity is 200,000tpa. The synthetic rutile is transported to the titanium dioxide pigment plant at Kwinana. The use of modern technology, debottlenecking and improved operational efficiencies have resulted in a current capacity of 90,000tpa of titanium dioxide.