The Tiwest Joint Venture was a joint venture between Tronox Western Australia Pty Ltd and subsidiaries of Exxaro Australia Sands Pty Ltd. The Tiwest Joint Venture was a mining and processing company, established in 1988, to extract ilmenite, rutile, leucoxene and zircon from a mineral sands deposit at Cooljarloo, 14 km north of Cataby, Western Australia.^[1] As of June 2012, the joint venture was formally dissolved, when Tronox acquired the mineral-sands-related divisions of Exxaro outright.[1]^{[citation needed]}

Tiwest's corporate office (sales/marketing/accounting/administration/IT/etc) was located in Bentley, five minutes drive south of the Perth central business district. During the joint-venture phase of operations, from 1988 through 2012, heavy mineral concentrate was trucked from Cooljarloo, 1 hour and 15 minutes south to the Chandala mineral sands processing plant, near Muchea, 70 km north of Perth. The concentrate was then separated in a facility known as a dry mill, using a magnetic separation-process. Ilmenite was further processed on-site into synthetic rutile, which is used by pigment plants to manufacture paints and similar products. Additional minerals,^[vague] produced as a byproduct of the rutile production process, were sold as-is. Most synthetic rutile from Chandala was then trucked to Kwinana, 30 km south of Perth, to the Tiwest-owned pigment plant, which produces titanium dioxide a.k.a. TiO₂. A $100M upgrade to this Kwinana pigment plant was approved^[when?] by the boards of both Tronox and Exxaro, and was expected^{[citation needed]} to increase TiO₂ pigment production by up to 50%^[vague] before 2013. TiO₂ is the best^{[citation needed]} commercially viable whiting agent known, and is typically used in the manufacture of paints, plastics, and food stuffs.

As part of the 2012 acquisition,[2] the assets of the TIWEST Joint Venture have been folded into the sole parent company, Tronox, which continues to operate in the mineral-sands industry.