EMERGING listed mineral sands miner Matilda Minerals has upgraded reserves at its Tiwi Islands project in the Northern Territory by 140 per cent. Perth-based Matilda’s exploration at the site takes the total proven reserves at the islands to 4.9 million tonnes, which it expects to increase project revenues by 92 per cent. Based on a production strategy outlined in the company’s feasibility study for the project, the reserve increase takes the total mine life to six years, Matilda said. On aver-age, the group expects the project to deliver 37,000 tonnes per annum of heavy mineral concentrate over this period. Production will yield about 12,000 tonnes of zircon and 8,000t of rutile and leucoxene, each year on average, according to Matilda. At this stage, the company anticipates a start-up date at the project of late 2006. The new reserve estimate is projected to produce a free cash flow of $40 million, representing a 92 per cent increase on the previous estimate released to the Australian Stock Exchange in March. Matilda estimates a capital cost for mine start-up at $2.5 million, of which $2 million has already been spent on the construction of a processing plant on the islands.