The Rentails project is focussed on the reprocessing of some 21.6 million tonnes of historical tailings from the Renison tin mine, with average grades of 0.45% Sn and 0.23% Cu, or 97,200 tonnes of tin and 49,700 tonnes of copper. The updated DFS scenario proposes annual production of 5,400 tonnes of tin and 2,200 tonnes of copper, using flotation and fuming to attain estimated tin recoveries of 59% and produce a high-grade tin fume product of around 72% Sn and copper matte of approximately 70% Cu.
The cash cost of the operation, net of the copper by-product revenues, is calculated at A$13,400 (~US$10,200) per tonne of tin produced, with an initial capital cost of A$205 million (US$156 M) and total capital costs of A$243 million (~US$185 M) over the projected 11 year life of the operation. A breakeven tin price of US$14,000 has also been calculated for the project, well below current LME price levels.
Metals X is currently discussing financing options with its JV partner as well as looking ahead at future suppliers and final approvals required to move ahead with development of the Rentails project. There is also some long-term upside from the potential integration of low-grade material from the Renison mine operation, but also from other regional projects and sources of historical slag and tailings.
ITRI View: Even without a decision to move ahead with the Rentails project, production from the Renison site is set to expand in the years ahead, with the current construction of a new ore sorting plant scheduled for completion by April 2018 that should increase annual tin output by 15-20% to between 8,000 and 8,500 tonnes. Total production from the site including the proposed tailings retreatment could therefore feasibly exceed 13,400 tonnes per year. It is notable that Rentails is not the only large-scale tin tailings project currently under reassessment, with Peruvian miner Minsur currently carrying out a feasibility study for its B2 tailings project near its San Rafael mine, which is due for completion in Q3 2017.