First Tin PLC has successfully completed end-to-end mineral processing testwork on a bulk sample taken from the Taronga tin project. The company believes it has developed a simple and cost-effective processing option for the tin mineralisation found at the asset. The testwork confirmed that the cassiterite (tin ore mineral) is easily liberated at a coarse crush size and that a good quality pre-concentrate can be obtained using simple gravity separation techniques. The processing flow sheet chosen for the DFS consists of coarse gravity techniques, crushing, jigs, spirals, grinding, shaking tables, and standard tin dressing techniques. The flow sheet has the potential for further optimization to increase recovery rates. Ongoing recovery studies on lower-grade samples are currently in progress.
The testwork results showed that 55-58% of the total tin is recovered into a plus 56% Sn, low impurity tin concentrate using the chosen processing flow sheet. An additional 5-6% recovery is possible from a fine tin circuit. The main losses of tin occur during the initial crushing stage, the spiral tail, and the shaking table tail. Further work is proposed to refine these steps and increase recovery. A fines circuit has also been shown to recover an additional 5-6% of the fine tin.
Based on the testwork results, a simple processing facility has been designed, including a 3-stage crushing circuit, screening, vertical impact crushers, jigs, spirals, and a ball/rod mill. The facility will operate during daylight hours to take advantage of a proposed solar farm that will reduce electricity costs. The oversize material from the crushers and jigs, as well as the tails from the spirals, will go to a proposed co-disposal tailings storage facility.
The company aims to complete the DFS during Q1 2024 and will continue to optimize and improve the grade and quality of the concentrate. The results of ongoing recovery studies on lower-grade samples will also be announced when received.