Sky Metals (ASX:SKY) reports it has produced a saleable tin concentrate from metallurgical testwork at the Tallebung Project, located near Condobolin in New South Wales.
Building on ‘exceptional’ results announced in September, the ore sorting products were sent for metallurgical testing to produce a saleable tin concentrate at ALS, and this testwork produced a saleable tin concentrate.
The company says the test work showed a tin concentrate from the Tallebung tin mineralisation can be achieved through concentration via a simple gravity circuit with gravity concentrate dressing via reverse sulphide floatation and wet high intensity magnetic separation (WHIMS) to produce an over 60% tin concentrate.
Sky Metals CEO Oliver Davies said these results establish that the tin mineralisation present as course cassiterite at Tallebung is very amenable to concentration using cost-effective and simple gravity processing.
“When combined with the exceptional ore sorting results, the testwork has demonstrated the extremely responsive nature of the Tallebung tin mineralisation to straightforward tin concentration”
“When combined with the exceptional ore sorting results, the testwork has demonstrated the extremely responsive nature of the Tallebung tin mineralisation to straightforward tin concentration.
In addition to these advantages, an over 60% tin concentrate can achieve a very high payability with few penalties at the smelter.
This work significantly strengthens the growing potential of the development of a bulk tonnage tin mine at Tallebung.”
These results were generated from samples of Tallebung tin mineralised collected from drillhole TBD002 (60.2m @ 0.54% Sn from 12.8m) from 2m to 92m for a total of 542kg, and this sample was sent to TOMRA Ore Sorting Solutions in Sydney to be crushed to less than 50mm grains.
The company says the samples were then split into 25mm to 50mm and 8mm to 25mm fine fractions for sorting and a less than 8mm fine fraction which was too fine to be sorted effectively.
Sky reports the 25mm to 50mm and 8mm to 25mm fractions were then sorted with TOMRA’s XRT ore sorter into a product and waste, and assays for this testwork showed a tripling of the tin grade with 98% recovery for tin, and further work will be conducted on ore sorting to continue to build on these results.
Following this, the company sent the sorted ore samples to ALS Metallurgy in Burnie, Tasmania where a testwork program has developed a gravity flowsheet, which started by combining the ore sorting product with the fines which were crushed and ground to under 1,180um before a series of spirals followed by a set of tables were used to produce a gravity concentrate.
Sky reports this process removed over 97% of the total mass produced and upgraded the tin concentration by over 25 times.
The tin grade in the gravity concentrate is then further increased with a reverse sulphide floatation and WHIMS dressing of the gravity concentrate to produce a saleable concentrate with ‘low’ smelter penalties and a ‘high’ payability produced.
The company says 70% to 75% is the standard range of tin recovery for operations using the conventional tin gravity concentration methods as used in this testwork program, and Sky has achieved over 73% recovery through the entire testwork process, and the company will be looking to increase the recovery with the addition of a gravity circuit for ultrafines to recover further fine tin and incremental improvements throughout the process.
Sky will continue to build on these results with ‘large-scale’ testing for ore sorting and further development of this simple flowsheet to refine the production of a saleable tin concentrate for the Tallebung tin mineralisation over the coming months.
Sky Metals is a New South Wales-based exploration and development company focused on ‘high-value’ mineral resources in Australia.
The company’s tin projects include Tallebung, Doradilla, New England, and its gold and copper-gold projects include Iron Duke, Galwadgere, Cullarin/Kangiara, and Caledonian/Tirrana Projects.
Images: Sky Metals Ltd and iStock