All images: Aus Tin Mining
BY: JESSICA CUMMINS
Australia’s second tin focused producer, Aus Tin Mining, remains focused on the delivery of high-value metals critical to the energy revolution, with three near-term projects and expansions underway.
AFTER resuming mining operations at the mothballed Granville project in 2016, the race has been on for Aus Tin to grow production.
Following an expansive approvals process, the Company obtained the final green light in April 2018 to expand the operation.
Once complete, this expansion will include the development of a tailings storage facility, the latest technology gravity equipment, and resumption of mining at the high-grade Granville East deposit via a cutback on the eastern wall.
The expansion will also enable Aus Tin to increase forecast production to a rate of 550 tonnes per annum (tpa) of contained tin.
Recent quarter results proved largely positive for Aus Tin, with significant advancements made at Granville.
In April, the company awarded Jemrock a contract to undertake mining activities at Granville East and begin construction of a new tailings storage facility required for Level 2 operations, set to be complete this quarter.
The company also entered into a new two-year tin purchase agreement with Traxys Europe, which it claims will be on “more favourable terms for the company”.
On the down side, forecast production cash costs at Granville increased from $15,600 per tonne to $17,300 per tonne.
“Incorporating the finalised contract mining costs and adopting a lower tin recovery of 60 per cent based on Level 1 operations, the forecast cash cost of production (C1) for the Granville Expansion has risen to $17,300/t of recovered tin,” Aus Tin chief executive Peter Williams said.
“Based on the current tin price, the operating margin is estimated at $9400/t of tin in concentrate.”
The Granville expansion was also set to provide cash flow to underpin the company’s other assets in its development portfolio; near term projects Taronga and Mt Cobalt.
Taronga Tin Project
Ranked fifth in the world for undeveloped global tin reserves, the Taronga project in NSW has been a priority for Aus Tin for some time.
Mr Williams said during the June quarter the project progressed various pre-construction work and regulatory plans.
“The design for the Tailings Storage Facility was finalised and submitted to the regulators for construction approval, and engineers were appointed to complete the preliminary design and cost estimate for the pilot plant,” Mr Williams said.
“To progress the Mining Lease Application, a survey of the lease boundary was completed and several technical reports were received for inclusion in the Mining Operations Plan.
“What’s notable about Taronga is that it is a world class asset with significant upside and subject to obtaining all regulatory approvals we are targeting ore product by the end of 2018.”
Results from recent preliminary test work also showed that the site is suitable for ore sorting.
“Analytical results for the standard static test indicate an overall 54 percent increase in head grade (0.56 per cent tin to 0.86 per cent tin) whilst achieving 96 percent tin recovery,” Mr Williams said.
Aus Tin will accelerate the next stage of test work with a two-tonne bulk sample through TOMRA’s pilot facility in Sydney, and the results will provide information for scale-up to a full-scale production plant.
With the design of its new Tailing Storage Facility completed and waiting approval, a cost estimate is being reviewed for the pilot plant as well as a survey of the lease boundary to progress the Mining Lease application.
Mt Cobalt
Drilling and substantial 3D modelling work has also been undertaken at Aus Tin’s Mt Cobalt copper-cobalt-nickel project in QLD.
“We’ve received some very good drilling results in January this year from Mt Cobalt with results of up to 28 metres at 0.3 per cent cobalt,” Mr Williams said.
“More recently 3D modelling of magnetic data generated three discrete targets with elevated magnetic susceptibilities of 0.2 SI and 0.129 SI iso-layer units were identified, the largest lying approximately 600m below Mt Cobalt.
“Based on collective work to date, the zone of 0.2 SI magnetic susceptibility may represent the sulphide source for cobalt and nickel mineralisation at Mt Cobalt.
“None of the targets have been validly tested by previous drilling and the Company is developing a program to drill test the target zones with a program of three holes up to 650m in depth.”
A geological comparison between Mt Cobalt and Glencore’s Koniambo nickel and cobalt resource in New Caledonia provides some direction for future exploration, supported by recent field work at Aus Tin’s Jackson North.
Mt Cobalt core
Both Mt Cobalt and Koniambo are “unusual and almost unique” in that they were deposited in two episodes, firstly by hydraulic fracturing and mixing of meteoric waters, followed an indeterminate time later by supergene enrichment.
Both deposits also exhibit veins of distinctive red-brown, micro crystalline hydrothermal quartz breccia, which has undergone fracturing and resealing above the serpentinite.
Aus Tin said discussions were underway with drilling contractors, and Aus Tin remained hopeful that pending all regulatory approvals, the next drilling program will commence during the September quarter.
Outlook
For the next three years, Mr Williams said Aus Tin plans to deliver sustainable tin and cobalt targeting low capital and low operating cost projects in Australia.
Aus Tin said a new $2.5 million funding package would help drive development across Granville, Taronga and Mt Cobalt.
“During the [June] quarter, shareholders ratified a new $2.5M, 24-month convertible security with the Lind Partners on superior terms,” Mr Williams said.
“Following the end of the quarter the Company received the balance of funding and currently holds its highest level of cash since 2013 when it merged with Taronga Mine Limited.
“Funds will be used will be used to meet exploration, development and working capital costs.”
