Tag Archives: Taronga

Aus Tin chooses different tack at Taronga Stage 1 project

There are changes afoot at Aus Tin Mining’s Taronga Stage 1 project, in Australia, after the ASX-listed company appointed a contractor for an initial program of mining, crushing and civil works, and made the decision to acquire its own crushing plant.

The company said it had appointed Townes Contracting, a firm with experience in quarrying and crushing operations, to undertake the initial mining, crushing and civil works associated with Taronga Stage 1. Expected to last three months, this contract should provide for site establishment, initial mining of some 50,000 t of ore and waste, crushing of ore and construction of a water dam, Aus Tin said.

Aus Tin’s decision to acquire its own crushing plant, meanwhile, follows a crushing trial completed with a preferred contractor in May. Aus Tin explained: “The company was unable to secure their services in a timeframe consistent with operational requirements.”

The Taronga tin project is the world’s fifth largest undeveloped tin reserve, based on a JORC resource of 57,200 t of contained tin, plus 26,400 t of contained copper and 4.4 Moz of silver, Aus Tin says.

The company completed a prefeasibility study in 2014 that outlined a project treating 2.5 Mt/y of ore, producing an average 2,800 t/y of contained tin over nine years. Following this, in 2015, the company commenced the approvals process to undertake trial mining and pilot processing of 340,000 t of ore to evaluate several areas of potential upside. This project – Taronga Stage 1 – is now fully permitted.

Peter Williams, CEO of Aus Tin, said: “Now that we are no longer constrained in any way by contractors at Granville, we have decided to take a different approach to the operation and believe this will provide the optimal means to exploit this small, but high grade tin deposit.”

Back in March, Aus Tin Mining commenced owner mining at the Granville East tin mine in Australia, just over a week after liquidators were named to its previously appointed mining contractors, Jemrok Pty Ltd.

Aus Tin said the initial programme of work to be carried out by Townes Contracting will provide “several important outcomes”. Included within this is a provisional metal reconciliation, with the average grade of ore mined compared with the respective mining blocks estimated in the 2014 probable reserve; productivity and cost data to optimise pricing for the remainder of Stage 1, and; material for additional metallurgical test work planned prior to the commencement of Stage 1 pilot plant operations.

The remainder of the Stage 1 project, including the expanded mine and pilot plant operations are expected to commence in late 2019.

In terms of the crusher Aus Tin is due to acquire, the company said it had made an initial payment on a second-hand mobile crushing plant, located in Tasmania, and refurbishment of the unit – expected to take three to four weeks – had commenced.

“The key benefits of owner crushing will be a lower operating cost and ability to crush ore on an ongoing basis rather than the campaign basis required for contractors,” Aus Tin said.

AusTin Mining weighing up ore-sorting at Taronga following positive tests

TOMRA is continuing to win praise for its sensor-based ore sorting technology, with AusTin Mining being the latest company to say pilot test work indicated the process could remove a significant amount of waste and boost grades.

The company had previously carried out a 60 kg trial with TOMRA on material from the Taronga project in New South Wales, Australia, which indicated X-ray Transmission (XRT) ore sorting was effective.

The latest test work went a step further, with 1.6 t of material grading 0.15% Sn from the Northern Zone of the Taronga deposit being crushed and run through an XRT-1200 sorter in a series of tests for different sizes.

In summary, the latest result indicated:

  • Significant mass rejection (up to 66%) to waste may be achieved. This could either reduce the scale of the downstream processing plant and/or enable an increased plat throughput;
  • Uplift (up to three times) in the grade of sorted product, which could increase the tin units reporting to a downstream processing plant;
  • Increase (over three times) in the grade of fines (-8 mm) material, highlighting the potential for preliminary beneficiation in conjunction with ore sorting, and;
  • Consistent waste grades across all tests, indicating the potential to increase tin recovery with increasing feed grade.

CEO, Peter Williams said of the results: “Aus Tin Mining is encouraged by the benefits ore sorting could deliver for the Taronga tin project, not only including the potential uplift in grade, but also the scope for lower costs and the long-term potential opportunity to exploit more of the mineral resource.”

Williams added that the Stage 1 project at Taronga would provide an “ideal opportunity to test and optimise the technology”.

In 2015, the company announced it would commence a Stage 1 development comprising a 340,000 t trial mine within the Northern Zone ore reserves and pilot processing plant able to produce a saleable concentrate over an 18-24 month period. The company is currently in the process of progressing outstanding regulatory approvals and contractor negotiations for this project.

In the coming weeks, AusTin intends to evaluate whether to proceed with an ore-sorting trial in conjunction with the Stage 1 project, including considerations for additional costs and existing approvals.

“The company will also transport the residual material from the ore-sorting test work to the Granville tin project to assess the material for downstream gravity and flotation processes,” the company said.

The Taronga tin project comprises two major zones of quartz-cassiterite, sheeted vein-style mineralisation. The Northern Zone accounts for approximately 70% of the total mineral resource (27 Mt at 0.15% Sn for 40,100 t contained tin) and is open at depth. The Southern Zone (9.3 Mt at 0.19% Sn for 17,100 t contained tin) comprises a very coarse cassiterite demonstrating superior metallurgical properties plus contains higher tin, copper and silver grades.