conglomerate gold Archives - International Mining

Novo Resources has advised that Phase 2 mechanical sorting trials of its Pilbara deposit bulk samples will commence from early December 2021 following the dispatch of a Steinert KSS 100F LIXT fine mechanical sorting unit, due to be commissioned at its operation in Western Australia over the next few weeks.

The sorter will be installed adjacent to the company’s Golden Eagle processing facility in Nullagine.

Fifty samples from four different deposits across the Pilbara, ranging in size from 800 kg to approximately five tonnes, will be crushed and screened into three size fractions prior to testing through the sorter. The bulk samples will be processed by the sorter to produce a concentrate for gold assay.

Once this second phase of testing is complete, expected around the June quarter of 2022, the next phase of the test work will involve relocating the sorter to the company’ Comet Well project in Karratha, Western Australia, and commencing proposed large-scale bulk sample sorting test work of 20,000 t, leading to potential commercialisation of mechanical sorting for Pilbara conglomerates, Novo said.

The sorter infrastructure, designed and constructed by OPS Screening and Crushing Equipment, is a fully modular and containerised turnkey plant deployable to any of Novo’s tenements in the future for test work and potential large bulk sampling and processing, according to Novo. The sorter includes feed and product transfer conveyors, allowing the sorter to produce gold-bearing concentrates in a single pass for further upgrading or downstream processing.

This trial of the sorter within the Golden Eagle processing facility area is a culmination of several years of test work conducted by Novo to determine the amenability of mechanical sorting to its 13,250 sq.km of tenements across Western Australia.

“Mechanical sensor-based sorting utilises X-ray technology, 3D colour laser and metal induction to identify gold-bearing material,” Novo said. “A high-pressure air jet ‘shoots’ these gold-bearing particles into a collection system to produce a concentrate for further downstream processing.”

Rob Humphryson, CEO and a Director of Novo, said: “Mobilising the mechanical sorter for Phase 2 field trials represents an important step in progressing this innovative technology. We are looking forward to observing sorter performance from field samples collected at Comet Well, Purdy’s Reward, Talga Talga and Egina ahead of larger-scale field trials at Comet Well and Purdy’s Reward scheduled for Q2 (June quarter) 2022.”

Novo Resources says initial laboratory-scale tests using Steinert mechanical ore sorting technology indicates an upgrade of gold into significantly reduced mass is achievable at the Beaton’s Creek project in Western Australia.

The mechanical sorting tests carried out in Australia on the Beaton’s Creek bulk sample showed that nuggety gold occurring in Beaton’s Creek conglomerates is finer grained (generally sub 1 mm) than gold at Novo’s Egina and Karratha projects (generally over 1 mm), the company said. The company is also considering using ore sorting at these two projects.

Test work was conducted on a 2.8 t split of crushed (-50 mm) and screened Beaton’s Creek bulk sample material, with analyses conducted as part of this sorting test work generating a calculated head grade of 5.72 g/t Au for the bulk sample. The vast majority of gold reported to mechanically sorted concentrates in each of the three size fractions tested, with 90.2% of gold recovered in 54.5% of the mass of the +18/-50 mm fraction; 68.8% of gold recovered in 42.4% of the mass of the +6/-18 mm fraction; and 95.5% of gold recovered in 20.3% of the mass of the +2.3/-6 mm fraction.

Material finer than 2.3 mm, comprising 17% of the total mass of the bulk sample, was not tested due to excessive dust issues, the company said. “Novo believes such material is treatable by means of gravity concentration,” it added.

“Test results are considered indicative, and Novo and Steinert see additional opportunity to optimise sorting conditions and parameters that may result in further efficiencies,” the company said. “Nevertheless, these tests indicate robust potential for upgrading nuggety conglomerate gold mineralisation, and perhaps, a broader spectrum of gold mineralisation types.”

A second 2.8 t split of the same bulk sample material has been delivered to TOMRA Sorting’s mechanical sorting test facility in Castle Hill, New South Wales, where it will soon undergo similar testing using various TOMRA mechanical sorters, the company said.

Rob Humphryson, CEO and Director of Novo Resources, said: “We are highly encouraged by these initial results. We are already fully confident about the outcome of Egina mechanical sorting test work, which demonstrated excellent recoveries into very small concentrates. Our Beaton’s Creek test work is more investigative in nature owing to the finer gold grain size, so to achieve such levels of upgrade in first phase testing is remarkable.”

He added: “Test work is being developed and supervised by Novo staff specialising in mining engineering, metallurgical processing, and importantly, our geology team. This means those people engaged in exploration are fully aware of the profound impact that mechanical sorting potentially imparts on the economic viability of our prospects. Mechanical sorting test work is likely to become an integral part of future exploration and economic modelling as we hopefully progress each of our projects towards production should the economic viability and technical feasibility of the project be established.”

Modular Steinert KSS sorting plant heading to Novo’s Pilbara deposits

Steinert ore sorting tech picks up the Beaton’s Creek gold fine print