Tag Archives: processing plant

Pantoro enlists GR Engineering to build Norseman gold processing plant

Pantoro Ltd has signed a Letter of Intent with GR Engineering Services that is likely to see the ASX-listed contractor take on the engineering, procurement and construction works for the processing facility at the Norseman gold project in Western Australia.

The gold company, which owns 50% of the asset, said detailed engineering works will commence immediately and orders will be placed for long lead items including the 3.3 MW ball mill. Contract documentation is being finalised and is expected to be executed before the end of February.

The contract value is around A$57 million ($44 million) and will be awarded as a guaranteed maximum price agreement, Pantoro noted. This value is inclusive of the crushing circuit associated with the plant.

The DFS announced in October 2020 contemplated a build-own-operate-transfer (BOOT) arrangement for the crusher at Norseman with the transfer planned in year three.

This study also outlined average production of 108,000 oz/y over a seven-year phase one life, peaking at 119,000 oz in year two of production. It also provided for a processing plant capacity of 1 Mt/y with flexibility to expand to 1.5 Mt/y.

Separately, demolition works for the existing plant on site have been awarded with commencement of site works planned for mid-February.

Pantoro Managing Director, Paul Cmrlec, said: “We are pleased that GR Engineering Services will undertake work with their proven track record in new processing plant builds in recent years. GR Engineering has been the dominant supplier of new processing plant builds in Western Australia in recent times, and we look forward to drawing on their experience in construction of the plant at Norseman.”

DRA under budget and ahead of schedule at NST’s Jundee expansion project

DRA Global says it has completed its engineering, procurement and construction management (EPCM) contract under budget and ahead of time for Northern Star Resources at the Jundee gold mine, near Wiluna, Western Australia.

The Jundee mining operation is situated in the Northern Yandal Greenstone Belt, with the mine yielding a record 300,000 oz for Northern Star in the year ending June 30, 2020.

Jundee’s processing circuit comprises a two-stage crushing circuit, SAG and ball mill, and conventional carbon-in-leach plant. The ball mill upgrade, undertaken by DRA, increased processing plant capacity to a nominal design throughput rate of 2.7 Mt/y, from 2.2 Mt/y.

DRA delivered the EPCM project scope under budget and ahead of time, with ore commissioning achieved some six weeks ahead of schedule in a total duration of 35 weeks, it said.

“DRA’s project team achieved this outcome by working in close collaboration with the Northern Star project and operations team, the equipment vendors and construction sub-contractors,” it said.

Delivery of the project required overcoming challenges presented by the COVID-19 pandemic, including risk mitigation strategies being initiated to maintain the accelerated project schedule, according to the company.

Northern Star’s General Manager Processing, Simon Tyrrell, said DRA had consistently met and exceeded performance expectations through a collaborative approach to the Jundee ball mill project delivery.

DRA was engaged on the EPCM contract after having completed an engineering and cost study which included scope definition, design, planning, capital and operating cost estimation. The project follows several previous plant upgrades and studies successfully completed by DRA at the Jundee gold mine, which have contributed towards the continuous production growth seen at the mine over the last four-to-five years, DRA said.

The process plant shutdown and tie-in of the new ball mill was performed in conjunction with the Northern Star operations team and contractors without incident, and the process plant has since ramped up to run consistently above nameplate design capacity, the company added.

NQ Minerals upgrades Hellyer processing plant, aims to maximise recoveries

NQ Minerals says it has successfully increased plant throughput at its flagship Hellyer gold mine, in Tasmania, Australia, following an upgrade and circuit optimisation exercise.

The plant now has a capacity just over 1.3 Mt/y (1.2 Mt/y at 92% plant availability), up from the 835,877 t throughput level achieved in 2019, NQ said.

“The new production rate of 150 t/h (1.314 Mt/y) is now being achieved after a June plant upgrade and circuit optimisation exercise,” the company said. “This new rate compares to 2019 Hellyer full year plant throughput totalling 835,877 t (average 103 t/h at 92% plant availability).”

A spokesperson for the company said the exercise in June saw a lot of work carried out on upsizing existing pumps and pipework to handle the extra flow rates of the various process streams. This saw the installation of bigger pumps and pipes, and the replacement of worn components in the plant.

“Process optimisation works are now underway to ensure that the plant achieves maximum recoveries and concentrate specifications at these new higher production rates,” NQ Minerals said. This could see new automation equipment installed on some of the process circuit, according to the spokesperson.

“Engineering assessments will continue to plan for further production rate increases later in the year, should higher production rates be required,” the company added.

David Lenigas, Chairman of NQ Minerals, said the Hellyer plant upgrade exercise had been successfully brought in some six months ahead of expectation.

“The increase in saleable mine product will have a very positive effect on the company’s top and bottom line revenues going forward, and will assist NQ greatly with its ability to service ongoing debt obligations and strongly position the mine for increased profitability as commodity prices improve with the world emerging from the COVID-19 pandemic,” he said.

NQ Minerals purchased the Hellyer operations in 2017, and as Phase 1 of its Hellyer operational plan, re-opened Hellyer in late 2018 with a tailing retreatment operation designed to last for at least 10 years. Production will initially focus on lead and zinc recovery from the reserves with gold and silver credits.

Phase 2 of Hellyer’s re-opening plan is to re-open the underground mine, which has 1.175 Mt of underground JORC resources grading 8.6% Zn, 4.9% Pb, 96 g/t Ag and 1.66 g/t Au.

NQ Minerals acquires Beaconsfield mine, plots new underground decline

NQ Minerals has added the historic Beaconsfield gold mine, in Tasmania, Australia, to its growing portfolio, with the London-listed company saying it plans to recommission the processing plant and re-develop the underground mine with a new decline.

The company announced this week that it had signed all necessary agreements and made the necessary payments to purchase and take immediate possession of the Beaconsfield mine.

The mine has historic production of circa-1.8 Moz of gold averaging around 15 g/t to its name, and was closed in 2012 due to the low gold price at that time.

“The gold price has since increased by over 100% and the company plans to re-open the mine as soon as practicably possible,” NQ Minerals said.

The 350,000 t/y processing plant, which is currently under care and maintenance, will be recommissioned as part of this plan.

NQ Minerals strategy for re-opening the underground mine, meanwhile, involves developing new modern mine decline access into the existing Beaconsfield mine from surface to reconnect into the existing mine workings at the lower section of the orebody, which comprises all of the current stated gold resources, the company said.

“This new decline will be capable of running large modern mining equipment and men/materials/rock from surface to anywhere in the mine underground workings and will allow for the most efficient low-cost operations possible,” it said.

The main decline currently in the mine is a 5 m x 5 m access way (running down at an angle of 1 m for every 7 m in horizontal length, pictured) that starts 400 m from surface all the way to the bottom of the mine at 1,200 m from surface, according to a NQ Minerals spokesperson.

“The main shaft that accesses that decline is now out of use and is part of the Beaconsfield Heritage Museum,” the spokesperson clarified.

The plan is to run a new 6 m x 6 m decline from surface (popping out near the processing plant) and connect it to the old decline at 400 m depth at the bottom of the Hart Shaft, according to the spokesperson.

“This way, we can run very large diesel trucks (50 t capacity), large front-end loaders and big drill and blast equipment from surface to anywhere in the mine,” the spokesperson added.

Up until 2012, all the big mining equipment had to be dismantled and taken down the old shaft in pieces and re-assembled at the 400 m depth level before it could get used. This big equipment is still down the mine, according to the spokesperson.

“This old way of getting mining equipment down the mine was very slow and very expensive,” the spokesperson explained.

“The other good thing about a new access to surface is the mine can also have smaller-sized equipment easily moved around the mine for mining of the gold orebody, ie equipment suitably sized for the job it has to do,” the spokesperson said.

“The combination of the above is that this will enable economies of scale and economies of suitability.”

NQ, which is currently increasing production at its flagship Hellyer gold mine in Tasmania, Australia, announced a new JORC-compliant mineral resource estimate of the lower section of the Beaconsfield gold mine of 1.454 Mt grading 10.3 g/t for 483,000 oz of gold, earlier this year.

David Lenigas, NQ’s Chairman, said: “Beaconsfield is an exceptional high-grade gold asset and will provide a solid platform to bring the company’s second mine in Australia into production.

“The company is now focused on bringing the Beaconsfield gold processing plant back into operational status as soon as practicable. The mine has a long and rich history in northern Tasmania, and we understand the importance of this heritage. We are looking forward to bringing jobs and economic activity back to Beaconsfield.”