Tag Archives: Carosue Dam

GR Engineering to build paste plant at Saracen’s Thunderbox operation

GR Engineering Services has been awarded additional work by Saracen Mineral Holdings at the Thunderbox and Carosue Dam gold operations in Western Australia.

The contract additions, which have a combined value of A$29 million ($19.9 million), include an engineering, procurement and construction contract for the Thunderbox Paste Plant project and an approved variation of the Carosue Dam Operations Plant Expansion project.

The Thunderbox paste plant work will involve the design, supply installation and commissioning of a new 150 m3/h paste backfill plant at Thunderbox. The project includes work at the existing Thunderbox operations’ (pictured) processing facility along with works at a new remote paste plant location. The contract price is A$22 million. GR Engineering says work will start immediately and is expected to complete in the first half of 2021.

At Carosue Dam, meanwhile, GR Engineering has been awarded a variation under the existing contract to install a paste pump at the Karari Paste Plant to distribute paste to the Whirling Dervish underground mine. The value of the variation is A$7 million.

These additions come on the back of being awarded a contract to carry out the engineering design, procurement and construction of expansion works on Saracen’s mineral processing plant at Carosue Dam, in November.

GR Engineering’s Managing Director, Geoff Jones, said: “GR Engineering has now worked with Saracen on three key projects in the last two years and we look forward to continuing our strong working relationship with one of Australia’s leading gold producers.”

BHP, Norton Gold Fields and Saracen join forces for screening and particle sorting study

A collaborative study with Australia mining companies BHP, Norton Gold Fields and Saracen on the integration of screening and particle sorting techniques is set to deliver benefits across the resources sector, according to CRC ORE.

The Integrated Screening and Particle Sorting Collaborative (ISPS) study aims to develop a robust and scientifically rigorous framework for collecting, testing and reporting results for integrated screening and particle sorting techniques in a variety of ore domains.

The study, which began in August 2019, is currently underway at BHP’s Cliffs nickel mine, Norton Gold Fields’ Paddington gold site and Saracen’s Carosue Dam gold operation, all in Western Australia. It is expected the study will further expand during its 15-month tenure to include an additional two sites, according to CRC Ore.

CRC ORE ISPS Study Program Manager and Discipline Lead – Metallurgical Engineering at Curtin University’s Western Australian School of Mines, Dr Laurence Dyer, said the opportunity existed to use particle sorting to upgrade ores.

“Trials have recently been conducted at several gold mining operations in the Goldfields region of Western Australia,” Dr Dyer said. “What commonly fails to be taken into consideration is the benefit of first assessing the natural deportment of metal to a size fraction through grade-by-size screening test work, prior to undertaking particle sorting test work.”

He added: “Missing this step has two impacts. First, there is a risk that particle sorting test results will be misinterpreted as being representative of the full sample without considering the mass balance impact of high-grade material that might have been lost in the fine fraction. This fine fraction will not be detected through the particle sorter.

“Secondly, the opportunity may exist to upgrade feed first through determining if there is a concentration of high grade to the fine (or coarse) fraction which can be separated through screening. Undertaking screening in the preparation stage of the particle sorting process will enable analysis and separation of the fine or coarse fractions of a rock mass.”

Dr Dyer said the study outcome would be a blueprint for understanding the opportunity for upgrading ore feeds, including an assessment of operational impacts, economic valuation and implementation approaches.

The three mining companies would benefit from insights and improvements generated from other sites, while CRC ORE will benefit from developing a broader understanding of the application and opportunity for applying particle sorting on a range of deposit types, he said. In CRC ORE’s case, this will be integrated with natural deportment grade-by-size screening opportunities to maximise value for mining operations, he said.

The ISPS study forms part of the CRC ORE Grade Engineering® program, which is focused on extracting metal more efficiently by separating ore from waste before the comminution process commences.

“Current industry perception is that declining feed grade is an unavoidable consequence of ore deposit geology and mass mining technologies for increasingly mature mining operations,” the CRC ORE said.

In typical crush-grind-float operations, value recovery only takes place at around the 100-micron particle size involving three to four orders of magnitude size reduction compared with run of mine feed, according to the organisation.

“For increasingly low-grade deposits, the cost of energy and capital intensity required to process and reject worthless material at micron scale drives poor productivity,” it said. “An alternative is to deploy a range of coarse rejection technologies.”

Grade Engineering is an integrated approach to coarse rejection that matches separation technologies to ore specific characteristics and compares the net value of rejecting low value components in current feed streams with existing mine plans as part of a system view, according to CRC ORE.

Dr Dyer said the Grade Engineering program and the ISPS study would be conducted through CRC ORE’s Kalgoorlie-Boulder Mining Innovation Hub and Curtin University’s Western Australian School of Mines.

“Particle sorting is an important lever of Grade Engineering,” Dr Dyer said. “Through this project, CRC ORE is looking to develop a better understanding of the value of particle sorting to upgrade mill feed, particularly when combined with grade-by-size screening.”

A not for profit organisation funded by the Australia Federal Government and the global minerals industry, CRC ORE commenced in mid-2010 and, after its initial five-year funding term, was awarded a further six years of funding until July 2021.

Rhino raiseborer has Raising Australia reaming ahead, Sandvik says

The arrival of the Rhino 100 mobile raiseborer has seen Raising Australia, part of the Byrnecut Group, slash slot-raise production times, improve productivity for its customers and significantly increase its own revenue, according to Sandvik.

‘Slot raises’ play a crucial role in the development of many underground mines in Australia, Sandvik says. Created by raiseboring machines, these wide-diameter holes provide void spaces in the stope into which blasted ore can expand, improving fragmentation.

The problem is traditional raiseboring machines used to drill slot raises are cumbersome to transport and have high demands for labour and time, according to Sandvik. “It can take two to three days of preparation before drilling begins, resulting in potential bottleneck and delays in production.”

In 2014, a team from Raising Australia travelled to Finland to inspect the Rhino 100, developed by TRB-Raise Borers and distributed by Sandvik. Mounted on rubber tyres, the Rhino 100 could travel under its own power within a mine, required just one operator, and could begin boring within 45 minutes of arrival on site, Sandvik said.

Raising Australia initially went down the route of developing and trialling its own mobile raiseborer, but, in 2016, General Manager, Mark Hanigan, inspected the latest generation Rhino 100 and realised it was what the company needed, Sandvik said. After working with TRB to tweak the borer to allow for additional drilling angles, Raising Australia took delivery of its first Rhino in September 2017.

“That first Rhino went straight to [Saracen’s] Carosue Dam Operation, near Kalgoorlie, and it’s been there ever since,” Hanigan says. “The previous contractors were drilling 150 m/mth, and we have achieved up to 400-m-plus a month. Between October 2017 and December 2019, we drilled just under 5,000 m, so we’ve doubled their output.”

After the initial success, Raising Australia ordered another two Rhino 100s. The first arrived in August 2018 and was sent to Northern Star’s Jundee gold mine, in Wiluna, Western Australia. The next was delivered in October 2018 and has been a campaign machine, travelling to a range of customer sites. The company has since ordered a fourth and fifth machine, which are being delivered in 2020 and are expected to be immediately put to work on major mining projects, according to Sandvik.

One of these rigs was recently commissioned on a 36 m long hole at Gold Fields’ Invincible operation.

Hanigan says the impact of the Rhino 100 on Raising Australia’s business has been significant. “We have significantly increased our revenues since 2017 when we took delivery of the first Rhino, and we’re hoping the next two Rhinos will help us grow again,” he says.

“The benefits for our customers are also huge. It used to be drilling the slot rises that would hold up the development process. Now, they can bring the stope online when they want and not have to wait for the hole to be drilled.”

In fact, so fast is the process with the Rhino 100, one of the biggest challenges for Raising Australia has been convincing clients that it will live up to its promises, Hanigan says.

“Every time we get a new client, we will tell them how it works and what it delivers, and they will be sceptical. That’s until they actually see it and their minds are blown,” he said.

Jarko Salo, Managing Director for TRB-Raise Borers, says the positive experience of Raising Australia is common among Rhino 100 customers across the globe. In one case, a Brazil miner reported productivity gains of up more than 90% due to more efficient working techniques enabled by the raiseborer.

Salo attributes the success of the rig to the ground-up approach taken during development. The needs of underground miners inspired the creation of the first mobile raiseborer and TRB has continued to be responsive to feedback.

“Right from the beginning here in Finland we have listened very carefully to our customers and produced designs that fit their needs,” he says.

Mark Hanigan says the key advantages for Raising Australia are the time and labour savings the Rhino offers over conventional raiseborers. While it takes a team of two people between two and three days to prepare a traditional raiseborer for duty, a single operator can tram the Rhino into the mine and be drilling within a matter of minutes. As well as slot raises, the Rhino 100 can be used to drill ventilation shafts, drainage shafts, escapeway shafts, ore passes and back fills, according to Sandvik.

Another key advantage of the Rhino 100 is safety. With older-style raiseborers, the operator is generally in the open less than 5 m from the hole being drilled and must drill deep into the rock before erecting a muck chute, according to Sandvik.

“With the Rhino 100, the muck chute opens and closes,” Hanigan says. “You open it up, push through the rod, and when you’re ready to start drilling you can close the chute up. It covers the hole, stopping the dirt cuttings flying out and hitting the operator. The Rhino 100 also removes the exposure of the operator to the risk of flying debris as you’re 6-7 m away from the work area and operate from within a cab.”

Raising Australia has recently begun taking advantage of the plug-‘n’-drill feature of its Rhino rigs, according to Sandvik. This allows for the quick change of drilling modules to permit down-reaming or conventional raiseboring. The module attaches to the borer, allowing for drilling even when access to the lower level in not possible, according to Sandvik.

“We just finished the first hole with that module last week and it was magic,” Hanigan said recently. “It drilled a 1.1 m diameter escape way in one third of the time of a normal raised drill.”

Salo says he has been pleased to witness Raising Australia’s journey with the Rhino 100: “Raising Australia and Byrnecut showed great vision in understanding the competitive advantages that mobile raiseboring provides early on,” he says.

GR Engineering to help expand Saracen’s Carosue Dam gold operation

GR Engineering Services says it has entered into a contract with Saracen Mineral Holdings that will see the company carry out the engineering design, procurement and construction of expansion works on its mineral processing plant at the Carosue Dam gold operations, in Western Australia.

The works under the contract include the upgrade of the existing processing plant capacity to a nominal throughput of 3.2 Mt/y by the installation of secondary grinding equipment, in addition to upgrades to the existing carbon-in-leach circuit and other process infrastructure, GR Engineering says.

The contract price is $24.5 million ($17 million), with work under the contract starting immediately with the completion of the upgrade expected to occur in the first half of its 2021 financial year.

Saracen has previously said Carosue Dam will soon undergo a mill expansion from 2.4 Mt/y to 3.2 Mt/y with feed coming from both underground and open-pit mines.

GR Engineering’s Managing Director, Geoff Jones, said: “Having been involved in the initial development of Carosue Dam in 2000, our team has maintained a strong relationship with Saracen and utilised its understanding of the project to deliver incremental benefits to the project. GR Engineering looks forward to achieving positive outcomes for Saracen through the safe and successful delivery of these expansion works.”

Pacific Energy to expand Saracen’s Carosue Dam dual-fuelled power station

Pacific Energy’s KPS subsidiary has signed contract variations for two power generation agreements with Saracen Mineral Holdings that will see the dual-fuelled power station at the Carosue Dam operation, in Western Australia, expanded at the same time as work is extended at the gold miner’s gas-fired power facility at the Thunderbox operation.

The Carosue Dam expansion will occur in two stages over the next 12 months, initially by 2 MW and subsequently by another 6 MW, to a total of 26 MW. The contract term will also be extended from January 2023 to August 2024, Pacific Energy said.

Carosue Dam will soon undergo a mill expansion from 2.4 Mt/y to 3.2 Mt/y with feed coming from both underground and open-pit mines.

The contract for the 17 MW gas fired power station at the Thunderbox site will be extended from November 2020 to August 2024, meanwhile.

Pacific Energy’s total contracted capacity now stands at 381 MW and the weighted average remaining contract duration is approximately four years, the company noted.

Pacific Energy’s Managing Director, James Cullen, said: “Saracen is a key and substantial customer for us, representing around 12% of build-own-operate revenues, so these awards are very material and important to us. We look forward to continuing the sound relationship that has been built over the years and completing the installations of additional capacity at Carosue Dam.”