Tag Archives: flotation

Euro Sun Mining plots Rovina Valley gold-copper production route in DFS

Euro Sun Mining’s definitive feasibility study (DFS) on the Rovina Valley gold and copper project in Romania has outlined the development of two open-pit mines for a 21,000 t/d operation producing 132,000 oz of gold-equivalent over a 16.8-year mine life.

The company plans to use a phased development approach at Rovina Valley, with the development of the two open pit gold-copper deposits, Colnic and Rovina, included in the DFS and the exploitation of the Ciresata underground deposit (not included in the study) phased in following completion of open-pit mining. Ciresata is envisioned as a bulk underground mining operation and will be evaluated for its economic potential in a later study, the company added.

Estimated initial capital expenditure came in at $399 million (including $12.7 million in pre-strip), with average all-in sustaining costs of $813/oz of gold-equivalent. Using $1,550/oz gold and $3.30/lb copper prices, the post-tax net present value (5% discount) came in at $359 million.

These results were broadly in line with a May 2020 target of outlining a DFS with an 18-year mine life, with initial capital expenditure in line with the preliminary economic assessment – which showed off a capital expenditure bill of $339.7 million.

The Rovina Valley project is planned to be mined with a standard open-pit mining method using articulated trucks and a hydraulic loader. The open-pit mining operation is anticipated to last around 16.5 years, during which the lower-grade material will be stockpiled on a pad close to the primary crusher location for treatment over another 18 months. The DFS incorporates simple flotation without the use of cyanide and dry-stack tailings, the company said.

On the latter, the company said: “KCB have designed a waste management facility within the project area for the co-deposition of waste rock and filtered rougher tailings. Process plant rougher tailings will be filtered in the plant where the resultant filter cake will be transported by conveyors and will be co-mingled with waste rock prior to deposition. The cleaner tails will be filtered separately from the rougher tailings and the resultant filter cake will be transported by conveyors and deposited separately within a lined zone contained within the boundary of the co-mingled facility and will be stored separately in a lined zone of the waste management facility.”

Euro Sun said the design had been engineered to reduce the risk of development of impacted seepage from potentially acid-generating waste rock and capture the impacted seepage from the cleaner tailings.

“After completion of mining the Colnic pit, the waste rock and rougher tailings will be preferentially backfilled into the Colnic pit, while the cleaner tails will continue to report to the lined zone of the waste management facility,” it added.

The company said it is targeting first production from Rovina Valley in 2024.

Anglo’s Quellaveco to receive the coarse particle recovery treatment

Anglo American has approved the construction of a coarse particle recovery (CPR) plant at its in-development Quellaveco copper project in Peru.

The announcement came within the company’s 2020 financial results, which showed Anglo generated underlying EBITDA of $9.8 billion and a profit attributable to equity shareholders of $2.1 billion for the year.

CPR, Anglo says, is one of many significant breakthrough technology initiatives that has the potential to increase throughput and productivity, while simultaneously reducing environmental footprint, through rejection of coarse gangue (near-worthless waste material), dry stacking of sand waste, minimising the production of traditional tailings and reducing overall water consumption.

The CPR plant signoff at Quellaveco follows a full-scale demo plant installation at the company’s El Soldado mine in Chile – which is ramping up to full capacity by mid-2021 – and the decision to construct a full-scale system at the Mogalakwena North PGM concentrator in South Africa.

The El Soldado plant used the HydroFloat™ CPR technology from Eriez’s Flotation Division. Here, a single 5 m diameter HydroFloat cell, the largest in the world, treats 100% of mill throughput, with the objective of proving the waste rejection process at full scale.

Anglo said of the Quellaveco CPR plant: “This breakthrough technology will initially allow retreatment of coarse particles from flotation tailings to improve recoveries by circa-3% on average over the life of the mine. This investment will also enable future throughput expansion which will bring a reduction in energy and water consumption per unit of production.”

The capital expenditure of the CPR project is around $130 million, with commissioning of the new plant expected in 2022. DRA Global previously carried out a feasibility study for the CPR plant at Quellaveco.

In terms of Quellaveco project progress, Anglo said today that, despite the COVID-19-related slowdown, first production was still expected in 2022. This was, in part, due to the excellent progress achieved prior to the national lockdown, and based on optimised construction and commissioning plans, Anglo said.

Key activities in 2021 include the start of pre-stripping, which will see the first greenfield use of automated hauling technology in Peru; progressing construction of the primary crusher and ore transport conveyor tunnel to the plant; completion of the 95 km freshwater pipeline that will deliver water from the water source area to the Quellaveco site; completing installation of the shells and motors for both milling lines; and completion of the tailings starter dam.

The mine, owned 60% by Anglo and 40% by Mitsubishi Corp, comes with a production blueprint of 300,000 t/y over the first 10 years of the mine.

Anglo American Platinum’s modernisation drive to continue into 2021

Anglo American Platinum says it is looking to deliver the next phase of value to its stakeholders after reporting record EBITDA for 2020 in the face of COVID-19-related disruption.

The miner, majority-owned by Anglo American, saw production drop 14% year-on-year in 2020 to 3.8 Moz (on a 100% basis) due to COVID-related stoppages. Despite this, a higher basket price for its platinum group metals saw EBITDA jump 39% to R41.6 billion ($2.8 billion) for the year.

As all its mines are now back to their full operating rates, the company was confident enough to state PGM metal in concentrate production should rise to 4.2-4.6 Moz in 2021.

Part of its pledge to deliver more value to stakeholders was related to turning 100% of its operations into fully modernised and mechanised mines by 2030. At the end of 2020, the company said 88% of its mines could be classified as fully modernised and mechanised.

There were some operational bright spots during 2020 the company flagged.

At Mogalakwena – very much the company’s flagship operation – Anglo Platinum said the South Africa mine continued its journey to deliver best-in-class performance through its P101 program.

Rope-shovel performance improved to 26 Mt in 2020, from 15 Mt in 2019, while drill penetration rates for big rigs increased from 15 m/h, to 16.7 m/h. Alongside this, the company said its Komatsu 930E truck fleet performance improved to 298 t/load in 2020, from 292 t/load in 2019.

These were contributing factors to concentrator recoveries increasing by two percentage points in 2020 over 2019.

During the next few years, the company has big plans to further improve Mogalakwena’s performance.

In 2020, the mine invested R500 million in operating and capital expenditure, which included commissioning a full-scale bulk ore sorting plant, coarse particle rejection project and development of the hydrogen-powered fuel-cell mining haul-truck (otherwise referred to as the FCEV haul truck).

First motion of the 291 t FCEV haul truck is still on track for the second half of 2021, with the company planning to roll out circa-40 such trucks from 2024.

Anglo Platinum said the bulk sorting plant (which includes a Prompt Gamma Neutron Activation Analysis and XRF sensor-based setup, pictured) campaign at the Mogalakwena operation is due to end this quarter.

The company’s hydraulic dry stacking project is only just getting started.

This project, which involves coarse gangue rejection before primary flotation for safer tailings storage facilities, is expected to see a construction start in the June quarter, followed by a campaign commencement and conclusion in the September quarter and December quarters, respectively.

On another of Anglo Platinum’s big technology breakthrough projects – coarse particle rejection for post primary milling rejection of coarse gangue before primary flotation – the company plans to start a campaign in the December quarter of this year and conclude said campaign by the end of the March quarter of 2022.

The company also has eyes on making progress underground at Mogalakwena, with a hard-rock cutting project to “increase stoping productivity and safety” set for Phase A early access works this year. This project is set to involve swarm robotics for autonomous, 24/7 self-learning underground mining, the company said.

Lastly, the company’s said the digital operational planning part of its VOXEL digital platform had gone live at Mogalakwena. VOXEL is expected to eventually connect assets, processes, and people in a new digital thread across the value chain to create a family of digital twins of the entire mining environment, the company says. Development is currently ongoing.

Looking back to 2020 performance at the Unki mine, in Zimbabwe, Anglo reflected on some more technology initiatives related to R26 million of expenditure for a digitalisation program. This included installing underground Wi-Fi infrastructure, as well as a fleet data management system to track analytics on primary production equipment. The company says these digital developments will enhance real-time data analysis, improve short-interval control and overall equipment effectiveness.

To step up mechanisation of its PGM operations at Amandelbult, Anglo American Platinum is also investing in innovation.

This includes in-stope safety technologies such as split panel layouts to allow buffer times between cycles, creating safer continuous operation and reduced employee exposure; improved roof support technology and new drilling technologies; a shift to emulsion blasting from throw blasting; and safety enhancements through fall of ground indicators, 2 t safety nets, LED lights, and winch proximity detection.

Meanwhile, at the company’s Mototolo/Der Brochen operations, it is working on developing the first lined tailings storage facility at Mareesburg in South Africa to ensure zero contamination of ground water. The three-phase approach adopted for construction of this facility will be completed this year.

VanGold adds El Cubo mine and mill to El Pinguico precious metals mix

VanGold Mining has signed a binding agreement with Endeavour Silver to acquire the El Cubo mine and mill complex in Mexico, accelerating the company’s transition from development to production at its nearby El Pinguico silver-gold project.

With a rated capacity of 1,500 t/d, the El Cubo complex is made up of two operating underground silver-gold mines and a flotation plant. It employed over 350 people and engaged over 200 contractors until Endeavour suspended operations at the end of November 2019.

For the year ended December 31, 2018, Endeavour produced a total of 4.58 Moz of silver-equivalent at the complex at an all-in sustaining cost of $8.86/oz.

Currently, the El Cubo mine, plant and tailings facilities are on short term care and maintenance. VanGold intends to re-start the mill at around 750 t/d using mineralised material from its surface and underground stockpiles at the El Pinguico project as a significant portion of its estimated throughput for the first 36 months of operation. Endeavour Silver states it has measured and indicated resources of 236,000 oz of silver equivalent at El Cubo.

VanGold Chairman and CEO, James Anderson, said: “After working well with the Endeavour team during our 1,000 t bulk sample in June 2020, it became clear that El Cubo would be the perfect production fit for VanGold.

“The availability of mineralised material from El Pinguico’s surface stockpile, El Pinguico’s underground stockpile, El Pinguico’s remaining high-grade historical stopes and pillars, as well as El Cubo’s historical resources, gives us great flexibility in deciding where to source material for the mill, and how to sequence that throughput.”

El Pinguico is a high-grade gold and silver deposit that was mined from the early 1890s until 1913. VanGold has recently gained access to some of the historical underground shafts and has drilling campaigns planned to explore these areas.

Kazchrome achieves chrome tailings flotation breakthrough

Engineers at the Donskoy Ore Mining and Processing Plant of JSC TNC Kazchrome, in Kazakhstan, have successfully completed trials of a first-of-its-kind industrial flotation technology to increase the enrichment of chrome oxide-bearing tailings, Eurasian Resources Group reports.

Kazchrome, the world’s largest high-carbon ferrochrome producer by chrome content with a total resource base of over 200 Mt of chrome ore, is owned by ERG.

The novel technology is part of the group’s R&D efforts to maximise chromite concentrate output and reduce the site’s environmental footprint, the company reports, with the process yielding the recovery of over 55% of chrome oxide and conforming to the applicable requirements for concentrate used in ferrochrome smelting.

As a result of these trials, the flotation technology will be used to construct a new facility to process over 10 Mt of chrome oxide-bearing tailings with a planned annual capacity of 1.7 Mt for 450,000 t/y of chrome concentrate, ERG says.

Benedikt Sobotka, CEO of Eurasian Resources Group, said: “This pioneering technology is a major milestone on our path towards ensuring sustainable and low-cost chromite concentrate supply for our operations in Kazakhstan, and is part of the group’s broader strategy to reinforce our leading position in the global ferrochrome market.”

Sergey Opanasenko, Chairman of the Management Board of ERG R&D Centre, added: “We are very pleased with the results of the flotation trials, particularly considering the complex mineralogy and physical characteristics of our ores. Building on this success, we look forward to working on incorporating this technology into the design of our new tailings processing facility.”

Newcrest leverages Eriez HydroFloat tech to help boost Cadia output

Having installed the first full-scale HydroFloat™ cells for the recovery of coarse composited copper and gold at Newcrest’s Cadia Valley operation in New South Wales, Australia, in 2018, Eriez is about to help the miner boost output at the operation.

Today, the Newcrest Board approved two projects moving to the execution phase, being Stage 2 of the Cadia Expansion project and the Lihir Front End Recovery project, in PNG.

The Stage 2 Cadia Expansion project primarily comprises the addition of a second coarse ore flotation circuit in Concentrator 1 (graphic above), using Eriez’s HydroFloat technology, and equipment upgrades in Concentrator 2.

These changes are expected to see plant capacity go from 33 Mt/y to 35 Mt/y, while life of mine gold and copper recoveries could increase by 3.5% and 2.7%, respectively. Alongside this, the company was expecting a A$22/oz ($16/oz) drop in its all-in sustaining costs.

An increase in throughput capacity in Concentrator 2 from 7 Mt/y to 9 Mt/y will be achieved through crushing, grinding, cyclone, pumps and flotation upgrades; while the installation of the second Coarse Ore Flotation circuit on Concentrator 1 and additional upgrades to Concentrator 1 will facilitate an increase in throughput capacity to up to 26 Mt/y, the company said.

“Stage 1, which is already in execution, was designed to maintain production continuity at Cadia through the development of PC2-3 (the next cave development) and increase the processing capacity to 33 Mt/y,” Newcrest said. “Stage 1 comprises an upgrade to the materials handling system and debottlenecking of the Concentrator 1 comminution circuit.”

The rate of ore mined from Cadia is expected to vary over time according to draw rates, cave maturity and cave interaction as further caves are developed, according to Newcrest. From the 2027 financial year onwards, life of mine Cadia mining rates are generally expected to be in the range of 33-35 Mt/y, with an average of 34 Mt/y used for financial evaluation purposes, the company said. Higher mine production rates may be possible, subject to further studies.

At throughput rates of 34 Mt/y, gold recovery improvements from Stages 1 and 2 are expected to achieve LOM gold recoveries of 80.3% and LOM copper recoveries of 85.2% compared to Stage 1 baselines of 76.8% for gold and 82.5% for copper.

The estimated capital cost for Stage 2 is A$175 million, A$5 million lower than the October 2019 estimate, according to Newcrest, which added that timing for delivery remains on schedule, with completion expected late in its 2022 financial year.

The Lihir Front End Recovery project, meanwhile, primarily comprises the installation of flash flotation and additional cyclone capacity, as well as cyclone efficiency upgrades, to improve grinding classification and reduce gold losses through the flotation circuits, Newcrest said.

The flash flotation and cyclone upgrades target the following process improvements:

  • Implement flash flotation to reduce mineral fines generated from overgrinding and send the higher-grade concentrate stream to the autoclaves; and
  • Improve cyclone efficiency to achieve a reduction in unliberated coarse mineral particles entering the cyclone overflow, which are not recovered in conventional flotation.

This is projected to result in LOM gold recoveries increasing by 1.2% and incremental LOM gold production increasing by 244,000 oz. It came with an estimated capital cost of A$61 million.

New Metso Outotec Courier on-stream analyser could reduce gold losses

Metso Outotec is launching its next-generation Courier® 6G SL on-stream analyser for direct measurement of gold, platinum and other valuable metal concentrations from ore feed, concentrate, and tailings streams.

The new analyser enables accurate real-time elemental analysis measurement critical for establishing efficient process control to improve process stability and maximise recovery, it says.

It builds on the Outotec Courier 6X SL analyser with a more powerful X-ray tube and measurement channels optimised for direct on-line measurement of gold and other elements from calcium to uranium, the company says. This makes it particularly suitable for applications where gold is recovered with other metals such as silver or copper.

The system can measure up to 24 individual process streams – each with an individually adjustable measurement time – to ensure optimal measurement accuracy and sampling frequency in even the most complex polymetallic flotation circuits. It can also provide direct measurement of gold concentrations down to 0.2 g/t

The new next-generation on-stream analyser combines Wavelength Dispersive X-ray Fluorescence and Energy Dispersive X-ray Fluorescence technologies with a high-power X-ray tube for unparalleled measurement performance, Metso Outotec claims. It also features an automatic internal reference measurement for guaranteed stability under changing environmental conditions.

Lauri Veki, Metallurgist at Agnico Eagle’s Kittilä operation in Finland, said: “Agnico Eagle Kittilä has used the new on-stream analyser for flotation control and optimisation since October 2019. Measurement information provided by the Courier 6G SL has enabled more efficient control of the pre-flotation circuit and helped to reduce gold losses.”

Appian, Atlantic Nickel reinvigorate Santa Rita as nickel sulphide fortunes rise

At the height of the most recent nickel boom – when prices were over $20,000/t on the LME – the Santa Rita mine looked like a great option to gain exposure to the stainless steel raw material.

Mirabela Nickel, the mine owner, represented a pure-play nickel stock; Brazil, as a jurisdiction, was looked at favourably by investors; and the operation, itself, was one of the largest open-pit nickel sulphide mines in the world slated to produce 16,500 t/y of nickel sulphide in concentrate.

Gaining exposure to such a large, low grade asset is great when the underlying commodity price is tracking well, but, as has been shown time and again, it proves problematic when the price moves south.

Such a price deterioration came to pass in the years following the mine’s start up in 2009.

The asset, in north-eastern Brazil, was eventually placed on care and maintenance in the March quarter of 2016 as Mirabela Nickel declared bankruptcy. This was the same year the nickel price dipped below $10,000/t.

Fortunately for the local community and personnel that had invested much hope in the development of the $1 billion-plus mine, Appian Capital Advisory more recently took the view that there was a way forward for Santa Rita.

Picking up on an emerging trend for clean and green nickel sulphide concentrate from the electric vehicle and stationary storage market, plus the ability to re-engineer the operation and make it a much more robust asset, the company carried out a six-month due diligence process on Santa Rita.

This process led Appian to refine its understanding of the presence of nickel sulphides within the deposit, as opposed to the asset’s total contained nickel. With this understanding in hand, a more defensive and low-cost mine plan was developed to see the asset through nickel price peaks and troughs.

Appian ended up acquiring Santa Rita and setting up the Atlantic Nickel operating entity to enact these changes.

Having restarted open-pit mining just over a year ago, the asset is starting to pay back the faith Appian has placed in this plan.

“Our resource now focuses on the estimation of nickel sulphide within the deposit and benefits from additional drilling we’ve undertaken post-acquisition,” Adam Fisher, Principal, Appian Capital Advisory LLP, explained to IM. “The mine design we’ve developed extracts the deposit more selectively and also moves less waste, resulting in the low cost performance we’ve been able to achieve to date.”

In the first half of 2020, the company declared first quartile C1 cost performance of $3.17/lb ($6,989/t) nickel, net of by-products. This compares favourably with Mirabela Nickel’s $6.19/lb operating cost recorded in the September quarter of 2013.

“Among the operating changes we’ve implemented are the use of a smaller, locally procured, equipment fleet of 40 t trucks (Santa Rita previously used Caterpillar 777 90 t and 785 137 t payload trucks), the use of shorter benches – we’ve gone from 10 m down to, on average, 6 m – and tighter blasting patterns,” Fisher said.

All this work is being carried out by a Brazil-based consortium of contract miners.

“With smaller benches, tighter blasting patterns and smaller equipment fleets, we have more consistent control on the grade and fragmentation of the material that is fed to the crusher,” Fisher said.

The focus has gone beyond the near term, with more than 100,000 m of drilling executed in the underground resource area. The drilling was optimised for resource growth and classification confidence. The program was extremely successful and supported the declaration of the underground resource of 168 Mt at 0.59% NiS and 0.19% Cu. The 2020 drill programs continue to intersect similar widths and grades while stepping out from the declared resource, the company added.

The NI 43-101 technical report, released earlier this month, outlined a 34-year mine life for Santa Rita, with eight years of open-pit production, underpinned by proven and probable reserves of 50.6 Mt at 0.31% NiS, followed by 26 years of underground mining.

While still preliminary, this represented a very different approach to the previous Santa Rita owner.

“The last owners designed an open-pit mine with a 6:1 strip ratio and were planning to mine a lot deeper into the resource via open-pit methods,” Fisher said. “This was back in a very different nickel market when prices were greater than $10/Ib.

“All we did was find the optimal transition to bulk methods at depth to understand that it only makes sense to mine this as an open pit over eight years at a strip ratio that comes down to, on average, 2.7:1.”

Backing up this open-pit mine plan has been a 6.5 Mt/y plant, which, having started production in 2009, was completely refurbished and recommissioned in the second half of 2019 to align with the nickel sulphide recovery focus.

The plant consists of crushing, grinding, flotation, thickening and filtration unit operations to produce a saleable nickel sulphide concentrate. Flotation tailings are pumped to a tailings storage facility, while grinding is performed by a SAG mill, two ball mills and two pebble crushers. This is followed by a conditioning circuit and a flotation circuit, with the final concentrate thickened and pumped to storage tanks ready for filtration. Concentrate is filtered in a Larox (Metso Outotec) pressure filter. Following filtration, the final concentrate is trucked to the port of Ilhéus where it is loaded onto ships for transport to market.

Since the restart, more than five shipments have been made to the mine’s offtake partners.

“While the mine and plant are still ramping up, the open-pit operation is not far off from achieving the PEA estimates of being able to produce 20,000-25,000 t/y of contained nickel sulphide equivalent at a C1 cost of $2.97/Ib nickel,” Fisher said.

Beyond this, the company is looking to leverage innovation to create one of the largest and most efficient sub-level cave (SLC) operations in the world able to produce more of the highly sought after nickel sulphide product Santa Rita is becoming known for.

Caving in

“When carrying out the due diligence on Santa Rita, we knew all along that there was some good, thick intersections underground, with the orebody getting thicker at depth and the nickel sulphide grade improving,” Marcus Scholz, Head of Underground Mining at Appian Capital Advisory, told IM.

This was evident in the PEA, with underground mining inventory of 134.1 Mt grading 0.54% NiS and 0.17% Cu, comparing favourably – in terms of grade – with the proven and probable reserves of 50.6 Mt at 0.31% NiS and 0.11% Cu calculated for the eight-year open-pit operation.

“You’re looking at a massive orebody with moderate grades,” Scholz said. “Factoring that in, the lowest cost methods will generate the better margins in this case. With SLC having come a long way in the last 20 years in terms of practices, philosophies and the ability to control dilution through effective planning and modelling, plus the suitable geometry of the Santa Rita orebody, it was a good fit.”

This low-cost caving method allows the company to exploit more of the resource than other methods such as long-hole open stoping with backfill, plus fill the existing plant, Scholz explained.

Scholz was keen to point out that the company did not come to this conclusion on its own. It sought assistance from Power Geotechnical out of Australia, which has worked on other sub-level cave operations such as Carrapateena and Ernest Henry, when assessing its options.

Ernest Henry, operated by Glencore in Queensland, Australia, is a good analogue here. The Ernest Henry orebody is located at a similar depth below a pit and has a similar width and dip, but Santa Rita is about twice the size due to it being longer along strike, according to Scholz. It also comes with a similar 6 Mt/y profile.

Photography of Glencore’s Ernest Henry Mine near Cloncurry in Western Queensland

The SLC mining layout in the PEA comprises 37 mining levels spaced at vertical intervals of 25 m. Each level is made up of parallel and evenly spaced drill drives from which production drilling and blasting occur. Once blasted, the mineralisation is loaded from the drill drives using LHDs and loaded into trucks for haulage to the surface during the initial ramp-up phase, and later to ore passes feeding an underground crushing station and conveying to surface via an inclined tunnel.

The PEA plans will have the company mine directly beneath the open pit to start with, hence the reason it expects to start up production in 2028 after open-pit mining has concluded.

The underground operation will start with two years of waste development ahead of ore production, followed by ore truck haulage over a three-year period, Scholz outlined. After this, the operation will transition to underground conveyor haulage, ramping up to 6 Mt/y capacity over the next four years.

Asked why the company was starting with truck haulage before moving to conveyors, Scholz said it was an economic decision.

“If we truck first, we can delay some of the underground spend in terms of getting the underground crusher in,” he said.

Over the life of the underground mine, the company plans to install two underground crushers, being fed with roughly equal amounts of ore. The first will serve the upper half of the deposit and the second crusher the lower half (circa-6 Mt/y each, staged as mining progresses deeper in the deposit).

The first crusher will be positioned about 650 m below surface, or 450 m below the ultimate depth of the open pit.

“This will take a bit of time to get down there and access it (in terms of mine development), so it makes sense to start haulage with trucks,” Scholz said.

Appian is looking to lease the 60 t trucks required for this stage of the operation, explaining that Atlantic Nickel will operate the 12 machines needed at the height of truck haulage, which is when mining rates hit the annualised 2.5 Mt/y mark.

The truck haulage route will be a short one, travelling some 200-300 m below surface to access material before going back above ground.

After the conveyor transition, the trucks are expected to be used in later years for waste haulage, which could amount to some 500,000 t/y of material, according to Scholz.

Automation and electrification transition

It is when the conveyor starts up that the automation element of Santa Rita Underground really kicks into gear.

The company assumed the use of automated LHDs, longhole drilling and jumbo development drilling in the PEA. This saw Epiroc, Caterpillar and Sandvik provide price inputs, with design layouts anticipating such equipment.

Scholz expanded on this for IM: “We foresee that loaders going from the SLC drawpoints to the ore passes would be automated, meanwhile, at the collection level at the bottom of ore passes, we would probably have up to three large automated loaders that transfer material to the crusher.”

Longhole drills would also be automated for the SLC, while the company plans to automate face drilling activities on the development jumbos it will use.

“I think in another eight years’ time when we start up production, a lot of this technology is going to be the norm in the industry,” Scholz said.

The current study assumes the use of a diesel-powered load and haul (initially) fleet, though electric vehicles could provide upside in future studies and further reduce energy costs, equipment maintenance costs and ventilation power costs, an Appian spokesperson recently told IM.

“Both tethered- and battery-powered machines will be looked at for specific applications within the mine, such as loading from drawpoints and feeding the underground crusher from the bottom of ore passes,” the spokesperson explained.

While much of the industry’s larger load and haul equipment has not yet made the commercial leap to battery power, the company is keen to pursue developments in the future as the technology became available, Scholz said.

The circularity of such a move will not be lost on Appian or Atlantic Nickel, knowing the nickel sulphide concentrate it will be offloading could end up in these battery-powered machines. In eight years, these end users will most likely be factoring such emissions-reducing technology into their raw material procurement choices.

For the time being, the company is focused on completing the underground drilling program at Santa Rita, which has, to date, shown much promise.

Fisher said every hole has intersected nickel sulphides to this point meaning the chances of a further underground resource upgrade in the early part of next year were high.

These figures will be factored into a prefeasibility study later in 2021, which will include more detailed geotechnical information on the SLC, as well as subsidence modelling, Scholz said.

Vale starts dry iron ore concentration pilot with New Steel technology

Vale has inaugurated its new dry pilot plant for processing iron ore in Minas Gerais, Brazil, as it continues to reduce its use of water in ore and waste processing.

The Brazilian technology, known as FDMS (Fines Dry Magnetic Separation), is unique and has been developed by New Steel – a company Vale acquired in late 2018.

The pilot plant, which cost $3 million, is the first step towards the construction of an industrial plant that will have a production capacity of 1.5 Mt/y. The investment in this project is near $100 million, with the commercial plant start-up scheduled for 2022, as the company announced back in February.

Vale estimates that, in 2024, 1% of all the company’s production will use this technology, whose patent is already recognised in 59 countries.

President of New Steel, Ivan Montenegro, said: “NS-03 is a semi-industrial plant to carry out tests on a pilot scale with different types of ore, allowing the definition of operational parameters for commercial-scale projects.”

Installed at Vale’s Ferrous Technology Center, in Nova Lima, the pilot plant is the second to start operating. Between 2015 and 2017, a unit operated at the Fábrica mine, also in Minas Gerais. The results allowed Vale to see the potential of the FDMS technology, it said, ultimately leading to Vale taking over New Steel.

The new pilot unit will be able to concentrate 30 t/h of ore using dry magnetic separation technology equipped with rare earth magnets.

Vale’s Executive Director of Ferrous, Marcello Spinelli, said New Steel puts the company at the “forefront” of investments in ore processing technology.

“We will continue to seek solutions that increase the safety of our operations,” he added.

With New Steel and its dry process technology, Vale estimates that, in 2024, 70% of production will come from dry or natural moisture processing, without adding water to the process and without using tailings dams. Today, the company produces 60% of iron ore using natural moisture processing.

By 2024, from the production using wet processing (30%), 16% will have filtered and dry-stacked tailings, with only 14% continuing to use the conventional method with wet concentration and tailings disposal in dams or deactivated extraction sites.

This transition will see Vale invest $1.8 billion in filtering and dry stacking in the coming years. The first units to use the technique will be Vargem Grande complex (in Nova Lima), Pico mine (in Itabirito), Cauê and Conceição mines (in Itabira), and Brucutu mine (in São Gonçalo do Rio Abaixo).

New Steel’s technology can deliver a concentrate with iron content up to 68% Fe from poor ore with content up to 40% Fe, depending on its chemical and mineralogical composition, according to Vale. Currently, this concentrate is produced by flotation, which uses water. In flotation, the tailings are usually disposed of in dams, but, with the dry concentration technology developed by New Steel, the tailings will be stacked.

Vale is studying methods to use these filtered cakes as raw materials for the civil construction industry, in addition to other initiatives, such as co-products.

Copper Mountain ups cleaner circuit efficiency, capacity with new flotation reactors

Copper Mountain Mining says it has successfully installed and commissioned the direct flotation reactors (DFRs) at its Copper Mountain mine, on schedule and on budget.

The installation represents the first stage of the mill expansion project at the operation in British Columbia, Canada, which will bring plant capacity to 45,000 t/d, from 40,000 t/d.

The installation of the Woodgrove DFRs increases the efficiency and the capacity of the current cleaner circuit, which is expected to increase the copper concentrate grade from about 25% to 28%, resulting in lower concentrate transportation, smelting and refining costs, Copper Mountain said.

Gil Clausen, Copper Mountain’s President and CEO, said: “The DFRs have been commissioned and turned over to operations. This is a testament to the great work of our operating and projects team. The DFRs are a low capital, high return project and we are already seeing improved concentrate grades.”

The next stage for the mill expansion project is the installation of the third ball mill, according to Clausen.

“We have the ability to rapidly restart this stage as we have maintained long-lead time expenditures and we also have the flexibility to accelerate the project as necessary,” he said. “With the installation of the third ball mill, we expect production to increase by 15-18% as a result of higher throughput and improved recoveries.”

The Copper Mountain mine, a conventional open pit, truck and shovel operation, is owned 75% by Copper Mountain and 25% by Mitsubishi Materials Corp.

It currently produces, on average, some 90 MIb (40,823 t) of copper equivalent annually, which is expected to increase to 120 MIb/y with the plant expansion.