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Woodsmith-MTS-Anglo

Anglo American lays out 5 Mt/y Woodsmith polyhalite plan ahead of full design review

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This week, Anglo American hosted an investor and analyst day at its in-development Woodsmith project, in the UK, with several key technology takeaways cropping up from an in-depth presentation from Tom McCulley, CEO, Crop Nutrients.

In reviewing progress and the past, McCulley stated that Anglo has decided to start Woodsmith as a 5 Mt/y operation, with a staged ramp-up planned to the 13 Mt/y rate. The plan to sink 1,600 m production and service shafts, establish a mechanised mine, construct the 37-km-long underground tunnel and build a materials handling facility with priority access export facilities remain part of this. The potential to phase ventilation & production level development within the underground mine, potential to phase conveyor upgrades in the underground tunnel and the potential to carry out a phased expansion as required for the export facilities are all options for the 13 Mt/y blueprint.

This change has required some of the scope to go back to study phase – hence the reason why Anglo has been mooting detailed design reviews and non-critical path studies – looking at how to optimise investment and modularise the construction to get maximum value from each phase, McCulley said.

“I feel far more comfortable today about how we are setting up the project for the long-term success but managing in a capital efficient way,” McCulley said during his presentation.

Some of the elements keen observers have been watching at Woodsmith are related to mechanised underground development – both vertical (via shaft sinking) and horizontally (via tunnel boring machines (TBMs) for the 37-km-long tunnel).

TBM-led tunnel transformation

In terms of the latter, Anglo American is soon expecting to set a World Record for the longest TBM tunnel developed by a single TBM. This is currently set at 25.8 km, with the Woodsmith team having already reached the 25-km (25.3 km) mark.

“Beyond this we will pass our next intermediate shaft at Ladycross, where we will take a 3-4 month maintenance pause as we set up the TBM for the final push to 37 km, and we expect to reach the Woodsmith mine in late 2026,” McCulley said.

The machine used at Woodsmith is a Herrenknecht hard-rock TBM that, McCulley says, works similarly to the Shaft Boring Roadheaders (SBRs) being used for shaft sinking (more on that soon) in that it cuts the soils, without blasting, and the material is transported through the machine and out of the tunnel via a conveyor that is part of the TBM.

“In addition to excavating the material, the TBM also simultaneously lines the tunnel via pre-cast concrete segments (six segments make up a ring around the circumference of the tunnel); these concrete segments are fabricated at the Teesside port by a project dedicated facility,” McCulley said.

He said in every measure the tunnelling on the project to date has been an amazing success, aided by a solid team performance. This team is made up of contractors from Strabag, Herrenknecht and Anglo’s in-house personnel.

Progress has been aided by consistent ground conditions across the tunnel within what is called Mudstone strata, McCulley said.

“These conditions are very predictable and cutting is easy for the machine which minimises the bearing wear, which is a key risk area for the TBM,” he said. “This consistent strata has allowed us to switch our strategy from three TBMs to one TBM for the entire 37 km, which means we will not only pass the World Record, but we will also smash it when we reach Woodsmith in late 2026. This reduction in TBMs had a knock-on impact of saving significant capital over what was originally planned.”

Anglo is consistently seeing average rates increase to over 20 m/d and trending closer to 25 m/d, which compares favourably with about 16-17 m/d in late 2021.

Tom McCulley-Anglo American
Tom McCulley, CEO, Crop Nutrients

SBRs on the up

Mine development via TBMs is relatively proven when compared with the use of Herrenknecht SBRs for shaft sinking in mining, with Woodsmith representing only the third deployment of the technology in mining following Jansen (BHP) and Nezhinsky (Slavkaliy).

Anglo has two SBRs on site at Woodsmith, sinking the production and service shafts at the project. Redpath, which carried out the shaft sinking work at Nezhinsky, is steering developments at these two shafts, in addition to the material transport system shaft. Only the much deeper production and service shafts are being sunk via mechanised means with the SBRs.

Overseeing this and all developments at the operation is Worley as an engineering, procurement and construction management contractor.

Sinking of the service shaft began in September-October 2022, followed some six months later with activities at the production shaft. McCulley said these two were now around 550-m deep and 340-m deep, respectively.

“We typically see more daily meters from the production shaft due to the service shaft lessons being applied to the production shaft, so I’m excited as I think we may have a race to polyhalite!” he said. “We are very pleased with the progress made on both shafts since Redpath started sinking in 2022.”

On the advantages associated with using SBRs, McCulley said: “Some of the primary benefits of these machines is they are inherently safer than traditional sinking. They also eliminate the need for explosives, which is a huge benefit to us with the community as we don’t encounter noise complaints experienced in other mines. I expect these machines to be the future of shaft sinking. They are just safer, quicker and more predictable.”

The SBR is generally working in autonomous mode for most of the time following a program with pre-set parameters for cutting, according to McCulley, who said the company is expecting an average rate of 1 m/d in each shaft over the full 1,600-m length of the shafts.

“This 1 m/d includes all routine maintenance and what we call non-routine work, like installing water cubbies for pumping water out of the shafts, probe drilling, tubbing and grouting,” he said.

“Ultimately, this is the right machine for the job at Woodsmith and the cutting rates we achieve are 1.5-2 times what we would do with traditional methods.”

Looking at current sinking progress and plans to hit the orebody in 2027 in the service shaft (with the production shaft being six months behind that), McCulley pointed out a 250-m section of sinking in Sherwood Sandstone, which the company expects to reach next year.

“This 250 m of strata will see our rates reduced from our 1 m/d to something between 0.5 m and 0.75 m a day, and this will impact us for most of next year and early 2025,” McCulley said. “Once through that strata, we do not expect any further issues with the ground conditions significantly impacting production.”

The Sherwood Sandstone is characterised as a strata of highly competent rock, about 120 Mpa, according to McCulley, which is at the top end of the SBR rock hardness capacity given by Herrenknecht.

In addition to the hardness, this strata has the potential for some water fissures (ie cracks in the rock with high pressure water), according to McCulley.

“The good news for us is we hit a 2.5-m layer of this material a few weeks ago and we learned from this that we need to make some adjustments to our cutter heads and cutting picks, and now we are far more prepared than we would have been otherwise,” he said. “We are also prepared with alternative plans, including potential use of lasers, plasma blasting and/or microwaves if needed, but we expect our updated cutter head and next generation picks, developed by Element 6 of De Beers, will cut through the rock at the rates I previously mentioned. In addition, to the hard rock, this strata has a risk of high-water flows in small sections of the strata so we will need to seal the shaft via grout from the shaft. This means as we come across water, we will inject chemical grout into the fractures to block water bearing cavities and control water inflow.”

Adding to McCulley’s confidence is the fact that the nearby Boulby mine encountered the same strata some time ago, which that team progressed through via the same exact grouting technique Woodsmith is planning today.

In terms of priorities for 2023, McCulley said the team expected the service shaft to be between 650-700 m at the end of the year, versus the current circa-550 metres today, whereas the production shaft could reach 450 m by this point.

“Both shafts, if they hit the numbers noted will exceed our planned targets for the year,” he said.

“The MTS shaft and Ladycross shafts are both sunk, and we are working to fit them out during the remainder of the year. In the tunnel we have driven 4.3 km this year, we are at 25.3 km and we expect to reach 27 km, which is our stretch target for the year.”

For 2024, while Anglo continues to work through the studies, it doesn’t see any changes to its plans right now and still expects to be around the $1 billon capex number for the next few years.

McCulley added: “Our vision at Woodsmith with regards to technology is to ultimately develop a peopleless underground mine, where operations and maintenance are all controlled from the surface. This is a journey, but many technologies are already out there, we just need to put the system in place and the wherewithal to help the vendors take the next step. This will not happen from the start, but with our vision and with the team we have in place, I have no doubt that in the future this vision will become a reality.”

When at full production, Woodsmith will be a FutureSmart Mine with all the modern technologies, according to McCulley, with these characteristics ensuring the company has a low cost, high volume mine for many years to come. Continuous miners are expected to be used in a room & pillar mining application, combined with mine cars, shuttle cars or conveyors.

“On top of the mining/processing technology, I see some interesting parallels with the farming industry. They are rapidly adopting technologies, and we are very well placed to support this transition in areas like sensing, scanning, AI, etc. I think with our Anglo American Woodsmith project experience in technology we are uniquely positioned to help support this transition in farming and this is something that will have added value to our product for years to come.”

Anglo American increases Woodsmith polyhalite scale as shaft sinking progresses

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Anglo American is upping the ante at its Woodsmith polyhalite project in the UK, increasing its planned spend while expanding its production scope following detailed design reviews and non-critical path studies.

In the company’s 2022 results release today, it said these reviews and studies had led to a number of areas being modified to align with Anglo American’s standards and its aim to optimise value for the long term.

The outcome is an enhanced project configuration to ensure the company delivers maximum commercial returns from Woodsmith over the expected multi-decade asset life, Anglo said. Included within this is an increase in the capacity of the shafts and other infrastructure to accommodate higher production volumes and more efficient and scalable mining methods over time.

More specifically, this has seen the company plan for a circa-13 Mt/y operation instead of the previous 10 Mt/y operation it had endorsed, subject to studies and approval.

“In light of these changes, Anglo now expects first product to market in 2027, with an annual capital investment of around $1 billion,” the company said.

Spending of $800 million is approved for 2023, with the bulk of initial spend on the shaft sinking and tunnel boring activities. As usual in developing underground mines, the schedule will largely be determined by the ground conditions encountered as sinking activities progress.

The Woodsmith project is located on the North Yorkshire coast, just south of Whitby, where polyhalite ore will be extracted via 1.6-km-deep mine shafts and transported to Teesside via an underground conveyor belt in a 37 km tunnel, thereby minimising any environmental impact on the surface. It will then be granulated at a materials handling facility to produce a low carbon fertiliser – known as POLY4 – that will then be exported from its port facility, where it has priority access, to a network of customers around the world.

During 2022, as part of the mentioned construction review, contracts were awarded for the shaft sinking operations, program management services and construction management to ensure the project can be executed in line with Anglo American’s stringent requirements. These contracts were awarded to Redpath (shaft sinking) and Worley (program management services and construction management).

With the award of these contracts and other infrastructure improvements, activities at the deep shafts have progressed. The service shaft is now more than 360 m deep, while shaft sinking began 120 m below the surface for the production shaft in January 2023, as planned. Both of these shafts are being sunk using Herrenknecht’s Shaft Boring Roadheader technology.

Three intermediate shafts will provide both ventilation and additional access to the mineral transport system (MTS) tunnel. The Lockwood Beck intermediate access shaft was successfully completed in 2022 and is fully lined and connected to the tunnel. Work on the MTS shaft at the mine head progressed through 2022 and is 85% complete, and the excavation at the final intermediate access shaft at the Ladycross site commenced in early 2023.

Following a planned maintenance pause in mid-2022 to refurbish the tunnel boring machine and allow the connection with the Lockwood Beck shaft, the MTS tunnel is now past the 21-km point and is more than 56% complete, progressing at rates not seen since the start of the tunnelling activities, Anglo said.

Anglo American concluded: “We believe that the changes we have made to the project have had a materially positive impact on the project’s long-term attractiveness and prospects. However, for accounting purposes at this early stage of the project’s development, we have recognised an impairment of $1.7 billion to the carrying value of the asset within special items and remeasurements, reflecting the extension of the development schedule and capital budget.”

Anglo American continues SBR-led shaft sinking progress at Woodsmith

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While Anglo American continues with its detailed technical review of the Woodsmith polyhalite project in the UK, shaft sinking activities at the asset continue to progress, the company confirmed in an investor update today.

The project was acquired by Anglo American in 2020 with the purchase of Sirius Minerals. Since then, Anglo American has been working on refining the development pathway and overall production potential of the asset.

In an investor presentation today, the company outlined physical progress on the site, explaining that shaft sinking for the circa-1.6-km deep service shaft had progressed to the circa-265-m level. It also said the mineral transport shaft, which it is working on with Redpath Group as sinking contractor, had reached the circa-230-m level of a planned 321-m depth.

Regarding horizontal development, it added that the 37-km mineral transport tunnel – which will connect to the mineral transport shaft – had reached the 20-km development mark with tunnel boring machine technology.

The Woodsmith project overview includes the sinking of production and service shafts with 6.75-m diameters – having depths of 1,594 m and 1,565 m, respectively – and the 37-km-long concrete-lined tunnel containing a conveyor belt, which transports the polyhalite ore from Woodsmith mine, near Whitby, to the Mineral Handling Facility, on Teesside, for processing and shipping.

Both the service shaft and production shaft at Woodsmith are being sunk using Herrenknecht’s Shaft Boring Roadheader technology, which has previously featured on the Jansen potash project in Saskatchewan, Canada, where it excavated two 8-11 m diameter blind shafts down to circa-1,000-m-depth and the Slavkaliy-owned Nezhinsky potash project, where it ended up breaking shaft sinking records under the guidance of contractor Redpath Deilmann on a project to sink two 8-m diameter shafts (one to 750-m depth and one to 697-m depth).

The first cut for the service shaft was made in July 2021, with Anglo American and Redpath Deilmann – which is now leading the sinking project as shaft sinking contractor – restarting sinking activities on this shaft earlier this year.

In the same investor presentation issued today, Anglo American said it planned to start sinking in the production shaft in the March quarter of 2023.

While the ongoing review takes place, Anglo American confirmed it had approved $800 million of capital expenditure for Woodsmith next year, focused on shaft sinking and other critical infrastructure as part of its phased approach to the asset.

Stephen Pearce, Finance Director of Anglo American, said on Woodsmith: “As we have said for some time, we are improving the project’s configuration to ensure we realise the full commercial value over the expected multi-decade asset life. This will extend the development schedule and the capital budget, compared to what was anticipated prior to our ownership, and so potentially impact our carrying value of Woodsmith for accounting purposes at the year end.

“Looking ahead, we are even more positive today about the prospects for Woodsmith and its potential to become a high margin, major contributor to our diversified product portfolio given the outstanding nature of the resource and the premium pricing upside we expect to realise for Poly4 – the highly effective, low carbon fertiliser we will produce.”

Herrenknecht making headway on hard-rock mechanised shaft sinking operations

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Herrenknecht used the Bauma 2022 stage last month to reveal details about its latest mechanised shaft sinking solution for mining, the Shaft Boring Cutterhead (SBC).

The company, which has successfully delivered its Shaft Boring Roadheader (SBR) to soft-to-medium rock sinking applications in mining, has equipped its latest concept for hard rock up to 250 MPa uniaxial compressive strength (UCS), with the machine able to carry out cutting, lining and mucking operations concurrently.

The SBC’s specification is based on the experiences from six past mechanised shaft sinking projects and was developed in tandem with a global shaft sinking company Redpath Deilmann.

Two of the projects that influenced the design used the SBR – the blind sinks at BHP’s Jansen mine in Canada and Slavkaliy’s Nezhinsky mine in Belarus. The company has also supplied two SBRs to Anglo American’s Woodsmith mine, with one already carrying out sinking operations.

Redpath Deilmann operates SBR shaft sinking operations at Woodsmith, with DMC Mining previously in charge of sinking operations at the Jansen project.

“This new generation of blind shaft machinery aims to update and adapt existing technology to current conditions and requirements,” Martin-Devid Herrenknecht, Member of the Board of Management, says.

Speaking in Munich in a presentation titled ‘Mechanised sinking of deep shafts in hard rock’, Patrick Rennkamp, Product Manager Mining, Herrenknecht, said the SBC had been designed for shaft diameters up to 9 m and shaft depths of circa-1,500 m. The machine weight starts from 450 t and it is 45 m in length.

One of the unique elements Rennkamp highlighted was the pneumatic mucking system on board the SBC.

Building on a similar system used for the SBR, the mucking process on the SBC is tied to the circular motion of the cutter discs situated on the full-face cutterhead. The movement of the discs and suction, combined, ensures the machine only cuts the material once, Rennkamp explained to IM on the side lines of the event, reducing wear on the cutters and keeping the machine cutting for longer.

The design ensures that the cut material filters into the centre of the machine where the suction element is most effective. The cuttings then go up the suction pipe into a suction box before being filtered into coarse and fine material and blown further upwards where they can be transported to another overhead station for removal – via buckets – to surface.

Like the SBR, the machine has a gripper system to keep it in place within the shaft. There is also a lining area directly above the grippers and further work decks for concurrent work.

The company is targeting sinking rates of 6-8 m/d with the new SBC. While this is short of the progress traditional TBMs make in horizontal developments, it is quicker than traditional drill and blast methods used for blind sinking.

Herrenknecht had a team of some 40 working on the development of the SBC at its Schwanau facility in Germany. This is complemented by a team at Redpath Deilmann’s facilities in Germany, who are also providing input to the project.

To this point, the company has carried out 600 tests with different sizes of material, completing some 9 m of shaft sinking in 30-40 MPa UCS concrete with a demonstration rig that is 1:3 the size of the full-size machine.

The next steps are to invite potential customers to supply their own material for testing on the rig and validate the hard-rock cutting potential.

Redpath continues mechanised sinking evolution with S20+ deployment at Odyssey

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Redpath is continuing its focus on mechanised shaft sinking operations, with the latest example being the planned use of the hydraulic shaft mucker S20+ at the Canadian Malartic Partnership’s (CMP) Odyssey gold project in Quebec, Canada.

Redpath Canada was recently contracted by the CMP to sink a 6.5-m diameter, 1,800-m deep concrete lined shaft at Odyssey, a project that has the potential to become one of Canada’s largest and most technologically advanced underground gold mines.

CMP, which is 50:50 owned by Yamana Gold Inc and Agnico Eagle Ltd, previously laid out plans to extract 19,000 t of ore at an estimated grade of about 2.75 g/t gold and roughly 5,000 t/d of waste rock during peak operations at Odyssey. The ore will be processed at the operation’s existing plant, which will eventually be adapted to the future mine’s needs including shifting from 57,000 t/d to 20,000 t/d. The ore will be hauled to surface using Blair production hoists with use of both shaft bottom and mid-shaft ore handling systems.

The sinking concept at Odyssey includes the use of the S20+, which was built by Redpath Deilmann in Germany. A previous iteration of this machine, the S20, was used with success on four shaft projects in both soft rock – with an integrated tool package – and hard rock.

The S20+ offers similar capacity/productivity to a North American pneumatic telescopic boom mucker but with a much easier learning curve for operators, according to Kevin Melong, Vice President – Shafts and Technical Services, at Redpath Canada.

Unlike the RD S100, which can move independently of the galloway within the shaft via a telescopic boom, the S20+ is connected to the galloway, requiring the lowering of the galloway to move the mucker into position for mucking.

Melong added: “The S20+ does present some potential for concurrent mucking when in and around the shaft station construction/excavation, but, in general, does not act independent of the stage as in the S100 design.”

Fitted with a bucket as standard, the S20+ offers a maximum digging depth of 7.96 m and a bucket volume of 560 litres. It also offers good flexibility, with the bucket capable of six rotations per minute.

Alongside the S20+ and the aforementioned S100, Redpath has been mechanising the shaft sinking process in mining through the use of large-diameter raiseboring equipment and operation of Herrenknecht’s Shaft Boring Roadheader (in soft-to-medium rock). The company is also working with Herrenknecht on the development of the Shaft Boring Cutterhead, a machine developed for medium-to-hard rock applications up to 250 MPa UCS.

Woodsmith Shaft Boring Roadheaders about to re-start cutting process

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One of the most-watched shaft sinking projects in the sector right now is located in the UK, with the Woodsmith project in north Yorkshire having been on the radar for a number of reasons.

First off, it is a project that has changed hands recently.

Originally guided by Sirius Minerals, the 10 Mt/y project was acquired by Anglo American in 2020, a transaction that came with a fresh look at the whole project execution phase.

The change in ownership and re-assessment of plans drawn up by Sirius – a much smaller company guided by different investor pressures and operating procedures – led to Anglo American relieving DMC Mining, the lead shaft sinking contractor, of its duties.

Another reason for watching the project is the planned use of Shaft Boring Roadheader (SBR) technology from Herrenknecht.

After debuting at the Jansen potash project in Saskatchewan, Canada, where it excavated two 8-11 m diameter blind shafts down to circa-1,000-m-depth with the help of DMC as the contractor, SBR 2.0 – the second generation of the technology – was put to the test in Belarus at the Slavkaliy-owned Nezhinsky potash project. It ended up breaking shaft sinking records under the guidance of contractor Redpath Deilmann on a project to sink two 8-m diameter shafts (one to 750-m depth and one to 697-m depth).

Herrenknecht, with its experience in mechanised tunnelling, developed the SBR for the mechanised sinking of blind shafts in soft-to-medium rock. Based on the proven technology of the Herrenknecht Vertical Shaft Sinking Machine, the SBR offers improved safety performance compared with conventional shaft sinking methods while also achieving higher advance rates, according to the company.

The SBR is a 60-m tall, suspended shaft sinking machine, with 12 work decks and two service platforms. A telescopic, boom-mounted cutting head is used to precisely excavate rock via a partial-face cutting method. The cutting head works in a cycle, starting each cut from shaft centre to shaft wall, repeating until a layer of material is removed. Excavation proceeds in 1-m increments, followed by SBR lowering sequences.

The SBR was chosen for Woodsmith by Sirius over the conventional drill and blasting method due to its advantages in improving safety and schedule. This methodology, Sirius said, would allow the company to satisfy several operational objectives, moving away from the use of explosives and providing a safer, more predictable work method. Instead of a linear process, the SBR allows work to be completed concurrently as the shaft is sunk, as well as minimising damage to exposed host rock, and further improving safety while minimising downtime. Work decks above the cutting head allow workers to install shaft lining and tubbing as excavation continues, while a pneumatic mucking system removes waste rock.

The third generation of technology – which builds on the first two deployments with, among other things, the addition of two retractable robotic probes to test and grout the ground ahead for safer excavation and an additional control cabin on surface for more remote operation – is due to sink production and service shafts with 6.75-m diameters to depths of 1,594 m and 1,565 m, respectively, at Woodsmith based on the Sirius plan.

These SBRs are being supported by four triple sheaved winches from SMS SIEMAG and conveyors from Herrenknecht-owned H + E Logistik GmbH, among other support equipment.

Work on the service shaft commenced in 2021 with former Anglo American Chief Executive, Mark Cutifani, confirming in July of that year that the “first cut” with the SBR had taken place in the service shaft.

This progress was made while the company was still completing a detailed technical review on Woodsmith to ensure the technical and commercial integrity of the full scope of its design. This review has a particular focus on the sinking of the two main shafts, the development of the underground mining area, and the changes required to accommodate both increased production capacity and the more efficient and scalable mining method of using only continuous miners, Anglo American said.

Since the first cut was made in July 2021, however, Anglo American and Redpath Deilmann – which is now leading the sinking project as shaft sinking contractor – have been reviewing the existing plans for sinking with the SBRs, carrying out minor hardware changes on the machines and ensuring all staff have the appropriate training to facilitate the completion of the shaft sinking process. The Redpath Group is also involved in the drill-and-blast-based sinking for the materials transport system (MTS) shaft.

Various shaft sinking rates have been mooted in the past at Woodsmith, and Anglo American is currently working to develop the optimal solution for the facility based on technical standards.

The sinking at Woodsmith represents a different challenge to the two previous SBR projects conducted to this point.

For starters, there is no ground freezing expected to take place at Woodsmith – unlike what happened in Canada and Belarus. This process, while time consuming and only used to freeze unstable water-bearing strata around the shaft, can create more rock uniformity to aide consistent cutting rates.

There is also the MTS level to consider at Woodsmith, with plans to carry out lateral development work around the 360-m-level to join up the production shaft with this level where polyhalite ore will be transported along a 37-km tunnel to Wilton near the port. This means vertical cutting and loading may be halted while the MTS level connection is established.

All these factors, along with the performance of previous SBR work, will be incorporated into the engineering work Anglo American is carrying out at Woodsmith, but, in terms of the SBR, signs are that work on the service shaft could recommence shortly, with plans to start sinking in the production shaft by the end of the year.

Anglo American signals design changes at Woodsmith polyhalite project

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Anglo American has outlined plans to change elements of the design at its Woodsmith polyhalite project in the UK, which will have a bearing on both the sinking of the two main shafts and development of the underground mining area at the project.

The company has been running a detailed technical review on Woodsmith since mid-2020 to ensure the technical and commercial integrity of the full scope of its design. This followed the acquisition of the asset as part of a takeover of Sirius Minerals earlier that year.

“Now largely complete, the review has confirmed the findings of Anglo American’s due diligence that a number of elements of the project’s design would benefit from modification to bring it up to Anglo American’s safety and operating integrity standards and to optimise the value of the asset for the long term,” the company said.

Anglo is also making a change to the leadership at Woodsmith following its integration into Anglo American and ahead of the full project execution phase. Tom McCulley, who has led the development of the Quellaveco copper project in Peru, will take over from Chris Fraser as CEO of Crop Nutrients. This will see Fraser step aside and take on a strategic projects role for Anglo.

“The Woodsmith team is further developing the engineering to optimise the configuration of the project, recognising the multi-decade life of the mine,” Anglo said.

Particular attention is on the aspects identified at the outset of Anglo American’s ownership – namely, the sinking of the two main shafts, the development of the underground mining area, and the changes required to accommodate both increased production capacity and the more efficient and scalable mining method of using only continuous miners, it said.

The sinking of the two main shafts is due to be carried out using Herrenknecht’s Shaft Boring Roadheader (SBR) technology. DMC Mining, a company familiar with the technology thanks to its work sinking shafts at Jansen in Saskatchewan, Canada, was previously tasked with sinking the production and service shaft, each around 1,500 m deep, and two smaller shafts associated with the materials transport system, each approximately 350 m deep. Its contract was ended in 2020.

These improvements will, the company said, require the installation of additional ventilation earlier in the development of the underground mining area.

“Anglo American expects that these changes to the design of the mine infrastructure – which will result in a different, enhanced configuration and therefore a different construction and production ramp-up schedule – will ensure that its exacting standards are met and the full commercial value of the asset is realised,” the company said.

Mark Cutifani, Chief Executive of Anglo American, said: “We are very happy with the high quality and exciting potential of Woodsmith, with the scale and quality of the polyhalite orebody pointing to a quartile one operating cost position and strong margins. This is a very long-life asset and we are going to take the necessary time to get every aspect of the design right to match our long-term vision and value aspirations.

“We have said from the outset that we expect to make improvements and that we will execute certain elements of the construction differently and with a more conservative schedule. We expect to have completed our design engineering, capital budget and schedule at the end of 2022, with a fully optimised value case that recognises the upside potential we see in Woodsmith, and we will then submit the full project to the board.”

In the meantime, construction of the major critical path elements of the project, principally the two main shafts and the mineral transport tunnel, is progressing, with approximately $700 million of capital expected to be invested in 2022, Anglo said.

The plan at Woodsmith under previous owners Sirius was to extract polyhalite via two mine shafts and transport this outside of the National Park to Teesside on a conveyer belt system in an underground tunnel. It would then be granulated at a materials handling facility, with the majority being exported to overseas markets. The company was previously aiming to achieve first product from the mine by the end of 2021, ramping up to an initial production capacity of 10 Mt/y and then full production of 20 Mt/y.

The changes to McCulley’s and Fraser’s roles are effective January 1, 2022. Anglo American has appointed Adolfo Heeren as CEO of Anglo American in Peru, effective from the same date. Heeren will work together with McCulley during the first half of 2022 to ensure a smooth transition from the construction and commissioning phase of Quellaveco into operations, expecting first copper production in mid-2022.

Anglo American ends DMC Mining shaft sinking contract at Woodsmith project

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Anglo American has confirmed its Crop Nutrients business has ended the contract of its shaft sinking contractor, DMC Mining Services UK Ltd, at the Woodsmith polyhalite project in the UK.

Anglo, which only took ownership of the asset earlier this year, said DMC staff were expected to transfer to Anglo American under the Transfer of Undertakings (Protection of Employment) Regulations, and construction progress was due to continue.

DMC was awarded the design and build contract for the construction of the deep shafts at the Woodsmith project back in February 2018 when the project was owned by Sirius Minerals.

This contract would have seen it engineer and construct four shafts at the project in North Yorkshire. Those shafts include a production and service shaft, each around 1,500 m deep, and two smaller shafts associated with the materials transport system, each approximately 350 m deep. It was to sink the deep shafts using Herrenknecht’s Shaft Boring Roadheader technology.

Herrenknecht developed the SBR for the mechanised sinking of blind shafts in soft to medium-hard rock. Based on the technology of the Herrenknecht Vertical Shaft Sinking Machine, the SBR offers improved safety performance compared with conventional shaft sinking methods while also achieving higher advance rates, according to the company.

DMC, itself, had become familiar with the technology after helping successfully sink two blind shafts to depths of -975 and -1,005 m, respectively, at the BHP-owned Jansen potash project in Saskatchewan, Canada.

Sinking activities with the SBRs at Woodsmith, meanwhile, were expected to start next year, with the machines having already arrived on site.

A spokesman for the Woodsmith project said of the DMC contract cancellation: “This new structure provides us with simpler internal processes and allows us to better manage the important transition between the sinking phase and ramp-up to steady state operations.

“It also gives us greater control over processes like local recruitment and training.”

DMC Mining invests in new Sandvik, Herrenknecht equipment for Chile projects

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DMC Mining Services says it is ramping up activity in Chile, after being awarded five new contracts at the end of 2019.

One of North America’s premier underground contractors, DMC recently secured work at KGHM’s Franke and Sierra Gorda mines, in the Antofagasta region, in addition to a boxhole boring assignment at Codelco’s El Teniente mine, near Rancagua.

To ensure maximum reliability and performance for its clients, the company has invested in new equipment, it said.

For its drilling project at the open-pit Franke mine, two truck mounted Sandvik DE712 diamond drills have been delivered to site. Two additional units, Sandvik DE881 multi-purpose drills, will follow in order to increase drilling capability for this project and an additional project at Sierra Gorda, a 110,000 t/d of ore open-pit operation, it said.

For the boxhole boring project at Codelco’s El Teniente mine, the biggest underground copper mine in the world, DMC has taken delivery of a Herrenknecht BBM1500 boxhole boring machine. Two additional BBR1500 units are on order, which include back-reaming capability to create larger diameter raises, it said.

DMC said: “We are proud of the progress our Chilean team has accomplished over several short months, and that our clients can always rely on DMC’s dedication, expertise and professionalism on any project, no matter where in the world we work.”

As its Chile team ramps up on these new projects, DMC is establishing a turnkey, comprehensive operation ready to serve not only new Chile clients, but all of the South American mining industry – with raiseboring, shaft sinking, underground mining and engineering capabilities – it said.

Herrenknecht heralds ‘game changer for shaft sinking in soft and medium-hard rock’

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Having successfully excavated two 8-11 m diameter blind shafts using Shaft Boring Roadheaders (SBRs) at the BHP-owned Jansen potash project, Herrenknecht is leveraging all the lessons it learnt in Saskatchewan, Canada, to ensure this technology proves to be a “game changer” for the sinking of shafts in soft and medium-hard rock.

Mining contractor DMC Mining Services used two SBRs to excavate the blind shafts at Jansen, with the successful project completion acting as proof of the feasibility and advantages of the Herrenknecht SBR concept for the mining industry, according to the Germany-based company.

In August 2018, the mining industry milestone was achieved with the successful completion of two blind shafts to depths of -975 and -1,005 m, respectively, at the Jansen potash project. For the first time, shafts in the mining business were sunk using only mechanical excavation for this reference project.

Two Herrenknecht SBRs excavated the ground by a partial-face cutting method, using a cutting drum mounted on a telescopic boom. The excavated rock was then conveyed from the bench by an innovative pneumatic mucking system (PNM) and transferred into muck buckets to be hoisted to surface, the company said.

An innovative laser navigation system designed by the Herrenknecht subsidiary, VMT Group, using target units mounted on the SBR and lasers connected to the shaft wall, was used to keep the machines on track.

Herrenknecht, with its experience as a technology leader in mechanised tunnelling, developed the SBR for the mechanised sinking of blind shafts in soft to medium-hard rock. Based on the proven technology of the Herrenknecht Vertical Shaft Sinking Machine (VSM), the SBR offers improved safety performance compared with conventional shaft sinking methods while also achieving higher advance rates, according to the company.

The geological conditions at Jansen, however, were anything but easy. At a depth of around 450 m, the SBR encountered a layer of extremely hard competent rock causing excessive pick wear and low rates of advance. To overcome this and some further hardness challenges, the cutting drum was upgraded to a hard-rock cutting drum and torque output was doubled.

Because an existing high-pressure underground waterway, known as the Blairmore aquifer, posed a risk for water ingress into the shaft, ground freezing was executed temporarily in 2011 by BHP to a depth of approximately 650 m.

A major success in this difficult geology was the use of a mechanical ring erector, which allowed the installation of steel tubbing segments with minimal risk to personnel and a high degree of accuracy, according to Herrenknecht. The steel liner rings were installed through the Blairmore aquifer to assist in the development of a composite steel and concrete watertight liner in both shafts.

Since the project-specific design changes at Jansen required modifications to the SBRs, Herrenknecht, together with contractor DMC Mining Services, refined the SBR technology over the long term. The result is the second generation of Herrenknecht SBR technology.

As an example, the second generation SBR is equipped with an additional stabilisation level that allows the fixation of the SBR centre pipe on both ends. This ensures a stable transfer of the reaction forces from the cutting process to the shaft wall without movement of the machine – even with fluctuating excavation diameter of 8-11 m, as encountered at the Jansen potash project.

In addition to an improved filter system, a new design of the PNM system was installed in the second-generation machine, which results in a higher degree of separation in the suction tank itself, allowing wet material and even water to be handled.

Martin-Devid Herrenknecht, General Manager Mining at Herrenknecht, said: “The technical development of the second SBR generation is based on the lessons learnt from the Jansen project.” Two SBRs of this generation are currently in operation in Belarus and achieving good performance as a result of the improvements made, Herrenknecht said. “This pioneering approach is certainly a game changer for shaft sinking in soft and medium-hard rock, impacting the whole mining industry,” he said.

After the successful excavation at Jansen, another task was to be managed: the disassembly of the huge machines in the deep shafts. To remove the SBR from the shaft bottom, it was necessary to reduce the weight of the machine from 390 t to 340 t. This was achieved by stripping all components off the SBR that were in the excavation chamber. Both SBRs were safely extracted from the two shafts at the Jansen potash project in May 2019.

The Jansen potash project, located approximately 140 km east of Saskatoon, Saskatchewan, is a BHP-owned future potential potash mine with an expected initial mining output of around 3-4.5 Mt/y with valuable expansion options.