Tag Archives: Redpath Deilmann

Redpath Deilmann, Thyssen Schachtbau to backfill Gorleben mine as part of closure plans

BGE, Germany’s federal agency for waste disposal, has taken what it says is the first important step towards the closure of the Gorleben mine in Lower Saxony with the award of contracts to backfill the mine using the salt originally excavated as part of plans for a nuclear storage project.

A consortium consisting of Redpath Deilmann GmbH and Thyssen Schachtbau GmbH Germany have been awarded with the work, with the pair expected to commence operations once mining permits have been obtained – currently estimated for mid-2024. The backfilling work is expected to take three years.

Redpath Deilmann sunk two exploration shafts at Gorleben to investigate its potential as a final disposal for nuclear waste using the ground freezing technique. These two shafts, sunk from 1986-1999, were 7.5 m in diameter and went down to depths of 933 m (Shaft 1) and 843 m (Shaft 2).

In September 2020, the Gorleben salt dome was withdrawn from the list of potential sites for a nuclear repository due to geological reasons based on an interim report by BGE. Following this, the Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection commissioned BGE to close the mine.

The original shaft sinking saw salt transported to the surface, which has since been stored in the immediate vicinity of the mine. Around 400,000 t of rock salt is currently stored there on a salt heap, which is now to be used to backfill the mine.

Dr Thomas Lautsch, Technical Managing Director of BGE, said: “By signing the contract, we are taking the first big step towards closing the mine in Gorleben. The striking salt heap will now gradually disappear and the exploration mine will be filled step by step.”

The Gorleben mine will be closed in phases. After the mine has been backfilled, the two shafts will be backfilled via another construction contract (phase 2) yet to be tendered. In a final order, the site will be made usable again (phase 3).

Anglo American continues SBR-led shaft sinking progress at Woodsmith

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

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

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

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.