Tag Archives: Shaft boring roadheader

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.

Anglo American signals design changes at Woodsmith polyhalite project

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

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.”

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

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.

BHP’s Jansen potash project set for early-2021 investment decision

While uncertainty remains around the construction of BHP’s Jansen potash project in Saskatchewan, Canada, the company, in its September quarter results, confirmed it is still spending money on the asset prior to making a development decision.

BHP said the Jansen Stage 1 potash project will be presented to the board for a final investment decision by February 2021. The currently Stage 1 plan, which is in the feasibility study stage, involves building out initial capacity of 4.3-4.5 Mt/y of potash, with expansion optionality.

The miner has, so far, committed to spending $2.7 billion on the project. This is expected to result in the excavation and lining of the 7.3 m diameter production (975 m deep) and service (1,005 m deep, pictured) shafts – sunk by DMC Mining using Herrenknecht’s Shaft Boring Roadheader – and the installation of essential surface infrastructure and utilities. The overall Stage 1 project is expected to have a capital outlay of $5.3-5.7 billion.

In the September quarter results, BHP said in order to make a final investment decision, work on engineering to support project planning and on finalising the port solution is required. The BHP Board has, as a result, approved $144 million of spending for these activities, with an additional $201 million in funding set aside to further de-risk the project. The latter is focused on the mine’s scope of work, advancing other engineering and procurement activities, and preparation works for underground infrastructure, it said.

“This will enable an efficient transition of the project team between the study and execution phase, should the project be approved,” BHP said, adding that the release of funding to the project will be staged over this period.

The company, meanwhile, gave an update on its South Flank iron ore development, in the Pilbara of Western Australia, with CEO Andrew Mackenzie saying the project was 50% complete, with all major items on schedule and budget.

South Flank, which is expected to cost $4.6 billion to build, is set to replace production from the existing Yandi mine, which is reaching the end of its economic life. BHP is targeting first ore extraction at the operation in 2021 and expects to ramp up to 80 Mt/y of output.