Tag Archives: North Yorkshire

ICL, Bunting-Redditch collaborate on new magnetic separators for Boulby mine

ICL is making significant upgrades to its magnetic separators at the Boulby mine in North Yorkshire, England, with the company having decided to replace an existing single air-cooled Overband Electromagnet with four modern ElectroMax Overband Magnets that have been designed and built by Bunting-Redditch.

The ElectroMax Overband Magnets are a major improvement over the previous model, providing a more efficient and effective way to separate magnetic materials from non-magnetic materials, according to Bunting-Redditch. This upgrade will help ICL improve its mining operations, resulting in higher quality minerals and a more efficient production process, the company says.

ICL Boulby is the largest employer in the East Cleveland and the North York Moors National Park and will continue to be part of the region’s economic and social landscape for decades to come. In 1968, ICL Boulby, then known as Cleveland Potash, started underground mining of potash and salt. By 2017, the mining company had mined 1 Mt of polyhalite at Boulby.

The project to upgrade the magnetic separators at Boulby started in May 2023 when Bunting’s Technical Sales Engineer, Tom Higginbottom, undertook an on-site review of the existing installation. Material transported on three feed conveyors converged onto one conveyor where the in-situ Overband Electromagnet, installed many years previously, was failing to capture some tramp ferrous metal including small bolts and heavy steel bars. The tramp metal damages processing equipment such as crushers and screens, resulting in significant repair costs and costly production downtime.

In operation, Overband Magnets sit over conveyors to magnetically attract and remove tramp ferrous metal from the mined material. A heavy-duty rubber belt rotates around two large pulleys mounted either side of the central electromagnetic block and transports captured ferrous metal away from the magnet face and into a separate collection area.

The underground location of the Overband Magnet meant any replacement had to be air and not oil cooled. Even the switchgear had to be oil-free.

Bunting’s applications engineers assessed the project and compared new designs of air-cooled Overband Magnets with the installed unit. At a suspension height of 450 mm, the new overbands would have over double the gauss, the unit of measurement of magnetic induction, also known as magnetic flux density. However, the force density factor, which relates to the rate of change in gauss and the ability to lift a ferrous metal part, was over four times higher.

Bunting’s engineers concluded that the optimum solution was to install four air-cooled ElectroMax-Plus Overband Magnets instead of a single large unit. Three of the ElectroMax-Plus Overband Magnets would remove tramp ferrous metal on the three feed conveyors, with the fourth replacing the existing Overband Magnet where the conveyors merged the material into a single stream.

The suspension height of all four ElectroMax-Plus Overband Magnets (model EMAX-X-140) is between 400 and 450 mm across a 1,400-mm wide conveyor belt. Each Overband Magnet weighs 3.3 t and measures 950 mm long, 1,641 mm wide (with the motor to drive the self-cleaning belt), and 764 mm high. The ElectroMax Overband Magnets also feature bearing rotation sensors, belt tracking switches and bespoke guarding.

Higginbottom said: “Working closely with the engineering team at ICL Boulby and understanding the application and installation was the key to determining the best solution.”

The order for all four ElectroMax Overband Magnets was placed in September 2023 with delivery agreed for January 2024.

Anglo American increases Woodsmith polyhalite scale as shaft sinking progresses

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.”