Tag Archives: Swiss Tower Mills Minerals AG

Swiss Tower Mills and its vertical grinding mills to come into the Metso fold

Comminution of minerals, Mineral processing, Mining equipment, Mining mergers and acquisitions, Mining services, Sustainable mining, , , , , ,

Metso says it is investing in the development of energy-saving comminution technology and has signed an agreement to acquire the outstanding shares of its long-term partner Swiss Tower Mills Minerals AG (STM).

Previously, Metso had a 15% minority ownership in the company. The parties have agreed not to disclose the transaction value.

Metso decided to exercise its right of first refusal following the divestment decision of STM’s other shareholders. As a result of the transaction, Metso’s ownership will increase to 100%. Metso has reported its previous 15% shareholding as a non-current financial asset.

Swiss Tower Mills Minerals, based in Baden, Switzerland, specialises in vertical grinding mill solutions. It is best known for the HIGmill™ grinding mill, which has been exclusively sold and serviced by Metso. This technology is crucial in modern grinding circuits and integral to the development of energy-efficient comminution processes, for example, in combination with Metso HRC™e high-pressure grinding rolls, Metso says. Over the years of cooperation, the use of vertical grinding mill technology has seen significant growth, and the trend is expected to continue.

Markku Teräsvasara, President, Minerals business area and Deputy CEO at Metso, said: “We are excited to have the Swiss Tower Mills Minerals team as part of Metso. For many years, we have collaborated in serving customers in the mining industry. Going forward, our customers will continue to benefit from an unrivalled comminution solutions offering, which we will develop further.”

Fritz Moser, Chairman of the Board of Swiss Tower Mills Minerals, said: “Being fully convinced that Metso is highly committed to further develop Swiss Tower Mills Minerals as the benchmark of the art of grinding, together with my private shareholder colleagues, we have decided to divest our ownership in the company. Hence, we are pleased to know that the technology we have established together with Metso for the mining industry will remain an essential part of Metso’s flowsheet capability.”

The acquisition, which is subject to the approvals of anti-trust authorities, is expected to be closed in early 2025.

In 2022, the Weir Group announced an alliance with STM in which Weir would market STM’s vertical stirred grinding mills for coarse grinding applications worldwide.

Last year, Weir announced the completion of the STM Minerals AG vertical stirred mill commissioning at the Weir Technology Hub in the Netherlands, as part of its energy-efficient comminution and classification solutions for customers.

Weir and Swiss Tower Mills align on energy efficient comminution pathway

Comminution of minerals, Environmental, Mining equipment, Mining services, Sustainable mining, , , , , , , , , ,

The Weir Group has announced a new alliance with Swiss Tower Mills Minerals (STM) in which Weir will market STM’s vertical stirred grinding mills for coarse grinding applications worldwide.

Integrating vertical stirred grinding mills into Weir’s minerals processing flowsheet will provide customers substantial improvements in throughput and energy efficiency, helping them to meet their productivity and sustainability goals, Weir says.

STM’s vertical stirred grinding technology is proven for energy efficient comminution in the mining market with more than 80 units currently operating in the hard-rock mineral processing industry across the globe, according to the company. It is used within the comminution segment of the minerals processing circuit as part of a series of crushing and grinding processes that create the fine particles from which minerals can be extracted through flotation.

Comminution, as has been well documented, is one of the most energy intensive parts of the mine, accounting for 25% of the final energy consumption of an average mine site.

Weir says it is already a leader in comminution technologies, offering solutions such as Enduron® high pressure grinding rolls (HPGRs) to drive down energy consumption by around 40% for customers.

This new alliance with STM takes things to the next level, offering the mining and minerals industry a proven low energy alternative to traditional high energy consuming tumbling mills, it said. Combining and integrating these energy-efficient technologies into a single, optimised flowsheet will deliver significant reductions in energy use, driving down costs and carbon emissions.

In order to prove the most beneficial flowsheet for specific projects, STM has already supplied two vertical test mills to the Weir Minerals HPGR test facility in Venlo (Netherlands). This will put Weir and STM in the unique position to provide clients combined energy efficient grinding test work of HPGR followed by STM’s vertical stirred mill, they said.

Ricardo Garib, Weir Minerals Divisional President, said: “Weir and STM share the same vision of enabling primary resource providers to produce resources in the most sustainable manner. This is a perfect match of best-in-class technology providers. Integrating STM mills with Weir’s comminution products, which includes Enduron HPGRs and Enduron screens, will improve throughput and help bring substantial reductions in carbon emissions.

“This is a real win-win.”

Fritz Moser, STM Chairman, said “Both the HPGR and the STM vertical stirred mills provide significant energy savings compared to conventional grinding technologies. Our new supply agreement with Weir will enable us to fast track the roll out of an innovative flowsheet using STM mills in conjunction with Weir’s Enduron HPGR.”

Swiss Tower Mills to deliver ‘largest, most powerful’ stirred mills in the world to Russian copper project

Base metals, Comminution of minerals, Mineral processing, Mining equipment, , , , ,

Swiss Tower Mills Minerals says it has been awarded an order for the delivery of four energy efficient VRM50000-6500 grinding mills for a large greenfield copper project in Russia.

The scope of the project, awarded in the June quarter of 2021, includes the design, manufacturing and delivery of four Vertical Regrind Mills (VRM), each complete with a 6,500 kW variable speed drive package and a user-friendly control system.

Each regrind circuit will process up to 500 t/h of flotation concentrate.

These mills will be by far the largest and most powerful stirred mills in the world, according to Swiss Tower Mills Minerals.

Deliveries will take place during 2022 and 2023.

Last month, Swiss Tower Mills Minerals confirmed the award of an order for the delivery of one VPM10 vertical stirred grinding mill for the Navachab gold mine plant expansion in Namibia.

Swiss Tower Mills Minerals backs Coalition for Eco-Efficient Comminution

Comminution of minerals, Mineral processing, Mining equipment, Mining industry recognition, Mining services, Sustainable mining, , , , , , , , , , , , ,

Swiss Tower Mills Minerals AG (STM) has become the latest sponsor to support the work of the not-for-profit Coalition for Eco-Efficient Comminution (CEEC).

An innovative company that has successfully translated the vertical stirred milling technology of industrial minerals to hard-rock minerals processing, STM’s support of CEEC’s work was a natural fit for the company, according to Managing Director, Ralf Hesemann.

“The uptake of new technology in the mining industry is traditionally a slow process,” Hesemann said. “Tapping into a trusted independent body that communicates the latest technical findings on efficient comminution practices is a win-win for both of us.

“I look forward to our collaboration.”

Swiss-based STM developed the Vertical Regrind Mill (VRM) and released it to the minerals market in 2012. More than 60 of the stirred media grinding mills have been sold to mines across the Americas, Europe, Africa, Asia and Australia. For fine and ultra-fine grinding applications, it is marketed under the name HIGmill, through the exclusive partner Metso:Outotec. For coarse regrind applications, STM offers the VRM mill directly to customers in the minerals market.

Since the grinding principle of multi-compartment grinding offers substantial energy savings, a new stirred mill has been developed for coarse grinding applications up to 6 mm feed size, the Vertical Power Mill™ (VPM). Mill sizes range from 700 kW to 12,500 kW with high flow rates, and potential energy savings of up to 40%. Due to its small footprint, STM is marketing the VPM as a viable ball mill replacement in HPGR circuits or for capacity increase in existing plants.

The energy savings are achieved through uniquely designed rotors and stator rings in a vertical arrangement that enable high power intensities, even with relatively low tip speeds, STM says. This results in higher energy efficiency, a smaller footprint and the potential for increased recoveries. Power intensities of 200-300 kW/cu.m are typical, and operational tip speeds range between 6-12 m/s, depending on application and mill size.

CEEC Director, Chris Rule, said it was encouraging to see energy efficient, stirred media mills being installed by industry as a step towards more sustainable mining practices, in line with ESG considerations and net zero emissions commitments.

One of the first HIGmills be commissioned, in 2015, was a 700 kW mill for a copper concentrate regrind application at the Kevitsa mine in Finland. Several papers have been published on the energy efficiency and metallurgical performance of this mill, including an Outotec paper presented at Comminution Capetown 2016, and ‘A Review of Published Full-Scale Stirred Mill Results’ by Michael Larson, Molycop, USA, presented at the SAG 2019 Conference.

The technology will also be installed at the Iron Bridge Magnetite Project in Western Australia. The joint venture between Fortescue Metals Group and Formosa Steel IB Pty Ltd is the world’s first large-scale plant without horizontal milling. The flowsheet consists of a two-stage HPGR circuit feeding in total 10 advanced HIGmill grinding mills.

Rule said stirred mill grinding technology had been well proven for decades in industrial mineral applications such as in the opacifiers, fillers, ceramics, paint and pharmaceutical industries.

“We commend STM for translating this technology to mineral processing, offering miners an energy-efficient, low footprint alternative to high-intensity ball milling,” Rule said.

“Having STM on board as a CEEC sponsor means greater opportunities for us to learn about and share alternative comminution approaches. This support from our valued sponsors over the past 10 years is what enables CEEC to help keep industry aware of demonstrated advances that help mining leaders tackle the challenges of reducing the energy consumption, emissions and overall footprint of their operations.”

Hesemann said declining ore quality meant energy efficient comminution was becoming a more critical stage for realising profit.

“We’re proud of the part our technology plays in lowering the footprint of mineral processing, while at the same time decreasing capital expenditure and operating expenditure and improving the bottom line.

“Being a CEEC sponsor will enable us to more widely share any advances in this field, as well as learning from the global network of industry experts that CEEC brings together through its events and online resources.”

Pictured is the factory acceptance test success for a new 50,000 litre Vertical Regrind Mill (VRM50000)