Minerals processing equipment specialist Metso’s local foundry Isithebe, one of six across the globe, has introduced the manufacture of metallic mill linings to facility – aimed at driving the company’s local and African business. A visit to the foundry was an eye-opener, writes Laura Cornish.

One of the largest components of Metso’s business, both globally and locally, is the supply of large-scale grinding and crushing equipment to the mining industry.

The nature of the business requires an extensive network of foundries – support structures and comminution wear solutions for the group manufacturing various components and castings for the company’s extensive product lines.

Situated in the remote Isithebe township, half way between Durban and Richards Bay, Metso’s South African foundry, Isithebe, was first founded in 1978 (under different ownership), and forms an integral part of the local company’s crushing and grinding business.

“Up until recently, our core function has been primarily the manufacture of large manganese crusher wear parts for the Metso crushing business – to both the African and Australian markets,” explains Cameron Mather, Isithebe foundry’s GM.

Considering Metso’s significant investment into its local foundry over the recent years, equipping the foundry largely with new and additional equipment, it was decided last year to expand the company’s service and manufacturing capability.

“The result of a 2011 new-born strategy is the manufacture of metallic mill lining products in manganese steel, low-alloy steel and high chromium iron – for AG, SAG and ball mills. Unlike any other foundry-manufactured product, the mill linings will not only be manufactured for Metso’s product range, but will be sold to the industry for any mill in operation.

Metso has been manufacturing rubber mill linings for decades, which is undertaken at its factory in Vereeniging.

“There are very specific strategic reasons for adding this product to our foundry manufacturing offer,” says Dennis Farnworth, Metso’s rubber and synthetic wears regional sales manager.

“Primarily because mining houses today require larger mills to increase their production volumes, even more so for low grade ores. This means that the correct liner design and material selection offer are extremely important to ensure an improved and optimum grinding performance.
The ideal situation for Metso is having the ability to offer our clients the entire lining range. Sometimes rubber is the best solution, sometimes poly-met or steel, and sometimes even a combination of these.”

Metallic-lined mills also offer:

  • improved grinding performance
  • increased wear life
  • reduced downtime for replacement
  • improved ergonomic conditions during installation
  • reduced liner breakage risk and reduced grinding media consumption.
“With an annual capacity of 12 000 t, the intention is to allocate 8 000 tpa to the crusher lining business, and the remaining 4 000 tpa to the metallic lining business as it takes off,” Mather continues.

The company will even consider a mechanised manufacturing stream once the product volume warrants it.

This new business avenue will form an integral part of Metso’s overall growth strategy, to triple its business in Africa in the next six years.

“Thanks to the addition of metallic mill liners, we are also now able to offer our clients the full comprehensive range of lining products, which in many cases is a combination of both rubber and metallic (poly-met). And because each lining design is customised to each client and their processing needs, we are the ultimate solutions and product provider,” Farnworth believes.

The immediate success of the foundry’s new product line is the group’s close working global network and standardised global best practice methods, first implemented in 2005.“We are able to share best practices and technologies across our globe of facilities. This includes material research and development, benchmarking and reporting systems, global compliance according to Metso specifications and controls, and ultimately, the promotion of a ‘one quality’ concept offering customers reliable and consistent wear part performance,” Mather outlines.

Because metallic lining applications can vary substantially from rubber linings, Isithebe is working closely with its Brazilian sister foundry, which already has extensive experience in metallic mill lining manufacturing. It is currently is the major supplier of metallic mill liners to the South American market.

Committed to the environment and its workforce

The Metso group is also committed to reducing its environmental footprint and practising energy efficiency, and recently introduced its Metso Energy Efficiency Programme (MEEP).

“The initiative aims to reduce the entire global group’s energy consumption by 15% by 2015, and 20% by 2020. The Isithebe foundry will contribute towards these targets, and is reviewing all its manufacturing lines and components,” Mather notes.

This includes purchasing a new air compressor, incorporating new furnace linings to better retain heat, introducing energy efficient motors and lighting, and even looking at technologies to convert its off-heat (generated from the foundry process) into energy.

The foundry, which thanks to Metso is a vital local business component, employs 377 employees – the majority sourced directly from the township. Among just a few major industrial players in the area, Metso is contributing substantially to the local community, providing social upliftment and employment.

It also providers HIV/Aids counselling and guidance – its workforce, and the entire area, has a high level of HIV infection.

Metso’s customer model (supplied by Farnworth)

  1. Supply and service agreements – focus on core business
–       pay per kilowatt-hour or tonne. Service where applicable

–       improved capital utilisation/cash flow

–       utilise Metso maintenance crew.

  1. Increased availability – revenue
–       liner parts in balanced life cycles

–       predictable maintenance stops

–       quick installation/change outs.

  1. Potential capacity increase – revenue
–       lining optimised in relation to operating conditions/objectives

  1. Reduced lining costs
–       long life from application unique design and materials.

  1. Improved environment/safety with rubber and      poly-met linings
–       low weight components reducing accidents risks

–       reduced noise levels.

Sidebar: The foundries (70 000 tpa total capacity)

Metso’s own foundries producing high chromium white iron, chrome-molybdenum steel and high chrome martensitic steels.



Annual   capacity

Maximum   cast capacity

Melting   process

Moulding   process

Sorocaba (Brazil)

30 000 t

30 t



Tampere (Finland)

12 000 t

45 t



Isithebe (South Africa)

12 000 t

12 t



Slaverna (Czek Republic)

13 000 t

8 t



Ahmedabad (India)


5 t



Foundry Annual


Sidebar: The history of Isithebe

  • 1979: Following a joint venture between Lennings Holdings (South Africa), Vickers (United Kingdom) and Vickers (Australia), Lennings Manganese was founded in Isithebe, KwaZulu–Natal.
  • 1985: Rexnord certified Lennings Manganese as a supplier of manganese steel castings. Lennings was officially recognised as a worldwide source for manganese parts to the Nordberg Group.
  • 1991: Scaw Metals took control of Lennings foundry.
  • 1998: Nordberg took control of the Lennings manganese facility.
  • 2001: Nordberg Lennings became part of Metso Minerals as Metso Minerals Isithebe plant.
Sidebar: Isithebe specs


  • Land area:                           55 950 m²
  • Production area:              19 300 m²
  • ICT programme:               SAP GPS, also high fidelity simulation, solidifications simulation by  Magma Soft
  • Delivery lead time:          six weeks
  • On time delivery:             95%
  • Smelting:                             12 t electric arc furnace and four 1.5 MW electric furnaces
  • Quality control: ISO9001:2008 and SANS 407:2008 (also chemical analysis, hardness tests, visual surface quality, ultrasonic tests, impact resistance, metallography, dimensions, strict temperature control on heat treatment ovens).
The cooling process: Quenching in water, oil or forced a

Additional Reading?

Request Free Copy