Ferroalloys Ferrosilicon Plant

Exxaro’s FerroAlloys ferrosilicon plant

Exxaro’s FerroAlloys ferrosilicon plant was established in 1996. Two new plants were commissioned in 2014 and 2016 respectively in order to guarantee supply of up to 12 000 tonnes of superior quality gas atomised and milled ferrosilicon (FeSi) per annum.

Over the last two decades, Exxaro has developed two groundbreaking processing technologies aimed at improving beneficiation processes and the recovery of mineral products from low grade stockpiles, in-situ resources and waste dumps in order to overcome global mining challenges such as depleting reserves and resource quality issues.

A key component of both the Ultra High Dense Medium Separation (UHDMS) and Ultra Fine (UF) processing technologies is the high-quality gas atomised ferrosilicon produced at Exxaro FerroAlloys.

Early commercialisation projects were conducted successfully in the iron ore industry with the support of Kumba Iron Ore, where Exxaro holds a 20% shareholding in its subsidiary, the Sishen Iron Ore Company. The UHDMS and UF processes are currently being commercialised across a number of other commodities with the intent of growing the market. The production of FeSi is therefore critical to Exxaro’s long-term growth and investment strategies.


Exxaro FerroAlloys is ISO 9001, ISO 14001 and OHSAS 18001 certified and adheres to strict control measures to ensure compliance with all quality, environmental and health and safety standards. In the six years since the original certification, Exxaro FerroAlloys has successfully met the criteria of surveillance and recertification audits conducted by an external certification body.

Production process

Ferrosilicon powder is made by melting a fixed ratio of high purity iron and crude ferrosilicon in an induction furnace. The molten metal is then atomised using a high pressure stream of inert nitrogen gas to produce a high-grade ferrosilicon powder with a silicon content varying between 14-16%, known as FeSi 15.

Exxaro FerroAlloys produces gas atomised and milled FeSi of various particle size distributions and can tailor production to produce FeSi for most application requirements.

Quality characteristics

Exxaro FerroAlloys FeSi has superior qualities with respect to physical properties such as sphericity, homogeneity, degradation resistance, specific gravity, corrosion resistance and magnetism.

The production process guarantees that each FeSi particle is consistently small, solid and dense to ensure superior performance as a dense medium compared to conventional atomisation methods using water/steam. The superior physical properties of the Exxaro FerroAlloys FeSi results in enhanced rheological properties for beneficiation through dense medium separation.

Benefits of Exxaro FerroAlloys Ferrosilicon

High particle density Range of particle size distributions Spherical shape (Gas atomised FeSi)
  • Enables preparation of low viscosity mediums at high density
  • Special coarse to fine
  • Enables FeSi product selection suited to the density range required
  • Results in low medium viscosity even when high separation densities are required
  • Leads to lower particle misplacement and higher separation efficiency
Superior magnetic properties/ susceptibility High corrosion resistance High medium stability
  • Enables unrivalled recovery of FeSi using LIMS (Low Intensity Magnetic Separator)
  • Results in significantly lower medium losses and lower FeSi consumption
  • Leads to lower operating costs
  • Results in improved medium stability
  • Reduces FeSi consumption
  • Leads to lower operating costs
  • Lower risk of H2(Hydrogen) gas evolution
  • Exxaro FerroAlloys FeSi is a stable dense medium with correct application
  • Results in good separation efficiency
Technical support for customers Packaging Transport
  • The Exxaro team possesses extensive experience and knowledge in mineral processing
  • Technical support is available to all customers
  • All packaging used for the FeSi is safe, water resistant, durable, stackable and biodegradable
  • Customers can choose between 1 tonne bulk bags or 50 kg bags
  • 1 tonne bulk bags have a bottom discharge for ease of handling
  • Transportation can be arranged if required


The Exxaro FerroAlloys ferrosilicon plant is situated in the province of Gauteng at 20 Roger Dyason Road, Pretoria West, 0001, South Africa.

GPS Coordinates:

25°45’57.8”S 28°08’35.8”E

Contact details

Hensa van Wyk

Specialist Marketing

Tel: +27 12 307 3489

Fax: +27 12 307 7157

E-mail: Hensa.vanWyk@exxaro.com