Ground Granulated Blast Furnace Slag (GGBFS), otherwise known as slag, is a by-product of the steel and iron industry which is milled to a fine consistency. Slagment is the registered trade name of our Ground Granulated Blast Furnace Slag (GGBFS). It is a latent hydraulic binder that is used in concrete and other construction applications as a partial cement replacement material. We have the capacity to produce over 800 000 tons of slag per year at our Slagment operation in Vanderbijlpark.

Architectural and Engineering Benefits

Slag offers a number of benefits when used in construction. These include:

  • Slag is known to produce durable concrete. A key characteristic of slag is that it possesses self-cementing properties. It’s been found that slag can double the lifespan of buildings.
  • It is a latent hydraulic binder commonly used in concrete and also serves as a partial cement replacement material in construction.
  • It is also a direct replacement for ordinary Portland cement by weight. 
  • It is usually used as an optional additive to cement and concrete mixes.
  • Its main function is to increase durability and workability.
  • It can be used together with lime and/or cement to stabilise soil prior to road construction.
  • It provides protection from both chloride and sulphate attack.
  • It reduces the thermal heat gradient generated when pouring the concrete and in the process reduces the likelihood of micro cracking which may tend to weaken the structure’s strength.
  • It can alter the colour of concrete to a near-white colour by replacing 50-70% of the concrete, giving the concrete a better appearance.
  • It also produces a smoother more defect free surface.

Operations and Capacity

Our plant in Vanderbijlpark has the capacity to produce over 800 000 tons of slagment and over 200 000 tons of blended cementitious products per year. We’ve produced slag for over 50 years, contributing to the construction of major structures such as dams, bridges and roads.

Custom-made Slag

We produce a number of different slag products including custom-made products such as:

  • A binder used for backfill in the mining industry, generally for cut-and-fill or room-and-pillar backfilling where high early strength gain is not required.
  • A binder designed for use with classified or unclassified mine tailings in backfill systems in deep level mining.
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