Where do I get iron ore returns from


Along with water and aggregates, cement is one of the raw materials for concrete. The main components of cement are:

  • Portland cement clinker (K)
    A hydraulic substance that essentially consists of calcium silicates. Portland cement consists mainly of natural raw materials such as limestone, clay, sand and iron ore, which are burned into clinker and then ground with gypsum to form the finished cement.

  • Slag sand (S)
    When iron ore is smelted in a blast furnace, blast furnace slag is produced. The slag is quenched (granulated) with water. The result is a glassy solidified, latent hydraulic substance that is ground to blast furnace slag.

  • Natural pozzolans (P)
    Powdered rock of volcanic origin, trass or sedimentary rock with a suitable chemical-mineralogical composition can react with dissolved calcium hydroxide and form hardenable compounds.

  • High silica fly ash (V, W)
    An artificial pozzolan is the fine-grained, glassy combustion residue from coal dust, which is produced during the cleaning of exhaust gases in coal-fired power plants. Its properties depend on the type and origin of the combustion conditions.

  • Burned Slate (T)
    Made from natural oil shale. Slate is a sedimentary rock that occurs around the world.
Depending on the proportion of the main components, five types of cement can be distinguished (CEM I to CEM V). The 27 subspecies of these five groups have different letter abbreviations depending on their composition, e.g. CEM II / A-S. Well, it is a Portland composite cement (CEM II) with a Portland cement clinker content of 80 to 94 percent (A) and the other main component of slag sand (S).

A nice explanatory video from Heidelbergcement shows step by step how cement is made:

Expertise on the subject


Binders, additives and additives

BindersBinders are inorganic or organic substances that can be processed in the plastic state and that are ...


Water-cement ratio

The water-cement value (w / c value) defines the ratio of water to cement in the cement paste of the fresh concrete: w / c = weight of the ...


Composition of concrete

Cement, water and aggregates are the raw materials for the building material. It can be adapted to the respective requirements by means of additives and substances.

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