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By-products from
Steel Production


Contributing to the circular economy

Steel production generates by-products that have been contributing to a sustainable circular economy and resource conservation in important ways for more than 100 years. Ferrous slag from blast furnaces in steel plants and coal recyclables from coking plants are valuable, quality-controlled by-products. They provide ideal solutions for numerous industries, including raw materials for use in the cement, chemical and pharmaceutical industries, and raw materials and finished products for the construction materials industry, the processing industry, and for agriculture.

Iron slag is used not only to build houses, roads and bridges but also to fertilize plants.

Crude benzene is used to produce plastics and medical products. Electrode binders required for aluminum production are produced from a basis of coal tar.

By using these by-products, we are significantly helping conserve natural resources and thus actively helping protect the environment.

By-produced offered by SHS – Stahl-Holding-Saar and its affiliated subsidiaries primarily consist of iron and steel slags, which include blast furnace slags and steelworks slags as well as by-products specific to coking plants (coal recyclables).

Production and Use of By-products

Granulated blast furnace slag

Granulated blast furnace slag is melted as blast furnace slag during hot metal production. This is then quickly cooled in a downstream granulation plant with large amounts of water to form glass-like, solidified granules with latent hydraulic properties.

Due to its hydraulic properties, granulated blast furnace slag is primarily used in the cement industry as an alternative raw material and as an aggregate for production of various cements.

Granulated blast furnace slag is also used in the glass industry as an aggregate for producing flat glass (window panes) and hollow glass (bottles).

Blast furnace lump slag (HOS)

Blast furnace lump slag (HOS) is also produced in the blast furnace during hot metal production, and slowly solidifies in slag beds in crystalline form. After being crushed and screened, lump slag can be used for a wide variety of applications.

Lump slag of various grain sizes is used as a construction material in road construction in unbound frost protection courses and gravel base courses as well as in asphalt base courses.

Blast furnace lump slag is not produced only as a pure construction material mixture for road construction. Construction material mixtures have been developed for specific customer specifications – particularly for French road construction – by adding granulated blast furnace slag (brand name: LAROGRAVE) or converter slag (brand name: COMBIDILL).

Blast furnace lump slag (HOS) is used as a raw material in the cement industry to produce cement clinker.

It is also used to produce rock wool. This material has numerous possible uses (exterior wall, roof, floor and ceiling insulation) and is especially suitable as sound and heat insulation.

LD slag

LD slag (converter slag) is produced during crude steel production in the converter using the Linz-Donauwitz process.

Construction materials produced from converter slag and marketed with the trade name SCODILL are used in various grain sizes for open road construction (e.g. forest roads, agricultural roads) and road verges.

Ladle slag

Ladle slag is produced as molten rock in secondary metallurgy and in continuous casting during steel production.

Because of its composition, our ladle slag is also used in the production of cement clinker.

Through selective processing of LD slag and ladle slag, silicate lime fertilizers are produced from the lime-containing by-products in line with the German Fertilizer Ordinance and the European Fertilizer Product Ordinance.

Other areas of application for ferrous slags

  • Use as blasting abrasive
  • Use as a precipitating and neutralizing agent
  • Feedstock material in metallurgical processes (e.g. as a slag former)
  • Use as a pH regulator in chemical processes

By-products from the coking plant for the chemical industry, pharmaceutical industry, and others

Coal derivatives

Hard coal is heated during the coking process to over 1,200 °C under airtight conditions. The volatile components escape and form coke oven crude gas, from which the coal recyclables tar, benzene and sulfur are extracted during various cooling and purification steps.

Coal tar

Formation: During the cooling of the coke oven gas produced during the coking process.
Use: Extraction of aromatics and carbon black oils for the chemical industry and tire production, electrode pitch for the aluminum industry.

Crude benzene

Formation: Separated from the coke oven gas during a scrubbing process.
Use: Benzene is one of the most important precursor products for a large number of products in the chemical industry (styrene).


Formation: Obtained in a Claus plant during desulfurization of the coke oven gas.
Use: Used in the chemical and pharmaceutical industries for production of sulfuric acid, dyes and fertilizers, among other things.


We work together with our customers to develop products that are perfectly tailored to their applications.

We will be happy to provide you with more information on request.

We look forward to hearing from you.


Product descriptions

Product description LC for rock wool (only in French)
Product description LC 0/32 (only in French)
Description Produit LAROGRAVE (only in French)
Product description Granulated blast furnace slag (only in German)
Air-cooled blast furnace slag 0/45 (only in german)
Product description Air cooled blast furnace slag (only in German)
Product description COMBIDILL (only in German)

Contact persons


Daniel Leidinger
General Manager Sales by-products

Phone: +49 6831 472425
Fax: +49 6831 475296


Antoine Zimmer

Phone: +49 6831 475360
Fax: +49 6831 475296