Steel industry

Steel Hard Competence

A wide range of Nordkalk lime products is used when iron ore is processed into steel. Production of each ton of steel requires more than 50 kg of quicklime. Lime forms a highly basic slag, which purifies iron ore to form the final steel product after complicated process chain.

Limestone and lime are used to make iron ore pellets. Iron ore pellets are stable and homogenous and therefore easy to transport and load into the blast furnace.

An alternative raw material for the blast furnace is iron ore sinter. Limestone and lime added to the sinter react with impurities and balance the slag composition of pig iron production.

Pellets and/or sinter are charged into the blast furnace together with limestone and coke. All raw materials smelt down forming pig iron and slag. Reliable raw materials, like good quality lime products, are essential for maintaining efficient blast furnace operation and a high pig iron quality. 

Fine quicklime powder with added ground limestone is an example of a special lime product. It is injected into pig iron to remove excess sulphur and phosphor before actual steelmaking step. 

In the steelmaking processes recycled metal and/or pig iron, flux and lumpy lime are melted down in a furnace. The LD-process uses pig iron and the Electric Arc Furnace uses recycled metal as the main metal carrier. During the melting processes lime produces slag, which in turn picks up impurities from steel.

The ladle furnace process is mainly used to adjust the analysis and temperature of steel before casting. Lime products melt and form a purifying top slag on top of the steel in the ladle. Slag efficiently decreases heat losses during processing.

Finally, liquid steel refined with lime is cast in a continuous casting process to make slabs or billets for further processing into final steel products.

The steel industry uses lime products for water treatment in the same way as the mining and metallurgical industries.

Sales in Finland:            Erja Kilpinen
Sales in Sweden:           Jan Olars
Sales in Germany:         Malte König
Sales in Poland:             Krzysztof Kielbik