Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Physical & Chemical properties

Endpoint summary

Administrative data

Description of key information

Additional information

Ferrosilicon is a grey, metallically lustrous alloy of iron and silicon. Ferrosilicon alloys have a wide range of composition with silicon content varying from 8 to 95 wt% and iron from 4 to 88 wt%. Ferrosilicon may be modified by refining or adding specific metals in the alloy. For example, ferrosilicon inoculants are produced by the addition of small amounts of elements either by a smelting process such as aluminium, barium, calcium, strontium or zirconium oxides during the production of the FeSi alloy or by a further process by melting rare earth (Ce, La, Pr, Nd, etc.), Mn and Mg.

Ferrosilicon is commercially available in the form of lumps, ingots, granules, and powders in different size ranges. The surface of ferrosilicon is covered with silicon-, iron-, and aluminium-rich oxide phases. The solubility of ferrosilicon in water is very low. The main element released from ferrosilicon in different fluids is usually silicon, and the release of other elements present in ferrosilicon is usually very low.