…. is a synthetic á-ferric oxide exhibiting physical consistency and high chemical purity. It is produced from the thermal decomposition of iron chloride solution in our new SAD spray roasting process of pickling liquid.
Merox Ferric Oxide is supplied mainly to manufacturers of soft and hard ferrite components.
Pickling of steel and regeneration of pickling liquid
Hot rolled steel sheet is treated with hydrochloric acid in the pickling line. The acid dissolves oxide and metal on the sheet surface for finishing hot rolled steel or before further processing by cold rolling, annealing, metallizing and coating.
Spent pickling liquid is regained in the regeneration plant. Water, ferrous chloride and residue acid is spray roasted in a vessel furnace. Hydro-chloric acid is regained from the exhaust gases and consequently recycled back to the pickling line. Ferric oxide is produced using a spray-roasting process. SSAB Tunnplåt in Borlänge operates an acid regeneration plant producing ferric oxide to the extent of about 7.000 - 8.000 Mt/year.
Purity and process control
Silica content of the pickling liquid is reduced and kept under controll at a low level by the advanced silica removal filter. Consistency of physical properties and low chlorine content is secured by modern process control of the furnace operating parameters and by careful maintenance.
SSAB’s favourable range of steel grades pickled contributes to low and stable content of other impurities. Condensed process water is extensively used and pure fresh water is available from the river Dalälven, running from the Swedish mountain district less than one hundred meters from the regeneration plant. The clean water provides our ferric oxide very low content of alkali.
