Iron and steel industry is the main consumer of quicklime.
Many millions of tons of iron and steel are produced in Italy every year, and the use of the calcium oxide with low granulometry and controlled reactivity is essential for this purpose. In this industrial sector lime is used in most metallurgical reactions, whose purpose is simply to combine, in the slag, the secondary elements to eliminate, i.e. sulphur and phosphorous.
Sulphur is introduced in primary smelting cast iron, mainly through the coke, used in the blast furnace as fuel and reducing substance, while steel is introduced through almost all charge stocks, differently from phosphorous which is already present in the same mineral. Due to the harmful action of sulphur and phosphorous on the metal properties, these must be reduced as much as possible, also in the use of high quality lime. And the calcium oxide produced by ITALCALCE perfectly satisfies this need.
NON FERROUS MATERIALS
Lime is extensively used for the treatment and recovery of non-ferrous metallic minerals. In the flotation of the copper mineral, the lime used as additive acts as reducing substance and contributes to maintain the proper degree of alkalinity.
In extracting gold and silver with the flotation process of cyanide, quicklime is used to control the pH value. Moreover, it is used in the flotation processes of lead, zinc and molybdenum. In South Africa, the uranium industry represents a great source of consumption of quicklime, which is mainly used in flotation processes from residues of gold mines.
In conclusion, quicklime is used as a fluidifying agent in the production of iron-chrome, iron-manganese, nickel, tin, titanium and other metals.