Ferrochrome (FeCr) is a corrosion-resistant alloy of chrome and iron containing between 50% and 65% chrome. It is a finishing material which contains about 50-70% chromium alloyed with iron.
Primarily ferrochrome is utilized in the production of stainless steel. Stainless steel depends on chrome for its appearance and its resistance to corrosion. The average chrome content in stainless steel is approximately 18%. It is also used when it is desired to add chromium to carbon steel. Ferrochrome known as 'charge chrome' produced from a Cr containing ore with a low Cr content is most commonly used in stainless steel production, where as High Carbon Ferrochrome produced from high grade ore is more commonly used in specialist applications such as engineering steels and production of finished metals takes place in electric arc furnaces.
Ferrochrome production is essentially a carbothermic reduction operation taking place at high temperatures. Cr Ore, an oxide of chromium and iron, is reduced by coal and coke to form the iron-chromium alloy. The heat for this reaction comes typically from the electric arc formed between the tips of the electrodes in the bottom of the furnace and the furnace hearth. This arc creates temperatures of about 2800°C. In the process of smelting, huge amounts of electricity are consumed.
The material is tapped from the furnace intermittently. When enough smelted ferrochrome has accumulated in the hearth of the furnace, the tap hole is drilled open and the molten metal and slag are rushed down to a sand bed or caught in ladles. Once the metal solidifies into cakes, these are shifted to the handling yard where they are cooled down, cleaned and further broken into pieces as per specification of the Customers and packed for shipment.
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