How is ferrochromium produced in an electric furnace?

Ferrochromium is produced in an electric furnace by smelting chromium ore with iron or iron ore and a carbon source, typically anthracite coal or coke.12

In the intense heat of the furnace, the carbon acts as a reducing agent, converting the metal oxides into a molten alloy. The specific characteristics of the resulting ferrochromium depend on the furnace conditions:1

• High-Carbon Ferrochromium: When ores are smelted with coke, the resulting metal is often carbon-saturated (approximately 9 percent). By adjusting the ore size, slag viscosity (often using lime), and silica content, producers can control the final carbon and silicon levels.2
• Charge Ferrochromium: By adding extra silica to the charge, a carbon-saturated alloy with higher silicon content is produced.2
• Low-Carbon Ferrochromium: This can be obtained by melting chromite and lime in an open electric-arc furnace and reacting the melt with ferrochrome silicon.3

Once the smelting process is complete, the molten metal and slag are tapped into a ladle, where they are separated by skimming or decanting. The molten alloy is then poured into slabs.21