How is Calcium Silicon produced?

Calcium silicon (CaSi) is an alloy composed primarily of calcium (Ca) and silicon (Si). It is used in steelmaking, where it acts as a deoxidizer and desulfurizer. It is mainly used in the form of filled cable but also as grains for powder injection. The production of calcium silicon generally follows these steps:

1. Raw Materials:
 - Lime (CaO): Source of calcium.
 - Silica (SiO₂): Source of silicon.
 - Carbon (C): Usually in the form of coke or coal, which serves as a reducing agent.

2. Reduction Process:
 The process is carried out in an electric arc furnace, where lime, silica, and carbon are added together. In the high-temperature environment, chemical reactions occur:
 - The carbon reduces the silica to produce silicon:
 SiO₂ + 2C → Si + 2CO
 - Simultaneously, calcium is produced by reducing lime with carbon:
 CaO + C → Ca + CO

3. Formation of Calcium Silicon:
 Once calcium and silicon are produced in the furnace, they combine to form calcium silicon (CaSi) alloy. The alloy is then tapped from the furnace.

4. Casting and Cooling:
 After tapping, the molten calcium silicon alloy is poured into molds, where it solidifies. The solid alloy is then broken into smaller pieces for further use in steelmaking.
The process is typically done in large-scale furnaces and requires precise control of temperatures and material proportions to ensure the desired composition of the CaSi alloy.