How is calcium silicon alloy produced and processed?

Calcium silicon alloy is often used as a deoxidizer in steel smelting. The conventional production methods of calcium silicon alloy can be divided into three types, namely: mixed feeding method, layered feeding method, and two-step method.
1. Mixing and adding materials, also known as one-step method. Use a carbonaceous reducing agent to simultaneously reduce silica and calcium oxide, that is, mix all the raw materials evenly and add them into the furnace in small batches. The mixing and feeding method is simple to operate and easy to control. However, this method has a fast rate of land sedimentation and a short production cycle.
2. Layered feeding method. First, add the mixture of lime and reducing agent into the furnace, melt and sink, and then cover it with the mixture of silica and reducing agent. The contact between calcium oxide and silicon dioxide in the furnace is reduced, and the formation of low melting point calcium silicate slag is reduced. Due to the higher furnace temperature, it can produce high-grade calcium silicon alloys.
3. Two-step method. Two electric furnaces are required. In one electric furnace, calcium carbide is first produced, in the other electric furnace, silicon dioxide is reduced with carbon, and calcium carbide is added to produce the alloy. This process avoids the direct contact between calcium oxide and silicon dioxide, thereby overcoming the problem of low slagging temperature.