How calcium silicon is made?

1. Raw Materials Selection

The primary raw materials used in the production of calcium silicon are:

• Calcium oxide (CaO): Usually derived from lime (limestone).
• Silicon (Si): Commonly obtained from silica (SiO₂) or quartz.
• Iron (Fe): Although not always necessary, small amounts of iron are sometimes added to adjust the alloy composition.

Each of these materials is carefully sourced and prepared to ensure the highest quality for the final product.

2. Smelting Process

The production of calcium silicon typically takes place in an electric arc furnace. This is the heart of the manufacturing process, where the raw materials are melted together at high temperatures. The steps involved are:

• Charging the Furnace: The raw materials (calcium oxide, silicon, and sometimes iron) are charged into the furnace.
• Reduction Reaction: At temperatures between 1500°C and 1800°C, calcium oxide and silica react to produce calcium silicate, calcium vapor, and silicon. The reaction proceeds as follows:2CaO+SiO2→2Ca+SiO42 \text{CaO} + \text{SiO}_2 → 2 \text{Ca} + \text{SiO}_42CaO+SiO2​→2Ca+SiO4​
• Collection of Molten Alloy: As the calcium vapor and silicon combine, they form the calcium silicon alloy. The molten alloy settles at the bottom of the furnace.

3. Refining and Tapping

Once the desired composition is achieved, the molten calcium silicon is tapped from the furnace. The alloy is then refined to remove any impurities, such as excess carbon, sulfur, or oxygen, which can affect its performance in steelmaking.

4. Casting and Cooling

After tapping, the molten calcium silicon is poured into molds or cast into small ingots. The casting process ensures that the alloy cools down gradually, forming a solid structure. Once cooled, the ingots are broken into smaller pieces suitable for use in various applications.

5. Crushing and Sizing

The solid calcium silicon is then crushed into smaller particles. The size of these particles is adjusted according to the customer’s requirements, with typical sizes ranging from granules to powders. This sizing is crucial, as different applications require different sizes of the alloy for optimal performance.

6. Packaging and Storage

The final step in calcium silicon production is packaging the alloy in airtight containers or bags to preserve its quality. Since calcium silicon is sensitive to moisture and oxidation, proper storage is essential to maintain its effectiveness as a deoxidizer and desulfurizer in steelmaking.

The production of calcium silicon is a sophisticated process that requires precision at every stage—from selecting high-quality raw materials to carefully controlling the smelting and refining process. Its role in steelmaking cannot be understated, as it plays a critical part in improving the mechanical properties of steel by reducing impurities. By understanding how calcium silicon is made, we can better appreciate its importance in the metallurgy industry.