What Is Calcium Silicon? Grades and Specifications
Calcium Silicon (CaSi) is a ferroalloy mainly used in steelmaking for deoxidation, desulfurization and inclusion modification. Calcium and silicon work together during secondary refining to help control oxygen, sulfur and non-metallic inclusions.
Common Calcium Silicon grades include Ca31Si60, Ca28Si60, Ca24Si60, Ca20Si55 and Ca16Si55. The main difference is the calcium and silicon content, while C, Al, P and S are controlled according to the product specification.
| Grade | Ca | Si | C | Al | P | S |
| Ca31Si60 | ≥31% | 50–65% | ≤1.2% | ≤2.4% | ≤0.04% | ≤0.06% |
| Ca28Si60 | ≥28% | 50–65% | ≤1.2% | ≤2.4% | ≤0.04% | ≤0.06% |
| Ca24Si60 | ≥24% | 55–65% | ≤1.0% | ≤2.5% | ≤0.04% | ≤0.04% |
| Ca20Si55 | ≥20% | 50–60% | ≤1.0% | ≤2.5% | ≤0.04% | ≤0.04% |
| Ca16Si55 | ≥16% | 50–60% | ≤1.0% | ≤2.5% | ≤0.04% | ≤0.04% |
For different steelmaking processes, CaSi grade, particle size and addition method can be adjusted according to the required calcium treatment and steel chemistry.
How Is Calcium Silicon Produced?
Calcium Silicon is mainly produced through high-temperature reduction in electric furnaces. The two common production routes are carbothermic and silicothermic processes, with differences in raw materials, reducing agents and furnace operation.
The carbothermic process uses carbon-based reducing materials, while the silicothermic process relies on silicon as the main reducing component. Production conditions influence calcium recovery, energy consumption and the chemical stability of the final CaSi Alloy.
For buyers, the production method matters mainly because it can affect CaSi quality and consistency. Stable raw materials, controlled furnace operation and proper crushing and screening are important for maintaining consistent composition and particle size.
How to Choose a Reliable Calcium Silicon Supplier?
Choosing a reliable Calcium Silicon Supplier requires more than comparing product prices. For regular procurement, buyers should pay attention to the supplier’s understanding of different steelmaking applications, communication efficiency and ability to respond to specific technical requirements.
A supplier with integrated production and processing capabilities can offer greater flexibility when requirements change. This is particularly useful for buyers who need different CaSi grades, customized specifications or regular shipments rather than one-time purchases.
Long-term supply also depends on effective quality management and order coordination. From raw material control and production to inspection, packing and shipment, a well-organized supply chain helps keep each order aligned with the agreed requirements.
For overseas buyers, stable supply, responsive communication and consistent service can be just as important as the product itself when establishing a long-term Calcium Silicon supply relationship.