Choosing the proper carbon raiser is essential for achieving the desired carbon content and quality of steel. The choice of carbon raiser depends on various factors such as the type of steel being produced, the scale of production, the availability of raw materials, and the cost of production. In general, small-scale, middle-scale, and large-scale steel plants have different requirements for carbon raisers.

Small-scale steel plants typically have lower production capacities and may not have access to high-quality raw materials. Therefore, they may choose carbon raisers that are cost-effective and readily available, such as coal, coke, or charcoal. These carbon raisers may have lower purity levels and higher ash content, which can lead to higher impurities in the steel. However, small-scale plants can compensate for this by adjusting the smelting process to achieve the desired carbon content.

Middle-scale steel plants typically have higher production capacities and require carbon raisers with higher purity levels and lower ash content. They may choose synthetic graphite, petroleum coke, or metallurgical coke, which have higher carbon content and lower ash content. These carbon raisers can help to reduce impurities in the steel and improve its quality.

Large-scale steel plants typically have the highest production capacities and require carbon raisers with the highest purity levels and the lowest ash content. They may choose high-quality synthetic graphite or calcined petroleum coke, which have the highest carbon content and the lowest impurities. These carbon raisers can help to produce high-quality steel with consistent properties.

In addition to the scale of production, the choice of carbon raiser also depends on the type of steel being produced. For example, low-carbon steels may require high-purity carbon raisers to avoid impurities that can lead to brittle steel. High-carbon steels may require carbon raisers with a high carbon content to achieve the desired carbon content.

In conclusion, the choice of carbon raiser for steelmaking depends on various factors, including the scale of production, the availability of raw materials, and the type of steel being produced. Small-scale plants may choose cost-effective carbon raisers, while larger plants require higher purity levels and lower ash content. The type of steel being produced also influences the choice of carbon raiser, with low-carbon steels requiring higher purity levels and high-carbon steels requiring higher carbon content.