Requirements for Lime Quality in Metallurgical Industry
In the metallurgical industry, lime is an important flux and slag material, and its quality directly affects the efficiency and product quality of metal smelting. The metallurgical process has clear requirements for the composition, physical properties, and activity of lime, mainly including the following aspects:
1. Chemical composition requirements
The content of calcium oxide (CaO) in lime should be high (usually ≥ 85%), and the impurity content should be strictly controlled. Harmful impurities such as silicon dioxide (SiO ₂), magnesium oxide (MgO), sulfur (S), and phosphorus (P) must be below industry limits to avoid affecting the fluidity of slag and metal purity.
2. Activity requirements
The reactivity of lime reflects its ability to react with other components in the slag. Metallurgical lime needs to have high activity (usually measured by hydration activity testing) to ensure rapid slag formation, improve desulfurization and dephosphorization efficiency, and shorten smelting time.
3. Granularity and physical state
Lime should maintain a suitable particle size distribution (usually 10-50mm) to avoid being too fine or too coarse. Uniform particles can ensure sufficient reaction at high temperatures, reduce flying losses, and improve the permeability and heat conduction efficiency inside the furnace.
4. Burning reduction and stability
The loss of ignition (LOI) should be low to ensure the volume stability of lime at high temperatures and prevent it from powdering. Incomplete decomposition of calcium carbonate (CaCO3) can lead to excessive gas release during the smelting process, causing splashing or compositional fluctuations.
The metallurgical industry requires the use of high-quality lime with high purity, high activity, uniform particle size, and strong stability. Production enterprises should strictly control the calcination process and raw material selection to meet the requirements of high efficiency, energy conservation, and environmental protection in the smelting process.
