Application of Quick Lime Kiln in Steel Industry
In modern industrial production, a quick lime kiln plays an indispensable role. Lime is widely used, especially in steel, chemical industry, building materials, etc. Among them, the steel industry has a robust demand for lime. As the main production equipment of quicklime (CaO), quick lime kiln directly affects the quality and efficiency of steel smelting. Quicklime has excellent chemical activity and can effectively remove impurities such as sulfur, phosphorus, and silicon in molten steel, thereby improving the performance of steel. Lime acts as a flux in many process steps such as blast furnace ironmaking and converter steelmaking to adjust the pH. Therefore, the operation of a quick lime kiln affects the production efficiency of the steel industry.
Factors to Consider
- Desulfurization: Sulfur in steel will reduce the plasticity and toughness of the steel, making it brittle and prone to cracking. Therefore, during the steelmaking process, lime is used to remove sulfur and other impurities from iron ore, preventing these impurities from affecting the quality of the final steel.
- Fluxing: In the steelmaking process, lime is one of the most important fluxes, which reacts with gangue and other impurities in iron ore to form liquid slag. Slag can absorb impurities in molten steel, such as silicon (Si), phosphorus (P), sulfur (S), etc.
- Adjust pH: The basicity of slag directly affects the effects of desulfurization and dephosphorization. When the alkalinity is too low, the desulfurization and dephosphorization effects are poor and the quality of steel decreases. By adding an appropriate amount of quicklime, the basicity of the slag is increased, making it more conducive to the removal of sulfur and phosphorus.
- Reduce Costs: Quicklime is relatively cheap and readily available, making it a cost-effective auxiliary material for steelmaking. The use of highly active quicklime can reduce smelting time and improve production efficiency, thereby reducing energy consumption and production costs.
Why Use Quicklime
| Lime Type | Main Ingredients | Reactivity | Is additional decomposition required? | Suitable for steelmaking |
|---|---|---|---|---|
| Quicklime | (CaO) | High | No | Yes |
| Slaked lime | Ca(OH)₂ | Low | Yes (decomposes at high temperature) | No |
| Limestone | CaCO₃ | Very low | Yes (needs high temperature decomposition) | No |
Quicklime Production Process
- Raw Material Preparation
The steel industry has high requirements for the quality of quicklime, so limestone with a CaCO₃ content ≥ 90% should be selected. The large pieces of limestone are fed into a limestone crusher and broken into particles of 40-80 mm to ensure uniform calcination.
- Quick Lime Kiln Calcination
The crushed limestone is sent to the quick lime kiln for calcination at a temperature of 900~1200°C. If the temperature is too high, quicklime will be overburned and its activity will be reduced; if the temperature is too low, the calcination will be incomplete, which will affect the desulfurization and dephosphorization effects. Commonly used kiln types include vertical lime kiln and limestone rotary kiln.
- Cooling
The temperature of calcined quicklime is as high as over 1000°C and needs to be cooled quickly. Prevent quicklime from overheating and causing powdering, which will affect the steel smelting effect. Avoid prolonged high temperature which may cause a decrease in activity. The heat after cooling can be recovered and reused.
- Screening and Processing
The cooled quicklime is classified according to particle size to meet the needs of different smelting processes. Lump quicklime (40-80mm) is suitable for blast furnace and converter steelmaking. Small particles of quicklime (10-40 mm) are used in refining furnaces or sintering processes. Quicklime powder (<10mm) can be further processed into mature lime (Ca(OH)₂).
Types of Quick Lime Kiln
Production Capacity: 100t/d – 600t/d
Limestone Particle Size: 30m-60mm / 40mm-80mm
Lime Activity Degree: Greater than 360ml
Heat Consumption: No more than 950kcal/kg
Twin Shaft Lime Kilns:
Production Capacity: 50-1200t/d
Limestone Particle Size: 30m-60mm / 40mm-80mm
Lime Activity Degree: Greater than 360ml
Heat Consumption: No more than 860kcal/kg
Double Beam Lime Kilns:
Production Capacity: 100t/d-600t/d
Limestone Particle Size: 30m-60mm / 40mm-80mm
Lime Activity Degree: Greater than 320ml
Heat Consumption: No more than 1050kcal/kg
Limestone Rotary Kiln:
Production Capacity: 200t/d-1200t/d
Limestone Particle Size: 20m-40mm
Lime Activity Degree: 360ml-400ml
Heat Consumption: About 1200kcal/kg
Single Shaft Kiln:
Production Capacity: 100-400t/d
Lime CaO Content: >90%
Limestone Consumption: 1.65t·lime
Exhaust Gas emission Concentration: <50Mg/m³
Indirect Fired Rotary Kiln:
Production Capacity: 15-3000kg/h
Kiln Body Length: 6-18 m
Calcination Temperature: 1100±50℃
Fuel: Gas, coal, oil, electricity, etc.
The Impact of Quick Lime Kiln on the Steel Industry
1.Improve production efficiency: The quicklime produced by quick lime kiln can improve the fluidity of slag, reduce temperature, accelerate reaction, increase smelting speed and shorten time. The foamy slag in the electric arc furnace increases the furnace temperature, reduces heat loss, stabilizes the process, and thus improves production efficiency.
2.Improve steel quality: In steel smelting, quicklime can improve the quality of steel by removing harmful elements (such as sulfur and phosphorus) in molten steel and adjusting the slag composition. Reduce scrap rate and increase finished product rate.
3.Reduce production costs: Quicklime can lower the melting temperature, reduce the required fuel consumption and reduce energy costs. 3. The use of quicklime can extend the service life of the furnace lining and reduce the maintenance and replacement costs of equipment.
4.Improve competitiveness: The high-quality quicklime production process and the environmental protection function of quicklime also help steel companies meet the requirements of green production. Enhance the environmental image and market competitiveness of enterprises.
The Future Development Trend of Quick Lime Kiln
In the future, Quick Lime Kiln will develop in the direction of greater efficiency, environmental protection, intelligence and low cost. Reduce energy consumption by improving energy efficiency, adopting waste heat recovery and high-efficiency combustion technology. Strengthen carbon emission control and adopt CCS and low-carbon fuel technologies. Introducing automation and intelligent systems to optimize the production process. And promote resource recycling and reduce waste gas and waste residue emissions. The quick lime kiln will effectively reduce production costs, meet increasingly stringent environmental protection requirements, and promote sustainable industrial development.
Hot-sale Lime Calcination Kilns
Calcining Limestone Equipment
Our Cases
Contact Us
- Email:
- Info@limecalcinationplant.com
- Phone:
- +86 13683722138
- Address:
- Room908, unit1, building2, Huaqiang Xintiandi, intersectiong of Pingyuan Road and Xiange Avenue, Anyang, Henan Province