Application of quicklime briquette press in steel smelting: preparation of efficient flux and cost optimization
In the steel smelting process, the quicklime briquette machine is one of the core equipment to improve efficiency and reduce energy consumption. It significantly optimizes the performance of blast furnace flux by pressing quicklime powder into high-density pellets to replace traditional lump limestone. The following is an analysis of its specific application scenarios, technical advantages and actual benefits in steel smelting.
1. Why does steelmaking need quicklime briquette machine?
Quicklime (CaO) is an indispensable flux in steelmaking, mainly used for:
- Desulfurization and dephosphorization: remove sulfur and phosphorus impurities in molten iron to improve steel quality;
- Slag adjustment: react with impurities such as silica to form slag for easy separation;
- Protect the furnace lining: reduce the corrosion of slag on the inner wall of the blast furnace.
Traditional problems:
Block quicklime is easy to absorb moisture and pulverize (pulverization rate exceeds 30%), with large transportation losses, and slow reaction speed after entering the furnace, resulting in high coke consumption and low smelting efficiency.
Solution:
The quicklime briquette machine is used to press the powdered quicklime into high-strength pellets with a density of 1.9-2.2g/cm³ and a compressive strength of ≥600N/ball, which significantly improves the above problems.
2. The core role of quicklime briquette machine in steel smelting
Improve flux reaction efficiency
- High pellet porosity: The microporous structure (porosity 10%-15%) formed during pressing can accelerate the contact reaction with molten iron at high temperature and shorten the smelting time.
- Uniform particle size: The pellet diameter is usually Φ15-30mm, avoiding the incomplete reaction caused by the different sizes of block limestone.
Reducing coke consumption
- The pellet reaction activity is better than that of block lime, which reduces the blast furnace coke ratio (coke/molten iron ratio) by 8%-12%, and saves 30-50 yuan per ton of iron.
Reducing raw material waste
- After pressing, the pellets are not easy to pulverize, and the transportation loss is reduced from 30% to less than 5%, and waste materials such as dust removal ash can be recycled to reduce procurement costs.
3. Steel smelting process of quicklime briquette machine
Raw material pretreatment
- After quicklime powder is screened (particle size 80-200 mesh), the natural humidity is controlled at 1%-3%, and no additional water is required.
High-pressure pressing and molding
- Use a hydraulic double-roll briquette machine (pressure 50-150MPa) to press the powder into high-density pellets, with a single machine output of 5-20 tons per hour.
Pellet drying (optional)
- If the ambient humidity is too high, a dryer (temperature 200-300℃) can be configured to further reduce the moisture content.
Blast furnace charging
- The pellets are mixed with coke and iron ore in proportion and put into the blast furnace, and the smelting temperature reaches 1500-1600℃.
4.Practical application cases and benefit analysis
Case name: Blast furnace flux optimization project of a large steel plant
Before transformation: using block limestone, coke ratio 480kg/ton iron, annual lime loss cost 12 million yuan.
After transformation: using quicklime briquette machine production line (15 tons per hour), achieving:
- The coke ratio is reduced to 430kg/ton iron, saving 18 million yuan in coke cost per year;
- The raw material loss is reduced by 25%, and the annual comprehensive benefit is increased by 25 million yuan;
- Dust emission is reduced by 60%, and the environmental protection compliance rate is 100%.
5.Selection and maintenance recommendations
Equipment selection
- Small and medium-sized steel mills: choose a machine with an output of 5-10 tons per hour (such as TD-650), a pressure of 80-100MPa, and an investment cost of about 500,000-800,000 yuan;
- Large steel mills: configure a fully automatic production line with an output of 20-35 tons per hour (such as TD-1250), including a hydraulic system and an intelligent feeding module.
Maintenance points
- Roller maintenance: Check the wear of the alloy roller every 500 hours of production, and the depth deviation of the die is ≤1mm;
- Lubrication management: Add high-temperature resistant grease (such as molybdenum disulfide) to the bearing every 8 hours;
- Emergency treatment: When the material is stuck, immediately enable the hydraulic overload protection to avoid deformation of the roller.
The quicklime briquette machine has completely solved the problems of low flux utilization and high cost in steel smelting through innovative technology. Choosing EP Machinery China's professional quicklime briquette machine manufacturer direct sales service can obtain customized equipment and process solutions, significantly improving the economic benefits and environmental protection level of steel mills.
