Introduction
Advanced oxidation desulfurization (AOD) is a type of desulfurization process used primarily in the metal casting industry. AOD utilizes an oxygen-rich atmosphere to oxidize sulfur compounds, reducing sulfur content and improving the quality of the melt. The process is used to reduce levels of sulfur compounds in the aluminum melts, reducing fumes from the furnace and improving specific properties of the alloy. However, when using an AOD process, the refractory lining of the furnace can be quickly damaged by the high temperatures and presence of gasses. As such, increasing the lifespan of the refractory liners is an important part of reducing the cost of implementing an AOD process.
Methods of Improving Refractory Lining Longevity
1. Use of Precast Refractory Liners: Precast refractory liners can be used to reduce direct contact with metal and metal alloys formed during the AOD process, helping to reduce the rate of refractory corrosion and wear.
2. Use of Refractory Lining with Artificial Aging: Artificial aging of the refractory liners is thought to improve their resistance to thermal shock and high temperature corrosion, which can prevent cracks and spalling of the refractories.
3. Use of a Protective Lining: Installing a protective layer between the refractory and the crucible wall of the AOD furnace can help to reduce the rate of corrosion and wear of the refractory. This protective layer can be made of insulating material, such as magnesium oxide and mullite, or even a thin steel sheet.
4. Postmelt Drying of the Refractory: Postmelt drying of the refractory can reduce its thermal shock when it is heated up, which can lead to greater lifespan of the lining. Postmelt drying is a process where the lining is heated up to a lower temperature for a longer period of time than would be required for melting, helping to reduce the thermal shock rate of the refractory.
5. Use of Continuous Monitoring Systems: Using continuous monitoring systems can help to detect any problems in the refractory lining before they become serious. These systems are designed to track the temperature, heat flux, and other important data points, alerting operators when there are any abnormalities in the system. In this way, operators can take corrective action before the refractory lining becomes too damaged.
Conclusion
Increasing the lifespan of refractory lining in an AOD furnace is important for reducing costs associated with the process. Taking steps such as using precast refractory liners, artificial aging, protective lining, and postmelt drying can help to extend the lifespan of the refractory liners. Additionally, using continuous monitoring systems can help to detect any problems before they become too serious. By taking these steps, the cost of implementing an AOD process can be significantly decreased.
