Meaning
Reductions in the mass of molten metal during heating operations in a specific type of industrial chamber occur due to high temperature reactions. These events are often categorized as reverberatory furnace loss. The design of the equipment reflects heat from the ceiling onto the hearth, creating an environment where oxidation and volatilization are common.
These losses represent the difference between the weight of the metal charged into the furnace and the weight of the usable metal tapped out.
Thermal Oxidation
Exposure to the furnace atmosphere at extreme temperatures causes the metal surface to react with oxygen. This reaction creates a layer of dross or scale that is removed during the cleaning process. The rate of loss depends on the surface area of the metal and the duration of the heat.
Aluminum and zinc are particularly susceptible to this type of weight reduction.
Slag Entrapment
Small particles of pure metal often become stuck in the non metallic waste layer. While the metal is not chemically changed, it is physically inaccessible.
Efficiency Measure
Readiness for full scale production is evaluated by measuring the demonstrated rate of metal recovery during pilot runs. A reverberatory furnace loss that exceeds the industry standard indicates a need for better atmosphere control or temperature regulation. Capability in a foundry is defined by the ability to maintain a consistent yield despite these inherent process challenges.
The cost of calling a melt successful early is the inaccurate reporting of the total inventory. Accurate tracking of the loss ensures that the procurement of raw material matches the requirements of the final order.
