dross
Dross is slag or impurities that rise to the surface of melting metals during either the melting, casting, or refining process. It comprises nonmetals such as oxides, or slag, and others, and results from the separation of these materials from the base metal due to differences in density or chemical composition. In order to achieve the purity and quality of the final metal product, this would normally be skimmed.
Key Features:
- Formation at Surface: Dross is formed at the surface of molten metals due to oxidation and other chemical activities that take place when the molten metal is in contact with air or fluxes in a molten state during high-temperature processing.
- Quality Assurance: Removal of dross becomes inevitable in order to avoid porosity, inclusions, or weak spots in castings or ingots produced from dross-contaminated metal.
- Recovery of Material: Dross is further processed in some processes such that it is possible to recover from it its valuable metal content, thereby minimizing waste and maximizing cost efficiency.
The quality, strength, and even the appearance of metal products are dependent on the management of dross. Aluminum casting, foundries, and metal recycling industries often pay great attention to controlling the formation and removal of dross to maintain production levels and loss of materials. To improve process efficiency, decrease contamination, and promote green metal manufacturing, continuous development is taking place in advanced melting technology and dross handling methods.