Aluminum-Chromium Slag
Aluminium-chromium slag is a by-product of the metallurgical extraction of chromium from its ore, chromite. It is a mixture of aluminium and chromium oxides and other metal oxides, obtained as a molten precipitate. It is mainly used as a flux agent and abrasive in the metallurgical, ceramic, foundry and refractory industries.
Aluminium-chromium slag is a valuable material for the industries producing metals and other products. Its high oxides content helps to improve the heat transfer and refractory resistance in the melting and casting processes. The slag has a low to moderate solubility in non-oxidized acids, and the flux is recycled even after repeated re-use. Aluminium-chromium slag reduces the shrinkage of castings, so that the moulds need to be smaller and the casting process is more efficient.
The initial aluminium-chromium slag is a deep black colour and it is broken into smaller fragments, either manually or mechanically, to enhance the fluxing action. The fragments may range in size from fine flour size to small rocks. The slag is often added to other materials like clay, sand and soda ash to form a slurry, which is then poured into a mould. During melting and casting, the slag serves to reduce the surface tension of the metal.
Aluminium-chromium slag also helps to reduce the thermal expansion of the metal and improves its machinability. It has good fire resistance, so is suitable for use in thermal insulations and also for fireplace hearths.
The slag can be found in powdered form and its main use is as an abrasive. The powder is employed in polishing, grinding and lapping operations, as well as in other particular metal-finishing jobs such as cleaning rust, cleansing steel surfaces and sharpening tools.
Aluminium-chromium slag is non-toxic and it can be recycled. It is low in hydrochloric acid. Recycling the slag is beneficial for both the environment and the economy, as it reduces the amount of waste material that is disposed.
Aluminium-chromium slag is an important component in the production of aluminium and chromium-based products. It reduces costs, improves the quality of the final products and reduces the environmental impact of waste materials. This makes it a popular material for use in a wide range of industries.
