Aluminium provides an ideal base for surface finishing in order achieving decorative coatings, mechanical protection or corrosion resistance. There are many aluminum products that benefit from surface finishing including consumer goods, automotive trim, architectural building products and many others. Colour, texture and improved hardness can be added to the surfaces for aesthetic and functional purposes. There are many factors that will influence the performance of a surface finish. Surface quality is directly dependent on the conditions and consistency of the surface treatment process.
The majority of aluminum finishing is based on simple inorganic chemical operations. These chemical operations produce wastes which are normally treated with relatively simple pH neutralization and solid separation processes. Ion exchange/sorption, evaporation, crystallization and membrane processes are the main systems employed for purification, recovery and recycle of chemicals in the aluminum industry.