Evaluation of extracting titanium dioxide from water-based paint sludge in auto-manufacturing industries and its application in paint production

Abstract

Almost 2555–4380 tons of paint sludge are produced annually in an auto-manufacturing plant; recycling and reproduction of beneficial materials such as titanium dioxide (TiO₂) and its application in paint production from paint sludge are evaluated in this article. The disposal of these sludge is environmentally important and is the main and most serious challenge for auto-manufacturing units. Today, these sludge are recognized as toxic wastes, whose disposal is much costly and constrained by environmental standards. Controlled disposal requires spaces, which are expensive and impermeable, because the sludge contains large amounts of hazardous materials such as heavy metals, solvents, and other materials polluting wells, springs, and other water resources. In this research, X-ray diffraction spectroscopy was carried out to determine the types of sludge combinations. Then, chemical digestion and centrifuge was used to extract TiO₂, the extracted TiO₂ reached 67.41% using these techniques. Next, a powder containing TiO₂ in a certain percentage was used for paint production. Here, not only the amount of sludge decreased to as much as 70% but also the fresh paint required annually will be reduced by 21%. Furthermore, all heavy metals and toxic wastes will be removed as an environmental challenge.