Characterization of Brown Color Pigment ..

• Main Author: Khugan A/l Gunasekar
• Published: 2023
• Subjects: Fluidized bed waste; brown color pigment; iron oxide pigment

During the hot rolling process, oxygen from the surrounding atmosphere reacts with the surface of the hot rolled steel and thus resulting in the formation of an oxide layer called scale. These scale and impurities need to be removed to improve the quality and overall strength of the steel. In the cold rolling process, the steels undergo a pickling process where they are dipped in strong acids such as hydrochloric acid, HCl, and sulfuric acid, H2SO4 to treat the steels and eliminate contaminants, rust, and scale from the surface of the steels. Once the acids are saturated with contaminants, they will be referred to as spent acid and needs to be replaced with new strong acids. Since the method to dispose of the spent acids is expensive, they will be dumped at landfills after neutralizing them with lime which is very harmful to the environment. Later on, it is found that they are some important compounds that are present in the spent acid where it can be used back through the acid generation plant process. Although the main objective of this process is to recycle the spent acid into reusable acid, iron (III) oxide, Fe2O3 waste will be generated as a by-product where it will be deposited at the bottom of the chamber in the acid regeneration plant. This project proposes the idea of using this iron oxide waste and converting them into a marketable colour pigment that can be applied on roof tiles. It was done by blending the raw materials into ultra-fine particles and then mixing with industrial graded powder in eleven different ratios. The colour properties of the colour pigment samples were determined using a chromameter to record their respective L* a* b* values where L* represents the brightness, a* shows how reddish it is and b* is for bluish. The importance was given to the colour property value of a* because iron (III) oxide, Fe2O3 exists in red colour and they were characterized and differentiated from each other to choose the best reddish looking colour pigment. Later on, the colour pigments were applied on roof tiles which are made from white sand and cement to determine their respective tinting power which is to cover the original colour of the tiles. They are then further characterized by using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and energy-dispersive X-Ray Spectroscopy (EDX) to