A new approach to enhance the anticorrosive properties of treated Egyptian kaolin

Abstract

PurposeKaolin (hydrated aluminum silicate) is one of few minerals that are found in nature in a relatively pure state which is abundant in many places of the world. In this research, a simple chemical treatment using traces of ammonium molybdate was carried out to enhance the anticorrosive properties of kaolin.Design/methodology/approachThe steps of treatment of kaolin at 1,000°C were estimated. Characterization of three different combinations of aluminum oxide with iron oxide were studied using spectroscopic methods of analysis via X‐ray diffraction (XRD), transmission and scanning electron microscopy (TEM and SEM). Also, evaluation of the prepared pigments using (oil absorption, specific gravity, water‐soluble matter, and pH) international standard testing methods were estimated. Then these prepared pigments were incorporated in anticorrosive paint formulations based on medium oil alkyd resin as a binder, the physico‐mechanical and anticorrosive properties of paint films were detected by testing them in 3.5 percent NaCl solution for 28 days.FindingsIntroduction of small amounts of ammonium molybdate in kaolin promoted its physico‐mechanical and anticorrosive properties. Although, this process of treatment is economically feasible, treated kaolin can replace expensive commercial pigments found in markets with an almost near quality to their performance.Originality/valueTreated kaolin can be applied in many industries beside pigment manufacture, and paint formulations, it can be applied as reinforcing filler in rubber, plastics, and ceramic composites. Also it is applied in paper filling, paper coatings, and electrical insulation.