Purification of raw palygorskite: a comparative study involving different processes and dispersing agents

Abstract Palygorskite (Pal) is a natural clay mineral with fibrous morphology and high surface area. Depending on the geological origin, it presents impurities, such as quartz and carbonates, which can harm some of its properties. Therefore, this work seeks to define a viable methodology for the purification of a Brazilian Pal. Two types of mixing processes (sonication and milling) and two types of dispersing agents (sodium silicate and sodium polyacrylate) were investigated. In addition, a subsequent acid activation with hydrogen peroxide and sulfuric acid was performed for complete purificat...