Attrition scrubbing is a common mechanical beneficiation method that promotes strong particle–particle interactions in water-based suspensions. It helps remove surface coatings, clays, oxide films, weathered layers, and loosely attached impurities from mineral particles. Unlike traditional grinding, attrition scrubbing primarily cleans surfaces rather than reducing particle size, thereby improving mineral liberation and boosting downstream separation processes such as flotation, leaching, gravity separation, and magnetic separation. This review carefully explores the basic mechanisms behind attrition scrubbing, including interparticle abrasion, hydrodynamic shear, and effects of slurry rheology, and assesses its industrial use across various mineral systems such as silica sands, phosphate ores, iron ores, heavy mineral sands, lithium pegmatites, rare earth minerals, and recycled industrial materials. Special focus is given to operational factors like pulp density, impeller design, residence time, energy input, and particle size distribution, as these significantly affect scrubbing effectiveness and cost efficiency. The review also discusses limitations related to energy use, equipment wear, and the creation of very fine particles that can hinder downstream processing. Emerging advances in process optimization, such as staged scrubbing, hybrid washing–attrition systems, and integration with modern beneficiation circuits, are highlighted to demonstrate potential for improved cleaning performance with lower energy consumption. Finally, the review highlights key research gaps in scale-up, numerical modeling of surface-cleaning mechanisms, and the lack of standardized performance metrics, providing a foundation for future improvements in the design and optimization of attrition-based mineral beneficiation systems.
Antonio Clareti Pereira* (Wed,) studied this question.