Mineral processing comprises comminution, beneficiation, and dewatering. Ores are ground to liberate valuable minerals, followed by separation (e.g., flotation) and subsequent tailings dewatering (e.g., thickening and filtration). As ore grades decline, finer grinding is increasingly preferred to improve mineral liberation and recovery, but it also generates more ultrafines and liberates clays. These fines and clay-rich tailings hinder solid–liquid separation and constrain filter-press performance, resulting in reduced throughput and higher filter-cake moisture.

Pelleting flocculation is a flocculation technique that converts micron-sized particles into dense, centimetre-sized pellets that can be separated from water more readily. In earlier work, we developed a helical uplift pelletiser and validated the concept using kaolin, demonstrating that pellet formation can significantly enhance filtration by improving both the compressibility and permeability (Luo et al. 2026).

In this study, we extend pelleting flocculation to real tailings and optimise performance through systematic selection of surfactants and flocculants, including dosage optimisation. The pelletiser prototype was redesigned to provide improved flow-rate control and enable pellet collection via screening. By converting ultrafine tailings into robust pellets, the dewatering process is simplified by shifting the separation step from slow filtration/settling to rapid screening, facilitating faster water release and more practical tailings management...