Title: Enhancing Solid-Liquid Separation In Nitric Acid Leaching Of Low-Grade Alumina Ores
Authors: Ruziyev Ulugbek Mamarasulovich
Volume: 9
Issue: 9
Pages: 58-65
Publication Date: 2025/09/28
Abstract:
This study investigates the enhancement of solid-liquid phase separation in nitric acid-leached pulps derived from low-grade alumina-containing raw materials, including kaolin and substandard bauxites. The application of polyelectrolyte flocculants (K-4, K-6, K-9, and AKS) was assessed under both laboratory and pilot-scale conditions. Key influencing parameters such as pH, flocculant dosage, particle size distribution, and liquid-to-solid ratios were systematically evaluated. Results indicate that flocculants significantly accelerate sedimentation and improve filtration efficiency, with K-4 showing the highest performance. Optimal clarification occurred within 20 minutes, achieving up to a 4-fold increase in sedimentation rate and a 2.7-fold increase in filtration rate compared to untreated pulps. Experimental findings were supported by chemical and mineralogical analysis of Vorukhsky, Turgaysky, and Tikhvinsky bauxites, revealing distinct responses to flocculation based on composition and dispersion behavior. Additionally, the residual flocculant was found to enhance the efficiency of sludge washing across multiple stages. The outcomes provide practical insights for optimizing the hydrometallurgical processing of low-grade aluminum ores, contributing to more efficient and sustainable alumina recovery via nitric acid technology.