Mixing intensification for the mineral industry

Abstract

The modern mineral industry uses hydrometallurgical processes to extract metals from ores. Typically, a large volume of ore slurry is treated in mixing tanks in a mineral processing plant, for leaching, digestion, precipitation, and other chemical processing to obtain pure metals or concentrated ores. This paper discusses mixing intensification as a means to achieve process intensification for the mineral process industry. Areas where mixing intensification can be applied are illustrated with case examples. Among them, it was suggested that for slowly reacting slurry systems typical in the mineral processing operations, high solid loadings should be considered to boost throughput. Improved agitator energy efficiency can be achieved by removing baffles, at very high solid loadings. Slurry stratification in tanks can be used to boost either solids residence time or slurry through flow.L'industrie moderne des minéraux utilise des procédés hydrométallurgiques pour extraire les métaux des minerais. Typiquement, un gros volume de boues de minerai est traité dans des réservoirs de mélange d'une usine de traitement des minéraux. Ces boues subissent de nombreux traitements dont lixiviation, digestion, précipitation et autres traitements chimiques en vue d'obtenir des métaux purs. Cet article propose d'adopter l'intensification du mélange pour permettre une intensification des procédés de l'industrie du traitement des minéraux. Les domaines pour lesquels l'intensification du mélange peutêtre appliqué sont identifiés et des exemples sont fournis pour illustrer le concept.

High solids concentration agitation for minerals process intensification

“…Process intensification could be defined as a means to drastically increase production yield per unit volume and per unit time and per unit cost. Wu et al 2 suggests that the term mixing intensification be used to describe efforts to achieve process intensification in mixing tanks.…”

Optimized Stirred Reactor for Enhanced Particle Dispersion

“…One major goal of PI is to intensify the processes that require handling of high‐concentration particles, catalysts, or droplets in complex slurry reactors 2, 3. Handling of solids in liquids in the processing units is involved in about 80 % of operations in various industries, ranging from leaching to homogenizing of catalysts 4–6. In particular, experimental and theoretical information regarding homogeneous suspensions or mixing of high‐concentration slurries seems rather rare in the literature.…”

Suspension of ultrahigh concentration solids in an agitated vessel

“…Process intensification in agitated vessels often requires that the production rate per unit volume has to be increased without going through major changes in the plant. It is achieved by increasing the throughput or yield mostly through improved physical processes such as efficient mixing while retaining the existing vessel volume, since it is often impractical to reduce the size or volume of operating vessels 1, 2. In such instances, the concentration of solids in the agitated slurry will increase, leading to a significant increase in impeller power draw to achieve off‐bottom solid suspension.…”