Rheological Perspectives of Clay-Based Tailings in the Mining Industry

Abstract

The mining industry faces a significant problem in regions with water scarcity and has had to put in place new strategies to preserve its environmental and economic sustainability. An attractive option in recent years has been the direct use of seawater, avoiding the construction of reverse osmosis plants to desalinate. But, some operational complexities are the subject of discussion and research for engineers; for example, the difficulties by the high presence of complex gangues like clays and the location of the plants, far from the coast and at high altitude. The latter requires high investments in pumping, the only option in some cases. In this scenario, it is imperative to improve the efficiency of water use and advance to effective closures of water circuits. A critical stage is the thickening that allows water to be recovered from the tailings, reusing it in upstream operations. However, the performance of the tailings management is usually limited by the rheological properties of the thickened slurries, which impact on the discharge from the underflow of the thickeners, pumping energy costs, disposal on the tailings storage facilities (TSFs). This text describes the consequences caused by a saline medium on the rheological properties of clay-based tailings, analysing scenarios that allow tackling this operation.

Use of Multi-Anionic Sodium Tripolyphosphate to Enhance Dispersion of Concentrated Kaolin Slurries in Seawater

“…In this context, it is interesting to compare what happens at pH 8 since it is a relevant condition of what happens in the mining industry. It is shown that seawater can create rheological problems in clay pulps, which is a detriment to the mineral processing operations [14,19,33]. Rheological modifiers may be applied in order to reduce the value of the rheological parameters, which is achieved through reagents that stabilize the pulp.…”

“…Meanwhile, the associations EF and EE form a three-dimensional structure, known as a house of cards, that increases the fraction of apparent suspension volume [16]. What happens with the fine particles and clays is essential for mineral processing, considering that they have a relevant impact on solid-liquid separation and make the rheological behavior of concentrated slurries more complex [17][18][19].…”

A Molecular Dynamics Simulation of Polymers’ Interactions with Kaolinite (010) Surfaces in Saline Solutions

“…For these reasons, it is difficult to anticipate whether a saline medium will be beneficial or detrimental to particle flocculation. Therefore, it is essential to improve our understanding of molecular-scale phenomena, because the phenomena that ultimately determine the macroscopic properties of a suspension and are of industrial interest, such as the sedimentation rate, the quality of water recovered in a thickener, the underflow density, or the rheological properties of the underflow, occur at the molecular level [8,9].…”

Rheological properties of bauxite residue: the role of tailings gradation and solids concentration

“…There are several factors that can influence the rheological properties of a material, including its type, mineralogy, moisture content, pH, temperature, salinity, and shear rate history [23], Jeong, [24,25]. Apart from dependency on these properties, a close relation of mudflow with liquidity index and Atterberg's limits has been reported by a few researchers [25][26][27].…”