Role of Montmorillonite, Kaolinite, or Illite in Pyrite Flotation: Differences in Clay Behavior Based on Their Structures

Abstract

It is widely acknowledged that clay minerals have detrimental effects on the process of flotation, but the mechanisms involved are still not fully understood. In this work, the effects of montmorillonite, kaolinite, and illite on pyrite flotation were investigated from the perspective of various structures of clay minerals. Flotation tests suggested that the detrimental effect of clay minerals on the flotation of pyrite increased as follows: montmorillonite > kaolinite > illite. With the help of rheology measurements, it was found that montmorillonite significantly increased pulp viscosity, which in turn substantially reduced pyrite recovery and grade. Scanning electron microscopy (SEM) images suggested that montmorillonite formed the “house-of-cards” structure by edge-to-edge and edge-to-face contact, while kaolinite and illite platelets were associated mainly in the face-to-face mode. In addition, it was clearly observed by SEM–energy dispersive spectrometry that montmorillonite and kaolinite coat on the pyrite surfaces, which would lower the surface hydrophobicity of pyrite. Kaolinite covered much larger area of pyrite surface than montmorillonite owing to the positive charge occurring at the exposed aluminum–oxygen octahedral sheet of kaolinite. Although illite has a similar 2:1 structure to montmorillonite, it showed little or no effect on pyrite flotation, which was attributed to its poor swelling nature. These findings shed light on the root cause of the adverse effect of clay minerals on pyrite flotation and are expected to provide theoretical guidance for mitigating the negative effects on flotation caused by clays.

Nano Clay-Polymer Composite for Water Treatment

“…Illite is 2:1 layered clay mineral, very similar to Smectite, in which silica tetrahedral sheet is substituted by Al2O3 and layers are tightly bonded together with high charge density. In illite, an interlayer K + cation, is embedded in the holes forms a grid of oxygen atoms between adjoining layers [30][31]. The structure of illite composite is K1-1.5Al4[Si6.5-7Al1-1.5O20](OH)4 [32].…”

Dewatered and Stacked Mine Tailings: A Review

“…Different types of ores will occur alongside different gangue clay minerals. For example, sodium montmorillonite (Na-Mt), the main component of bentonite, is widely encountered in copper, gold, and other ore processing , and is extremely detrimental to mineral processing operations due to its high swelling nature and particle–particle interactions. Dewatering is extremely challenging in tailings having montmorillonite due to the presence of interlayer water molecules, which require high osmotic pressure to drain out …”

Effect of 3-Mercaptopropyltriethoxysilane Modified Illite on the Reinforcement of SBR

“…Illite, a typical clay mineral belonging to the family of 2:1 layered silicates with a crystal structure of two silicon−oxygen tetrahedrons fused to an edge-shared aluminum−oxygen octahedron, has huge reserves and low production cost [ 1 , 2 , 3 ]. Owing to its moderate cation exchange capacity and large specific surface area, it is now most widely used in the fields of adsorption of dyes, perchlorate, and antibiotics in aqueous environment [ 4 , 5 , 6 ], remediation of soil [ 7 ], or removal of hazardous radionuclides or toxic heavy metal pollutants [ 8 , 9 ].…”