Viscoelastic behaviour of flocculated silica sediments in concentrated monovalent chloride salt solutions

Quezada, Gonzalo R.; Jeldres, Ricardo I.; Goñi, Christian; Toledo, Pedro G.; Stickland, Anthony D.; Scales, Peter J.

doi:10.1016/j.mineng.2017.04.017

Cited by 15 publications

(5 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The reduction of the absolute value of zeta potential due to addition of NaCl is possibly due to migration and adsorption of Na + ions on the negatively charged CNC elongated surfaces, therefore retracting the double layer surrounding the nanocrystal particles. In similar colloidal systems, zeta potential has been impacted by adjusting the ionic strength of the medium, which is in agreement with the double‐layer theory . Please note that the zeta potential of CNCs is considerably higher than the cellulosic fibres produced by copious extraction processes (between −20 mV and −50 mV) ,.…”

Section: Resultssupporting

confidence: 79%

Colloidal Behavior of Cellulose Nanocrystals in Presence of Sodium Chloride

et al. 2018

View full text Add to dashboard Cite

Aggregation and gelation of cellulose nanocrystals (CNCs) induced by sodium chloride (NaCl) were investigated as a function of NaCl and CNC concentrations. Incorporation of NaCl improved CNCs ability to form clusters via screening surface charges of CNCs. Transmission electron microscopy (TEM) images revealed the formation of porous CNC clusters following NaCl addition. The confocal laser scanning microscopy (CLSM) micrographs indicated the presence of regions with colloid‐rich and colloid‐poor patterns in CNC clusters. Fluorescent brightener 28 was found to have a strong hydrogen bonding to the cellulose surface and used as the staining agent in CLSM. The CLSM images also indicated a dynamic structure for gels, continually rearranging over the course of time. Zeta potential data coupled with CLSM images confirmed the impact of NaCl on the gel formation of CNCs.

show abstract

Section: Resultssupporting

confidence: 79%

Colloidal Behavior of Cellulose Nanocrystals in Presence of Sodium Chloride

et al. 2018

View full text Add to dashboard Cite

show abstract

“…In the creep-recovery test, a constant stress was applied to the sample for 600 s, which caused an increase in the creep angle, θ, as a function of time. As in previous studies [16,27,31], the shear strain was obtained from Equation (1) for linear materials:…”

Section: Rheologymentioning

confidence: 99%

Analysis of Silica Pulp Viscoelasticity in Saline Media: The Effect of Cation Size

et al. 2019

Self Cite

View full text Add to dashboard Cite

The effect of alkali metal chlorides on the viscoelastic behavior and yielding properties of silica suspensions was studied through creep-recovery and dynamic oscillatory tests with stress control. Then, the viscoelasticity of the pulps was correlated with the silica zeta potential, aggregate size, and the percentage of cations adsorbed on the surface of the ore. The results indicate that larger cations are more prone to adhere to the silica surface, which increases the number of ionic bonds that bind the particles. This generates stronger particle networks and a greater agglomeration of particles, especially those smaller than 10 µm. As the size of the bare cations increases, the rheological response provides higher values of yield stress, complex viscosity, and viscoelastic moduli, but in turn, pulps undergo minor deformations under the application of stress. Dynamic oscillatory tests suggest structural changes, with the phase angle following the inverse relationship with the bare cation size, indicating that the liquid-like character of the pulps increases as the size of the cations increases.Minerals 2019, 9, 216 2 of 15 water that surrounds them. Small ions such as Li + are known as maker ions because they attract water molecules more strongly than water molecules do to each other, forming a layer of structured water around the ions. On the other hand, large ions such as Cs + are known as breakers; they interact weakly with water, generating a layer of structureless water around them. This implies that the hydrated size of ions in solution follows the trend Li + > Na + > K + , which is opposite to the bare ion size.More than a century ago, Hofmeister related the precipitation of proteins with the size of bare ions in solution [8]; interestingly, the order established by Hofmeister has been found in various systems, such as colloidal suspensions of tungsten trioxide, magnetite, alumina, titanium, hematite, and silica [9][10][11][12][13]. Here, we focus on silica, which has been studied extensively due to its relevance in numerous industrial applications [14-16]; however, it has not been studied combining rheological and physicochemical results in the presence of a series of alkali metal chloride salts. A particularly important result for our work is that of Franks [9], who measured the zeta potential and yield stress of quartz suspensions in concentrated solutions of monovalent electrolytes, finding that poorly hydrated ions, such as Cs + and K + , have a greater impact in reducing the absolute value of the zeta potential than highly hydrated ions, such as Li + and Na + . Franks found a higher yield stress when the pulp was in the presence of breaker ions, although the results were highly dependent on the pH. A challenge that is not yet fully resolved is that of high isoelectric point minerals, such as alumina, the properties of which follow a trend with the size of ions opposite to silica; for example, maker ions generate stronger alumina networks [17][18][19][20][21]. Parson et al. [19] developed a Poisson...

show abstract

“…Various studies have shown that rheology is significantly affected by salts, the presence of clays, and the content of fine minerals in the tailings [9][10][11][12][13]. Clays are fine solids ubiquitous in mineral processing, often only a few microns in diameter.…”

Section: Introductionmentioning

confidence: 99%

Polyacrylic Acid to Improve Flotation Tailings Management: Understanding the Chemical Interactions through Molecular Dynamics

Quezada¹,

Piceros

Robles

et al. 2021

Metals

Self Cite

View full text Add to dashboard Cite

Molecular dynamic simulations of polyacrylic acid polyelectrolyte (PAA) analyzed its interaction with the main minerals that make up characteristic tailings of the mining industry, in this case, quartz, kaolinite, and montmorillonite. The simulations were carried out with the package Gromacs 2020.3. The interaction potentials used were General AMBER Force Field (GAFF) for PAA and CLAYFF-MOH for mineral surfaces. The SPC/E model described water molecules and Lennard-Jones 12-6 parameters adjusted for SPC/E model were used for Na+ and Cl− ions. The studied systems were carried out at pH 7, obtaining stable adsorption between the PAA and the studied surfaces. Interestingly, the strongest adsorptions were for montmorillonite at both low and high salt concentrations. The effect of salinity differs according to the system, finding that it impairs the absorption of the polymer on montmorillonite surfaces. However, a saline medium favors the interaction with quartz and kaolinite. This is explained because montmorillonite has a lower surface charge density and a greater capacity to adsorb ions. This facilitated the adsorption of PAA. It was possible to identify that the main interaction by which the polymer is adsorbed is through the hydroxyl of the mineral surface and the COO−Na+ complexes. Molecular dynamics allows us to advance in the understanding of interactions that define the behavior of this promising reagent as an alternative for sustainable treatment of complex tailings in highly saline environments.

show abstract

Viscoelastic behaviour of flocculated silica sediments in concentrated monovalent chloride salt solutions

Cited by 15 publications

References 53 publications

Colloidal Behavior of Cellulose Nanocrystals in Presence of Sodium Chloride

Colloidal Behavior of Cellulose Nanocrystals in Presence of Sodium Chloride

Analysis of Silica Pulp Viscoelasticity in Saline Media: The Effect of Cation Size

Polyacrylic Acid to Improve Flotation Tailings Management: Understanding the Chemical Interactions through Molecular Dynamics

Contact Info

Product

Resources

About