Yield stress and maximum packing fraction of concentrated suspensions

1995 ◽  
Vol 34 (6) ◽  
pp. 544-561 ◽  
Author(s):  
James Z. Q. Zhou ◽  
Peter H. T. Uhlherr ◽  
Fang Tunan Luo
Keyword(s):  
Yield Stress ◽  
Packing Fraction ◽  
Concentrated Suspensions ◽  
Maximum Packing Fraction

The effects of an addition of force-free particles on the rheological properties of fine suspensions

1995 ◽  
Vol 32 (2) ◽  
pp. 263-270 ◽  
Author(s):  
Philippe Coussot ◽  
Jean-Michel Piau
Keyword(s):  
Shear Rate ◽  
Yield Stress ◽  
Packing Fraction ◽  
Solid Concentration ◽  
Power Parameter ◽  
Rate Range ◽  
Water Suspensions ◽  
Rate Of Increase ◽  
Free Particles ◽  
Maximum Packing Fraction

This study provides some elements for understanding the behavior of water–debris mixtures containing clay, silt, sand, and boulders at high solid concentrations. Accurate, simple shear rheometrical results for various clay–water mixtures and fine debris flow fractions with different added sand concentrations, in the shear rate range from 10−2 to 10−2 s−1 are presented. In this shear rate range, the behavior of these fluids is similar to the behavior of the initial fluid (without sand), i.e., it may be well represented by a Herschel–Bulkley model (with a power parameter close to 1/3). With the initial fluids (yield stress from 20 to 200 Pa) the suspension yield stress increases exponentially with the increase in sand (diameter between 100 and 200 μm) concentration, as long as the latter does not exceed 30%. However the rate of increase is less than the corresponding rate for the initial fluid and is correspondingly smaller as the grain size distribution is less well sorted. Diagrams showing the increase of yield stress with solid concentration may help to estimate the yield stress of coarser suspensions as long as the solid fraction is not too close to the maximum packing fraction. Key words : clay–water suspensions, water–debris mixtures, rheology, yield stress, sand addition, rheometry.

scholarly journals Yield stress in magnetorheological suspensions near the limit of maximum-packing fraction

2012 ◽  
Vol 56 (5) ◽  
pp. 1209 ◽  
Author(s):  
Modesto T. López-López ◽  
Pavel Kuzhir ◽  
Jaime Caballero-Hernández ◽  
Laura Rodríguez-Arco ◽  
Juan D. G. Duran ◽  
...  
Keyword(s):  
Yield Stress ◽  
Packing Fraction ◽  
Magnetorheological Suspensions ◽  
Maximum Packing Fraction

Yielding and flow of highly concentrated, few-layer graphene suspensions

Soft Matter ◽  
2015 ◽  
Vol 11 (16) ◽  
pp. 3159-3164 ◽  
Author(s):  
Sebastian Barwich ◽  
Jonathan N. Coleman ◽  
Matthias E. Möbius
Keyword(s):  
Simple Model ◽  
Bond Energy ◽  
Packing Fraction ◽  
Viscoelastic Response ◽  
Concentrated Suspensions ◽  
Layer Graphene ◽  
Graphene Platelets ◽  
Few Layer Graphene

We propose a simple model to explain the measured yielding behaviour of concentrated suspensions of graphene platelets which allows us to model the viscoelastic response in terms of bond energy, packing fraction and platelet dimensions.

scholarly journals Reducing Magnesium within Seawater Used in Mineral Processing to Improve Water Recovery and Rheological Properties When Dewatering Clay-Based Tailings

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 339
Author(s):  
Matías Jeldres ◽  
Norman Toro ◽  
Sandra Gallegos ◽  
Pedro Robles ◽  
Iván Salazar ◽  
...  
Keyword(s):  
Yield Stress ◽  
Aggregate Size ◽  
Complete Removal ◽  
Mineral Processing ◽  
Water Recovery ◽  
Concentrated Suspensions ◽  
Reflectance Measurement ◽  
Pre Treatment ◽  
A Minor ◽  
The Impact

In areas where access to water for mineral processing is limited, the direct use of seawater in processing has been considered as an alternative to the expense of its desalination. However, efficient flotation of copper sulfides from non-valuable phases is best achieved at a pH > 10.5, and raising the pH of seawater leads to magnesium precipitates that adversely affect subsequent tailings dewatering. Seawater pre-treatment with lime can precipitate the majority of magnesium present, with these solids then being removed by filtration. To understand how such treatment may aid tailings dewatering, treated seawater (TSw) was mixed with raw seawater (Rsw) at different ratios, analyzing the impact on the flocculated settling rate, aggregate size as measured by focused beam reflectance measurement (FBRM), and vane yield stress for two synthetic clay-based tailings. A higher proportion of Tsw (10 mg/L Mg2+) led to larger aggregates and higher settling rates at a fixed dosage, with FBRM suggesting that higher calcium concentrations in Tsw may also favor fines coagulation. The yield stress of concentrated suspensions formed after flocculation decreased with higher proportions of Tsw, a consequence of lower flocculant demand and the reduced presence of precipitates; while the latter is a minor phase by mass, their high impact on rheology reflects a small particle size. Reducing magnesium concentrations in seawater in advance of use in processing offers advantages in the water return from thickening and subsequent underflow transport. However, this may not require complete removal, with blending Tsw and Rsw an option to obtain acceptable industrial performance.

Investigation on maximum packing fraction of bitumen particles during emulsion drying

2021 ◽  
Vol 54 (5) ◽  
Author(s):  
Jian Ouyang ◽  
Peng Cao ◽  
Taixiong Tang ◽  
Yan Meng
Keyword(s):  
Packing Fraction ◽  
Maximum Packing Fraction

Measurement of yield stress for concentrated suspensions using a plate device

2009 ◽  
Vol 43 (1-2) ◽  
pp. 47-62 ◽  
Author(s):  
Min-Hong Zhang ◽  
Chiara F. Ferraris ◽  
Huaning Zhu ◽  
Vincent Picandet ◽  
Max A. Peltz ◽  
...  
Keyword(s):  
Yield Stress ◽  
Concentrated Suspensions

scholarly journals A new empirical viscosity model for composed suspensions used in experiments of sediment gravity flows

RBRH ◽  
2021 ◽  
Vol 26 ◽  
Author(s):  
Camila Castro ◽  
Ana Luiza de Oliveira Borges ◽  
Rafael Manica
Keyword(s):  
Physical Simulation ◽  
Relative Viscosity ◽  
Packing Fraction ◽  
Turbidity Currents ◽  
Single Model ◽  
Gravitational Flow ◽  
Sediment Gravity Flows ◽  
Gravity Flows ◽  
Clay Percentage ◽  
Maximum Packing Fraction

ABSTRACT Sediment gravity flows are natural flows composed by water and sediment in which the gravitational flow acts on the sediment. The distinct physical properties of the cohesive (clay) and non-cohesive (sand) sediment, and the interaction between these particles alter the ability of the flow to resist to the movement (rheology) along time and space, represented by the viscosity of a mixture suspension. Hence, we propose to study the rheological properties of those mixtures and calculate their relative viscosity when used in the physical simulation of turbidity currents. Rheological tests were performed with various mixtures composed by water, clay and/or coal. Two equations are proposed to estimate the relative viscosity as a function of volume concentration of each sediment, the maximum packing fraction and the percentage of clay present in the mixture. The results also show an error close to 20% comparing similar models from the literature, which are satisfactory. The results also demonstrate that caution should be exercised when generalizing the use of a single model to predict the relative viscosity of suspensions. The influence of density (ρ), grain shape, clay percentage (Cclay), volumetric concentration (ϕ) and maximum packaging fraction (ϕmax) should be considered in the formulation of the equations.

The Cox–Merz rule extended: A rheological model for concentrated suspensions and other materials with a yield stress

1991 ◽  
Vol 35 (4) ◽  
pp. 647-685 ◽  
Author(s):  
D. Doraiswamy ◽  
A. N. Mujumdar ◽  
I. Tsao ◽  
A. N. Beris ◽  
S. C. Danforth ◽  
...  
Keyword(s):  
Yield Stress ◽  
Rheological Model ◽  
Concentrated Suspensions
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