Use of Particle Size Distribution Measurements for Selection and Control of Solid/Liquid Separation Processes

1980 ◽  
pp. 305-328 ◽  
Author(s):  
MICHAEL C. KAVANAUGH ◽  
CAROL H. TATE ◽  
ALBERT R. TRUSSELL ◽  
R. RHODES TRUSSELL ◽  
GORDON TREWEEK
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Liquid Separation ◽  
Separation Processes ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
And Control

scholarly journals Determination of Size Distribution of Precipitation Aggregates Using Non-Invasive Microscopy and Semiautomated Image Processing and Analysis

2019 ◽  
Author(s):  
Michelle Quilaqueo ◽  
Minghai Gim-Krumm ◽  
René Ruby-Figueroa ◽  
Elizabeth Troncoso ◽  
Humberto Estay
Keyword(s):  
Image Processing ◽  
Particle Size ◽  
Size Distribution ◽  
Laser Diffraction ◽  
Aggregation Behavior ◽  
Liquid Separation ◽  
Image Processing And Analysis ◽  
Non Invasive ◽  
Solid Liquid ◽  
Solid Liquid Separation

Precipitation processes are technologies commonly used in hydrometallurgical plants to recover metals or to treat wastewaters. Moreover, solid-liquid separation technologies, such as thickening or filtering, are relevant unit operations, included in the precipitation technologies. These methods are strongly dependent on the characteristics of the solid precipitates formed during the specific precipitation reaction. One of these characteristics is the particle size distribution (PSD) of the solid precipitates which are fed into a solid-liquid separation process. Therefore, PSD determination is a typical practice for the characterization of the slurries generated in a precipitation plant. Furthermore, the precipitates generated in these processes have a colloidal or aggregation behavior, depending on the operational conditions. Nevertheless, the conventional methods used to estimate PSD (e.g., laser diffraction and/or ciclosizer) have not been designed to measure particles that tend to aggregate or disaggregate, since they include external forces (e.g., centrifugal, agitation, pumping and sonication). These forces affect the true size of the aggregates formed in a unit operation, thereby losing representativity in terms of aggregates particle size. This study presents an alternative method of measuring the size distribution of particles with aggregation behavior, particularly, by using non-invasive microscopy and image processing and analysis. The samples used have been obtained from an experimental precipitation process by applying sulfidization to treat the cyanide-copper complexes contained in a cyanidation solution. This method has been validated with statistical tools and compared with a conventional analysis based on laser diffraction. Our results show significant differences between the methods analyzed, demonstrating that image processing and analysis by microscopy is an excellent and non-invasive alternative to obtaining size distribution of aggregates in precipitation processes.

The Role of Colloid Interactions in Solid-Liquid Separation

1993 ◽  
Vol 27 (10) ◽  
pp. 1-17 ◽  
Author(s):  
John Gregory
Keyword(s):  
Particle Size ◽  
Fine Particles ◽  
Major Effect ◽  
Liquid Separation ◽  
Separation Processes ◽  
Polymer Bridging ◽  
Colloid Interactions ◽  
External Forces ◽  
Solid Liquid ◽  
Solid Liquid Separation

Forces between particles in water become especially important when the particles are in the colloidal size range (less than a few mm). To a first approximation inter-particle forces or colloid interactions are linearly dependent on particle size and they become stronger, relative to external forces, as particle size decreases. The separation of fine particles from water by processes such as coagulation, filtration and flotation can be crucially dependent on the manipulation of colloid interactions, usually to promote attachment of particles to each other or to surfaces. The most important types of colloid interaction are briefly discussed. These include van der Waals forces, electrical interaction, hydration forces, hydrophobic interaction and effects associated with adsorbed polymers, such as steric repulsion and polymer bridging. These are all short-range interactions, which have little influence on the transport of particles but which can have a major effect on collision efficiencies and on the adhesion between particles. Some examples of solid-liquid separation processes in which colloid interactions are important are given.

In-Process Particle Size Distribution Measurements and Control

1995 ◽  
Vol 12 (6) ◽  
pp. 309-313 ◽  
Author(s):  
Thomas L. Harvill ◽  
Jared H. Hoog ◽  
Donald J. Holve
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
And Control

Obtaining Constitutive Equations for Thickening and Filtration Non-Newtonian Fluids

2014 ◽  
Vol 802 ◽  
pp. 274-279 ◽  
Author(s):  
Helio de Oliveira ◽  
Bruno Arantes Moreira ◽  
João Jorge Ribeiro Damasceno ◽  
Fabio de Oliveira Arouca
Keyword(s):  
Constitutive Equations ◽  
Xanthan Gum ◽  
Sediment Concentration ◽  
Particulate Material ◽  
Newtonian Fluids ◽  
Liquid Separation ◽  
Separation Processes ◽  
Medium Permeability ◽  
Solid Liquid ◽  
Solid Liquid Separation

The study of filtration and thickening of particulate systems are used in many industrial processes involving processes of solid-liquid separation, such as in sedimentation ponds, filters, the drilling of oil wells, among others. This paper aims to advance the empirical mechanisms involved in the processes of solid-liquid separation and obtain constitutive equations relating the pressure in solids and porous media permeability from non-Newtonian fluids. In the experiments used aqueous solutions of xanthan gum concentration of 0.1% in weight basis in order to ensure non-newtonian means. For the preparation of suspensions, was used calcium carbonate as particulate material in the separation process involved an initial concentration of 12% by volume. The concentrated sediment was maintained between 30 and 48% by volume. Settling tests were carried to term and sediments resulting from each test were evaluated by making use of the Gamma Rays Attenuation Technique (GRAT). The results show that GRAT is effective in determining sediment concentration distributions formed from non-Newtonian solutions, allowing the constitutive equations to obtain pressure and the solid porous medium permeability, very important for simulations of solid-liquid separation processes.

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