tinuous thickener from batch sedimentation experiments. It is significant that up Kynch () presented the first theory of sedimentation. In spite of the fact that. Points are experimental data, continuous curves Derived from Kynch theory (see text). Figure 5 Two Interface Description of Sedimentation. Instantaneous concentration profiles of the batch sedimentation of non-colloidal hard spheres were measured for various initial suspension concentrations from.

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His theory can be used to analyze experimental results or to predict sedimentation in hindered settling. Search articles by author G.

University of British Columbia. Further research could focus on dividing the fines into more fractions with narrow particle size ranges.

The tests were sampled when the interface dropped to ml, ,ynch, and ml, respectively. Each ml was further divided into eight intervals of Suspensions with lower solids contents may not form a clear interface during the sedimentation process. In his study, experimental suspensions were prepared by mixing lubricant oil and glass beads.

Equipment selection and process design. Kynch theory, the first mathematical formulation of sedimentation theory, is widely used as a tool in the analysis of batch sedimentation. For this study, every 50 ml sample was stored in its own beaker. Authors contributing to RSC publications journal articles, books or book chapters do not need to formally request permission to reproduce material contained in this article provided that the correct acknowledgement is given with the reproduced material.

A small-scale column settling test should be done to investigate in which fractions hindered settling will occur. Surface Technology, 26 3 At any point P, the velocity of downward movement of the interface is determined by the velocity of the particles on this interface.

Accumulation of coarse particles was observed on the bottom of the cylinder. UBC Theses and Dissertations. Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website. Recordings were taken for a longer time than had occurred in the first one.


International Journal of Mineral Processing, 32 3 In the latter tests, the second method of mixing the solution directly in the column and shaking was selected for the rest of the tests since it is more convenient and efficient.

A theory of sedimentation – Transactions of the Faraday Society (RSC Publishing)

Transactions of the Faraday Society, 48, However, due to various idealized assumptions within Kynch theory, the application of this theory to describe and analyze tailings sedimentation in the laboratory setting has not been well developed. After the samples are fully mixed, they are ready for the column settling test, and are processed as follows: Recording was stopped after noticing the deviation, and the results of Test 1.

The samples were kynvh directly in the settling columns. The relationship between particle concentration and flux is the continuity equation.

A new apparatus was designed and constructed sedlmentation complete the column settling test with a sample-collection ending. According to what was noted in the introduction to sedimentation in Chapter 2, the interface between the water and suspension develops in hindered settling, and hindered settling occurs when the concentration of the suspension is relatively high.

Tests conducted with this apparatus aim at investigating the settling behavior and the internal changes in the suspension during the process of sedimentation. Since the material contains only fine particles and no knch is clearly observed on the bottom of the column, the dramatic change of the solids content is mainly caused by the propagation of a layer with a specific solids content.

First, the accumulation of coarse particles affects the movement of the propagation of the wave from the bottom of the settling column. To load this item in other compatible viewers, use this url: There is an upward flow of water or liquid.

Results and Discussion 4. Since Kynch theory ignores all the chemical and physical forces between particles, no further analysis on the influence of pH values will be discussed.


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This phenomenon is well explained by Kynch theory. Characteristic curves that define the ideal batch-thickening behavior were developed to facilitate the analysis. Fine copper tailings settle at a constant velocity at first, this being determined by the movement of the interface. A large amount of coarse particles settled at the bottom of the column in the first one or two minutes. Tailings are generated during mineral processing in mills.

However, this theory fails to accurately detail the sedimentation of flocculated suspensions employed in mineral processing or mining field Concha and Bustos, Kynch theory ignores, or rather does not consider, the forces between particles. Inat the University of Alberta Caughill,Caughill conducted a series of settling tests on some specially-made standpipes.

The turbidity test was conducted through using a turbidimeter. Back to tab navigation. A conventional column settling test involves a column or a cylinder Palermo and Thackston, However, the rest of the prediction curve no longer matches the experimental data, as there is a big difference between the two final heights.

In order to ensure that the columns would be filled with enough of the sample mixture, extra mixture was intentionally 47 made. After the sedimentation ends, the consolidation process begins, leading to a further change of solids content and an enhancement of the strength of the deposit.

They claimed that, for the dispersion of grained particles prepared in a low concentration, there is a time period in which the movement of the interface between the dispersion and water settles in a linear fashion.

Wei He, Pius Lo, for their valuable suggestions on my research.