Wyniki wyszukiwania - BazTech

1

Effect of shear-induced breakage and reflocculation on the floc structure, settling, and dewatering of coal tailings

Fan Yuping, Ma Xiaomin, Song Shuai, Dong Xianshu, Chen Ruxia, Dong Yingdi

Physicochemical Problems of Mineral Processing

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2020

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Vol. 56, iss. 2

363--373

EN

Flocculation is crucial for the treatment of coal tailings in industries. In this paper, the effects of shear-induced breakage and reflocculation of the floc, settling, and dewatering of coal tailings were investigated. The results show that as shear strength increases, the settling velocity of flocculated tailings decreases. A shear rate of 200 rpm (170.6 s-1) leads to the loss of half the settling velocity. However, at high dosage cases, 200 rpm-300 rpm shear could improve the clarity of the supernatant. Small particles are flocculated preferentially, especially for particles below 10 µm. With the increase in dosage, the critical particle size for the occurrence of flocculation increases. The chaos index proposed can quantitatively reflect the degree of flocculation or reflocculation of coal tailings. At high dosage conditions, shear could enhance the dewatering performance of flocs by reconstructing the filter cake. Controlling the structure of flocs by dosage and shear strength can help obtain appropriate settling, clarifying, and dewatering performance of coal tailings.

2

Basic Regularities of Assessing Ore Pulp Parameters in Gravity Settling of Solid Phase Particles Based on Ultrasonic Measurements

Morkun Vladimir, Morkun Natalia, Tron Vitaliy, Hryshchenko Svitlana, Serdiuk Oleksandra, Dotsenko Iryna

Archives of Acoustics

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2019

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Vol. 44, No. 1

161--167

EN

The article describes the method of controlling the recovered grade based on measuring the intensity of volume ultrasonic oscillations and Lamb waves covering a fixed distance through the test medium and on a metal plate contacting the test medium at various time points of deliberate motion of ground materials. The authors suggest a method of determining density of ground ore particles in the pulp periodically after isolating the pulp flow in the vertical part of the measuring vessel based on measuring attenuation change values in Lamb waves covering a fixed distance on a plate contacting the medium under study and high frequency volume ultrasonic oscillations that have come through it within a certain time period. There are given dependencies of amplitudes of measuring channels based on volume ultrasonic oscillations and surface Lamb waves, size distribution according to solid phase pulp particles for various types of ores under study, a set of curves for determining the recovered grade with regard to various types of ores under study.

3

Analiza sedymentacji w roztworach zagęszczaczy spożywczych

Szafrański W., Mitkowski P. T.

Inżynieria i Aparatura Chemiczna

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2012

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Nr 6

385-386

PL

Celem niniejszej pracy było przeprowadzenie testów sedymentacyjnych wybranych środków spożywczych - mielonych przypraw roślinnych i znalezienie środków zapobiegających sedymentacji podczas przechowywania gotowych produktów (sosów, dipów). Badano sedymentację czerwonej papryki mielonej oraz ziołowego pieprzu mielonego o wielkości cząstek od 400 do 500 (un w wodnych roztworach gumy arabskiej oraz gliceryny. Najlepszy wynik otrzymano dla roztworu gumy arabskiej o stężeniu 25%.

EN

The aim of this study was to perform sedimentation tests of selected foodstuff (such as ground vegetable spices), and to find methods preventing sedimentation during storage of finished products (sauces, dips). Sedimentation of ground red pepper and ground herb pepper of particle sizes from 400 to 500 microns in aqueous solutions of gum Arabic and glycerol was studied. The best result was obtained for gum Arabic solution at concentration of 25%.

4

Analiza sedymentacji zawiesin produktów roślinnych

Broniarz-Press L., Szaferski W.

Inżynieria i Aparatura Chemiczna

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2008

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Nr 6

15-16

PL

W pracy przedstawiono wyniki testów sedymentacyjnych w wodzie dla ciał stałych występujących w procesach produkcyjnych przemysłu spożywczego: kaszy jęczmiennej, gorczycy, mielonej gałki muszkatołowej i mielonej czerwonej papryki.

EN

The paper contains the results of sedimentation tests in water for solids presented in manufacturing process of food industry, such as barley groats, white mustard, powdered nutmeg and powdered red paprika.

5

Why do the spheres stay suspended in Orbitz (sometimes!)?

Walters K., Williams G. B.

Applied Mechanics and Engineering

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1999

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Vol. 4, no spec.

447-454

EN

Orbitz is a non-carbonated soft drink, within which flavoured gel spheres (orbs) are suspended. It comes in five different flavours and colours; in the current experiments, we have concentrated on orange, red, white and yellow orbitz, particularly the first two. Interestingly, in what must have been a rogue batch of red Orbitz, the orbs readily settled. In the present communication, we address two related questions. First, why do the orbs generally remain in suspension? Is it the matched densities of the orbs and the surrounding liquid or is it the distinctive rheology of the liquid? We show that, although both may be involved, rheology is certainly the dominant influence. Secondly, why did the orbs settle readily in the rogue red sample? We again show that (imperfect) rheology is responsible for the malfunction.