Concentration Profiles and Iso-Concentration Curves for Batch Settling Using the Gamma Rays Attenuation Technique

Abstract

Knowledge of particle concentration is of extreme importance for the settling phenomenon. For well-diluted suspensions the solids concentration can be measured by sampling techniques. However, the use of such a technique for more concentrated suspension does not lead to good results. Knowledge of concentration distribution in sediments formed by decantation of aqueous suspensions inside a vertical vessel is fundamental for the evaluation of performance of some pieces of equipment such as continuous thickeners. In this work, the phenomenon of batch settling of aqueous suspensions of calcium carbonate was studied by using a nondestructive technique based upon the measurement of gamma-ray attenuation when the radiation beam goes through the physical medium as a function of the local concentration in several vertical positions of the vessel, and the sampling of suspension by aliquots is not necessary. The main objective of this work is to evaluate the use of gammaray attenuation technique for achieving concentration distributions in the phenomenon of batch settling as well as curves of iso-concentrations.

Electrical conductivity measurements and the nonhomogeneous settling behavior of aqueous suspensions of barite

“…Concerning a height of 27.25 cm, specifically, Figure 5A shows an increase of concentration up to a local maximum before the passage of the descending interface (Region II). Similar behavior was found by Moreira et al 12 when studying the batch settling process in a non‐Newtonian fluid (xanthan gum solutions at 0.2% w/w) employed as the continuous phase and by Arouca et al 34 when evaluating how particles settle in water. The aforementioned authors used calcium carbonate as dispersed phase: Moreira et al, 12 at a concentration of 9% v/v, and Arouca et al, 34 at a concentration of 3% v/v.…”

Study on the stability of a shear-thinning suspension used in oil well drilling

“…The relationship between position and time in which curves had the same concentration value, the constant concentration curves, allowed to interpret sedimentation as the propagation of waves with equal concentration and to evaluate the characteristics of the materials settling in the drilling fluid [28] (Fig. 7).…”

Monitoramento Da Variação Da Concentração De Sólidos Em Ensaios De Sedimentação Gravitacional Utilizando Fluidos Pseudoplásticos

“…Outro trabalho utilizando a mesma técnica é o estudo realizado por Arouca e Damasceno (2005a) no qual usaram caulim em testes de sedimentação em batelada. Os autores admitiram a concentração local como uma função da curva de atenuação e aplicaram a técnica para determinação de parâmetros de equações constitutivas para pressão nos sólidos e permeabilidade do meio poroso.…”