# Mathematical modeling of separation characteristics of a coal-washing spiral

Das, Suchandan K and Godiwalla, K M and Panda, Lopamudra and Bhattacharyya, K K and Singh, Ratnakar and Mehrotra, S P (2007) Mathematical modeling of separation characteristics of a coal-washing spiral. International Journal of Mineral Processing, 84 (1-4). pp. 118-132.

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## Abstract

An improved mathematical model to simulate the particle and flow behavior in a coal-washing spiral has been developed. The modeling framework addresses three main components of the spiral system: (i) geometry of the spiral and its trough, (ii) fluid motion along the curvilinear path of the spiral and (iii) principal forces acting on a particle incorporating “Bagnold effect”. This effect has been addressed for both particle–inertial and macro-viscous regimes. The modeling components have been combined seamlessly by assuming that the particles eventually attain dynamic equilibrium in the forward longitudinal direction and static equilibrium in the transverse direction. The resulting force function provides a spectrum of the particle's radial location on the trough according to their size and relative specific gravity. The model predicts relative specific gravity distribution as a function of equilibrium radial position for different particle sizes. It also computes particle size variation as a function of equilibrium radial position for various values of relative specific gravity. Sensitivities of radial equilibrium distribution of particle size and relative specific gravity with respect to mean flow depth have also been investigated. Simulation results validated with the published data, are found to be reasonably consistent. The model provides an analytical tool for understanding of the separation behavior of particles in a coal-washing spiral.

Item Type: Article http://dx.doi.org/10.1016/j.minpro.2007.05.007 Spiral separator; Coal washing; Separation characteristics; Equilibrium force balance; Mathematical modeling Mathematical Modelling and Simulation 165 INVALID USER 19 Oct 2009 15:29 14 Dec 2011 14:48 Citation

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