Predicting Viscosity of Limestone–Water Slurry

Pradipta Kumar Senapati, Dibakar Panda, Ashutosh Parida

Department of Chemical Engineering, C.V.Raman College of Engineering,Bhubaneswar-752054, India.
Institute of Minerals & Materials Technology (IMMT), Bhubaneswar-751013, India.

DOI: 10.4236/jmmce.2009.83018                

Abstract

The rheological behavior of limestone–water slurry samples was investigated for different volume concentrations, particle size distribution and slurry temperature. Experiments were conducted over a range of volumetric solids concentration (Q= 0.20 - 0.46) in shear rate range of 1-300 s^-1. The slurry showed Newtonian behavior up to a volumetric solids concentration of 37.8 vol. %, beyond which the slurry was highly pseudoplastic in nature and fitted excellently to a non-Newtonian Power law model. The relative viscosity (N_r) of the mixture slurry, defined as the suspension viscosity over the viscosity of the suspending medium was found to be increasing exponentially when Q exceeds 0.404. By adopting an experimental approach, the rheological data indicated that Q might reach 0.462. Using the ( 1-N_r^-1/2 ) -Q relationship proposed by Liu, the theoretical maximum solids fraction (Q_m) was evaluated as Q_m= 0.504 for the given slurry samples and was then used to predict the relative viscosity (N_r) by some existing models. Five empirical models namely; Liu, Dabak et al., Krieger-Dougherty, Mooney and Chong et al. were considered for the purpose. Liu’s model better predicted the relative viscosity and thus would be helpful in evaluating the hydraulic parameters accurately for design of limestone slurry pipelines operating at high concentrations.

Keywords

Limestone-water slurry, Relative Viscosity, Maximum solids concentration

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Govier, G.W, Aziz, K., (1972). “The Flow of Complex Mixtures in Pipes”, Van Nostrand Reinhold Company: New York.
[2]	Muster, T.H. & Prestidge, C.A., (1995), “Rheological investigations of sulphide mineral slurries”, Minerals Engineering, vol.8, pp.1541-1555.
[3]	Weltmann, R.N. & Green, H., (1943), “Rheological Properties of Colloidal Solution, Pigment Suspensions and Oil mixtures”, Journal of Applied Physics, vol.14, pp.569-576.
[4]	Goodwin, J.W., (1975), “The Rheology of Dispersions”, Colloid Science, vol. 7, pp. 246-293.
[5]	Firouzi, J., Akbar Yousefi, A. & Langroudi, A.E., (2006), “Rheological Behaviour of Metal powder Suspensions under Dynamic loading”, Iranian Polymer Journal, vol. 15(2), pp. 127-134.
[6]	Garcia, F., Bolay, N. le. & Frances, C., (2003), “Rheological behaviour and related granulometric properties of dense aggregated suspensions during an ultrafine comminution process”, Powder Technology.130, 407-414.
[7]	Liu, D.M., (1999), “Control of yield stress in low-pressure ceramic moldings”, Ceramic International, vol. 25, pp. 587-592.
[8]	Liu, D.M. & Tseng, W.J., (2000), “Rheology of injection-molded zirconia–wax mixtures”, Journal of Material Science, vol. 35, pp. 1009-1016.
[9]	Liu, D.M., (2000), “Particle packing and rheological property of highly-concentrated ceramic suspensions: Qm determination and viscosity prediction”, Journal of Materials Science, vol. 35 , pp. 5503-5507
[10]	Tseng, W.J. & Yu Li, S., (2002), “Rheology of Colloidal BaTiO3 suspension with ammonium polyacrylate as a dispersant”, Journal of Materials Science and Engineering.A vol. 333, pp. 314-319.
[11]	Yuanling, S., Xiaolin, L. & Jianfeng, C., (2004), “The maximum solid loading and viscosity estimation of ultra-fine BaTiO3 aqueous suspensions”, Colloids and surfaces A:Physicochemical Engineering Aspects, vol. 247, pp. 27-34.
[12]	He, M., Wang, Y. & Forssberg, E., (2004), “Slurry rheology in wet ultra-fine grinding of industrial minerals: a review”, Powder Technology. Vol. 147, pp. 267-304.
[13]	He, M., Wang, Y. & Forssberg, E., (2006, “Parameter studies on the rheology of Slurries”, International Journal of Mineral Processing, vol. 78, pp. 63-77
[14]	Tangsathitkulchai, C., Austin, L.G., (1988), “Rheology of concentrated slurries of of natural size distribution produced by grinding”, Powder Technology, vol. 56, pp. 293-299.
[15]	Gao. M., Forsberg. E., (1993), “The influence of slurry rheology on the ultra-fine grinding in a stirred ball mill”, Proceedings of XVIII International Mineral Processing Congress, Sydney, Australia, vol.2. pp. 237-244.
[16]	Dabak, T. & Yucel, O., (1986), “Shear Viscosity behaviour of highly concentrated suspensions at low and high shear rates”, Rheologica Acta, vol. 25,pp. 527 533
[17]	Krieger, I.M & Dougherty, T.J., (1959), “A Mechanism for non-Newtonian flow in suspensions of rigid spheres”, Trans. Soc. Rheol. Vol. 3, pp. 137-148.
[18]	Mooney, M., (1951), “The viscosity of concentrated suspension of spherical particles”, Journal of Colloid Science, vol. 6, pp. 162-170.
[19]	Chong, J.S., Christiansen, E.B. & Baer, A.D., (1971), “Rheology of concentrated Suspensions”, Journal of Applied Polymer Science, vol. 15, pp. 2007-2021.
[20]	Bergstrom, L., (1994), “Surface and Colloid Chemistry in Advanced Ceramic ,Processing”, Marcel Dekker: New York