Role of critical parameters on the rheology and pipeline transportation of concentrated non-Newtonian iron ore slurry

Abstract

Achieving optimal flow characteristics while handling a complex slurry system in the pipeline needs greater attention. This study aims to demonstrate the role of iron ore concentration and size distribution on slurry rheology and their subsequent effect on slurry pipeline transportation. The concentrated iron ore slurries are sheared in the shear rate range between 0.1 - 500 s-1, where the experimental data is well-represented by the Bingham-plastic model. The model parameters are employed to calculate pressure drop and energy consumption. A thorough investigation through rheomicroscopy analysis reinforces the validity of the rheological hypothesis. The rheological analysis reveals the yieldpseudoplastic flow behaviour of iron ore slurries irrespective of particle concentrations and coarse particle addition. The slurry containing iron ore fines contributes to an increase in viscosity, mitigated by introducing coarse particles. Rheomicroscopy suggests that the viscosity reduction is attributed to the obstruction of floc formation and disintegration of the slurry structure. The pressure drop and energy consumption escalate with increasing slurry velocity regardless of pipe diameters. However, these entities decrease by including coarse iron ore particles in slurries. This work advocates optimizing rheology to reduce pipeline transportation costs while handling bulk iron ore with minimum environmental repercussions.