Flow Regime of Mineral Suspensions with Preserved Structure of Flocs

Abstract

The breakage mechanism of flocs in mineral suspensions under shearing is considered. The relationship of limiting dynamic shear stress, diameter of particles and flocculant consumption is determined. It is calculated that for the floc structure to be preserved, it is required that the maximum allowable flow velocity of suspensions in pipelines 0.2–0.6 m in diameter is on average 1.8, 2.6 and 3.9 m/s at flocculant consumptions of 50, 100 and 200 g/t, respectively. The inverse problem on minimum allowable diameters of pipelines is solved. At the suspension flow rates of 100–1000 m³/h and flocculant consumption of 50–200 g/t, these values range from 0.1 to 0.4 m. The increase in the flocculant consumption by 2 times, all other things being equal, conditions reduction in the allowable diameter of pipelines by 20%.