Mineral Processing
Seyyed Mohsen Zamzami; Javad Vazifeh Mehrabani
Abstract
In this research, solid phase settling process from the liquid phase were optimized simultaneously on the different responses, using the response surface methodology (RSM). The effect of solid percentage, flocculant dosage, temperature, and pulp pH were evaluated on the responses of solid settling velocity, ...
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In this research, solid phase settling process from the liquid phase were optimized simultaneously on the different responses, using the response surface methodology (RSM). The effect of solid percentage, flocculant dosage, temperature, and pulp pH were evaluated on the responses of solid settling velocity, water turbidity, viscosity and density of settled pulp. The results showed that by increasing the flocculant dosage from 0.5 to 3.5 g/ton, settled pulp viscosity decreases from 49.05 cSt to 17.54 cSt. The higher values of pulp pH as well as low amount of solid percentage resulted in high water turbidity, which shows the lack of contact between flocs and suspended particles. The results indicated that the pulp solid percentage and the flocculants dosage are the most significant parameters on the responses. Optimum test conditions were obtained in industrial mode by using 5 g/t flocculant, solid percentage 23.96%, pH=7.5 temperature of the pulp 21.5°C in which condition, settling rate, pulp viscosity, pulp density and water turbidity were predicted to be 13.23 cm/min, 5.1 cSt, 1.61 g/cm3 and 15.7 NTU respectively. Repetition test in the model predicted optimum condition was carried out and verified the predicted optimized condition.
J. Vazifeh Mehrabani; M. Goharkhah
Abstract
In the current research work, a piping system is designed for slurry transport to the tailing dam in the Kooshk lead-zinc mine, Iran. The experiments are carried out primarily to investigate the rheological behavior of the slurry at different densities and obtain a non-Newtonian model for the shear stress ...
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In the current research work, a piping system is designed for slurry transport to the tailing dam in the Kooshk lead-zinc mine, Iran. The experiments are carried out primarily to investigate the rheological behavior of the slurry at different densities and obtain a non-Newtonian model for the shear stress variation with the deformation rate. It is shown that the shear stress of concentrated slurry follows the plastic Bingham model. The results obtained also indicate the increasing trend of the yield stress and the apparent viscosity of the slurry with the density. Appropriate correlations are proposed for the apparent viscosity and yield stress as a function of pulp concentration. At the next step, the required design parameters such as the slurry flow rate, pressure drop, critical velocity, and minimum required head for flow initiation and head losses are calculated for different slurry densities and pipe sizes. The appropriate piping system is finally designed based on the experimental data and the calculated parameters. It is concluded that the 3 in diameter pipe can be used to deliver the slurry with solid concentrations between 44% < Cw < 60% by weight, without a pumping system.
