Electromembrane separation of mineral suspensions: Influence of process parameters

Results of a parameter study concerning cross-flow electromembrane separation of a solid/liquid suspension containing silicium oxide particles are presented. The effects of various operation parameters such as applied voltage (0-200 V), feed concentration (1-5 wt.%), temperature (15-50degreesC), transmembrane pressure (1-3 bar), and cross-flow linear velocity (0.1-0.34 m/sec) are examined and discussed. The results clearly demonstrate the utility of the electromembrane process for concentration of mineral suspensions. Applied electric field strength of E = 133 V/cm leads to permeate flux enhancement by 366%, (enhancement factor 4.7) when a suspension containing 50 g/L of SiO2 is treated at appropriate operation conditions. It is proved that applying a constant electric field across the membrane significantly improves the permeation rate by reducing the solute-related resistance. Optimal experimental conditions were found at which the solute resistance could be practically eliminated. Data, which show that the influence of the temperature on the permeate rate is more sensitive when all electric field is applied, were represented.