hardness and chloride removal in dewatering system: modeling and optimization of electrochemical reaction

The electrocoagulation (ec) process is a novel approach in the mining industry, especially to recycle water in the dewatering system of a mineral processing plant. in this research, the electrocoagulation process was studied to remove the hardness and chloride ions from concentrate thickener overflow water under different operating conditions: retention time (5–15 min), initial ph (4–10), current density (41.6–166.6 a/m^2) and electrode type (fe, fe-al, al). four factors with three levels with the d-optimal response surface design were applied for optimization. as a result, the optimal situation for the electrocoagulation process was characterized by a retention time of 15 min, initial ph of 9.08, the current density of 139.59 a/m^2, and electrode type fe-al. in this situation, the maximum removal efficiency of hardness (60.11%) and chloride (98.38%) were yielded with a desirability value of 0.989. these results illustrated the effectiveness of the ec process as an influence method for the removal of hardness and chloride in terms of separation