Coagulation tests of waste pulp from copper mineral processing

Abstract

The sustainable use of water in mineral processing is essential for maintaining the ecosystem that supports the mining environment and, consequently, for the operation itself that uses water resources. As an area that has such a finite resource as a basic operating condition and that uses this resource on a large scale, it is necessary to constantly seek to optimize its use, having as pillars quality and economy in the treatment of effluents generated. It is in stages like this that coagulating reagent work. In the processing unit in question, more than 90% of the water is recirculated and reused, a process that relies on the support of a coagulant to accelerate the sedimentation of solids and guarantee the reuse of water of sufficient quality to provide operations with the solvent necessary for the environment. physicochemical. The coagulant currently used in tailings dam operations is aluminum sulfate. Due to the high use and cost spent on this reagent, tests were conducted with two other alternative coagulants (iron III chloride and iron III sulfate), comparing the cost-benefit between the reagents assessed. To this end, a cost-benefit factor was used, calculated using the cost of the reagent, dosage, residual turbidity of the clarified liquid and the sedimentation speed of the solids. After the tests, it was found that aluminum sulfate, the reagent used in the operation until then, was the best option among the reagents assessed. However, a reduction of 21.43% in the dosage currently used of this reagent by the company, maintaining the final turbidity target is possible, thus generating cost reduction.