Estudo de parâmetros para coagulação de efluente visando reuso da água em uma indústria de mineração

Abstract

The optimization of coagulation processes for effluents generated by the mining industry is crucial for the efficient reuse of water in the industrial environment, as well as for reducing the risks involved in handling tailings dams. However, the increase in demand results in the exploitation of lower-quality ores, leading to the extraction of minerals with increasingly lower grades, and with a tendency toward reduced particle size of the ore used, which compromises the efficiency of natural particle sedimentation. In this study, key parameters for improving these processes are investigated through detailed characterization of the effluent. The effectiveness of different commercially available coagulant agents - both inorganic salts and polymers - is evaluated, considering variables such as sedimentation rate and residual turbidity. The experimental methodology involves laboratory tests, including advanced techniques such as Scanning Electron Microscopy (SEM) for sample analysis. The results demonstrated that charge neutralization alone, operating at the pH corresponding to the point of zero charge, is not sufficient to achieve satisfactory removal of suspended particles. Therefore, tests were conducted with different dosages at the natural pH of the sample. Among the coagulants evaluated, the group of polymeric coagulants achieved the best performance, reaching up to 98.9% removal of residual turbidity. What makes it possible return of the supernatant to industrial process, in the wet grinding stage. This study contributes to the sustainability of the mining industry by promoting efficient water resource management and minimizing the environmental impacts associated with effluent disposal.