Wastewater from a potash mine in the central region of Catalonia is transported by means of a collector that runs more than 100 km, spilling into the sea on the Catalan central coast. To analyze the hydraulics of this infrastructure, the values of the basic parameters that condition the flow, such as the absolute roughness of poly(vinyl chloride) (PVC) pipes and the viscosity of the transported brine mixtures, must be characterized. There exists uncertainty about the value of absolute roughness of a PVC pipe as described in the literature; nevertheless, if the pipe is smooth, the influence of the absolute roughness in the hydraulic determination of viscosity will not be significant. In this work, an experimental procedure based on a hydraulic analysis was applied to estimate the kinematic viscosity of a brine mixture, depending on its temperature and concentrations of salts and fines. The results obtained were compared with the results from experiments using an Ostwald viscometer.

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