Extractive waste influenced waters or acidic mine drainages are of strong concern due to anionic pollutants such as sulphates as well as soluble forms of metals and metalloids, radionuclides, rare earth elements. Strict restrictions on the content of sulphates in waters along with other key parameters have been introduced in European legislation, consistent with the policies regarding the protection of water quality and human health. The present work examines the optimization of a proven in practice ettringite precipitation as a second step after liming in laboratory conditions in continuous mode with a pre-selected suitable source of aluminium in form of commercial cement. This allows reaching the ecological standards for sulphate content, as well as reducing the electrical conductivity in the effluent, thus eliminating the disadvantages of the classic scheme for lime treatment due to the high solubility of the formed precipitates of gypsum. However, the chemical composition and large quantities of formed sludge at the investigated method are still subject of particular attention from an economic and environmental point of view.