Abstract

The low availability of fresh water in Chilean deserts has encouraged research into new alternative water sources in the mining industry. One of alternative is the use of saline water; however, there are few data about this new approach. For the production of copper sulfate pentahydrated (CuSO4 center dot 5H(2)O) crystals, the effect of NaCl in the crystallization area must be known; therefore, the solid liquid equilibrium of the CuSO4 + NaCl + (H2O or H2SO4/H2O) system at 298.15 K was experimentally determined by the wet residue method. The density and refractive index of saturated solutions were also measured. The addition of NaCl has a clear effect on the solid liquid equilibrium, promoting the formation of solid phases. In the phase equilibrium diagram that includes sulfuric acid, the pH affects the solubility curve. Using the information of the new phase diagrams, six simulation cases, varying in NaCl content and the addition of sulfuric acid in the feed, were evaluated in terms of mass and energy balance. The addition of sulfuric acid increases the total fluxes but decreases the heat requirement. Contrary to the expected results, the yields for the cases that include sulfuric acid were lower. The best results were obtained using a 50% NaCl pulp, which,produced the lowest total flux and a high yield of 75.6%.