Removal of Calcium from Scheelite Leaching Solution by Addition of CaSO4 Inoculating Crystals
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In this work, the solubility behaviors of gypsum and anhydrite in the H2SO4-H3PO4-H2O system were investigated over the temperature range T = 30–80°C, and the results showed that the solubility of anhydrite was considerably lower than that of gypsum. On the basis of the differential solubilities of gypsum and anhydrite, a method was developed to remove calcium from the scheelite leaching solution by adding anhydrite as an inoculating crystal. The effects of the reaction time, concentration of the CaSO4 inoculating crystals, and temperature were investigated. With an addition of CaSO4 inoculating crystals at a concentration of 60 g/L, the Ca2+ concentration of the scheelite leaching solution decreased to a low level of approximately 0.76 g/L after 10 h at 70°C.
The authors express sincere thanks to the NSFC (Natural Science Foundation of China, No. 51334008) for financial support.
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