Sustainable Mining and Metallurgy

The heavy metals in dilute acid were removed and recovered by the vulcanization method. The hydrogen sulfide was prepared by the reaction of sodium hydride and sulfuric acid. The by-product sodium sulfate solution was prepared into sodium sulfate solid by evaporation crystallization device. In view of the problems existing in the existing three-effect evaporation device, such as pipeline blockage, high salt content of evaporative condensate water, too fine crystal particle size, and mother liquor running and mixing, the equipment structure and process flow were optimized: the salt leg was designed at the bottom of the primary and three-effect separators,and each effect circulating pump was changed to the axial flow pump with large flow rate and low head, and the storage volume of the crystal evaporation chamber was increased. After the optimization, the evaporation crystallization system runs continuously and stably, the driving rate is improved, and the salt content of condensate water is less than 0.1g/L.