PROCESS AND DEVICE FOR DIRECTLY OBTAINING THENARDITE BY MEANS OF FLASH EVAPORATION- CRYSTALLIZATI ON

摘要

pProvided are a process for directly obtaining anhydrous sodium sulfate by flash evaporating and crystallizing and an apparatus thereof. The process comprises the following steps: (1) controlling the specific gravity of acid bath in the range of 1.4-1.44, (2) continuously flash evaporating and crystallizing in a continuous-flash-evaporation/crystallization device, (3) thickening to obtain slurry of anhydrous sodium sulfate, (4) separating the slurry of anhydrous sodium sulfate, spray rinsing or neutralizing, and drying to directly obtain finished product of anhydrous sodium sulfate. The apparatus comprises a preheater (A1-A8), a heater (H), a last-stage flash evaporation chamber (V11), a condenser (MK1, MK2), and a circulating pump (XP), and further comprises a continuous-flash-evaporation/crystallization device, a thickener (ZC), and a slurry pump (JP). The continuous-flash-evaporation/crystallization device comprises at least two stages flash evaporation crystallizers (V5J-V10J), which are connected with pipeline in turn. The flash evaporation crystallizers have a vertical and conic bottom structure. In the process, the procedures of crystallizing, separating, heating and melting, and evaporating mirabilite are omitted, and the construction investment and cost are reduced./p[WO2011140855A1]