Do you know the recovery process of magnesium sulfate heptahydrate

Do you know the recycling process of magnesium sulfate heptahydrate? I hope everyone can learn more about this point.

China's magnesium resources are considered a major country in the world, and magnesium sulfate heptahydrate has superior performance in flue gas desulfurization and sewage treatment; Magnesium oxide desulfurization has the characteristics of high desulfurization efficiency and avoiding the generation of solid waste with magnesium sulfate heptahydrate. Moreover, the magnesium sulfate produced by magnesium desulfurization has good water solubility and is not easy to scale. The byproduct magnesium sulfate heptahydrate has broad prospects for utilization and a relatively large market demand. Therefore, magnesium desulfurization is gradually replacing calcium desulfurization.

After desulfurization, the magnesium sulfate waste liquid can be evaporated, concentrated, cooled, crystallized, and dried to produce industrial grade magnesium sulfate heptahydrate, which is relatively discharged directly compared to the desulfurization liquid. The production process of magnesium sulfate heptahydrate will not cause environmental pollution; During the evaporation and concentration process, the secondary steam is condensed and recycled, saving a large amount of water resources and reducing a portion of production consumption. The temperature of the desulfurized magnesium sulfate waste liquid after impurity removal is about 30 ℃, and the content of magnesium sulfate is about 12%. After multiple processes, the heptahydrate magnesium sulfate product is packaged.

After being depressurized by a heat pump, magnesium sulfate heptahydrate enters the shell side of the first effect heating chamber for heat exchange and condensation, and the condensed water enters the third effect evaporator for waste heat reuse; The treatment capacity of magnesium sulfate waste liquid after desulfurization is relatively large, and the boiling point of magnesium sulfate increases relatively low. In order to greatly reduce steam consumption, a three-effect heating pump evaporation process is adopted.

The temperature and pressure of the secondary steam generated by the magnesium sulfate heptahydrate first effect evaporator are lower than that of the raw steam. A portion of the high-pressure and high-temperature steam is consumed, and the pressure of some of the secondary steam is increased through a heat pump. The temperature will also increase accordingly. The increased pressure of the secondary steam will replace the raw steam as the heat source of the first effect evaporator, and the remaining secondary steam will be used as the heat source of the next effect evaporator; The addition of a heat pump to the three effect evaporation system greatly saves steam consumption.