System for preparing potassium sulfate from high-salt-content industrial wastewater and technology of system

The invention relates to a system for preparing potassium sulfate from high-salt-content industrial wastewater and belongs to the field of water treatment. The high-salt-content industrial wastewater is pretreated through a regulating pool, a pipeline mixer, a high-density precipitate pool, a V-type filter pool, ion exchange resin and an ultrafiltration membrane system and then concentrated through a first section reverse osmosis membrane system and a second section reverse osmosis membrane system and then enters a nanofiltration membrane system for salt separation, nanofiltration produced water and thick water enter a plate-pipe type high-pressure flat sheet membrane system II and a plate-pipe type high-pressure flat sheet membrane system I respectively to be concentrated again, the concentrated thick water enters a freezing crystallization system for crystallization, crystals enter a potassium sulfate preparing system to be converted, freezing mother liquor and the concentrated nanofiltration produced water enter an advanced oxidizing system for oxidation and then enter an evaporative crystallization system for crystallization, and produced sodium sulfate crystal salt enters a potassium sulfate preparing system for conversion. The system has the advantages that the scale of the nanofiltration system is reduced, and investment cost is reduced; salt separation is thorough, and operation cost is low; the purity of the crystallization salt is high; mirabilite and sodium sulfateare converted into potassium sulfate, and the economic value is improved.