The invention discloses a
recovery method of a
magnesium oxide flue gas desulfurization product, belonging to the technical field of
resource utilization of
flue gas desulfurization products and comprising the following steps of: inhibiting the oxidation of an absorption liquid during circulation desulfurization, facilitating the
crystallization and the
precipitation of MgSO3 (
magnesium sulfite), pumping out concentrated
slurry from the bottom of a circulation
pool by using a
centrifugal pump when the concentrated
slurry is reached, filter-pressing the concentrated
slurry into a
solid through a plate frame, transporting the
solid to a professional desulfurization
product recovery plant, and reacting concentrated
sulfuric acid with the MgSO3 to generate an MgSO4 (
magnesium sulfate) serous liquid and an SO2 (
sulfur dioxide) gas; and collecting the SO2 through a tiny negative pressure,
drying, cooling, liquefying and canning the SO2, filtering, crystallizing and centrifugally
dewatering the serous liquid so that the separation of
solid-phase and
liquid phase impurities is realized, and stoving to form an industrial product. By virtue of the method, the industrial production of MgSO4.7H2O and liquid-state SO2 is realized, a set of green
chemical process is created with the
flue gas desulfurization, the desulfurization, the
recovery efficiency and the economic benefit are improved, and the technical and economical properties of the magnesium
oxide flue gas desulfurization are comprehensively enhanced.