Improved magnesium method flue gas desulphurization technique

The invention provides an improved magnesium method flue gas desulphurization technique, which comprises the following steps: (a) mixing 1 portion of magnesium oxide desulfurizing agent with 2.3 to 5 portion of water and 0.1+/-0.05 portion of water vapor in portion by weight at a temperature of between 0 and 20 DEG C so as to generate a magnesium hydroxide slurry; (b) ageing the magnesium hydroxide slurry obtained in the step (a) at a temperature of between 50 and 80 DEG C for 2 to 4 hours to obtain a desulfurizing agent slurry; and (c) spraying the desulfurizing agent slurry obtained in the step (b) to perform contact reaction with a flue gas containing sulfur dioxide so as to obtain a magnesium sulfite slurry or a magnesium sulfate slurry and the flue gas without the sulfur dioxide. The process has good reactivity and high desulphurization efficiency, and effectively avoids the problems of scaling, blockage and the like in a desulphurization system.