The invention discloses a method for producing
hydrogen and co-producing alpha-semi-hydrated
gypsum from waste
gypsum, and belongs to the field of high value-added
resource utilization of typical bulk
solid waste. The method comprises the following steps: 1) adding water into waste
gypsum, stirring and pulping to obtain
slurry; 2) continuously producing
hydrogen from the
slurry through an electrochemical
hydrogen production process to obtain hydrogen, and collecting the
slurry after
hydrogen production is finished; 3) removing impurities from the slurry through a
solid-liquid
separation process to obtain liquid; and 4) crystallizing the liquid in a
crystal transformation directional regulation process, and
drying at high temperature after
crystallization to obtain the alpha-semi-hydrated gypsum. The method for producing hydrogen and co-producing alpha-semi-hydrated gypsum from waste gypsum is simple in process and low in
raw material cost, high-added-value
resource utilization of waste gypsum can be achieved, the purity of produced hydrogen is larger than 60%, the purity of co-produced alpha-semi-hydrated gypsum is larger than 98%, the whiteness is larger than 95, and the utilization efficiency of waste gypsum is larger than 80%; the method can effectively solve the problems of high difficulty, high cost, low added value and the like of the existing waste gypsum treatment technology.