The invention discloses a method for recovering mercury from a waste mercury catalyst. The method comprises the following steps that (1) through the water
solubility of HgCl2, the waste mercury catalyst is pretreated through water, the leaching reaction time is 80.0-90.0 min, the leaching
reaction temperature is 50.0-80.0 DEG C, the liquid-
solid ratio is (20.0:1.0)-(10.0:1.0), the magnetic stirring speed is 200.0 r / min, the pH value is 0.5-1.5, and at this time, the
leaching rate of Hg2+ in the waste mercury catalyst is 85.5-93.2%; and (2) a leaching solution containing the Hg2+ is filtered bythe step (1), a suitable flow carrier, surfactant and
solvent are selected,
emulsion is made under high-speed stirring and mixing, and low-speed stirring for
mass transfer is conducted with an external water phase containing the Hg2+ for a period of time. According to the method, an
emulsion membrane
system is adopted as a
chemical separation method for recovering the mercury, the advantages of high efficiency,
environmental protection, new type, easy operation and good selectivity are achieved, meanwhile, the operation flow is short, the operating conditions are mild, the operation cost andthe equipment cost are low, and the mercury in the waste mercury catalyst can be efficiently and quickly recovered.