KAl(SO4)2·12H2O + 2Ba(OH)2 == 2BaSO4↓+ K[Al(OH)4] + 12H2OAl3+ + 2SO42- + 2Ba2+ + 4OH- == [Al(OH)4]- + 2BaSO4↓或Al3+ +2SO42- +2Ba2+ +4OH-===2BaSO4↓+AlO2- +2H2O