The invention discloses a making method of two-agent typed polysilicate coagulant, which comprises the following steps: diluting one or more metal salt and or polymeric metal salt solution by water to produce 5-15 percent weight density at metal elemental unit; adjusting the pH value through inorganic acid as agent A; diluting the solution with silicon material by water to produce 2-10 percent weight density at SiO2 unit as agent B; packing agent A and B separately; mixing agent A and B evenly to produce the molar rate at 1:0.5-5.0 for silica dioxide and metal; obtaining the final polysilicate coagulant. The invention can produce excellent property of polysilicate coagulant with impurity-removing and high decolouring efficiency, which forms rapid and dense floccules. |