A INORGANIC COAGULANT OF FLUORIDE ION IN WATER TREATMENT AND THE PREPARATION METHOD THEREOF

The present invention relates to an inorganic coagulant for water treatment for fluoride removal and a preparation method thereof to improve the fluoride removal efficiency using an inorganic coagulant and to significantly reduce costs for removing fluoride from waste water. To achieve this, the inorganic coagulant is composed of 57-65 wt% of a mixed composition, 1-5 wt% of a zirconium compound, 19-23 wt% of hydrochloric acid, and 15 wt% of water, wherein the mixed composition is composed of 30-35 wt% of aluminum hydroxide and 65-70 wt% of hydrochloric acid. The preparation method of the inorganic coagulant comprises: a step (a) of mixing and stirring 30-35 wt% of aluminum hydroxide with 65-70 wt% of hydrochloric acid to produce the mixed composition; a step (b) of producing a primary composition of aluminum chloride represented by the chemical formula 1 ([Al_2(OH)nCl_6-n]m, wherein n is equal to or lower than 0.6 and m is equal to or lower than 10.) by making the mixed composition from the step (a) have a chemical reaction; a step (c) of mixing and stirring 57-65 wt% of the primary composition from the step (c), 1-5 wt% of a zirconium compound, 19-23 wt% of hydrochloric acid, and 15 wt% of water at predetermined temperatures to produce a secondary composition; and a step (d) of stirring the secondary composition from the step (c) at temperatures in the range of 30°C and 80°C for thirty minutes to one hour to produce aluminum zirconium chloride.