METHOD FOR PRODUCING IRON-BASED COMPLEX HYDROXIDE AND WATER-TREATING MATERIAL USING THE SAME COMPLEX HYDROXIDE

摘要

PROBLEM TO BE SOLVED: To provide a method for simply producing an iron-based complex hydroxide without adding any carbonate and provide a water-treating material by using the above complex hydroxide capable of removing harmful substances contained in water in high surface coverage at a high speed and free from anxiety on human health in drinking water treatment.;SOLUTION: An aqueous solution of an alkali is gradually added to an aqueous solution of a raw material obtained by mixing an aqueous solution of an alkaline earth metal salt with an aqueous solution of a trivalent iron salt so that a molar ratio of Fe to M becomes 1 to 4 when the alkaline earth metal is defined as M, until pH of the mixed solution becomes ≥13 while strongly stirring the aqueous solution of raw material or while applying ultrasonic wave to the above aqueous solution of raw material in the air and the above aqueous solution of raw material is crystallized through gel state to produce the objective layered iron-based complex hydroxide having pyrooolite type structure and represented by the formula M2+(8-x)Fe3+x(OH)16(CO32-)x/2.mH2O (wherein M is Mg or Ca and 0x≤6 and 0m≤5).;COPYRIGHT: (C)2001,JPO