METHOD AND APPARATUS FOR PREPARING FE^3+(TRIVALENT IRON)

摘要

PURPOSE: A method and an apparatus for preparing Fe¬3+(trivalent iron) are provided to reduce into NaNO2 nitrogen oxide which is a harmful gas generated when Fe¬2+ is oxidized using nitrogen compounds as catalyst and recycle NaNO2 as catalyst, thereby not only being environmentally friendly but also reducing chemical costs. CONSTITUTION: In a method for preparing Fe¬3+ by air oxidizing Fe¬2+ in an acid solution using one chemical selected from NaNO2 and HNO3 as a catalyst as in the following reaction formula: £Reaction Formula| Fe¬(2+) + H¬(+) + NaNO2 or (HNO3)→Fe¬(3+) + NO + H2O the method for preparing the Fe¬3+ is characterized in that nitrogen oxides produced in the reaction is reduced into NaNO2 by reacting the nitrogen oxides with NaOH, and the produced NaNO2 is reused as a catalyst during oxidation reaction of the Fe¬2+. The apparatus for preparing Fe¬3+ comprises an oxidation reaction tank(10) which is equipped with an air supply means(12) supplying air into the oxidation reaction tank(10) and a catalyst injection means(18) for injecting NaNO2 or HNO3, and on one side of which injection ports(14,16) are formed so that an acid solution and Fe¬2+ are supplied into the oxidation reaction tank(10) through the injection ports(14,16), and the Fe¬2+ is oxidized into Fe¬3+ by air in the oxidation reaction tank(10); a Fe¬3+ storage tank(20) in which the Fe¬3+ oxidized in the oxidation reaction tank(10) is stored; and a NaOH absorption column(40) in which NaOH is stored so as to reduce nitrogen oxides produced after the catalyst is dissolved into NaNO2, wherein the NaOH absorption column(40) further comprises a NaNO2 transfer line(50) transferring NaNO2 produced after the nitrogen oxides are reduced to the catalyst injection means(18) or the oxidation reaction tank(10), thereby reusing the NaNO2 produced by the nitrogen oxides as a catalyst.