Method for production of iron oxide from ferrous chloride solution

The present invention relates to a method for preparing iron oxide red and iron oxide yellow from ferrous chloride aqueous solution by using air as oxidant and lime as neutralizing agent. The seed crystal used for preparing iron red is prepared from the reaction of iron trichloride aqueous solution and lime, and the preparation of iron yellow is implemented at ordinary temp.. The air used as oxidant is sucked by the impeller of mechanically-stirring flotation machine used as stirrer and highly dispersed in aqueous solution. Said invention is applicable to treatment of industrial wastes, such as hydrochloric acid waste liquid resulted from acid-washing steel and iron and waste liquid resulted from production of artificial rutile by using hydrochloric acid method.