IRON-SUPPLYING AGENT, IRON SUPPLYING AGENT FOR PLANT COMPRISING THE SAME, AND PROCESS FOR PRODUCTION OF THE SAME

摘要

[PROBLEMS] To provide an iron-supplying agent and an iron-supplying agent for plant which can provide an aqueous solution having a high Fe2+ ion concentration and reduced in the oxidation of Fe2+ ions. [MEANS FOR SOLVING PROBLEMS] The iron-supplying agent comprises an aqueous solution which has dissolved therein an organic acid having a carboxyl group and/or a hydroxyl group (particularly citric acid) and FeO. Alternatively, the iron-supplying agent may be prepared by removing water from an aqueous solution which has dissolved therein an organic acid having a carboxyl group and/or a hydroxyl group (particularly citric acid) and FeO. The iron-supplying agent can be prepared by a process comprising the dissolution step in which a mixture of an organic acid powder (particularly a citric acid powder), an FeO powder and water is heated to give an aqueous solution having the organic acid and FeO dissolved therein. The FeO powder used is preferably produced by heating under vacuum granules which are produced by granulating an iron-containing dust and/or granules which are produced by granulating an iron-containing dust together with a reducing agent and then quickly cooling the resulting granules under reduced pressure.