| 摘要 |
PURPOSE:To decompose the titled substance to be treated easily and recover metallic iron by a method wherein ammonium iron fluoride or iron fluoride obtained by treating the waste liquid of a pickling liquid used in an ironmarking plant, a steelmaking plant or the like is heated in an H2 gas flow. CONSTITUTION:The used pickling liquid is extracted with an organic solvent which is prepared by diluting at least one extractants such as alkylphosphoric acids, dialkylphosphoric acids and the like with a hydrocarbon diluent. Then, the Fe ions extracted into the organic solvent are contacted to an aqueous solution of a stripping agent containing at least one member selected from a group consisting of HF, NH4HF2 and NH4F so separate ammonium iron fluoride or iron fluoride by precipitation. Then, metallic iron is recovered from the thus obtained ammonium iron fluoride or iron fluoride by heating the fluoride in a hydrogen gas stream.
|
