| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for efficiently producing a phosphate resource raw material having high phosphorus content at a low cost by recovering and concentrating the phosphorus in a steel-making slag containing phosphorus. SOLUTION: The steel-making slag containing the phosphorus, is reduced by using a reduction-agent containing one or more among carbon, silicon and aluminum, and thus, iron-oxide and phosphorus-oxide in the steel-making slag are reduced to obtain the phosphorus. To molten iron containing ≥0.5% phosphorus obtained like this, oxygen-source having ≥40 vol.% of the supplied oxygen-source, is supplied by blowing into the molten iron through a top-blowing lance as the oxygen gas and also, ≥40 mass% of the supplied lime-source expressed in term of pure CaO is together with a gas for trnsformation, and the dephosphorizing-treatment is applied by supplying the oxygen-source and the lime-source without using fluorine-source as slag-making promoting agent of the lime-source, and the phosphate concentration in the generated dephosphorus slag is concentrated to ≥10 mass% and thus, the dephosphorus slag is recovered to make the phosphate resource raw material. COPYRIGHT: (C)2010,JPO&INPIT |
