| 摘要 |
<p>PROBLEM TO BE SOLVED: To recover phosphorus in wastes as phosphoric acid manures by fusing a metal residue containing iron as a main component and discharged from an ash-fusing oven, adding calcium ferrite, extracting phosphorus in the metal residue into a slag and producing citric acid-soluble phosphorus compounds. SOLUTION: This treatment of metal residue from an ash-fusing oven is to put iron residue 7 discharged from the ash-fusing oven and containing iron as a main component into an induction-fusing oven 1 wound with an induction coil 2 around a refractory oven body 1a, feed an alternating current having 150-3,000 Hz to the induction coil 2 from an alternating current source 4, fuse the metal residue 7 by developing heat caused by electric resistance of inducing current generated in the metal residue 7 to form molten metal 6, then, add calcium ferrite to the molten metal 6 as a slag-forming agent to extract phosphorus contained in the metal residue 7 into a slag 5 and produce citric acid-soluble phosphorus compounds.</p> |
