| 摘要 |
<p>PURPOSE:To immobilize residual harmful materials in slag and to make them unharmful by blowing an elution preventing material for lead ions such as blast furnace slag together with the pellets of electric furnace dust into molten slag and recovering the evaporated valuable oxides of metals efficiently. CONSTITUTION:A slag pan 2 contg. molten slag 1 is contained in a dust treating chamber 3, and a lance 5 supplied with pressurized air by opening a valve 4 is charged into the slag 1, thereby bubbling the slag. In this state, a valve 6 is opened to blow the pellets of electric furnace dust and a lead ion elution preventing material consisting of >= 1 kind of blast furnace slag, red mud, etc. together with air into the slag 1. The valve 6 is closed and the slag is bubbled by supplying the air alone. At the point of the time when virtually no volatile materials are left, the lance 5 is pulled up from the slag 1, and the valve 4 is closed. The volatile dusts consisting mainly of oxides of Zn and Pb produced during this bubbling are recovered with a dust collector 7, after which the slag 1 is cooled, whereby the harmful materials in the dust pellets are immobilized and made unharmful.</p> |
