| 摘要 |
<p>PURPOSE: To improve the metal recovery rate from used large-size iron and steel products by bringing a liquefied gas into contact with the large-size iron and steel products subjected to crushing to cool these iron and steel products down to the embrittlement temp. area of ferrous metals and pulverizing the cooled large-size iron and steel products, then refining and recovering iron and copper therefrom. CONSTITUTION: The liquefied gas is brought into contact with the large-size iron and steel products contg. the copper based metals to precool these iron and steel products in a precooling and crushing device 1; thereafter, the iron and steel products are crushed by a hammer mill or press crushing machine and the crushed steel products are transferred to a cooler 2. The liquefied gas is brought into contact with the crushed large-size iron and steel products to completely cool the products down to the embrittlement temp. of the ferrous metals in this cooler 2. The cooled large-size iron and steel products are pulverized by a low-temp. pulverizing machine 3. The pulverized scrap is treated with an insulating oil, etc., by a high heat treatment in a reforming device 4. The scrap is thereafter classified to magnetic materials and nonmagnetic materials by magnetic sepn in a recovering device 5. These materials are transported to a stage for recovering the copper based metals. The magnetic materials are efficiently recovered as iron scrap. The treatment costs are thus reduced.</p> |
