| 摘要 |
A process is disclosed for treating iron or steel base scraps such as automobile scrap vehicles to reduce the alloy content of the scrap to a sufficient level to permit the scrap to be reprocessed in an electric furnace. The process treats the entire scrap vehicle. In the process, the vehicle is first shredded, or chopped, to a manageable size which is then utilized as a charge to a kiln. The kiln is maintained as an oxidizing atmosphere at about 1700 degrees F. at the feed end to cause zinc oxide and cuprite to be formed, which are then removed as dust. As the charge moves through the kiln, the kiln atmosphere is gradually changed from oxidizing, through neutral, to reducing, and the kiln temperature is raised to about 1900 degrees F. at the discharge end. These conditions cause formations of the metallic form of copper, nickel, chromium, lead and zinc as a brittle scale. Aluminum forms a melt which adheres to the scale. An autogenous mill, where the feed particles are tumbled against each other, descales them. The metallic scale produced thereby is removed. The feed remaining has now had sufficient residual alloys removed to allow its use as a direct charge to an electric furnace.
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