| 摘要 |
A process is disclosed for treating tin scraps such as tin cans and home scrap, to reduce the tin content of the scrap to a sufficient level to permit the scrap to be reprocessed in an electric furnace. In the process, the scrap metal is first shredded, or chopped, to a managable size which is then utilized as a charge to a kiln. The kiln is maintained as an oxidizing atmosphere. The beginning feed end temperature is not less than 2000 degrees F. The temperature is reduced to not less than about 1650 degrees F. to convert a part of the iron-tin alloy into its epsilon phase. The kiln temperature is then further reduced to not less than 1400 degrees F. to further convert a part of the iron-tin alloy to form the zeta phase. The epsilon and zeta phases additionally produce an oxide laden dust that is then removed. As the charge moves through the kiln, the temperature is further reduced to not less than 900 degrees F. to form the eta phase of the iron-tin alloy and additionally a metallic scale formation. 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 in a steel producing furnace.
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