| 摘要 |
Molten aluminum or other metals are purified by contacting with a fluorocarbon, such as CCl2F2, in order to decrease the amount of impurity metal elements along with gas and inclusions therein preferably in the presence of an agitator to enhance efficiency. An oxidizer, such as oxygen, is employed to prevent the carbon in the fluorocarbon from forming carbide inclusions. Oxidizing the carbon to carbon monoxide is preferred in treating aluminum since the monoxide effectively removes the carbon from the system without oxidizing aluminum. Preferably, a fluorine acceptor is employed to temporarily combine with the fluorine in the fluorocarbon and prevent it from reacting with carbon such that the fluoride is still available to treat the molten metal. The gases employed to treat the molten metal can be passed over a bed of carbon immediately prior to introduction into the melt. The system operates with low skim generation and without providing a salt cover and is capable of substantially fume-free operation.
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