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US 6,183,620 B2Granted
Process for controlling the A1F3 content in cryolite melts
AssigneeHeraeus Electro-Nite International N.V.
InventorPaul Clement Verstreken
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AssigneeHeraeus Electro-Nite International N.V.
InventorPaul Clement Verstreken
Estimating the term…
A process is provided for controlling the AlF3 content in cryolite melts for aluminum reduction, wherein the temperature of the melt is measured. In order to produce a very precise process which makes it possible to perform the aluminum reduction at the lowest posssible temperature, and thus as energy-saving as possible, the liquidus temperature of the cryolite melt is measured and compared with a first target value. AlF3 is added to the bath if the measured liquidus temperature is higher than the first target value. If the measured liquidus temperature is lower than the first target value, the measured liquidus temperature is compared with a second target value which is lower than the first target value. NaF or Na2CO3 is added to the bath if the measured liquidus temperature is lower than the second target value.
A process for controlling the AlF3 content in cryolite melts for aluminum reduction, comprising measuring the liquidus temperature of a cryolite melt, comparing the measured liquidus temperature with a first target value, adding AlF3 to a molten bath of the cryolite melt if the measured liquidus temperature is higher than the first target value, comparing the measured liquidus temperature with a second target value which is lower than the first target value, and adding NaF or Na2CO3 to the molten bath of the cryolite melt if the measured liquidus temperature is lower than the second target value.
Dependencies are inferred from the claim text.