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US 4,900,535 AGranted
Recovery of fluoride values from waste materials
AssigneeComalco Aluminum Limited
InventorsChristopher G. Goodes, Grant A. Wellwood, Howard W. Hayden, Jr.
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AssigneeComalco Aluminum Limited
InventorsChristopher G. Goodes, Grant A. Wellwood, Howard W. Hayden, Jr.
Estimating the term…
A process for the treatment of waste materials such as spent cathode liners involving combustion of the contained carbonaceous material, decomposition of the contained cyanides, sulphides and nitrides, and recovery of fluoride values by a sulpholysis reaction, is characterized in that the sulpholysis reaction is carried out in a separate stage. The process enables a recovgery of fluoride values from smelter wastes which is especially favourable environmentally. A further advantage of the invention is that recovery of the contained fluoride values, initially in the form of gaseous fluoride species, may subsequently be treated with alumina to produce aluminium trifluoride, which is of significant economic importance.
Process for recovery of fluoride values from material containing fluoride salts together with combustible components, said process comprising combustion of the said components and sulpholysis of the fluoride salts, characterized in that the material is subjected to combustion in a first step, and the combustion product is subjected to sulpholysis in a separate step, without an intermediate leaching step, wherein the sulpholysis produces a gaseous product containing fluoride values.
A process for recovery of fluoride values from material containing fluoride salts together with combustible components, said process consisting essentially of the steps of:
A process for recovery of fluoride values from material containing fluoride salts together with combustible components, said process consisting of the steps of:
Dependencies are inferred from the claim text.