Alumina production
OwnerHyman Moses Lowenstein, Arthur Michael Lowensteininventors
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Abstract
A method of producing an alumina bearing product in which the alumina is substantially soluble in cold alkali including the steps of contacting an aluminium bearing material with concentrated sulphuric acid containing 30 to 100 weight percent sulphuric acid, heat treating the acid and material to cause the acid to react with the material to form a substantially anhydrous hard product and decomposing the product by heat treatment to produce the alumina bearing product. The alumina values may be recovered from the resulting alumina bearing product using the known Bayer process. The process has particular application to non-bauxitic ores.
Claims6
A method of producing a product containing alkali soluble alumina consisting essentially of the steps of contacting an aluminum silicate material selected from the group consisting of clay minerals, coal ash and aluminum silicate ores with concentrated sulphuric acid containing 80 to 100 weight percent sulphuric acid, heating the aluminum silicate material and the acid to a temperature above 190.degree. C and below the boiling point of the acid to produce a substantially anhydrous hard product containing aluminum sulfate and silica and decomposing the hard product by heat treatment at a decomposing temperature below 800.degree. C. in the presence of a reducing agent to produce a product containing alkali soluble alumina.
Dependencies are inferred from the claim text.