Manufacture of .gamma.-Fe.sub.2 O.sub.3
AssigneeSuntech, Inc.
InventorMargaret M. Desmond
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Abstract
A process for the preparation of essentially pure ferromagnetic .gamma.-Fe.sub.2 O.sub.3 by bringing a solution of a water soluble iron salt to a pH between about 8.0 and 11.0 to obtain a suspension of iron hydroxide, passing air through the iron hydroxide suspension at a temperature of from about 25.degree. to about 80.degree. C., and separating said pure .gamma.-Fe.sub.2 O.sub.3.
Claims7
A process for the preparation of ferromagnetic .gamma.-Fe.sub.2 O.sub.3 by bringing a solution of a water soluble ferrous iron salt to a pH of between about 8.5 to about 10.5 by the addition of an aqueous alkaline solution to said iron salt solution under a blanket of an inert gas to obtain a suspension of iron hydroxide, heating said iron hydroxide suspension to a temperature of between about 25.degree. to about 80.degree. C., and passing air through said heated suspension for a period of about 0.3 to 10 hours to form pure .gamma.-Fe.sub.2 O.sub.3 and separating said .gamma.-Fe.sub.2 O.sub.3.
A process for the preparation of pure ferromagnetic .gamma.-Fe.sub.2 O.sub.3 by bringing a solution of a water soluble ferrous iron salt to a pH between about 8.0 and about 11.0 to obtain a suspension of ferrous iron hydroxide, passing an oxygen containing gas through the iron hydroxide suspension at a temperature of from about 25.degree. to about 80.degree. C, and separating pure .gamma.-Fe.sub.2 O.sub.3 from the solution.
Dependencies are inferred from the claim text.