Abstract: Digestion of impure alumina with sulfuric acid dissolves all constituents except silica. Resulting sulfates, produced from contaminants in the impure alumina, remain in solution at approximately 90° C. Hot filtration separates silica. Solution flow over metallic iron reduces ferric sulfate to ferrous sulfate. Controlled ammonia addition promotes hydrolysis and precipitation of hydrated titania from titanyl sulfate that is removed by filtration. Addition of ammonium sulfate forms ferrous ammonium sulfate and ammonium aluminum sulfate solutions. Alum is preferentially separated by crystallization. Addition of ammonium bicarbonate to ammonium alum solution precipitates ammonium aluminum carbonate which may be heated to produce alumina, ammonia, and carbon dioxide. The remaining iron rich liquor also contains magnesium sulfate. Addition of oxalic acid generates insoluble ferrous oxalate which is thermally decomposed to ferrous oxide. Carbon monoxide reduces the ferrous oxide to metallic iron.

Abstract: Digestion of impure alumina with sulfuric acid dissolves all constituents except silica. The resulting sulfates—aluminum sulfate, ferric sulfate, titanyl sulfate, and magnesium sulfate for alumina contaminated with iron-, titanium-, and/or magnesium-containing species—remain in solution at approximately 90° C. Hot filtration separates silica. Solution flow over metallic iron reduces ferric sulfate to ferrous sulfate. Controlled ammonia addition promotes hydrolysis and precipitation of hydrated titania from titanyl sulfate that is removed by filtration. Addition of ammonium sulfate forms ferrous ammonium sulfate and ammonium aluminum sulfate solutions. Alum is preferentially separated by crystallization. Addition of ammonium bicarbonate to an ammonium alum solution precipitates ammonium aluminum carbonate which may be heated to produce alumina, ammonia, and carbon dioxide. The remaining iron rich liquor also contains magnesium sulfate.

Abstract: Digestion of a laterite with sulfuric acid dissolves all constituents except silica. The resulting sulfates—aluminum sulfate, ferric sulfate, titanyl sulfate, and magnesium sulfate—remain in solution at approximately 90° C. Hot filtration separates silica. Solution flow over iron reduces ferric sulfate to ferrous sulfate. Controlled ammonia addition promotes hydrolysis and precipitation of hydrated titania from titanyl sulfate that is removed by filtration. Addition of ammonium sulfate forms ferrous ammonium sulfate and ammonium aluminum sulfate solutions. Alum is preferentially separated by crystallization. Addition of ammonium bicarbonate to an ammonium alum solution precipitates ammonium aluminum carbonate which may be heated to produce alumina, ammonia, and carbon dioxide. The addition of oxalic acid generates insoluble ferrous oxalate which thermally decomposes to ferrous oxide and carbon monoxide which is used to reduce the ferrous oxide to metallic iron.

Abstract: Digestion of a laterite ore with sulfuric acid dissolves all constituents except silica. The resulting sulfates—aluminum sulfate, ferric sulfate, titanyl sulfate, and magnesium sulfate—remain in solution at approximately 90° C. Hot filtration separates silica. Solution flow over metallic iron reduces ferric sulfate to ferrous sulfate. Controlled ammonia addition promotes hydrolysis and precipitation of hydrated titania from titanyl sulfate that is removed by filtration. Addition of ammonium sulfate forms ferrous ammonium sulfate and ammonium aluminum sulfate solutions. Alum is preferentially separated by crystallization. Addition of ammonium bicarbonate to an ammonium alum solution precipitates ammonium aluminum carbonate which may be heated to produce alumina, ammonia, and carbon dioxide. The remaining iron rich liquor also contains magnesium sulfate.

Abstract: Digestion of a laterite ore with sulfuric acid dissolves all constituents except silica. The resulting sulfates—aluminum sulfate, ferric sulfate, titanyl sulfate, and magnesium sulfate—remain in solution at approximately 90° C. Hot filtration separates silica. Solution flow over metallic iron reduces ferric sulfate to ferrous sulfate. Controlled ammonia addition promotes hydrolysis and precipitation of hydrated titania from titanyl sulfate that is removed by filtration. Continued addition of ammonia forms ferrous ammonium sulfate and ammonium aluminum sulfate solutions. Alum is preferentially separated by crystallization. Ammonia addition to ammonium alum solution precipitates aluminum hydroxide, leaving ammonium sulfate in solution. The remaining iron rich liquor also contains magnesium sulfate. The addition of oxalic acid generates insoluble ferrous oxalate which is thermally decomposed to ferrous oxide and carbon monoxide which is used to reduce the ferrous oxide to metallic iron.

Abstract: Digestion of a laterite ore with sulfuric acid dissolves all constituents except silica. The resulting sulfates—aluminum sulfate, ferric sulfate, titanyl sulfate, and magnesium sulfate—remain in solution at approximately 90° C. Hot filtration separates silica. Solution flow over metallic iron reduces ferric sulfate to ferrous sulfate. Controlled ammonia addition promotes hydrolysis and precipitation of hydrated titania from titanyl sulfate that is removed by filtration. Continued addition of ammonia forms ferrous ammonium sulfate and ammonium aluminum sulfate solutions. Alum is preferentially separated by crystallization. Ammonia addition to ammonium alum solution precipitates aluminum hydroxide, leaving ammonium sulfate in solution. The remaining iron rich liquor also contains magnesium sulfate. The addition of oxalic acid generates insoluble ferrous oxalate which is thermally decomposed to ferrous oxide and carbon monoxide which is used to reduce the ferrous oxide to metallic iron.

Abstract: This is a self-regenerating catalyst member which may be used to remove particulate carbon and residual hydrocarbonaceous material from engine exhaust, especially those emanating from diesel engines. Specifically, the invention is an oxidation catalyst preferably placed onto a particulate trap or collector and placed in the exhaust circuit of a diesel engine. The catalytic material involved is specially formulated to form what are believed to be large particle, multi-metal oxide-based catalytic particles. The catalytic particles may be perovskites. The catalytic materials of this invention include at least one member selected from Group IB metals, preferably copper, and at least one member selected from Group VIII metals, preferably iron, and compounds thereof and Group 5B metals, preferably vanadium or vanadium compounds. Optionally, one or more Platinum Group metals (Ru, Rh, Pd, Re, Os, and Pt) may be added if so desired.

Abstract: This is a self-regenerating catalyst member which may be used to remove particulate carbon and residual hydrocarbonaceous material from engine exhaust, especially those emanating from diesel engines. Specifically, the invention is an oxidation catalyst preferably placed onto a particulate trap or collector and placed in the exhaust circuit of a diesel engine. The catalytic material involved is specially formulated to form what are believed to be large particle, multi-metal oxide-based catalytic particles. The catalytic particles may be perovskites. The catalytic materials of this invention include at least one member selected from Group IB metals, preferably copper, and at least one member selected from Group VIII metals, preferably iron, and compounds thereof and Group 5B metals, preferably vanadium or vanadium compounds. Optionally, one or more Platinum Group metals (Ru, Rh, Pd, Re, Os, and Pt) may be added if so desired.

Abstract: A kiln system for heat treating ceramic and metallic material. The system comprises an insulated housing having an open-ended through passageway, a plurality of kiln cars adapted to be received in and pass through the passageway, a plurality of spaced seals coupled to the housing and engageable with leading and trailing walls on each kiln car, and heating and cooling sources. The leading and trailing walls of each kiln car together with the spaced seals subdivide the passageway into zones of differing temperatures. By use of seals located at the ends of the passageway, outer doors for the passageway are unnecessary. By forming the zones of differing temperatures by use of the plurality of spaced seals, a plurality of kiln cars can be moved through the passageway in series one after the other and be subject to pre-heating, heating and cooling temperatures typically used in heat treating without the need of inner doors or a long housing.