The disclosed technology includes a method for producing ultrafine alumina from salt slag waste generated in aluminum recycling useful in the manufacture of durable ceramic products; a system for recovering alumina from salt slag waste; a method and systems for recovering salts, aluminum and alumina from salt slag waste; and a method and systems of capturing ammonia in a process recovering salts, aluminum and alumina from salt slag waste. The methods and systems provided crush the dry particles of the salt slag waste, scrub the slag with water, and with steam and by means of a vented alumina press, dewater the scrubbed slag particles. In some methods and systems of the disclosed technology, the particles of the pressed alumina cake are further reduced. In some methods and systems, the salt in the salt effluent is crystalized. In some methods and systems of the disclosed technology, the ammonia is contained and captured.

The disclosed technology includes a method for producing ultrafine alumina from salt slag waste generated in aluminum recycling useful in the manufacture of durable ceramic products; a system for recovering alumina from salt slag waste; a method and systems for recovering salts, aluminum and alumina from salt slag waste; and a method and systems of capturing ammonia in a process recovering salts, aluminum and alumina from salt slag waste. The methods and systems provided crush the dry particles of the salt slag waste, scrub the slag with water, and with steam and by means of a vented alumina press, dewater the scrubbed slag particles. In some methods and systems of the disclosed technology, the particles of the pressed alumina cake are further reduced. In some methods and systems, the salt in the salt effluent is crystalized. In some methods and systems of the disclosed technology, the ammonia is contained and captured.

An alumina exhibiting a structure with a porosity such that the volume of the pores having a diameter of between 70 and 2000 Å is between 0.15 and 0.50 ml/g, and comprising at least one alkali metal (M), such that the content by weight of alkali metal, expressed as M.sub.2O, is between 400 and 1500 ppm, with respect to the total weight of the alumina, and a process for the transformation of a feedstock comprising at least one alcohol into an olefinic effluent, said process comprising a stage of dehydration of said alcohol in the presence of the alumina according to the present invention, having an acidity and a structure with a porosity which are optimal.

This invention relates to treated geothermal brine compositions containing reduced concentrations of lithium, iron and silica compared to the untreated brines. Exemplary compositions contain concentration of lithium ranges from 0 to 200 mg/kg, concentration of silica ranges from 0 to 30 mg/kg, concentration of iron ranges from 0 to 300 mg/kg. Exemplary compositions also contain reduced concentrations of elements like arsenic, barium, and lead.

This invention relates to treated geothermal brine compositions containing reduced concentrations of lithium, iron and silica compared to the untreated brines. Exemplary compositions contain concentration of lithium ranges from 0 to 200 mg/kg, concentration of silica ranges from 0 to 30 mg/kg, concentration of iron ranges from 0 to 300 mg/kg. Exemplary compositions also contain reduced concentrations of elements like arsenic, barium, and lead.

This invention relates to treated geothermal brine compositions containing reduced concentrations of lithium, iron and silica compared to the untreated brines. Exemplary compositions contain concentration of lithium ranges from 0 to 200 mg/kg, concentration of silica ranges from 0 to 30 mg/kg, concentration of iron ranges from 0 to 300 mg/kg. Exemplary compositions also contain reduced concentrations of elements like arsenic, barium, and lead.

This invention relates to treated geothermal brine compositions containing reduced concentrations of lithium, iron and silica compared to the untreated brines. Exemplary compositions contain concentration of lithium ranges from 0 to 200 mg/kg, concentration of silica ranges from 0 to 30 mg/kg, concentration of iron ranges from 0 to 300 mg/kg. Exemplary compositions also contain reduced concentrations of elements like arsenic, barium, and lead.

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. Further oxalic acid addition precipitates magnesium oxalate which is thermally decomposed to magnesium oxide.

The present disclosure describes a non-destructive process for removing metals, metal ions and metal oxides present in alumina-based materials without destroying alumina, allowing the regeneration of alumina-based catalysts. Known conventional procedures and/or methods for removing metals, metal ions and metal oxides present in alumina-based materials use some inorganic acid or its mixtures to carry out digestion, which modifies the properties of alumina and those of any other element contained in the material, destroying alumina and preventing its reuse. The present disclosure is characterized by using an extracting agent that sequesters metals, metal ions and/or metal oxides present in alumina-based materials without modifying their properties. The employed extracting agent is an alcohol. The non-destructive process introduced in the present invention reaches metal (M) removal rates of at least 42% when using a continuous flow reactor and of at least 27% when a batch reactor is employed.

The present disclosure describes a non-destructive process for removing metals, metal ions and metal oxides present in alumina-based materials without destroying alumina, allowing the regeneration of alumina-based catalysts. Known conventional procedures and/or methods for removing metals, metal ions and metal oxides present in alumina-based materials use some inorganic acid or its mixtures to carry out digestion, which modifies the properties of alumina and those of any other element contained in the material, destroying alumina and preventing its reuse. The present disclosure is characterized by using an extracting agent that sequesters metals, metal ions and/or metal oxides present in alumina-based materials without modifying their properties. The employed extracting agent is an alcohol. The non-destructive process introduced in the present invention reaches metal (M) removal rates of at least 42% when using a continuous flow reactor and of at least 27% when a batch reactor is employed.