Processes for treating red mud
AssigneeOrbite Aluminae Inc.
InventorsRichard Boudreault, Joel Fournier, Denis Primeau, Marie-Maxime Labrecque-Gilbert
Life of this patent
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Abstract
There are provided processes for treating red mud. For example, the processes can comprise leaching red mud with HCl so as to obtain a leachate comprising ions of a first metal (for example aluminum) and a solid, and separating said solid from said leachate. Several other metals can be extracted from the leachate (Fe, Ni, Co, Mg, rare earth elements, rare metals, etc.). Various other components can be extracted from solid such as TiO2, SiO2 etc.
Claims55
A process for treating red mud, said
- process comprising:
- leaching red mud with HCl at a temperature of about 125 to about 225° C. to obtain a leachate comprising aluminum ions and iron ions and a solid, and separating said solid from said leachate;
- reacting said leachate with HCl to obtain a liquid comprising said iron ions and a precipitate comprising said aluminum ions in the form of AlCl3, and separating said precipitate from said liquid;
- and
- heating said precipitate under conditions effective for converting AlCl3 into Al2O3 and optionally recovering gaseous HCl so-produced.
The process of 1, wherein said red mud is leached at a pressure of about 4 to about 10 barg.
The process of 5, wherein said red mud is leached at a pressure of about 4 to about 10 barg.
A process for treating red mud, the
- process comprising:
- leaching said red mud comprising a first metal with HCl at a temperature of about 125 to about 225° C. to obtain a leachate comprising ions of said first metal and a solid, and separating the solid from the leachate;
- reacting the leachate with HCl to obtain a liquid and a precipitate comprising a chloride of the first metal, and separating the precipitate from the liquid;
- and
- heating the precipitate under conditions effective for converting the chloride of the first metal into an oxide of the first metal.
A process for treating red mud comprising:
- leaching red mud with an acid to obtain a leachate and a solid residue, and separating said leachate from said solid residue;
- at least partially removing iron ions from said leachate by substantially selectively precipitating said iron ions at a pH greater than 10 by reacting said leachate with a base and at least partially removing said precipitated iron ions from said leachate, thereby obtaining an Al-rich composition comprising Al3+ ions;
- precipitating said Al3+ ions in the form of Al(OH)3 at a pH of about 7 to about 10;
- optionally purifying said Al(OH)3;
- and
- converting said Al(OH)3 into alumina.
A process for preparing titanium chloride, said process comprising:
- leaching red mud with HCl to obtain a first leachate comprising ions from at least one metal and a solid, and separating said solid from said first leachate;
- at least substantially isolating said ions of said at least one metal from said leachate;
- and
- leaching said solid with HCl in the presence of at least one chloride that is an alkali metal chloride or an alkaline earth metal chloride to obtain a second leachate comprising titanium chloride.
A process for treating red mud, said process comprising:
- leaching red mud with HCl to obtain a leachate comprising aluminum ions and iron ions and a solid that comprises less than 10 weight % of the aluminum atoms contained in said red mud, and separating said solid from said leachate;
- reacting said leachate with HCl to obtain a liquid comprising said iron ions and a precipitate comprising said aluminum ions in the form of AlCl3, and separating said precipitate from said liquid;
- and
- heating said precipitate under conditions effective for converting AlCl3 into Al2O3 and optionally recovering gaseous HCl so-produced.
A process for treating red mud, said process comprising:
- leaching red mud with HCl under conditions effective to obtain a solid and a leachate comprising at least 90 weight % of the aluminum contained in said red mud in the form of aluminum ions and iron ions, and separating said solid from said leachate;
- reacting said leachate with HCl to obtain a liquid comprising said iron ions and a precipitate comprising said aluminum ions in the form of AlCl3, and separating said precipitate from said liquid;
- and
- heating said precipitate under conditions effective for converting AlCl3 into Al2O3 and optionally recovering gaseous HCl so-produced.
The process of 12, wherein said red mud is leached at a pressure of about 4 to about 10 barg.
The process of 20, wherein said red mud is leached at a pressure of about 4 to about 10 barg.
The process of 21, wherein said red mud is leached at a pressure of about 4 to about 10 barg.
Dependencies are inferred from the claim text.