Disclosed herein, is a process for recovering valuable metals and/or their oxides from red mud bauxite residues or similar. The process comprises: calcining a red mud residue having a pH of less than about 10 to provide a calcinated red mud residue; acid leaching the calcinated red mud residue to provide a silica rich solid component and an acid leachate; separating the silica rich solid component and the acid leachate; precipitating an iron rich solid component from the acid leachate; and separating the precipitated iron rich solid component from the acid leachate to provide an aluminium rich liquor.

Bauxite residue recovery includes mixing a solution of hydrochloric acid (HCL) according to a predetermined concentration, and adding the HCL solution to a quantity of raw red mud recovered from industrial operations as waste material. The highly alkaline property of the bauxite residue, commonly known as red mud is at least partially neutralized from the HCL, and makes the resulting washed red mud more amenable to subsequent uses in various applications in fields such as construction, wastewater treatment, and metal recovery processes. The process recovers washed red mud from the red mud and HCL solution by filtering the raw red mud and HCL solution for generating a stream of leach liquor from the filtrate and the recovered washed red mud from the residue.

Bauxite residue recovery includes mixing a solution of hydrochloric acid (HCL) according to a predetermined concentration, and adding the HCL solution to a quantity of raw red mud recovered from industrial operations as waste material. The highly alkaline property of the bauxite residue, commonly known as red mud is at least partially neutralized from the HCL, and makes the resulting washed red mud more amenable to subsequent uses in various applications in fields such as construction, wastewater treatment, and metal recovery processes. The process recovers washed red mud from the red mud and HCL solution by filtering the raw red mud and HCL solution for generating a stream of leach liquor from the filtrate and the recovered washed red mud from the residue.

A method of dewatering sludge is provided herein. In some embodiments, the method includes introducing micronized dry water soluble polymer (DWSP) particles into a sludge, wherein the sludge includes water and solids; separating water of the sludge from solids of the sludge using the micronized DWSP particles; and collecting a wet solid including water and solids of the sludge, wherein a concentration of solids in the wet solid is higher than a concentration of solids in the sludge, wherein the micronized DWSP particles comprise a DWSP wherein the DWSP is selected from the group consisting of a dry anionic water soluble polymer, a dry cationic water soluble polymer, a dry nonionic water soluble polymer, and mixtures thereof, and wherein a mean particle size of the micronized DWSP particles ranges from about 100 to about 300 microns.

Methods are provided for reducing friction during fracturing of a subterranean formation. In some embodiments, a method includes introducing micronized dry water soluble polymer (DWSP) particles into a fracturing liquid to form a mixture; and pumping the mixture into a subterranean formation to fracture the subterranean formation, the micronized DWSP particles include a DWSP, DWSP is selected from the group consisting of dry anionic, dry cationic, dry nonionic water soluble polymer, and mixtures thereof, mean particle size of the micronized DWSP particles ranges from about 115 to about 225 microns.

A process for purifying red mud including reduction of the red mud to reduced material, and traversing the reduced material with an oxygen-containing gas in the presence of a catalyst suitable for iron oxidation.

The present disclosure relates to processes for recovering rare earth elements from an aluminum-bearing material. The processes can comprise leaching the aluminum-bearing material with an acid so as to obtain a leachate comprising at least one aluminum ion, at least one iron ion, at least one rare earth element, and a solid, and separating the leachate from the solid. The processes can also comprise substantially selectively removing at least one of the at least one aluminum ion and the at least one iron ion from the leachate and optionally obtaining a precipitate. The processes can also comprise substantially selectively removing the at least one rare earth element from the leachate and/or the precipitate.

The present disclosure relates to an inorganic, halogen-free flameproofing agent produced from modified, carbonized red mud (MKRS-HT) having, in some examples, a mineral composition of 10 to 50 weight % of iron compounds, 12 to 35 weight % of aluminum compounds, 5 to 17 weight % of silicon compounds, 2 to 10 weight % of titanium dioxide, 0.5 to 6 weight % of calcium compounds, the weight ratio of Fe (II) carbonate to the oxides of iron being at least 1. Examples of the agent can be used as a flame retardant in the high-temperature range. The disclosure further relates to an agent produced from modified, carbonized and rehydrated red mud, which can be used as a flame retardant in the low-temperature and high-temperature ranges, methods for producing same and use as flame retardants. The disclosure further relates to a flameproofed material system and methods for producing same.

The disclosure relates to an inorganic, halogen-free flameproofing agent produced from modified, recarbonized red mud (MKRS-HT). The agent may have a mineral composition of 10 to 50 weight % of iron compounds, 12 to 35 weight % of aluminum compounds, 5 to 17 weight % of silicon compounds, 2 to 10 weight % of titanium dioxide, 0.5 to 6 weight % of calcium compounds the weight ratio of Fe (II) carbonate to the oxides of iron being at least 1. The agent, according to examples, can be used as a flame retardant in the high-temperature range. The disclosure further relates to flameproofing agent produced from modified, recarbonized and rehydrated red mud, which may be a flame retardant in the low-temperature range as well as in the high-temperature range, methods for producing same and use as flame retardants, substitutes, synergists, thermal stabilizers, heat accumulators, heat insulators and/or sound insulators and/or as electromagnetic radiation shielding materials.

Compositions and methods used in the modification of crystallization of aluminum hydroxide from liquor in an aluminum hydroxide production process, such as the Bayer process. More particularly, crystal growth modifier compositions comprising a component of crude corn oil derived from a bioethanol production process and/or a component of biodiesel and methods of using such compositions to modify particle size and distribution of precipitated alumina trihydrate in a precipitation liquor crystallization process.