A method of midstream production of Ge and Ga from an REE extraction process is compatible with downstream industrial processes, and may produce Ge and Ga that is 90% pure as oxides, salts, or metals. A method for producing critical minerals includes vaporizing a feedstock comprising the critical minerals; cooling the vaporized feedstock to a condensation temperature of a critical mineral; and capturing the condensed critical mineral. Systems and methods disclosed herein for producing critical minerals are integrated into a rare earth extraction process to co-produce germanium and gallium concentrates.

An improved direct smelting system and process using a smelt reduction vessel (SRV), and optionally, a cyclone converter furnace (CCF). The improved system and process utilizes a fast quench system in which hot process offgas containing molten material is quench-cooled from greater than 1400? C. (2552? F.) to no more than 600? C. (1112? F.) in a time-of-flight of no greater than 1 second. The quenching occurs using water spray injection and vaporization to cool, stress and break solid slag into slag pieces small enough to remove from the quenching system. The improved system eliminates plant availability problems associated with (i) accretion formation in the offgas train as hot process offgas cools down in a conventional (slow) manner to allow for steam-raising for power generation or other heat recovery purposes, and (ii) trigger mechanisms causing slag foaming events in the SRV that propagate up the offgas train.

A process disclosed herein is related to the isolation and purification of substantially pure chemicals, including silica gel, sodium silicate, aluminum silicate, iron oxide, and rare earth elements (or rare earth metals, REEs), from massive industrial waste coal ash. In one embodiment, the process includes a plurality of caustic extractions of coal ash at an elevated temperature, followed by an acidic treatment to dissolve aluminum silicate and REEs. The dissolved aluminum silicate is precipitated out by pH adjustment as a solid product while REEs remain in the solution. REEs are captured and enriched using an ion exchange column. Alternatively, the solution containing aluminum silicate and REEs is heated to produce silica gel, which is easily separated from the enriched REEs solution. REEs are then isolated and purified from the enriched solution to afford substantially pure individual REE by a ligand-assisted chromatography. Additionally, a simplified process using one caustic extraction and one acidic extraction with an ion exchange process was also investigated and optimized to afford a comparable efficiency.

A process disclosed herein is related to the isolation and purification of substantially pure chemicals, including silica gel, sodium silicate, aluminum silicate, iron oxide, and rare earth elements (or rare earth metals, REEs), from massive industrial waste coal ash. In one embodiment, the process includes a plurality of caustic extractions of coal ash at an elevated temperature, followed by an acidic treatment to dissolve aluminum silicate and REEs. The dissolved aluminum silicate is precipitated out by pH adjustment as a solid product while REEs remain in the solution. REEs are captured and enriched using an ion exchange column. Alternatively, the solution containing aluminum silicate and REEs is heated to produce silica gel, which is easily separated from the enriched REEs solution. REEs are then isolated and purified from the enriched solution to afford substantially pure individual REE by a ligand-assisted chromatography. Additionally, a simplified process using one caustic extraction and one acidic extraction with an ion exchange process was also investigated and optimized to afford a comparable efficiency.

A method for the treatment of sludge containing iron, the method including a leaching step wherein the sludge containing iron is mixed with an acid and an oxidation agent so as to create an oxidized leachate, and a step of precipitation of iron wherein the oxidized leachate is mixed with a neutralizing agent so as to create a mixture composed of a solid part including precipitated iron and of a liquid part, the neutralizing agent including at least 30% in weight of dust recovered from a bag filter treatment of ironmaking, steelmaking, coke making or sintering gas.

A method for the treatment of sludge containing iron, the method including a leaching step wherein the sludge containing iron is mixed with an acid and an oxidation agent so as to create an oxidized leachate, and a step of precipitation of iron wherein the oxidized leachate is mixed with a neutralizing agent so as to create a mixture composed of a solid part including precipitated iron and of a liquid part, the neutralizing agent including at least 30% in weight of dust recovered from a bag filter treatment of ironmaking, steelmaking, coke making or sintering gas.

A method for recycling processing of dust generated in a converter furnace, includes: crushing and drying a cake formed by adding a binder to a slurry containing iron powder-containing dust that is generated at the time of converter blowing and wet-collected to produce a mixed slurry and subjecting the produced mixed slurry to a dehydration treatment in a filter press; accumulating the cake in an accumulation tank; and charging the cake into a converter furnace 10, the crushed product in the accumulation tank 25 is kept at a temperature of less than 90 C. by forcibly passing air into the accumulation tank 25 and charged into a converter furnace according to the converter operation.

A method for recycling processing of dust generated in a converter furnace, includes: crushing and drying a cake formed by adding a binder to a slurry containing iron powder-containing dust that is generated at the time of converter blowing and wet-collected to produce a mixed slurry and subjecting the produced mixed slurry to a dehydration treatment in a filter press; accumulating the cake in an accumulation tank; and charging the cake into a converter furnace 10, the crushed product in the accumulation tank 25 is kept at a temperature of less than 90 C. by forcibly passing air into the accumulation tank 25 and charged into a converter furnace according to the converter operation.

A method and recovering method of recovering zinc oxides and other metal oxides having an injection chamber where a mixture of natural gas and oxygen is formed and then ignited to form high temperature combustion gases of greater than 2000 C. with a high concentration of carbon monoxide. Then, the mixture is transported through a quiescent chamber to a feed chamber where the ignited high temperature combustion gases are mixed with finely divided material, including EAF dust. The mixture is transported to a reaction chamber, wherein zinc vapor and other metal vapors and molten slag particles are formed. The zinc vapor and other metal vapors are separated from the molten slag particles and transported to an insulated plenum. Zinc vapor and other metal vapors are mixed with air and become airborne zinc oxide and other metal oxides. The airborne zinc oxide and other metal oxides are collected.

A vanadium recovery approach utilizes oil fly ash (OFA), in contrast to coal fly ash, for separation and recovery of vanadium. OFA is first carbon burned to reduce the volume for recycling, and also to provide a fuel for other industrial processes. Following an almost 90% weight reduction from carbon burning, the remaining material includes about 18% vanadium. A salt roasting performed at the same temperature (about 650 C.) as the carbon burning allows use of the same oven or furnace, reducing heat requirements for the overall process. Salt roasting generates a water-soluble material from which a water leaching process yields a vanadium leach solution containing recovered vanadium, avoiding a need for caustic or volatile leaching agents. Ammonium metavanadate is precipitated from the vanadium leach solution through addition of ammonium sulfate, and a calcination process used to generate vanadium oxide (V.sub.2O.sub.5).