A pyro-metallurgical process for producing at least one non-ferrous metal or a compound thereof, wherein said metal is selected from the group consisting of arsenic (As), antimony (Sb), lead (Pb), cadmium (Cd), mercury (Hg), silver (Ag), tin (Sn), nickel (Ni), and zinc (Zn), and wherein at least one raw material is fed into a rotary kiln, wherein said at least one raw material comprises at least said metal, and wherein said raw material is heated to produce a volatized material, in which the non-ferrous metal or compound thereof is produced from the volatized material, in which process a magnesium-based additive, is additionally fed in the rotary kiln in an amount of between 0.5 wt. % and 9.5 wt. % relative to the total weight of said raw materials, which magnesium-based additive is heated together with said raw material to produce at least the volatized material and a solid product, thereby counteracting ring formation in the rotary kiln.

A system for recovering rare earth elements from coal ash includes a leaching reactor, an ash dryer downstream of the leaching reactor, and a roaster downstream of the ash dryer that is cooperatively connected to both the leaching reactor and the ash dryer. Coal ash is mixed with an acid stream such that rare earth elements present in the coal ash are dissolved in the acid stream, thereby creating (i) a leachate containing the rare earth elements and (ii) leached ash. The leachate is heated to obtain acid vapor and an acid-soluble rare earth concentrate. Mixing of the coal ash with the acid stream can occur in a leaching reactor and heating of the leachate can occur in a roaster. The acid-soluble rare earth concentrate can be fed to a hydrometallurgical process to separate and purify the rare earth elements.

A system for recovering rare earth elements from coal ash includes a leaching reactor, an ash dryer downstream of the leaching reactor, and a roaster downstream of the ash dryer that is cooperatively connected to both the leaching reactor and the ash dryer. Coal ash is mixed with an acid stream such that rare earth elements present in the coal ash are dissolved in the acid stream, thereby creating (i) a leachate containing the rare earth elements and (ii) leached ash. The leachate is heated to obtain acid vapor and an acid-soluble rare earth concentrate. Mixing of the coal ash with the acid stream can occur in a leaching reactor and heating of the leachate can occur in a roaster. The acid-soluble rare earth concentrate can be fed to a hydrometallurgical process to separate and purify the rare earth elements.

A process for making modified diethylenetriaminepentaacetic acid (DTPA)-associated media for use in solid-liquid extraction of rare earth elements is disclosed. The process includes functionalizing DTPA with hydrophobic groups to form modified DTPA; dissolving the modified DTPA into a methanol solution; loading the modified DTPA solution to a solid support; rotating the modified DTPA-loaded solid support to allow for association; and removing the methanol to obtain the modified-DTPA-associated media.

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.

Embodiments of the present disclosure generally relate to the recovery and extraction of rare earth elements. More specifically, embodiments of the disclosure relate to methods for separating rare earth elements from coal, coal by-product(s), and/or coal-derived product(s). In an embodiment, a method of removing rare earth elements from a coal-derived product is provided. The method generally includes introducing supercritical CO.sub.2 to the coal ash to form a first mixture, introducing a first acid to the first mixture to form a second mixture, and removing a first composition from the second mixture, the first composition comprising the one or more rare earth elements.

A method of manufacturing a valuable material product from an industrial dust is described. The method comprises: i) providing the industrial dust which comprises at least one valuable material and a first concentration of volatile constituents to a heating device with an operation temperature of 600° C. or more, ii) processing the industrial dust by the heating device, wherein processing comprises: iia) heating the industrial dust with a rate of 20° C./min or more, iib) thermally treating the industrial dust by the heating device with a treating temperature in the range of 900° C. to 1200° C., in particular in the range of 1000° C. to 1100° C., for 30 minutes or more, and iic) controlling and/or regulating the oxidizing conditions during processing, wherein processing comprises: at least partially removing the volatile constituents from the industrial dust, and iii) providing the valuable material product. Furthermore, the processed valuable material product is described.

A method of manufacturing a valuable material product from an industrial dust is described. The method comprises: i) providing the industrial dust which comprises at least one valuable material and a first concentration of volatile constituents to a heating device with an operation temperature of 600° C. or more, ii) processing the industrial dust by the heating device, wherein processing comprises: iia) heating the industrial dust with a rate of 20° C./min or more, iib) thermally treating the industrial dust by the heating device with a treating temperature in the range of 900° C. to 1200° C., in particular in the range of 1000° C. to 1100° C., for 30 minutes or more, and iic) controlling and/or regulating the oxidizing conditions during processing, wherein processing comprises: at least partially removing the volatile constituents from the industrial dust, and iii) providing the valuable material product. Furthermore, the processed valuable material product is described.

The present invention relates to a sustainable regeneration process for metallurgical plant dusts and sludges for producing iron-containing, heavy metal-depleted secondary raw materials and recovering lead and zinc, by providing a first starting material which comprises at least one iron, zinc, lead and further heavy metal components containing metallurgical plant dust and/or sludge, and a second starting material containing at least one chlorine component, mixing the starting materials and drying the mixture, pyrolyzing the mixture for expelling zinc, lead and further heavy metal components, capturing the gas phase of the pyrolysis in sulfuric acid, and providing the residue which remains as an iron-containing secondary raw material depleted in zinc, lead and further heavy metal components.