The present invention provides a method for the treatment of sludge containing iron and between 4.5% to 12% by weight of zinc. This method includes a leaching step wherein leaching agents include hydrochloric acid and chlorate, and wherein the pH of the leachate directly resulting from this leaching step is set at a value below 1.5. A recycling method and treatment installation are also provided.

The present invention relates to methods for capturing carbon dioxide and permanently sequestering carbon dioxide in the form of Group II metal carbonates. The invention involves production of HCl by reacting steam with a material that includes a magnesium chloride hydrate. The HCl that is generated from this process is used to leach Group II mineral salts from a variety of different materials, including minerals and industrial waste materials. The leached Group II mineral salts are used to capture carbon dioxide by forming Group II mineral salt carbonates.

The present disclosure provides for a method of obtaining metals from a source, including contacting the source with an ionic liquid in the absence of acid, thereby extracting the metals from the source and providing an ionic liquid extraction composition; and recovering the metals from the ionic liquid extraction composition, wherein the source includes coal, coal by-products, ore, tar, or electronic waste. Further, the present disclosure provides for a carbon material made by a process that includes contacting a source with an ionic liquid in the absence of acid, thereby extracting metals from the source and providing an ionic liquid extraction composition; and recovering the metals from the ionic liquid extraction composition, wherein the source includes coal, coal by-products, ore, tar, or electronic waste, further wherein the carbon material includes solids, liquids, carbon films, carbon fibers, carbon nanomaterials, or any combination thereof.

The present disclosure provides for a method of obtaining metals from a source, including contacting the source with an ionic liquid in the absence of acid, thereby extracting the metals from the source and providing an ionic liquid extraction composition; and recovering the metals from the ionic liquid extraction composition, wherein the source includes coal, coal by-products, ore, tar, or electronic waste. Further, the present disclosure provides for a carbon material made by a process that includes contacting a source with an ionic liquid in the absence of acid, thereby extracting metals from the source and providing an ionic liquid extraction composition; and recovering the metals from the ionic liquid extraction composition, wherein the source includes coal, coal by-products, ore, tar, or electronic waste, further wherein the carbon material includes solids, liquids, carbon films, carbon fibers, carbon nanomaterials, or any combination thereof.

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.

[Object] To provide a method for processing steelmaking dust, a method for producing zinc, and a method for producing an iron- and steelmaking raw material, which are more advantageous than the Waelz method in terms of energy and economy.

[Solving Means] A method for processing steelmaking dust according to an embodiment of the present invention includes: adding a calcium compound containing Ca to steelmaking dust containing zinc, the number of moles of Ca being equivalent to or more than the number of moles of Fe in the steelmaking dust; and heating and reducing, in a furnace, the steelmaking dust to which the calcium compound has been added. A ratio of the number of moles of Ca in the calcium compound to the number of moles of Fe in the steelmaking dust is adjusted to be not less than 1.3 and not more than 1.5.

[Object] To provide a method for processing steelmaking dust, a method for producing zinc, and a method for producing an iron- and steelmaking raw material, which are more advantageous than the Waelz method in terms of energy and economy.

[Solving Means] A method for processing steelmaking dust according to an embodiment of the present invention includes: adding a calcium compound containing Ca to steelmaking dust containing zinc, the number of moles of Ca being equivalent to or more than the number of moles of Fe in the steelmaking dust; and heating and reducing, in a furnace, the steelmaking dust to which the calcium compound has been added. A ratio of the number of moles of Ca in the calcium compound to the number of moles of Fe in the steelmaking dust is adjusted to be not less than 1.3 and not more than 1.5.

A process and its relating plant for recycling zinc oxide residues. Thereby, zinc oxide residues are granulated to particles with a size of d.sub.80 between 0.3 and 5 mm, preferably between 0.5 and 2 mm. These particles are fed into a roaster where they are thermally treated at a temperature in the range of 500 and 1.200? C., preferably 800 to 1.100? C. in a fluidized bed to form a calcine. The zinc oxide residues are zinc oxide dusts with a particle size below d.sub.80 100 ?m, preferably below d.sub.80 75 ?m coming from kiln, submerges lances furnaces, ferric reduction furnaces, galvanizing and/or recycling processes, particularly recycling of steel, copper, lead, nickel and/or electronic scrap, and/or that the zinc oxide residues comes from foundry for lead and zinc, ashes and/or dross from a Zamac process, oxide zinc ash, catalysts, melting and casting of Zn and/or zinc slag.

A process and its relating plant for recycling zinc oxide residues. Thereby, zinc oxide residues are granulated to particles with a size of d.sub.80 between 0.3 and 5 mm, preferably between 0.5 and 2 mm. These particles are fed into a roaster where they are thermally treated at a temperature in the range of 500 and 1.200? C., preferably 800 to 1.100? C. in a fluidized bed to form a calcine. The zinc oxide residues are zinc oxide dusts with a particle size below d.sub.80 100 ?m, preferably below d.sub.80 75 ?m coming from kiln, submerges lances furnaces, ferric reduction furnaces, galvanizing and/or recycling processes, particularly recycling of steel, copper, lead, nickel and/or electronic scrap, and/or that the zinc oxide residues comes from foundry for lead and zinc, ashes and/or dross from a Zamac process, oxide zinc ash, catalysts, melting and casting of Zn and/or zinc slag.