The present invention provides a polymer based bulk conducting electrodes. These electrodes have several advantages over the conventional screen printed and coated electrodes. The present invention also provides biodegradable variant of these electrodes. Such electrode are found comparable to the conventional noble metal electrode and glassy carbon electrode in various electrochemical techniques like cyclic voltammetry of different redox couple, amperometric sensing of hydrogen peroxide, stripping voltammetry of lead (II) ion, electrodeposition of zinc and electropolymerization of aniline in aqueous medium.

A method of recovering metals from electronic waste comprises providing a powder comprising electronic waste in at least a first reactor and a second reactor and providing an electrolyte comprising at least ferric ions in an electrochemical cell in fluid communication with the first reactor and the second reactor. The method further includes contacting the powders within the first reactor and the second reactor with the electrolyte to dissolve at least one base metal from each reactor into the electrolyte and reduce at least some of the ferric ions to ferrous ions. The ferrous ions are oxidized at an anode of the electrochemical cell to regenerate the ferric ions. The powder within the second reactor comprises a higher weight percent of the at least one base metal than the powder in the first reactor. Additional methods of recovering metals from electronic waste are also described, as well as an apparatus of recovering metals from electronic waste.

A method of recovering metals from electronic waste comprises providing a powder comprising electronic waste in at least a first reactor and a second reactor and providing an electrolyte comprising at least ferric ions in an electrochemical cell in fluid communication with the first reactor and the second reactor. The method further includes contacting the powders within the first reactor and the second reactor with the electrolyte to dissolve at least one base metal from each reactor into the electrolyte and reduce at least some of the ferric ions to ferrous ions. The ferrous ions are oxidized at an anode of the electrochemical cell to regenerate the ferric ions. The powder within the second reactor comprises a higher weight percent of the at least one base metal than the powder in the first reactor. Additional methods of recovering metals from electronic waste are also described, as well as an apparatus of recovering metals from electronic waste.

An electrode, and use and a preparation method thereof. The electrode includes a metal substrate and a catalytic layer. The electrode includes at least one of the following features: i) the substrate is a corrosion inhibitor-containing titanium alloy, the corrosion inhibitor being selected from at least one metal of platinum, palladium, osmium, iridium, ruthenium, rhodium, tantalum, zirconium and niobium, and the content of the corrosion inhibitor being 0.05 wt %-0.5 wt % of the total mass of the alloy; ii) the catalytic layer is an iridium oxide layer or an iridium-tantalum mixed oxide layer, with a mass ratio of iridium element to tantalum element being 1:4 to 1:0; and iii) an interlayer is disposed between the substrate and the catalytic layer, the interlayer being a titanium-tantalum alloy layer. For the electrode, its corrosion resistance is greatly improved, its lifetime is extended, and its production cost is reduced.

Provided is a method for dislodging material from a surface of an electrode. The surface of the electrode is generally covered by a liquid electrolyte. The method comprises forcing a mass of gas onto a surface of the liquid electrolyte, thereby causing movement of the liquid electrolyte in a direction generally parallel to a plane of the surface of the electrode. The movement of the liquid electrolyte imparts a force to the material on the surface of the electrode thereby causing the material to dislodge. Also provided is an apparatus for dislodging material from a surface of an electrode. The apparatus comprises an electrode generally covered by a liquid electrolyte, a body containing the liquid electrolyte with at least one liquid inlet, at least one liquid outlet, and at least one gas inlet. The at least one gas inlet is positioned such that the at least one gas inlet and the at least one liquid outlet are separated by a volume in which a portion of some of the liquid electrolyte at or near the surface of the electrode is present, and a pressurized gas source operably connected to the at least one gas inlet.

A zinc recovery method includes an alkali fusion step (102) of, at a temperature equal to or higher than a melting point of sodium hydroxide, bringing a material (1) and molten sodium hydroxide being sodium hydroxide (5) or (14) in a molten state into contact with each other to decompose the zinc ferrite contained in the material (1) into zinc oxide components and iron oxide components in the molten sodium hydroxide, a water leaching step (103) of, at a temperature lower than a boiling point of water, bringing water into contact with sodium hydroxide being the molten sodium hydroxide with a decreased temperature, the zinc oxide components, and the iron oxide components and leaching the zinc oxide components in a sodium hydroxide aqueous solution.

A zinc recovery method includes an alkali fusion step (102) of, at a temperature equal to or higher than a melting point of sodium hydroxide, bringing a material (1) and molten sodium hydroxide being sodium hydroxide (5) or (14) in a molten state into contact with each other to decompose the zinc ferrite contained in the material (1) into zinc oxide components and iron oxide components in the molten sodium hydroxide, a water leaching step (103) of, at a temperature lower than a boiling point of water, bringing water into contact with sodium hydroxide being the molten sodium hydroxide with a decreased temperature, the zinc oxide components, and the iron oxide components and leaching the zinc oxide components in a sodium hydroxide aqueous solution.

The disclosure provides a method of producing hydrogen. The method comprises conducting a thermochemical reaction by contacting a metal, or an alloy thereof, with steam to produce a metal oxide and/or a metal hydroxide and hydrogen. The method then comprises contacting the metal oxide and/or the metal hydroxide produced in the thermochemical reaction with water or a basic aqueous solution to produce a solution comprising a metal ion. Finally, the method comprises conducting an electrochemical reaction by applying a voltage across an anode and a cathode, whereby at least a portion of the cathode contacts the solution comprising the metal ion, to produce hydrogen, oxygen and the metal, or the alloy thereof.

The disclosure provides a method of producing hydrogen. The method comprises conducting a thermochemical reaction by contacting a metal, or an alloy thereof, with steam to produce a metal oxide and/or a metal hydroxide and hydrogen. The method then comprises contacting the metal oxide and/or the metal hydroxide produced in the thermochemical reaction with water or a basic aqueous solution to produce a solution comprising a metal ion. Finally, the method comprises conducting an electrochemical reaction by applying a voltage across an anode and a cathode, whereby at least a portion of the cathode contacts the solution comprising the metal ion, to produce hydrogen, oxygen and the metal, or the alloy thereof.

Provided herein are assemblies and methods for calcium and/or other valuable element extraction. An assembly includes a dissolution tank defining an interior chamber having a first inlet, a second inlet, and a mixture outlet. The dissolution tank is configured to combine one or more substrates and a solvent into a mixture. The one or more substrates contain one or more target elements. The assembly optionally includes a sonic probe, a sonic plate, or both the sonic probe and the sonic plate. The assembly further optionally includes a membrane concentrator fluidically coupled to the mixture outlet of the dissolution tank. The assembly further includes a sequential electrolytic precipitation reactor fluidically coupled to the mixture outlet of the dissolution tank or the membrane concentrator, if present. Each precipitate outlet is configured to output a precipitate of the one or more target element.