Provided is a method for separating impurities and cobalt without using an electrolysis process from a cobalt chloride solution containing impurities and producing a high purity cobalt sulfate. The production method for cobalt sulfate includes: a copper removal step (S1) of adding a sulfurizing agent to a cobalt chloride solution containing one or more impurities of copper, zinc, manganese, calcium, and magnesium and generating a precipitate of sulfide of copper to separate to remove copper; a neutralization step (S2) of adding a neutralizer or a carbonation agent to a cobalt chloride solution having undergone through the copper removal step (S1) and generating cobalt hydroxide or basic cobalt carbonate to separate magnesium; a leaching step (S3) of adding sulfuric acid to the cobalt hydroxide or the basic cobalt carbonate to obtain cobalt sulfate solution; and a solvent extraction step (S4) of bringing an organic solvent containing an alkyl phosphoric acid-based extractant to the cobalt sulfate solution and extracting zinc, manganese, and calcium into the organic solvent to separate to remove zinc, manganese, and calcium. These steps are sequentially executed.

A nanocrystal preparation method comprises the following steps: dissolving, in a first selected solvent, a first precursor which is in a gaseous state under normal temperature and normal pressure, to form a first precursor solution; dissolving a second precursor in a second selected solvent to form a second precursor solution, wherein the second precursor is a precursor of a metal element of Group I, Group II, Group III or Group IV; and in an inert gas atmosphere, adding the first precursor solution into a reaction vessel which contains the second precursor solution, wherein the first precursor chemically reacts with the second precursor to generate a nanocrystal. The present invention further discloses a nanocrystal prepared by the above method and an apparatus for preparing and storing a gas-dissolved solution. With the preparation method according to the invention, the amount of the first precursor in a gaseous state can be accurately controlled, the reaction is more uniform and more controllable, and the obtained nanocrystal has uniform volume distribution and a higher luminescent quantum yield.

A nanocrystal preparation method comprises the following steps: dissolving, in a first selected solvent, a first precursor which is in a gaseous state under normal temperature and normal pressure, to form a first precursor solution; dissolving a second precursor in a second selected solvent to form a second precursor solution, wherein the second precursor is a precursor of a metal element of Group I, Group II, Group III or Group IV; and in an inert gas atmosphere, adding the first precursor solution into a reaction vessel which contains the second precursor solution, wherein the first precursor chemically reacts with the second precursor to generate a nanocrystal. The present invention further discloses a nanocrystal prepared by the above method and an apparatus for preparing and storing a gas-dissolved solution. With the preparation method according to the invention, the amount of the first precursor in a gaseous state can be accurately controlled, the reaction is more uniform and more controllable, and the obtained nanocrystal has uniform volume distribution and a higher luminescent quantum yield.

A methodology for synthesizing a nanoparticle batch, such as but not limited to a metal chalcogenide nanoparticle batch and further such as but not limited to a metal sulfide nanoparticle batch is predicated upon an expectation and observation that at elevated concentrations of at least one reactant material within a heat-up nanoparticle batch synthesis method, the resulting nucleated batch comprises nanoparticles that may be dimensionally focused to provide a substantially monodisperse nanoparticle batch. The embodied methodology is also applicable to a continuous reactor. The embodied methodology also considers viscosity as a dimensionally focusing result effective variable.

A methodology for synthesizing a nanoparticle batch, such as but not limited to a metal chalcogenide nanoparticle batch and further such as but not limited to a metal sulfide nanoparticle batch is predicated upon an expectation and observation that at elevated concentrations of at least one reactant material within a heat-up nanoparticle batch synthesis method, the resulting nucleated batch comprises nanoparticles that may be dimensionally focused to provide a substantially monodisperse nanoparticle batch. The embodied methodology is also applicable to a continuous reactor. The embodied methodology also considers viscosity as a dimensionally focusing result effective variable.

Proposed are copper sulfide nanoparticles having a core-shell structure included in a coating composition for blocking near-infrared light, and a method of manufacturing the same. More particularly, a method of manufacturing copper sulfide nanoparticles having a core-shell structure includes manufacturing CuS nanoparticles, manufacturing Cu.sub.2-xS nanoparticles by heating a mixed solution of the CuS nanoparticles, a reducing agent, and a solvent, and manufacturing Cu.sub.2-xS@Cu.sub.2-yO core-shell nanoparticles by heating a mixed solution of the Cu.sub.2-xS nanoparticles, an oxidizing agent, and a solvent.

Disclosed herein are embodiments of chalcogenide materials and chalcogenide-based materials that exhibit improved light-driven properties and performance in comparison to conventional materials. Also disclosed herein are embodiments of cost- and time-efficient methods of making such materials.

Provided is a method for producing metal chalcogenide nanomaterials, comprising the steps of forming an aqueous solution of a chalcogen precursor, a reducing agent and a metal salt; mixing the aqueous solution for a duration of time at a reaction temperature of between about 10 C. to about 40 C., inclusively; and separating the produced metal chalcogenide nanomaterials from the aqueous solution. Also provided is a method of converting metal chalcogenide nanoparticles into metal chalcogenide nanotubes or nanosheets, comprising the steps of forming an aqueous mixture of a chalcogen precursor, a reducing agent and the metal chalcogenide nanoparticles in water; and forming the nanotubes or nanosheets by stirring or not stirring the aqueous mixture, respectively.

Provided is a method for producing metal chalcogenide nanomaterials, comprising the steps of forming an aqueous solution of a chalcogen precursor, a reducing agent and a metal salt; mixing the aqueous solution for a duration of time at a reaction temperature of between about 10 C. to about 40 C., inclusively; and separating the produced metal chalcogenide nanomaterials from the aqueous solution. Also provided is a method of converting metal chalcogenide nanoparticles into metal chalcogenide nanotubes or nanosheets, comprising the steps of forming an aqueous mixture of a chalcogen precursor, a reducing agent and the metal chalcogenide nanoparticles in water; and forming the nanotubes or nanosheets by stirring or not stirring the aqueous mixture, respectively.

A method of controlling frothing during atmospheric or substantially atmospheric leaching of a metal sulfide is disclosed. In some embodiments, the method may comprise the steps of (a) producing a metal sulfide concentrate via flotation; (b) producing a tailings stream via flotation; and, (c) diverting a portion or all of said produced tailings stream to an atmospheric or substantially atmospheric sulfide leach circuit. A metal recovery flowsheet is also disclosed. In some embodiments, the metal recovery flowsheet may comprise a unit operation comprising: (a) a sulfide concentrator comprising a flotation circuit, the flotation circuit producing a metal sulfide concentrate stream, and a tailings stream; and, (b) an atmospheric or substantially atmospheric metal sulfide leach circuit. The sulfide concentrator may be operatively connected to the atmospheric or substantially atmospheric metal sulfide leach circuit via both of said metal sulfide concentrate stream, and said tailings stream.