A method for producing 225.sup.A including: a method (X) for purifying a .sup.226Ra-containing solution, including an adsorption step of allowing a .sup.226Ra ion to adsorb onto a carrier having a function of selectively adsorbing a divalent cation by bringing a .sup.226Ra-containing solution into contact with the carrier under an alkaline condition, and an elution step of eluting the .sup.226Ra ion from the carrier under an acidic condition; a method for producing a .sup.226Ra target, including an electrodeposition liquid preparation step of preparing an electrodeposition liquid by using a purified .sup.226Ra-containing solution obtained by the method (X), and an electrodeposition step of electrodepositing a .sup.226Ra-containing substance on a substrate by using the electrodeposition liquid; and a step of irradiating a .sup.226Ra target produced by the method for producing a .sup.226Ra target with at least one selected from a charged particle, a photon, and a neutron by using an accelerator.

A method for electrochemical extraction of uranium from seawater using an oxygen vacancy (OV)-containing metal oxide includes the following steps: adding glycerin to a solution of indium nitrate in isopropanol, transferring a resulting mixture to a reactor, and conducting reaction to obtain a spherical indium hydroxide solid; dissolving the solid in deionized water, transferring a resulting solution to the reactor, and conducting reaction to obtain a flaky indium hydroxide solid; calcining the solid to obtain calcined OV-containing In.sub.2O.sub.3-x; adding the In.sub.2O.sub.3-x to ethanol, and adding a membrane solution; coating a resulting solution uniformly on carbon paper, and naturally drying the carbon paper; clamping dried carbon paper with a gold electrode for being used as a working electrode for a three-electrode system; and adding simulated seawater to an electrolytic cell, placing the three-electrode system in the simulated seawater, and stirring the simulated seawater for electrolysis to extract uranium from the seawater.

A method for electrochemical extraction of uranium from seawater using an oxygen vacancy (OV)-containing metal oxide includes the following steps: adding glycerin to a solution of indium nitrate in isopropanol, transferring a resulting mixture to a reactor, and conducting reaction to obtain a spherical indium hydroxide solid; dissolving the solid in deionized water, transferring a resulting solution to the reactor, and conducting reaction to obtain a flaky indium hydroxide solid; calcining the solid to obtain calcined OV-containing In.sub.2O.sub.3-x; adding the In.sub.2O.sub.3-x to ethanol, and adding a membrane solution; coating a resulting solution uniformly on carbon paper, and naturally drying the carbon paper; clamping dried carbon paper with a gold electrode for being used as a working electrode for a three-electrode system; and adding simulated seawater to an electrolytic cell, placing the three-electrode system in the simulated seawater, and stirring the simulated seawater for electrolysis to extract uranium from the seawater.

Disclosed are an electrolytic reduction system of a vanadium electrolyte and a method for producing the electrolyte. The electrolytic reduction system includes a separating device and an electrolytic tank. The separating device is configured to separate a mixture consisting of a vanadium pentoxide (V2O5) solid and a sulfate acid solution, thereby obtaining a vanadium solution from a liquid discharging port of the separating device and a vanadium solid from a solid discharging port. The vanadium solution includes pentavalent vanadium ions. The electrolytic tank connects to the liquid discharging port of the separating device to contain the vanadium solution. In the method for producing the vanadium electrolyte, other chemical reagents are unnecessarily to be added into the mixture, and the vanadium solution is subjected to an electrolytic reduction process, such that the pentavalent vanadium ions are reduced to tetravalent vanadium ions and trivalent vanadium ions in the electrolytic tank.

Disclosed are an electrolytic reduction system of a vanadium electrolyte and a method for producing the electrolyte. The electrolytic reduction system includes a separating device and an electrolytic tank. The separating device is configured to separate a mixture consisting of a vanadium pentoxide (V2O5) solid and a sulfate acid solution, thereby obtaining a vanadium solution from a liquid discharging port of the separating device and a vanadium solid from a solid discharging port. The vanadium solution includes pentavalent vanadium ions. The electrolytic tank connects to the liquid discharging port of the separating device to contain the vanadium solution. In the method for producing the vanadium electrolyte, other chemical reagents are unnecessarily to be added into the mixture, and the vanadium solution is subjected to an electrolytic reduction process, such that the pentavalent vanadium ions are reduced to tetravalent vanadium ions and trivalent vanadium ions in the electrolytic tank.

A method for electrochemical extraction of uranium from seawater using an oxygen vacancy (OV)-containing metal oxide includes the following steps: adding glycerin to a solution of indium nitrate in isopropanol, transferring a resulting mixture to a reactor, and conducting reaction to obtain a spherical indium hydroxide solid; dissolving the solid in deionized water, transferring a resulting solution to the reactor, and conducting reaction to obtain a flaky indium hydroxide solid; calcining the solid to obtain calcined OV-containing In.sub.2O.sub.3-x; adding the In.sub.2O.sub.3-x; to ethanol, and adding a membrane solution; coating a resulting solution uniformly on carbon paper, and naturally drying the carbon paper; clamping dried carbon paper with a gold electrode for being used as a working electrode for a three-electrode system; and adding simulated seawater to an electrolytic cell, placing the three-electrode system in the simulated seawater, and stirring the simulated seawater for electrolysis to extract uranium from the seawater.

A method for extracting uranium with a coupling device of wind power generation and uranium extraction from seawater includes the following steps: adding oxygen vacancy (OV)-containing In.sub.2O.sub.3-x to absolute ethanol, and subjecting a resulting mixture to stirring and ultrasonic treatment to obtain a solution of In.sub.2O.sub.3-x in absolute ethanol; coating the solution uniformly on carbon cloth, and drying to obtain carbon cloth coated with OV-containing In.sub.2O.sub.3-x; inserting the coated carbon cloth (as a working electrode) and another blank carbon cloth (as a counter electrode) into a plastic carrier of a coupling device; fixing a small wind power generation apparatus above the plastic carrier, and connecting the working electrode and the counter electrode to a storage battery of the apparatus via wires; and placing the coupling device in seawater, and after the storage battery is charged, energizing the working electrode and the counter electrode to extract uranium from the seawater.

A method for extracting uranium with a coupling device of wind power generation and uranium extraction from seawater includes the following steps: adding oxygen vacancy (OV)-containing In.sub.2O.sub.3-x to absolute ethanol, and subjecting a resulting mixture to stirring and ultrasonic treatment to obtain a solution of In.sub.2O.sub.3-x in absolute ethanol; coating the solution uniformly on carbon cloth, and drying to obtain carbon cloth coated with OV-containing In.sub.2O.sub.3-x; inserting the coated carbon cloth (as a working electrode) and another blank carbon cloth (as a counter electrode) into a plastic carrier of a coupling device; fixing a small wind power generation apparatus above the plastic carrier, and connecting the working electrode and the counter electrode to a storage battery of the apparatus via wires; and placing the coupling device in seawater, and after the storage battery is charged, energizing the working electrode and the counter electrode to extract uranium from the seawater.

A method for refining bismuth is provided, which comprises recovering bismuth from a solution obtained after recovery of noble metals from a copper electrolytic slime.

The method comprises:
1) a neutralization step of adding alkali to an acid solution to adjust the pH to the range of 2.0 or more and 3.0 or less, and then performing solid-liquid separation to obtain a neutralized filtrate and a neutralized precipitate;
2) an alkaline leaching step of adding alkali to the neutralized precipitate obtained in the neutralization step to separate the resultant into an alkali leachate and an alkaline leaching residue;
3) a sulfuric acid leaching step of adding sulfuric acid to the alkaline leaching residue to separate the resultant into a sulfuric acid leachate and a sulfuric acid-leaching residue;
4) a cooling step of cooling the sulfuric acid leachate obtained in the sulfuric acid leaching step to obtain crystals of bismuth sulfate;
5) a bismuth oxidation step of adding alkali to the crystals of bismuth sulfate obtained in the cooling step to obtain bismuth oxide; and
6) an electrolysis step of adding an acid solution to the bismuth oxide obtained in the bismuth oxidation step for dissolution and then electrowinning the thus obtained solution to obtain metal bismuth.

A method for refining bismuth is provided, which comprises recovering bismuth from a solution obtained after recovery of noble metals from a copper electrolytic slime.

The method comprises:
1) a neutralization step of adding alkali to an acid solution to adjust the pH to the range of 2.0 or more and 3.0 or less, and then performing solid-liquid separation to obtain a neutralized filtrate and a neutralized precipitate;
2) an alkaline leaching step of adding alkali to the neutralized precipitate obtained in the neutralization step to separate the resultant into an alkali leachate and an alkaline leaching residue;
3) a sulfuric acid leaching step of adding sulfuric acid to the alkaline leaching residue to separate the resultant into a sulfuric acid leachate and a sulfuric acid-leaching residue;
4) a cooling step of cooling the sulfuric acid leachate obtained in the sulfuric acid leaching step to obtain crystals of bismuth sulfate;
5) a bismuth oxidation step of adding alkali to the crystals of bismuth sulfate obtained in the cooling step to obtain bismuth oxide; and
6) an electrolysis step of adding an acid solution to the bismuth oxide obtained in the bismuth oxidation step for dissolution and then electrowinning the thus obtained solution to obtain metal bismuth.