An electrochemical process implements, in a decoupled manner, a first step of electrolysis of an electrolyte to produce gaseous oxygen in a chamber and a second step of electrochemical conversion of H+ ions into gaseous hydrogen in a chamber which contains a liquid phase and a gas phase not dissolved in the liquid phase. Gaseous hydrogen produced in the conversion step is partly present in the gaseous headspace of chamber and as bubbles in the electrolyte, and partly dissolved in the electrolyte which is saturated with hydrogen. The electrolyte has at least one redox pair (A/B) forming at least one intermediate vector enabling the decoupling of the first and second steps. The interface between the gas and liquid phases is increased during the second step to accelerate the diffusion, from liquid phase to gas phase, of the dissolved hydrogen able to supersaturate the electrolyte. Pressurized gaseous hydrogen is then collected.

Provided is a method for manufacturing high purity tin including: depositing electrodeposited tin on the surface of a cathode by electrowinning in an electrolytic bath in which a diaphragm is placed between an anode and the cathode, by using a raw material for tin as the anode and a leachate obtained by electrolytically leaching the raw material for tin in a sulfuric acid solution as an electrolytic solution, the electrolytic solution containing a smoothing agent for improving a surface property of the electrodeposited tin; discharging the electrolytic solution from the electrolytic bath such that lead in the discharged electrolytic solution is removed; and putting the electrolytic solution from which lead is removed back into the electrolytic bath.

Provided is a method for manufacturing high purity tin including: depositing electrodeposited tin on the surface of a cathode by electrowinning in an electrolytic bath in which a diaphragm is placed between an anode and the cathode, by using a raw material for tin as the anode and a leachate obtained by electrolytically leaching the raw material for tin in a sulfuric acid solution as an electrolytic solution, the electrolytic solution containing a smoothing agent for improving a surface property of the electrodeposited tin; discharging the electrolytic solution from the electrolytic bath such that lead in the discharged electrolytic solution is removed; and putting the electrolytic solution from which lead is removed back into the electrolytic bath.

Any metal having a low α-ray emission, the metal being any one of tin, silver, copper, zinc, or indium, wherein an emission of an α-ray after heating the metal at 100° C. in an atmosphere for six hours is 0.002 cph/cm.sup.2 or less. Any metal of tin, silver, copper, zinc and indium each including lead as an impurity is dissolved to prepare a hydrosulfate aqueous solution of the metal and lead sulfate is precipitated and removed in the solution. The lead sulfate is precipitated in the hydrosulfate aqueous solution by adding a lead nitrate aqueous solution including lead having an α-ray emission of 10 cph/cm.sup.2 or less to the hydrosulfate aqueous solution, from which the lead sulfate has been removed, and, at the same time, the solution is circulated while removing the lead sulfate to electrowinning the metal using the hydrosulfate aqueous solution as an electrolytic solution.

Any metal having a low α-ray emission, the metal being any one of tin, silver, copper, zinc, or indium, wherein an emission of an α-ray after heating the metal at 100° C. in an atmosphere for six hours is 0.002 cph/cm.sup.2 or less. Any metal of tin, silver, copper, zinc and indium each including lead as an impurity is dissolved to prepare a hydrosulfate aqueous solution of the metal and lead sulfate is precipitated and removed in the solution. The lead sulfate is precipitated in the hydrosulfate aqueous solution by adding a lead nitrate aqueous solution including lead having an α-ray emission of 10 cph/cm.sup.2 or less to the hydrosulfate aqueous solution, from which the lead sulfate has been removed, and, at the same time, the solution is circulated while removing the lead sulfate to electrowinning the metal using the hydrosulfate aqueous solution as an electrolytic solution.

In the present invention, a high-purity metallic tin suitable for use in an EUV exposure device is provided through use of an oxidation-resistant metallic tin, the oxidation-resistant metallic tin containing 99.995 mass % or more of tin, and unavoidable impurities, and the thickness of an oxide film being 2.0 nm or less when the surface of a cut face of the oxidation-resistant metallic tin is measured by AES.

A method for recovering metals from scrap sources. The method includes obtaining scrap sources that include the metal to be recovered. The method also includes removing the metal from the scrap sources. Removing the metal from the scrap sources includes adding a reagent to the scrap sources, the reagent configured to leach the metal from the scrap sources creating a leachate. Removing the metal from the scrap sources also includes extracting the metal from the leachate and regenerating the reagent.

A method for recovering metals from scrap sources. The method includes obtaining scrap sources that include the metal to be recovered. The method also includes removing the metal from the scrap sources. Removing the metal from the scrap sources includes adding a reagent to the scrap sources, the reagent configured to leach the metal from the scrap sources creating a leachate. Removing the metal from the scrap sources also includes extracting the metal from the leachate and regenerating the reagent.

The invention related to a method for extracting tin and/or lead contained in an electrically conductive mixture derived from waste, using a solution comprising methane sulphonic acid as an electrolytic solution.

The invention related to a method for extracting tin and/or lead contained in an electrically conductive mixture derived from waste, using a solution comprising methane sulphonic acid as an electrolytic solution.