A cation exchange chromatographic matrix comprising a base material, and a copolymer with one monomer unit having at least a sulfonic acid group, the copolymer being immobilized on the base material, wherein: the copolymer forms substantially no cross-linked structure, and the copolymer comprises neither acrylamide nor an acrylamide derivative as a monomer unit, or comprises acrylamide or an acrylamide derivative as a monomer unit in a range which has no substantial influence; the ratio of the mass of the copolymer to the mass of the base material is 5% or more and 200% or less; and the density of the sulfonic acid group is higher than 30 mmol/L and 200 mmol/L or lower.

A cation exchange chromatographic matrix comprising a base material, and a copolymer with one monomer unit having at least a sulfonic acid group, the copolymer being immobilized on the base material, wherein: the copolymer forms substantially no cross-linked structure, and the copolymer comprises neither acrylamide nor an acrylamide derivative as a monomer unit, or comprises acrylamide or an acrylamide derivative as a monomer unit in a range which has no substantial influence; the ratio of the mass of the copolymer to the mass of the base material is 5% or more and 200% or less; and the density of the sulfonic acid group is higher than 30 mmol/L and 200 mmol/L or lower.

An ion exchanger filled cartridge accommodated inside an accommodating container of a metal removing column and in which an ion exchanger is filled is provided. The ion exchanger filled cartridge includes a cylinder portion, an upper lid in which a through hole for a liquid to be treated is formed and which is provided on an upper end of the cylinder portion, a lower lid in which a through hole for a treated liquid is formed and which is provided on a lower end of the cylinder portion, an insertion pipe connected to the lower lid, having an O-ring attached to an outer side, and inserted into a treated liquid discharge pipe provided on a bottom portion of the accommodating container of the metal removing column, and the ion exchanger filled inside the cylinder portion.

An ion exchanger filled cartridge accommodated inside an accommodating container of a metal removing column and in which an ion exchanger is filled is provided. The ion exchanger filled cartridge includes a cylinder portion, an upper lid in which a through hole for a liquid to be treated is formed and which is provided on an upper end of the cylinder portion, a lower lid in which a through hole for a treated liquid is formed and which is provided on a lower end of the cylinder portion, an insertion pipe connected to the lower lid, having an O-ring attached to an outer side, and inserted into a treated liquid discharge pipe provided on a bottom portion of the accommodating container of the metal removing column, and the ion exchanger filled inside the cylinder portion.

A proton-conductive membrane includes a hydrophobic organic polymer and a hydrophilic proton-conductive component. The hydrophilic proton-conductive component includes one of an urea-containing material and a complex formed from an acidic substance and a basic substance, and a combination thereof. The hydrophilic proton-conductive component is present in an amount ranging from 23 parts by weight to 70 parts by weight based on 100 parts by weight of the proton-conductive membrane.

A proton-conductive membrane includes a hydrophobic organic polymer and a hydrophilic proton-conductive component. The hydrophilic proton-conductive component includes one of an urea-containing material and a complex formed from an acidic substance and a basic substance, and a combination thereof. The hydrophilic proton-conductive component is present in an amount ranging from 23 parts by weight to 70 parts by weight based on 100 parts by weight of the proton-conductive membrane.

Provided is a water softening device including a water softening tank that softens raw water using a weakly acidic cation exchange resin, a pH adjustment tank, an electrolytic cell that produces acidic electrolyzed water, a conductivity measurement unit S.sub.1 that measures conductivity of the raw water, a conductivity measurement unit S.sub.2 that measures conductivity of soft water, a water flow amount detecting unit, and a control unit, wherein the control unit calculates a regeneration time for the weakly acidic cation exchange resin based on an amount of the hardness component adsorbed to the weakly acidic cation exchange resin calculated from a difference between the conductivity of the raw water and the conductivity of the soft water and from the accumulated water flow amount of the raw water, and performs a regeneration treatment of the weakly acidic cation exchange resin during the regeneration time.

Methods and systems for separation of thorium from uranium and their decay products are provided. The method comprises combining a nuclear fuel feedstock comprising thorium and uranium with a first acid to form a first solution. The first solution is contacted an ion exchange resin that is selective for thorium or uranium. The thorium or uranium is at least partially removed from the first solution by binding the thorium or uranium to the ion exchange resin thereby forming a second solution. The second solution is combined with oxalic acid to precipitate uranium or thorium from the second solution to form a precipitate. The precipitate is separated from the second solution.

Methods and systems for separation of thorium from uranium and their decay products are provided. The method comprises combining a nuclear fuel feedstock comprising thorium and uranium with a first acid to form a first solution. The first solution is contacted an ion exchange resin that is selective for thorium or uranium. The thorium or uranium is at least partially removed from the first solution by binding the thorium or uranium to the ion exchange resin thereby forming a second solution. The second solution is combined with oxalic acid to precipitate uranium or thorium from the second solution to form a precipitate. The precipitate is separated from the second solution.

A method for producing an ion-exchange resin having a water content of 5% by weight or less, a method for producing a lithography coating film forming-composition using the ion-exchange resin, and a method for washing the ion-exchange resin. The methods include the step of passing an organic solvent having a water content of 150 ppm or less through an ion-exchange resin precursor having a water content of 40% by weight or more, where a dehydration efficiency defined by the following equation is 5 or more: Dehydration efficiency=Dehydration rate (%)/[Weight of the organic solvent used per unit weight of the ion-exchange resin precursor (kg/kg)×Washing time (h)].