Abstract: The present invention relates to a method for recovering a rare metal salt, the method including: an acid treatment step of obtaining a rare metal-containing acidic aqueous solution by bringing a material including a monovalent rare metal and a polyvalent rare metal into contact with an acidic aqueous solution; a separation step of obtaining permeated water including the monovalent rare metal and non-permeated water including the polyvalent rare metal from the rare metal-containing acidic aqueous solution by using a nanofiltration membrane satisfying the condition (1); and a concentration step of obtaining non-permeated water having a higher concentration of the monovalent rare metal and permeated water having a lower concentration of the monovalent rare metal than that of the permeated water in the separation step, by using a reverse osmosis membrane.

Abstract: A method of separating and recovering a cobalt salt and a nickel salt includes a separation step of separating, by using a nanofiltration membrane, a cobalt salt and a nickel salt from a rare metal-containing aqueous solution containing at least both the cobalt salt and the nickel salt as rare metals, in which the nanofiltration membrane has a glucose permeability of 3 times or more a sucrose permeability, the sucrose permeability of 10% or less, and an isopropyl alcohol permeability of 50% or more when a 1,000 mg/L glucose aqueous solution, a 1,000 mg/L sucrose aqueous solution, and a 1,000 mg/L isopropyl alcohol aqueous solution, each having a pH of 6.5 and a temperature of 25° C., individually permeate through the nanofiltration membrane at an operating pressure of 0.5 MPa.

Abstract: The present invention relates to a method for recovering a rare metal salt, the method including: an acid treatment step of obtaining a rare metal-containing acidic aqueous solution by bringing a material including a monovalent rare metal and a polyvalent rare metal into contact with an acidic aqueous solution; a separation step of obtaining permeated water including the monovalent rare metal and non-permeated water including the polyvalent rare metal from the rare metal-containing acidic aqueous solution by using a nanofiltration membrane satisfying the condition (1); and a concentration step of obtaining non-permeated water having a higher concentration of the monovalent rare metal and permeated water having a lower concentration of the monovalent rare metal than that of the permeated water in the separation step, by using a reverse osmosis membrane.

Abstract: The present invention relates to a separation membrane including an organic polymer resin, in which a volume V1 of fine pores having a pore diameter of 100 nm or more is 0.3 cm3/g or more and 0.5 cm3/g or less, a volume V2 of fine pores having a pore diameter of less than 100 nm is 0.02 cm3/g or more and less than 0.1 cm3/g, and a ratio V1/V2 of the fine pore volume V1 to the fine pore volume V2 is 3 or more and 60 or less.

Abstract: The present invention relates to a separation membrane including an organic polymer resin, in which a volume V1 of fine pores having a pore diameter of 100 nm or more is 0.3 cm3/g or more and 0.5 cm3/g or less, a volume V2 of fine pores having a pore diameter of less than 100 nm is 0.02 cm3/g or more and less than 0.1 cm3/g, and a ratio V1/V2 of the fine pore volume V1 to the fine pore volume V2 is 3 or more and 60 or less.

Abstract: Provided is a gas separation membrane that can be used continuously. The gas separation membrane comprises: a porous support membrane that contains an aromatic polyamide in which an aromatic ring has been replaced with a chloro group; and a separation functional layer that is disposed on the surface of the porous support membrane and contains a cross-linked polyamide obtained by polycondensation of a polyfunctional amine and a polyfunctional acid halide.

Abstract: An object of the present invention is to provide a separation membrane having high permeability and selective removability of divalent/monovalent ions. The separation membrane of the present invention includes a supporting membrane and a separation functional layer formed on the supporting membrane, in which the separation functional layer contains a polymerized product of a polyfunctional amine with a polyfunctional acid halide, the polyfunctional amine contains a polyfunctional aliphatic amine as a main component, the separation functional layer has a hollow protuberant structure, and the separation functional layer has a relative surface area of 1.1-10.0.

Abstract: The present invention relates to a gas separation membrane including: a supporting membrane; and a separation functional layer which is provided on the supporting membrane and includes a crosslinked polyamide obtained by polycondensation of a polyfunctional amine and a polyfunctional acid halide, in which, in the crosslinked polyamide, the number A of terminal amino groups, the number B of terminal carboxy groups, and the number C of amide groups satisfy (A+B)/C?0.66.

Abstract: A composite semipermeable membrane includes a porous supporting membrane and a separation functional layer, in which, in cross-sections having a length of 2.0 ?m in a membrane surface direction, the average number density of projections in the separation functional layer which have a height of one-fifth or more of the 10-point average surface roughness is 10.0-30.0 projections/?m and the projections have an average height less than 100 nm, and in which a water production rate and a salt rejection are predetermined values or more after an aqueous solution is passed through under certain conditions.

Abstract: Provided is a gas separation membrane that can be used continuously. The gas separation membrane comprises: a porous support membrane that contains an aromatic polyamide in which an aromatic ring has been replaced with a chloro group; and a separation functional layer that is disposed on the surface of the porous support membrane and contains a cross-linked polyamide obtained by polycondensation of a polyfunctional amine and a polyfunctional acid halide.

Abstract: The present invention pertains to a gas separation membrane comprising: a porous supporting layer; and a separation function layer disposed on the porous supporting layer and including a crosslinked aromatic polyamide obtained by polycondensation of a multifunctional aromatic amine and a multifunctional aromatic acid halide, wherein the crosslinked aromatic polyamide includes at least one of a fluorine atom bonded to an aromatic ring and a fluorine atom bonded to a nitrogen atom.

Abstract: The present invention relates to a gas separation membrane including: a supporting membrane; and a separation functional layer which is provided on the supporting membrane and includes a crosslinked polyamide obtained by polycondensation of a polyfunctional amine and a polyfunctional acid halide, in which, in the crosslinked polyamide, the number A of terminal amino groups, the number B of terminal carboxy groups, and the number C of amide groups satisfy (A+B)/C?0.66.

Abstract: An object of the present invention is to provide a separation membrane having high permeability and selective removability of divalent/monovalent ions. The separation membrane of the present invention includes a supporting membrane and a separation functional layer formed on the supporting membrane, in which the separation functional layer contains a polymerized product of a polyfunctional amine with a polyfunctional acid halide, the polyfunctional amine contains a polyfunctional aliphatic amine as a main component, the separation functional layer has a hollow protuberant structure, and the separation functional layer has a relative surface area of 1.1-10.0.

Abstract: A spiral separation membrane element including a plurality of separation membrane pairs wound around the outer peripheral surface of a water collection pipe, wherein the plurality of separation membranes include at least two sets of separation membrane pairs in which two adjacent separation membranes are stacked such that the water supply sides of the separation membranes form opposing surfaces, and the water supply-side surfaces at the ends of separation membranes close to the water collection pipe and parallel to the lengthwise direction of the water collection pipe are sealed by a sealing material.

Abstract: A separation membrane element includes a water collecting pipe, a separation membrane main body having a feed-side face and a permeate-side face, a feed-side channel material and permeate-side channel materials. The separation membrane main body, the feed-side channel material and the permeate-side channel materials are spirally wound around the water collecting tube. A plurality of the permeate-side channel materials are discontinuously provided on the permeate-side face of the separation membrane main body, along a first direction that is a longitudinal direction of the water collecting pipe. The feed-side channel material has a thickness of from 0.15 to 0.5 mm.

Abstract: A separation membrane includes a separation membrane main body having at least a substrate and a separation function layer; and a channel material having a composition different from that of the separation membrane main body and affixed to a substrate-side surface of the separation membrane main body, wherein the channel material is discontinuous in a first direction and continuous in a second direction from one end to another end of the separation membrane main body.

Abstract: A spiral separation membrane element includes a water collection tube; a separation membrane wound around the water collection tube, having a feed-side surface and a permeate-side surface, and including a band-shaped region on at least one end of the feed-side surface in an axial direction of the water collection tube; and a channel material fused to the band-shaped region.

Abstract: A separation membrane for water treatment, comprising a porous layer that is obtained by a phase separation method using a solution containing a resin and at least one of either an N,N-disubstituted isobutylamide or an N-monosubstituted isobutylamide.

Abstract: To provide a separation membrane element that is able to increase the amount of permeate fluid per unit time and also able to improve stability performance, provided is a separation membrane element, comprising a separation membrane and a permeate spacer, wherein a separation functional layer is arranged on the surface of said separation membrane and a nonwoven fabric served as a substrate is arranged on the back surface of said separation membrane, wherein said permeate spacer is arranged on the back surface side of said substrate, wherein said permeate spacer is made of a different material from said separation membrane, and a projection area ratio of said permeate spacer to said separation membrane is 0.03 to 0.80.

Abstract: A separation membrane including: a separation membrane main body having a feed-side face and a permeate-side face; and a plurality of channel members adhered to the permeate-side face of the separation membrane main body, in which a weight W (g) of the plurality of channel members and a volume V (cm3) of the plurality of channel members, exclusive of portions impregnated into the permeate-side face, satisfy the following relational expression: 1.0?W/V?2.5, and the channel members have a melting temperature of 200° C. or lower as measured with a differential scanning calorimeter.