Toray Industries, Inc.

Tomoya Yoshizaki

Masakazu Koiwa

Shigehisa Hanada

Takafumi Ogawa

Tsuyoshi Hamada

Harutoki Shimura

Masami Ogata

Takanori Soya

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.

Method of separating and recovering cobalt salt and nickel salt

The present invention relates to a composite semipermeable membrane including: a substrate; a porous support layer disposed on the substrate; and a separation functional layer disposed on the porous support layer, in which the separation functional layer includes: a first layer including a crosslinked aromatic polyamide; and a coating layer existing on the first layer and including an aliphatic polyamide including a fluorine atom, and the composite semipermeable membrane has a proportion of the number of fluorine atoms to the total number of atoms of all elements of 0.5% or more and 8% or less, and has a ratio (N/O ratio) of the number of nitrogen atoms to the number of oxygen atoms of 0.8 or more and 1.3 or less.

Composite semipermeable membrane

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.

Method for recovering rare metal salt

Growing community of inventors

Shiga, Japan

Tomoya Yoshizaki