Abstract: A porous membrane laminate of the present disclosure includes a porous support layer and a porous membrane laminated on one surface of the support layer and containing polytetrafluoroethylene as a main component. The porous membrane is formed of a uniaxially stretched material, the porous membrane has a mean pore size of 25 nm to 35 nm and a maximum pore size of 49 nm or less, and the porous membrane has an average thickness of 0.6 ?m to 3.5 ?m.

Abstract: The present invention provides a rare metal/platinum-group metal extractant, which has a completely new structure compared with the conventional rare metal/platinum-group metal extractant and which exhibits excellent extraction performance; it also provides a method for extracting rare metals and platinum-group metals using the extractant. The rare metal/platinum-group metal extractants of the present invention is the one to extract rare metals and platinum-group metals by contacting a solution, in which several kinds of rare metals and platinum-group metals are dissolved, with a solution in which a cyclic phenol sulfide of the following Formula (1) is dissolved to make the rare metals and platinum-group metals move into the cyclic phenol sulfide solution.

Abstract: The present invention provides a rare metal/platinum-group metal extractant, which has a completely new structure compared with the conventional rare metal/platinum-group metal extractant and which exhibits excellent extraction performance; it also provides a method for extracting rare metals and platinum-group metals using the extractant. The rare metal/platinum-group metal extractants of the present invention is the one to extract rare metals and platinum-group metals by contacting a solution, in which several kinds of rare metals and platinum-group metals are dissolved, with a solution in which a cyclic phenol sulfide of the following Formula (1) is dissolved to make the rare metals and platinum-group metals move into the cyclic phenol sulfide solution.