Compound, metal extractant, and application of the same

A method for extracting at least one of palladium and platinum, comprising:

• adjusting a pH of an aqueous solution, which contains at least one of palladium and platinum, at 25° C. to less than 7;
• and
• bringing an organic phase, which contains at least a metal extractant comprising a compound represented by General Formula (1) below, into contact with the aqueous solution, whose pH has been adjusted and which contains at least one of the palladium and the platinum, and extracting at least one of the palladium and the platinum into the organic phase,
• where R denotes a C1-C10 hydrocarbon group, Z denotes any one of a sulfide group, a sulfinyl group and a sulfonyl group, and n denotes an integer of 4 to 8.

A method for extracting zirconium, comprising:

• adjusting a pH of an aqueous solution, which contains zirconium, at 25° C. to less than 7;
• and
• bringing an organic phase, which contains at least a metal extractant comprising a compound represented by General Formula (1) below, into contact with the aqueous solution, whose pH has been adjusted and which contains the zirconium, and extracting the zirconium into the organic phase,
• where R denotes a C1-C10 hydrocarbon group, Z denotes any one of a sulfide group, a sulfinyl group and a sulfonyl group, and n denotes an integer of 4 to 8.

A metal recovering method comprising:

• adjusting a pH of an aqueous solution, which contains zirconium and at least one of palladium and platinum, at 25° C. to less than 3 as a first pH adjusting step;
• bringing an organic phase, which contains at least a metal extractant comprising a compound represented by General Formula (1) below, into contact with the aqueous solution, whose pH has been adjusted in the first pH adjusting step, and extracting at least one of the palladium and the platinum into the organic phase as a first extracting step;
• recovering at least one of the palladium and the platinum from the organic phase obtained in the first extracting step as a first recovering step;
• adjusting the pH of the aqueous solution, which has undergone the first recovering step and contains the zirconium, to 3 or greater, but less than 7 as a second pH adjusting step;
• bringing an organic phase, which contains at least the metal extractant, into contact with the aqueous solution, whose pH has been adjusted in the second pH adjusting step and which contains the zirconium, and extracting the zirconium into the organic phase as a second extracting step;
• and
• recovering the zirconium from the organic phase obtained in the second extracting step as a second recovering step,
• where R denotes a C1-C10 hydrocarbon group, Z denotes any one of a sulfide group, a sulfinyl group and a sulfonyl group, and n denotes an integer of 4 to 8.

A method for separately extracting palladium and platinum, comprising:

• adjusting a pH of an aqueous solution, which contains palladium and platinum, at 25° C. to less than 7;
• bringing a first organic phase, which contains at least an extractant having selectivity for the palladium, into contact with the aqueous solution, whose pH has been adjusted and which contains the palladium and the platinum, and extracting the palladium into the first organic phase;
• and
• bringing a second organic phase, which contains at least a metal extractant comprising a compound represented by General Formula (1) below, into contact with the aqueous solution, which has undergone the extraction of the palladium and contains the platinum, and extracting the platinum into the second organic phase,
• where R denotes a C1-C10 hydrocarbon group, Z denotes any one of a sulfide group, a sulfinyl group and a sulfonyl group, and n denotes an integer of 4 to 8.