Selective extraction film for mining application

A polymer membrane, comprising

• i) about 5.0 to about 33.0 wt.-% of a base polymer (B),
• ii) optionally at least about 18 wt.-% of a plasticizer (P),
• iii) at least about 22 wt.-% of an extractant (E), and
• iv) at least about 26 wt.-% of a modifier (M) comprising an aromatic or aliphatic ester of phosphoric acid,
• each based on the overall weight of the polymer membrane,
• comprising the base polymer (B) and the extractant (E) in a weight ratio w(B)/w(E) in the range of 0.1 to 0.7, wherein w(B) is the overall amount of the base polymer (B) in wt.-% and w(E) is the overall amount of the extractant (E) in wt.-%, based on the overall weight of the polymer membrane, respectively.