Preparation of ReO4-thermosensitive imprinting polymers and their application in rhenium recovery from high-temperature alloy electrolytes

Abstract

Rhenium, as a critical strategic metal in the aerospace sector, demands efficient recovery solutions due to its scarcity and the limitations of conventional recycling techniques, which suffer from poor selectivity and cumbersome processes. This study synthesised porous interpenetrating thermosensitive rhenium ion-imprinted polymers (ReO₄⁻-TIIP) by combining thermosensitive block copolymer PDEA-b-P(DEA-co-AM) with Pickering high-inner-phase emulsion technology via RAFT polymerisation. At pH = 2 and 33 °C, the material exhibited a maximum adsorption capacity of 0.185 mmol/g. The adsorption behaviour conformed to pseudo-first-order kinetics and the Langmuir model. For binary solutions containing interfering ions such as Cu²⁺ and MnO₄⁻, the separation factor R ranged from 3.448 to 3.862. Desorption efficiency reached 87.3% using 1% ammonia solution, with adsorption capacity and other properties remaining above 73% after seven cycles. In high-temperature alloy electrolytes pretreated with sodium bicarbonate (pH 7, 40 °C, 2 h), the ReO₄⁻-TIIP adsorption-desorption combined optimised crystallisation process (15% ammonia solution, 1000 r/min, -2 °C, 0.5 g seed crystals) yielded ammonium rhenate with 99.9% purity. with a total recovery rate of 71.35%, providing technical support for efficient short-path recovery of rhenium in complex systems.