In recent years

with the rapid development of the economy and society

pollution of valuable metal ions in wastewater has become a major challenge to environmental sustainability. In order to solve the pollution caused by metal ions

researchers have conducted continuous researches and explored various remediation methods. Crown ether has attracted great attention because of its ionic radius and cavity size matching well with metal ions

which makes it have the ability to selectively complex metal ions. This unique property enables the directed removal and recovery of metal ions and makes crown ethers increasingly popular in extraction and separation processes. In this paper

the research progress of crown ethers in the extraction and separation of valuable metal ions was reviewed

with emphasis on the principles

extraction systems and the key factors affecting the extraction process. This study can provide some technical support for the application of separation and extraction of valuable metal ions by crown ether.