Efficient and sustainable recovery of Au(I) from thiosulfate solution by tri-n-butylphosphine functionalized chitosan microspheres with abundant pores
Thiosulfate as a green and environmentally friendly lixiviant has received great attention in the field of gold extraction. However, the problem of gold ion recovery in thiosulfate gold leaching solution has hindered the large-scale application of this technology. Here, tri-n-butylphosphine (TBUP) was used as a functional monomer to prepare an adsorbent (CTS-TBUP) with abundant pores through the ion crosslinking reaction of chitosan, which was used to recover Au(I) from Au[(S 2 O 3 ) 2 ] 3− solution with high efficiency and large capacity. CTS-TBUP exhibited good potential for industrial applications with a gold loading capacity of 46.34 mg/g. CTS-TBUP exhibited a similar gold recovery performance for all pH ranges from 6 to 11, and the adsorption process of Au(I) on CTS-TBUP was well described by pseudo-second-order kinetics and Langmuir isothermal model. The mechanism by which CTS-TBUP adsorbs gold ions involves ligand exchange between TBUP and Au[(S 2 O 3 ) 2 ] 3− . In addition, Au(I) on CTS-TBUP will be reduced to elemental gold by TBUP in CTS-TBUP. The mechanism of Au(I) adsorption by CTS-TBUP was also confirmed by density functional theory calculations, and confirmed the rationality of forming a complex with a coordination ratio of 2:1 between TBUP and Au(I) at the theoretical level. CTS-TBUP has a good affinity for gold ions in thiosulfate solution, which provides a new idea for the preparation of gold adsorbent.
危险品化学品经营许可证（带存储）