Abstract
This chapter describes the extractability of as-chelates and solubility of different Rh, Pd-chelates in supercritical fluid (sc) CO2. The solubility in sc CO2 of different metal chelates with systematically modified ligands was studied. For dialkyl dithiocarbamates, the maximum solubility for all studied conditions was observed when a butyl substituent was attached to the chelate ligand. Fluorination further increases the solubility; however fluorinated ligands are of major environmental concern, and thus not derived in technical processes. Attaching aryl instead of alkyl does not increase the solubility. This is in accordance with literature data. The dialkyldithiocarbamate ligands are suitable for an efficient extraction of the precious metals, and this also holds true as this ligand can be synthesized without great expense and because the basic chemicals are relatively moderate in price. It is suggested that to improve the understanding of the relation structure and solubility in sc CO2 further studies are necessary. The solubility of metal chelates in sc CO2 are relatively low, and thus currently not suitable for technical applications.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
