Extraction of metals and/or metalloids from acidic media using supercritical fluids and salts
US5770085A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 2, 1995 |
| Grant date | Jun 23, 1998 |
| Priority date | — |
| Expiry date | Jun 2, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S210/912
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a fluid solvent, particularly supercritical carbon dioxide, containing a chelating agent is described. The chelating agent forms chelates that are soluble in the fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent comprises a trialkyl phosphate, a triaryl phosphate, a trialkylphosphine oxide, a triarylphosphine oxide, or mixtures thereof. The method provides an environmentally benign process for removing contaminants from industrial waste. The method is particularly useful for extracting actinides from acidic solutions, and the process can be aided by the addition of nitrate salts. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.