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Cation-exchange in thiourea-hydrochloric acid solutions
C H -Siegfried1, W Weinert, F W Strelow
1National Chemical Research Laboratory, P.O. Box 395, Pretoria 0001, Republic of South Africa.
Talanta
|June 1, 1983
Summary
This study details ion-exchange separation methods for precious metals like gold and platinum using hydrochloric acid and thiourea solutions. These techniques effectively isolate valuable elements from base metals, aiding in recovery processes.
Area of Science:
- Analytical Chemistry
- Inorganic Chemistry
- Separation Science
Background:
- Ion-exchange chromatography is crucial for separating metal ions.
- Transition and post-transition elements pose separation challenges due to similar chemical properties.
Purpose of the Study:
- To determine ion-exchange distribution coefficients for various metals.
- To develop and illustrate effective separation methods for precious metals using specific eluents.
- To demonstrate the stripping of metal complexes from ion-exchange resins.
Main Methods:
- Utilized AG50W cation-exchange resins.
- Employed solutions of hydrochloric acid (0.1-3.0M) and thiourea.
- Analyzed elution curves for separation efficiency.
- Investigated bromine-containing solutions for stripping.
Main Results:
- Reported ion-exchange distribution coefficients for multiple transition and post-transition elements.
- Demonstrated successful separation of gold, palladium, platinum, rhodium, and iridium from base metals.
- Validated the use of 1.5M hydrochloric acid-0.1M thiourea as an effective eluent.
- Showcased the efficacy of bromine solutions for stripping thiourea complexes.
Conclusions:
- The developed ion-exchange systems provide efficient separation of precious metals.
- The hydrochloric acid-thiourea eluent is effective for isolating valuable elements from complex mixtures.
- Bromine solutions offer a viable method for regenerating cation-exchange columns.
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