Platinum metals-solution chemistry and separation methods (ion-exchange and solvent extraction)
1Department of Chemistry, University of Manitoba, Winnipeg, Manitoba, Canada.
Talanta
|October 1, 1984
Summary
This review examines how understanding platinum metal solution chemistry aids separation via solvent extraction and ion-exchange. It highlights knowledge gaps in chloro-complexes needing further research for effective separation methods.
Area of Science:
- Analytical Chemistry
- Inorganic Chemistry
- Separation Science
Background:
- Platinum metals (PMs) exhibit complex solution chemistry.
- Effective separation of PMs is crucial for various industrial and research applications.
- Historical data (1950-1983) on PM separation methods is extensive but fragmented.
Purpose of the Study:
- To review the impact of solution chemistry knowledge on platinum metal separation.
- To focus on solvent extraction and ion-exchange techniques.
- To identify areas requiring further investigation for improved separation.
Main Methods:
- Literature review of scientific publications from 1950 to 1983.
- Analysis of studies focusing on the solution chemistry of platinum metals.
- Evaluation of solvent extraction and ion-exchange methodologies.
Main Results:
- Knowledge of solution chemistry significantly influences the efficiency of platinum metal separation.
- Chloro-complexes are key species dictating separation behavior in aqueous solutions.
- Specific challenges remain in achieving complete separation and purification.
Conclusions:
- A deeper understanding of platinum metal chloro-complexes is essential for optimizing solvent extraction and ion-exchange methods.
- Further research is needed to address current limitations in separation techniques.
- Bridging knowledge gaps will lead to more robust and efficient platinum metal recovery and purification processes.
Related Concept Videos
00:56Extraction: Advanced Methods
Metal ions can be separated from one another by complexation with organic ligands–the chelating agent– to form uncharged chelates. Here, the chelating agent must contain hydrophobic groups and behave as a weak acid, losing a proton to bind with the metal. Since most organic ligands used in this process are insoluble or undergo oxidation in the aqueous phase, the chelating agent is initially added to the organic phase and extracted into the aqueous phase. The metal-ligand complex is formed in...
01:09Ion-Exchange Chromatography
Ion-exchange chromatography, or IEC, is a technique for separating ions based on their affinity for the stationary phase. The stationary phase is a cross-linked polymer resin with covalently attached ionic functional groups. The functional groups can be either positively charged (cation exchangers) or negatively charged (anion exchangers). A cation exchanger consists of a polymeric anion and active cations, while an anion exchanger is a polymeric cation with active anions. The choice of...
01:08Electrodeposition
Electrodeposition is a technique used to separate an analyte from interferents by electrochemical processes. Here, the analyte is a metal ion that can be deposited on an electrode immersed in the sample solution. The electrochemical setup consists of an anode and a cathode. When an electric current is applied to the setup, oxidation occurs at the anode. At the cathode, which consists of a large metal surface, metal ions undergo reduction and deposit onto the surface.
Electrodeposition can...
Electrodeposition can...
01:17Ion Exchange
Ion exchange chromatography separates charged molecules from a solution by reversibly exchanging them with mobile, or 'active', ions associated with the oppositely charged stationary phase. This method can be used to separate ions, soften and deionize water, and purify solutions. The polymers comprising the ion-exchange column are high-molecular-weight and chemically stable polymers, crosslinked to be porous and essentially insoluble. They are also functionalized with either acidic or basic...
01:17Precipitation and Co-precipitation
Precipitation and coprecipitation methods can be used to separate a mixture of ions in a solution. In qualitative inorganic analysis, ions that form sparingly soluble precipitates with the same reagent are separated based on the differences in solubility products. For example, consider the separation of Cu(II) and Fe(II) ions by precipitation as insoluble sulfides. First, copper(II) sulfide is precipitated by the addition of acidic H2S, where the dissociation of H2S is suppressed. Adding H2S...
03:46Qualitative Analysis
For solutions containing mixtures of different cations, the identity of each cation can be determined by qualitative analysis. This technique involves a series of selective precipitations with different chemical reagents, each reaction producing a characteristic precipitate for a specific group of cations. Metal ions within a group are further separated by varying the pH, heating the mixture to redissolve a precipitate, or adding other reagents to form complex ions.
For instance, group IV...
For instance, group IV...