Rhodium - Rh
| Atomic number | 45 |
|---|---|
| Group / period / block | 9 / 5 / d |
| Relative atomic mass | 102.90549 |
| Density at 20 °C | 12.4 g/cm3 |
| Melting point | 1963 °C |
| Boiling point | 3695 °C |
| Electron configuration | [Kr] 4d8 5s1 |
Rhodium
Rhodium is a hard, reflective, silvery-white platinum-group metal. Its principal use is as a catalyst, especially in vehicle catalytic converters; it is also used in chemical processes and plated coatings. The metal is distinct from rhodium ions or complexes that may occur in industrial water.
Rhodium is scarce and is mainly recovered as a by-product of mining and refining other platinum-group metals. Potential water-treatment concerns are therefore associated with specific production or metal-bearing waste streams.
Rhodium in water treatment
Water-treatment context: Establish whether rhodium is dissolved, complexed or present in suspended solids, and account for ligands and co-occurring metals. Precious-metal recovery and wastewater treatment may be linked; process selection should be supported by stream characterization and treatability testing.
Elemental metals and dissolved metal species behave differently in water. Water chemistry and the exact compound or complex must be considered when assessing treatment.
Back to the periodic table of elements
Sources and further reading
Rhodium page last reviewed: by Lenntech.