Iridium - Ir

Iridium — chemical properties and water context

Iridium is a rare, hard, corrosion-resistant platinum-group metal. Its water-related relevance is generally connected to specialized refining, catalyst or alloy processes.

Atomic number	77
Standard atomic weight	192.217 g/mol
Density	22.5622 g/cm³
Melting point	2446 °C
Boiling point	4428 °C
Electron configuration	[Xe] 4f¹⁴ 5d⁷ 6s²

Chemical properties

Iridium is in Group 9 and Period 6. It is one of the most corrosion-resistant metals and has a high density and melting point. Iridium can form compounds in several oxidation states; dissolved speciation depends on oxidation conditions and ligands such as chloride.

Uses and applications

Iridium is used in specialized alloys, spark-plug contacts and some catalysts and electrochemical equipment. It is commonly recovered as a by-product of platinum and nickel processing.

Iridium in water treatment

If iridium is present in an industrial water stream, measure and distinguish dissolved and particulate fractions, and document pH, redox conditions and complexing agents. Platinum-group metal recovery from process solutions may use ion exchange, but the charge and stability of iridium complexes determine whether a particular resin or separation step is suitable. Bench testing is needed for the specific stream.

Environmental and health context

Iridium is naturally rare, and its chemical form governs mobility and potential exposure. Avoid inferring dissolved-metal behaviour from the properties of the corrosion-resistant bulk metal. Handle process residues according to their measured composition and applicable requirements.