이리듐

22.42 at 17 °C

21.56 @25 °C

4,428 °C

4428 °C @760 [mm Hg]

Powdered iridium metal can ignite in air.

Enthalpy of fusion 41.12 kJ/mol

Specific heat 0.0307 cal/g/deg C; Mohs' hardness 6.5

Best solvent: concentrated hydrochloric acid and sodium perchlorate at 125 to 150 °C

For more Other Experimental Properties (Complete) data for IRIDIUM, ELEMENTAL (6 total), please visit the HSDB record page.

This chemical does not meet GHS hazard criteria for 36.9% (92 of 249) of reports.

Danger

H228 (18.1%): Flammable solid [Danger Flammable solids]

P210, P240, P241, P264+P265, P273, P280, P305+P351+P338, P337+P317, P370+P378, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 249 reports by companies from 9 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Chemical: Iridium

Status: Active Update: 17-03-2021 https://echa.europa.eu/registration-dossier/-/registered-dossier/17763

Iridium, powder: Does not have an individual approval but may be used under an appropriate group standard

Iridium salts can cause immunologic, occupational contact urticaria; [Kanerva, p. 219] The metals in this group [platinum, palladium, iridium, osmium, rhodium, and ruthenium] generally are nontoxic in the metallic state, but the soluble halide salts (particularly of Pt) and osmium tetroxide are highly reactive. Exposure to these elements results in hypersensitivity allergic reactions in susceptible individuals. [Sullivan, p. 911] See Iridium-192.

Used to harden platinum alloys for pen points, compass bearings, electrical contacts, laboratory ware, extrusion dies, and jewelry; [HSDB]

Metal Preparation and Pouring [Category: Foundry]

Jewelry making [Category: Hobbies]

Alloy with platinum for ammonia fuel-cell catalyst, electric contacts and thermocouples, commercial electrodes and resistance wires, laboratory ware, extrusion dies for glass fibers, jewelry. Primary standards of weight and length. /The meter was intended to equal 10-7 or one ten-millionth of the length of the meridian through Paris from pole to the equator. However, the first prototype was short by 0.2 millimeters because researchers miscalculated the flattening of the earth due to its rotation. Still this length became the standard (the platinum-iridium alloy called the "1874 Alloy.") In 1889, a new international prototype was made of an alloy of platinum with 10 percent iridium, to within 0.0001, that was to be measured at the melting point of ice. In 1927, the meter was more precisely defined as the distance, at 0 deg, between the axes of the two central lines marked on the bar of platinum-iridium kept at the BIPM, and declared Prototype of the meter by the 1st CGPM, this bar being subject to standard atmospheric pressure and supported on two cylinders of at least one centimeter diameter, symmetrically placed in the same horizontal plane at a distance of 571 mm from each other. The 1889 definition of the meter, based upon the artifact international prototype of platinum-iridium, was replaced ... in 1960 using a definition based upon a wavelength of krypton-86 radiation. (See http://physics.nist.gov/cuu/Units/meter.html for a discussion of the platinum-iridium bar as the historical standard of length.)

Its principal use is as a hardening agent for platinum. With osmium, it forms an alloy which is used for tipping pens and compass bearings.

In manufacturing crucibles; in hardening platinum; in making nibs for fountain-pen points.

(2000) 2,700 kg

(2001) 3,110 kg

(2002) 2,100 kg

(2003) 2,200 kg

(2004) 3,900 kg (estimated)

The best method of producing iridium is to reduce ammonium hexachloroiridate(IV), (NH4)2[IrCl6], in a hydrogen atmosphere ca. 800 °C, yielding the metal powder. Calcination in air gives an oxide-containing material. Wet chemical reduction with hydrazine is possible only in strongly alkaline sodium hydroxide solution and does not always go to completion.