Element · Ru

Ruthenium

A platinum-group metal that hardens its relatives, catalyses ammonia synthesis, and sits on almost every hard disk platter.

Ruthenium is the least expensive of the platinum-group metals and is recovered mainly as a by-product of nickel and platinum refining. It is hard, brittle and extremely resistant to corrosion, dissolving in neither acid nor aqua regia under ordinary conditions.

Its most consequential property is that very small additions transform other metals. A few per cent ruthenium markedly improves the hardness and wear resistance of platinum and palladium, and its presence in nickel superalloys allows turbine blades to run hotter.

Uses

Ruthenium's largest use by value is in electronics: thin ruthenium layers are used in hard disk drive platters to control the magnetic coupling between layers, and ruthenium oxide forms the resistive element in thick-film chip resistors.

It is an important catalyst — in ammonia synthesis as an alternative to iron, in hydrogenation, and in the metathesis reactions that earned a Nobel Prize and are now routine in pharmaceutical synthesis. Ruthenium complexes are also studied intensively as light absorbers in dye-sensitised solar cells.

Medium confidence Weak evidence

How we know: checked recently · only one source, so there is nothing to cross-check it against · stated directly by the source.

How this connects

Where a connection has been confirmed by an outside reference, that reference is named beside it.

is sourced from

Nickel — element · a by-product of nickel refining
Platinum — element · and of platinum refining

is used as

Catalysis — application · ammonia synthesis, hydrogenation and metathesis

is produced by

Electrorefining — process · separated late in the platinum-group refining sequence, after the more valuable metals have been taken

is a component of

Nickel superalloy — alloy · 0–4% · in the newest generations, to stop the heavy elements segregating into phases that embrittle the blade

Sources

Material World
Our own writing
Wikidata
Wikimedia Foundation · Creative Commons CC0 1.0 Universal (public domain dedication)
PubChem
US National Library of Medicine · Mixed — aggregated third-party content, rights retained by depositors
NIST — National Institute of Standards and Technology
United States Department of Commerce · US Government work — public information, credit requested

Questions this page answers

Where it comes from, and what it becomes

Follow Ruthenium back to what it starts as, and forward into what it becomes. Each step is a documented one — a real route material takes, not a chain of inference.

Upstream — what it comes from

Ruthenium → is sourced from (a by-product of nickel refining) → Nickel → is produced by (reduced from roasted pentlandite concentrate, with the platinum-group metals following into the refinery) → Smelting → takes as input (as the element removed, not added) → Oxygen → is produced by (the largest output by tonnage, and the reason air separation units sit beside steelworks) → Air separation → takes as input (the feedstock, and an unusual one in being free, unlimited and available anywhere — the cost is entirely the energy to liquefy it) → Air
Ruthenium → is sourced from (and of platinum refining) → Platinum → is produced by (collected in the slimes, where the copper's own refining concentrates it) → Electrorefining → takes as input (as impure smelted anodes, around 99% copper, which is not pure enough for wire) → Copper → is produced by (as blister copper, refined electrolytically afterwards) → Smelting → takes as input (roasted to drive off sulfur, then reduced to copper) → Chalcopyrite
Ruthenium → is produced by (separated late in the platinum-group refining sequence, after the more valuable metals have been taken) → Electrorefining → takes as input (as impure smelted anodes, around 99% copper, which is not pure enough for wire) → Copper → is produced by (as blister copper, refined electrolytically afterwards) → Smelting → takes as input (as the element removed, not added) → Oxygen → is produced by (the largest output by tonnage, and the reason air separation units sit beside steelworks) → Air separation
Ruthenium → is sourced from (a by-product of nickel refining) → Nickel → is produced by (reduced from roasted pentlandite concentrate, with the platinum-group metals following into the refinery) → Smelting → takes as input (roasted to drive off sulfur, then reduced to copper) → Chalcopyrite
Ruthenium → is sourced from (a by-product of nickel refining) → Nickel → is produced by (reduced from roasted pentlandite concentrate, with the platinum-group metals following into the refinery) → Smelting → takes as input (reduced with carbon to metallic tin) → Cassiterite
Ruthenium → is sourced from (a by-product of nickel refining) → Nickel → is produced by (reduced from roasted pentlandite concentrate, with the platinum-group metals following into the refinery) → Smelting → takes as input (reduced with coke in a blast furnace) → Hematite

These are the most distinct paths back. Ruthenium can be traced through others besides.

Downstream — what it becomes

Ruthenium → is a component of (in the newest generations, to stop the heavy elements segregating into phases that embrittle the blade) → Nickel superalloy → is used in (cast as a single crystal, because at temperature and sustained load the failure mode is creep along grain boundaries — so the boundaries are removed entirely) → Turbine blade → is associated with (the jet engine created the superalloy industry, because no existing material survived the turbine inlet — and turbine temperature has risen about 500 °C since, almost entirely on the blade) → The wartime materials programmes complete chain
Ruthenium → is used as (ammonia synthesis, hydrogenation and metathesis) → Catalysis
Ruthenium → is a component of (in the newest generations, to stop the heavy elements segregating into phases that embrittle the blade) → Nickel superalloy → is associated with (the jet engine created the industry, because no existing material survived the turbine inlet) → The wartime materials programmes complete chain
Ruthenium → is a component of (in the newest generations, to stop the heavy elements segregating into phases that embrittle the blade) → Nickel superalloy → is used as (the turbine blade carries its own centrifugal load at four fifths of its melting point, which is structural engineering under the hardest conditions anybody attempts) → Structural engineering
Ruthenium → is a component of (in the newest generations, to stop the heavy elements segregating into phases that embrittle the blade) → Nickel superalloy → is used in (the turbine hot section, which runs above the alloy's own melting point and only works because of internal cooling and ceramic coating) → Aerospace manufacture
Ruthenium → is a component of (in the newest generations, to stop the heavy elements segregating into phases that embrittle the blade) → Nickel superalloy → is used in (gas turbine blades and vanes, in the same alloys and for the same reasons as aerospace) → Energy generation

These are the most distinct paths onward. Ruthenium ends up in others besides.