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Material World
Element · Ac

Actinium

The element that named the actinides, now valued for a decay that destroys cells at very short range.

Medicinal

Actinium gives the actinide series its name and occurs naturally only in vanishing traces in uranium ores, as a step in a decay chain. Practically all of it is made deliberately.

Its interest is medical and recent. Actinium-225 decays through a series of alpha emissions, and alpha particles deposit their energy within a few cell diameters. Attached to a molecule that binds a tumour cell, that is a way of irradiating one cell while barely touching its neighbour.

Uses

Targeted alpha therapy is the use driving demand, particularly against cancers that have spread too widely for surgery or beam radiotherapy to reach.

Supply is the constraint rather than demand: actinium-225 is produced in small quantities from a handful of facilities, and the effort now goes into accelerator routes that do not depend on decades-old stockpiles.

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

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

Questions this page answers

Where it comes from, and what it becomes

Follow Actinium 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

  • Actinium → is sourced from → Uranium → is produced by (as yellowcake rather than metal: leaching and solvent extraction end at a uranium oxide concentrate, and the metal is several conversion steps further on) → Solvent extraction and electrowinning → takes as input (in the low-grade and oxidised ores that flotation cannot economically treat, with bacteria oxidising the sulfide into a form the acid can attack) → Chalcopyrite
  • Actinium → is sourced from → Uranium → is extracted from (the principal uranium ore, and the pitchblende the Curies worked) → Uraninite
  • Actinium → is sourced from → Uranium → is produced by (as yellowcake rather than metal: leaching and solvent extraction end at a uranium oxide concentrate, and the metal is several conversion steps further on) → Solvent extraction and electrowinning → takes as input (a carbonate dissolves straight into acid, which is why an oxidised orebody goes to a leach pad and the sulfide beneath it goes to a smelter) → Malachite
  • Actinium → is sourced from → Uranium → is produced by (as yellowcake rather than metal: leaching and solvent extraction end at a uranium oxide concentrate, and the metal is several conversion steps further on) → Solvent extraction and electrowinning → takes as input (leached with acid or alkali depending on the host rock, which is what decides the flowsheet of a uranium mill) → Uraninite