Element · Bi

Bismuth

The heaviest element that is, for practical purposes, stable — and the least toxic heavy metal.

Bismuth was long listed as the heaviest stable element. It is in fact very slightly radioactive, with a half-life around a billion times the age of the universe, which is a distinction without a practical difference.

It is unusual among heavy metals in being essentially non-toxic, which is why it replaced lead in solders, fishing weights and free-machining brass once lead restrictions arrived. Like antimony and water, it expands as it freezes.

Uses

Bismuth's use is defined by being the benign heavy metal. It is dense and soft like lead but not appreciably toxic, so it substitutes for lead in fishing weights, shot, free-machining brass and plumbing solder as lead is regulated out.

Bismuth subsalicylate is the active ingredient of common stomach remedies. Low-melting bismuth alloys are used in fire sprinkler links and safety plugs, where the alloy is meant to melt at a specific temperature, and bismuth oxychloride gives cosmetics their pearlescent shimmer.

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 an alternative to

Lead — element · the standard non-toxic replacement in solders and weights

is extracted from

Bismuthinite — mineral · the principal bismuth ore, though most bismuth comes from lead refining Wikidata

is produced by

Electrorefining — process · separated from the lead it accompanies during refining, which is where essentially all of it comes from

is sourced from

Lead — element · separated during lead refining, which is where essentially all of it comes from — bismuth ores exist and are not worked

is used as

Alloying — application · in low-melting alloys, and as the non-toxic replacement for lead in solders, free-machining brass and fishing weights — an element most people have also swallowed, as the subsalicylate taken for indigestion

is found in

Bismuthinite — mineral Wikidata

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 Bismuth 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

Bismuth → is produced by (separated from the lead it accompanies during refining, which is where essentially all of it comes from) → 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
Bismuth → is sourced from (separated during lead refining, which is where essentially all of it comes from — bismuth ores exist and are not worked) → Lead → is produced by (as the oxide, from galena, by the same route) → Roasting → takes as input (a copper sulfide; roasting drives off the sulfur that would otherwise prevent reduction) → Chalcopyrite
Bismuth → is extracted from (the principal bismuth ore, though most bismuth comes from lead refining) → Bismuthinite
Bismuth → is sourced from (separated during lead refining, which is where essentially all of it comes from — bismuth ores exist and are not worked) → Lead → is produced by (as the oxide, from galena, by the same route) → Roasting → takes as input (roasted for its sulfur as much as for its iron) → Pyrite
Bismuth → is sourced from (separated during lead refining, which is where essentially all of it comes from — bismuth ores exist and are not worked) → Lead → is produced by (as the oxide, from galena, by the same route) → Roasting → takes as input (roasted to the oxide, the sulfur going to an acid plant rather than the air) → Galena
Bismuth → is sourced from (separated during lead refining, which is where essentially all of it comes from — bismuth ores exist and are not worked) → Lead → is produced by (as the oxide, from galena, by the same route) → Roasting → takes as input (roasted to zinc oxide before reduction or electrolytic winning) → Sphalerite

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

Downstream — what it becomes

Bismuth → is used as (in low-melting alloys, and as the non-toxic replacement for lead in solders, free-machining brass and fishing weights — an element most people have also swallowed, as the subsalicylate taken for indigestion) → Alloying