Definitions
from The American Heritage® Dictionary of the English Language, 5th Edition.
- adjective Spontaneously igniting in air.
 - adjective Producing sparks by friction.
 
from The Century Dictionary.
-     Same as 
pyrophorous . 
from the GNU version of the Collaborative International Dictionary of English.
- adjective Light-producing; of or pertaining to pyrophorus.
 - adjective (Chem.) finely reduced iron, which ignites spontaneously on contact with air.
 
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- adjective   
spontaneously igniting inair , especially when in afinely divided state - adjective   
producing sparks , especially byfriction  - adjective   Able to 
oxidize withexposure toatmospheric oxygen atnormal temperatures . 
Etymologies
from The American Heritage® Dictionary of the English Language, 4th Edition
from Wiktionary, Creative Commons Attribution/Share-Alike License
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Examples
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The company got a chance to show that when a customer had an accidental release of a "pyrophoric" gas that can ignite on contact with air.
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Depleted uranium is "pyrophoric", which makes it uniquely effective at piercing hard targets, because upon impact, it immediately burns, vaporizing the majority of its bulk and leaving a hard, thin, sharpened tip - and large amounts of radioactive particles suspended in the atmosphere.
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Finely divided uranium powder is pyrophoric, meaning it will ignite spontaneously at room temperature.
About.com Chemistry 2010
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Uranium in its pure form is a silver-colored heavy metal that is nearly twice as dense as lead and is pyrophoric when finely divided.
Uranium 2009
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Finely divided uranium metal, being pyrophoric, presents a fire hazard.
Uranium 2009
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Raney-Ni is known to be a very active catalyst for hydrogenation and a pyrophoric material, indeed a dangerous one to be handled with care that has on occasion exploded.
Rabett Run EliRabett 2008
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It turns out the uranium from nuclear waste is very dense and possesses pyrophoric properties.
BLOW-HARDS News from Mad Plato 2008
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It turns out the uranium from nuclear waste is very dense and possesses pyrophoric properties.
Archive 2008-03-01 News from Mad Plato 2008
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A bit more about DU  When fired or exploded, it is pyrophoric, becoming a tremendous fiery explosion, and reaches high temperatures between 3,000-6,000 degrees Centigrade.
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Due to the pyrophoric nature of uranium metal and the extreme temperatures generated on impact of depleted uranium ammunition on a hard target, it ignites and produces an aerosol of fine particles of uranium oxides if the temperature exceeds 600°C.
Depleted uranium 2008
 
sherry28 commented on the word pyrophoric
So is this another way to describe spontanious combustion?
September 27, 2010
			
		
	
alan212 commented on the word pyrophoric
I would say yes - spontaneous combustion under certain conditions.
December 20, 2022