On Sun, 18 Mar 2012 23:13:24 +0000 (UTC), Custos Custodum <
m...@privacy.net>
>
news:ll0cm7hi50a8ggbht...@4ax.com:
>
>> Soldiering on...
>> And spontaneously combust weeks after an accident.
>> Lithium in the presence of water, burns with almost the same heat as
>> Thermite
>
>No it doesn't. Lithium reacts less vigorously with water than do either
>sodium or potassium. It doesn't even get hot enough to melt. Flooding
>the area with water is usually the recommended way to tackle a lithium
>fire.
As always, it depends...
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA238154
"Solid lithium reacts rather slowly with water (Reference 5),"
"Bulk solid lithium at room temperature did not burn spontaneously in
water, and the hydrogen formed did not ignite in air. When a pea-sized
piece of lithium was dropped into a container of water, it reacted much
more slowly than did sodium, and it did not splatter or evolve light. A
solid piece of lithium when immersed in liquid water at room temperature
retained its original shape, but decreased slowly in size as it reacted
with the water. A 3/8-inch sphere of lithium immersed in 250 em8 of water
at ambient temperature in either air or argon atmosphere became warm (98 to
103'C), and the temperature of a 3S-inch sphere of lithium immersed in
water/Ice slurry in an air atmosphere, where the water volume > > lithium
volume, rose to approximately 40"C. In boiling water under an argon
atmosphere, solid lithium reacted without combustion.
These examples demonstrate the effectiveness of the surrounding water as a
heat sink".
"Lithium reacts with water but it does not ignite unless the metal is
finely divided (Reference 12).
When a 40-gram sample of lithium was ignited, it attained a flame
temperature of 1350C (Reference 67)."
"When the metal burns strongly, RH.90% the flame is dazzling white
(References 1, 15, 29), and the reaction of lithium vapor with air forms an
intense white flame (Reference 42) that is brighter than any of the other
alkali metal fires (Reference 36).
The combustion of lithium in air involves the reactions of lithium with
both oxygen and nitrogen, and these reactions are influenced by the
presence of moisture. This review described the known information regarding
these reactions. A lithium fire in air burns brilliantly white and emits
substantial aerosol consisting primarily of lithium oxide, hydroxide, and
carbonate, while the combustion residue consists of lithium oxide, nitride,
and hydroxide. Many substances were tried as extinguishants for lithium
fires; the most effective ones appear to be various forms of carbon."
CONCLUSIONS
"The combustion of lithium in air involves the reactions of lithium with
both oxygen and nitrogen, and these reactions are influenced by the
presence of moisture." Halon is ineffective.
Lithium batteries have been implicated in two fatal airplane crashes.
http://www.utsandiego.com/news/2011/nov/26/feds-probe-new-battery-fires-in-chevrolet-volt/?page=2#article
"The Federal Aviation Administration issued a warning to airlines about the
potential for fires in cargo containing lithium-ion and non-rechargeable
lithium metal batteries after a United Parcel Service plane crashed near
Dubai last year, killing both pilots. The plane, which was on fire, was
carrying thousands of lithium batteries.
Incorrectly packaged, damaged or overheated batteries can catch fire, the
FAA said. Fires involving lithium-ion batteries can reach 1,100 degrees,
close to the melting point of aluminum, a key material in airplane
construction. *_Lithium-metal battery fires are far hotter, capable of
reaching 4,000 degrees."_*
I assume they mean F and I guess that is the figure being repeated in the
various reports.
Lithium Battery Fire Could Burn Through a Cargo Hold
http://findarticles.com/p/articles/mi_m0UBT/is_29_18/ai_n6280925/
"There is one case where a lithium battery fire may have played a role in
the crash of a transport category airplane. In November 1987 a South
African Airways B747 combi (a hybrid freighter with a partition separating
cargo from passengers on the main deck), with 159 passengers aboard and
cargo which included a consignment of lithium watch batteries, disappeared
into the Indian Ocean off Mauritius".
Although pay-walled figs. 5 and 6 both show temps approaching 1700C in dry
air.
http://www.sciencedirect.com/science/article/pii/S0010218011000381
What is not contested is that a Chevy Volt ignited spontaneously,
destroying several nearby cars and that GM have redesigned and strengthened
the battery compartment.
Scott