Lithium

PYROPHORIC METALS

DOE-HDBK-1081-94

Spontaneous Heating and Pyrophoricity

Lithium

Lithium, like sodium and potassium, cesium, and rubidium is one of the alkali

metals. Lithium undergoes many of the same reactions as sodium. For

example, both sodium and lithium react with water to form hydrogen; but

whereas the sodium-water reaction can generate sufficient heat to ignite the

hydrogen, the far less violent lithium-water reaction does not. Lithium ignites

and burns vigorously at a temperature of 180 C (356 F), which is near its

melting point. Unlike sodium and potassium, it will burn in nitrogen. The

caustic (oxide and nitride) fumes accompanying lithium combustion are more

profuse and dense than those of other alkali metals burning under similar

conditions. Lithium is the lightest of all metals. During combustion, it tends to

melt and flow.

Storage and Handling

Because of their reactivity with water, alkali metals require special precautions

to prevent contact with moisture. Drums and cases containing alkali metals

should be stored in a dry, fire-resistive room or building used exclusively for

alkali metal storage. Since sprinkler protection would be undesirable, no

combustible materials should be stored in the same area. It is good practice to

store empty as well as filled alkali metal containers in the same area, and all

containers should be on skids. There should be no water or steam pipes, but

sufficient heat should be maintained to prevent moisture condensation caused

by atmospheric changes. Natural ventilation at a high spot in the room is

desirable to vent any hydrogen that may be released by accidental contact of

alkali metal with moisture.

Large quantities of alkali metal are often stored outdoors in aboveground

tanks. In such installations weatherproof enclosures should cover tank

manholes, and the free space within the tank should contain a nitrogen

atmosphere. Argon or helium atmospheres should be substituted for nitrogen

in the case of lithium.

For small-scale transfer of solid alkali metal from a storeroom to the use area, a

metal container with a tight cover is recommended. Alkali metal should be

removed from storage in as small quantities as practicable. When stored on

work benches, it should be kept under kerosene or oil in a closed container.

Alkali metal, with its great affinity for moisture, may react at the time it is

sealed in a container with any atmospheric moisture. Because of the possible

presence of hydrogen, containers should not be opened by hammering on the

lid.

Pyrophoricity

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