Pyromet Powder

Spontaneous Heating and Pyrophoricity

DOE-HDBK-1081-94

PYROPHORIC METALS

it is not recommended for fires in sodium, sodium-potassium alloy, and

lithium. TMB reacts violently with lithium and sodium-potassium alloy. It will

extinguish sodium in-depth, but the protective coating formed by the TMB

absorbs moisture very rapidly and in time may penetrate through to the

sodium, resulting in a violent reaction. Field experience has been limited to

aircraft fires.

Pyromet Powder

Pyromet powder is composed of specially processed sodium chloride,

diammonium phosphate, protein, and a waterproofing and flow promoting

agent. The powder is discharged under pressure provided by a carbon dioxide

gas cartridge. The unit contains 11 kg (25 lb) of powder. The applicator

consists of a tubular extension from the control valve, terminating in a

cone-shaped nozzle. A mechanism in the nozzle absorbs the discharge pressure

by swirling the powder as it is expelled. This enables the operator to let the

powder fall gently on the burning metal rather than to scatter burning material

under the blast of a jet of powder.

Pyromet has proven effective in handling fires involving sodium, calcium,

zirconium, and titanium, as well as magnesium and aluminum in the form of

powder or chips.

TEC Powder

TEC (ternary eutectic chloride) powder is a mixture of potassium chloride,

sodium chloride, and barium chloride that is effective in extinguishing fires in

certain combustible metals. The powder tends to seal the metal, excluding air.

On a hot magnesium chip fire its action is similar to that of foundry flux. In

tests reported in Fire Technology, TEC powder was the most effective salt for

control of sodium, potassium, and sodium-potassium alloy fires. TEC should

not be used on plutonium, uranium, and alkali metal fires because it is

hygroscopic.

Nonproprietary Combustible Metal Extinguishing Agents

Talc (Powder)

Talc, which has been used industrially on magnesium fires, acts to control

rather than extinguish fire. Talc acts as an insulator to retain the heat of the

fire, rather than as a coolant. It does, however, react with burning magnesium

to provide a source of oxygen. The addition of organic matter (such as protein)

to talc assists in the controlling action, but does not prevent the reaction which

releases oxygen to the fire.

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Pyrophoricity