Light metal

Light metals are commonly referred to as metals and alloys, the density of which is less than 5 g / cm ³. All other metals are heavy metals, of which europium having a density of 5.244 g / cc is the lightest. In the technical field are mainly of aluminum, magnesium, titanium and a small extent in the use of beryllium and lithium - and other elements as alloying elements in small concentrations. The processing of metallic materials are generally in light metals such as other metals also.

List of light metals

A complete list of light metal elements with their densities at 20 ° C:

Light metal fires

When extinguishing fires of light metals must be noted that this water must not be used. Light metals such as alkali and alkaline earth metals tend to react with water violently with formation of alkali metal hydroxides and release of hydrogen. In the event of a fire test with water, the released hydrogen could ignite and it would possibly lead to explosions ( oxyhydrogen gas formation with oxygen in the air ). The reactivity of lithium to cesium, beryllium or rises to barium, strongly. As of potassium occurs spontaneous combustion.

In addition, many light metals, such as magnesium and aluminum burn at very high temperatures. Water decomposes thermally here which also leads to hydrogen and oxygen to an explosive spread of fire.

Also extinguishers containing water, such as foam, prohibit these reasons. Other extinguishing agents show at light metal fires often have no effect, because magnesium continues to burn even under carbon dioxide atmosphere by carbon dioxide removes the oxygen. Normal Dry powder is also not suitable for alloy fires.

The extinguishing agent may be used:

• Metal fire powder
• Dry cement, sand or salt
• Noble gases