what are metal fires and what causes them?

Answer 1

two most common metal fires are magnesium and aluminum. Once these are hot enough they start to burn. When they burn they chemically release oxygen. Feeding the fire even more. A way to totally stop them is to throw them in water. IE jets on Naval vessels. You can use a mist of water to try and cool it, but if you use a stream and hit the hot metal it will fragment and "blow up". It is so hot when straight water hits it, it turns into O2 and H2. Hydrogen can be explosive and O2... well you know the rest.


Edit: Sorry aluminum powder, much like overheated milling and cutting. Not solid blocks of aluminum but aluminum dust. Much like the coal dust fires. Not dangerous until in power form in the air

Answer 2

Combustion is rapid oxidation (neutral metal changes to cation). Rusting or corrosion is slow oxidation. Explosions are "simply" very rapid oxidation. The only difference is rate of reaction.

The chemical nature of metal is to oxidize (lose electrons), if its going to react.

So, if you put the metal in contact with the appropriate material (usually oxygen, but it can be another metal or nonmetal), it will react. Sometimes, a bunch of extra energy is needed; other times, not, depending on the element and its physical form.

Some metals (like the alkali and alkaline earths) are active enough (see "activity series" in any chemistry text) to react with water, heat, and hydrogen gas (which subsequently detonates).

Thermite is powdered metal which is "easily" ignited.

If a metal is more active than water, you don't have much of a choice except to use solid or foam to cool the fire and/or block the flow of oxygen to the fire (you could use halon gas for the latter, also).

Once a fire is hot enough, regardless of its reactivity, water isn't particularly effective is pulling away energy (part of the fire triangle) and it's "easier" to work on cutting off the supply of oxygen or fuel.

Answer 3

Magnesium burns easily. Aluminium, once ignited, burns with a very high temperature flame. Some metals such as sodium and potassium need to be stored out of contact with air to prevent spontaneous combustion.
Electrical spark or contact with a powerful oxidising agent.

Answer 4

the most reactive elements are the alkaline metals such as sodium, potassium etc. Due to their electronic arrangement, they have a single valence electon which is easily lost to whatever is adjacent. They react violently producing flame and heat with atmospheric oxygen, and with molecular oxygen in water, releasing hydrogen as a byproduct. When magnesium burns it is oxidising, ie removing oxygen from the air and forming a skin of MgO which will inhibit its reaction with air. I think it releases Nitrogen but stand to be corrected.

Answer 5

Sodium is the chemical element in the periodic table that has the symbol Na (Natrium in Latin) and atomic number 11. Sodium is a soft, waxy, silvery reactive metal belonging to the alkali metals that is abundant in natural compounds (especially halite). It is highly reactive, burns with a yellow flame, reacts violently with water and oxidizes in air necessitating storage in an inert environment.
Like the other alkali metals, sodium metal is a soft, light-weight, silvery white, reactive metal. Owing to its extreme reactivity, in nature it occurs only combined into compounds, and never as a pure elemental metal. Sodium metal floats on water, and reacts violently with it releasing heat, flammable hydrogen gas and caustic sodium hydroxide solution.

Sodium ions are necessary for regulation of blood and body fluids, transmission of nerve impulses, heart activity, and certain metabolic functions. It is widely considered that most people consume more than is needed, in the form of sodium chloride, or table salt, and that this can have a negative effect on the health. See Edible salt.

Under extreme pressure, sodium departs from standard rules for changing to a liquid state. Most materials need more thermal energy to melt under pressure than they do at normal atmospheric pressure. This is because the molecules are packed closer together and have less room to move. At a pressure of 30 gigapascals (300,000 times sea level atmospheric pressure), the melting temperature of sodium begins to drop. At around 100 gigapascals, sodium will melt near room temperature.

A possible explanation for the aberrant behavior of sodium is that this element has one free electron that is pushed closer to the other 10 electrons when placed under pressure, forcing interactions that are not normally present. While under pressure, solid sodium assumes several odd crystal structures suggesting that the liquid might have unusual properties such as superconduction or superfluidity. (Gregoryanz, et al., 2005)

Answer 6

They are caused by very reactive metals in the surrounding. For example, potassium which not only burns in air but also burn in water hence used as a torch underwater.

Answer 7

There are metals, like magnesium, that will burn when the get hot enough. Once they start to burn they are very difficult to extinguish because they generate so much heat.

Answer 8

Its accessible, yet approximately as possibly as prevailing the lottery two times in an afternoon. the fabric you %. up is beside the point something that jams the motor could reason the motor to overhaet and in case you in basic terms stare at it for a on the same time as there is the distant threat that the motor will warmth up sufficient to combust the fabric around it. Ie flammable dirt, lint, etc...

Answer 9

Magnesium burns, it is usually caused by friction. The only thing that will put it out, is sand.