Formula: Alloy of magnesium and aluminum. Sometimes written: MgAl
Description: Magnalium is a very brittle alloy of magnesium and aluminum. Some common uses are in for spark effects, in strobing compositions and in crackling stars.
Hazards: Magnalium dust is harmfull and a dust mask should be worn when handling fine dust. Mixtures containing nitrates and mangalium sometimes heat up and may ignite spontaneously, especially when moist. This can usually be prevented by treating the magnalium with potassium dichromate. This is done by boiling the magnalium in a 5% potassium dichromate solution. Adding fine potassium dichromate powder to such compositions may also help.
Sources: Magnalium can be made at home. Plan well and prepare yourself for working with molten metals that may ignite if you plan to make it at home. If the metal ignites expect it to burn very brightly and hot. Explosions are not common but may occur if the hot melt is allowed to contact water or oxidisers. Do it outside and away from anything flammable. If it ignites don't try to extuingish it but get away from the burning mass and let it burn out and cool before approaching it. Don't look directly into the burning metal as it may damage your eyes. Start by melting aluminum in a stainless steel container. The molten metal should be covered with a blanked of inert gas. In this case neither nitrogen nor carbon dioxide will function as an inert gas. It is best to get a cylinder of argon gas at a welding supply store. Using an electric furnace for the melting is very convenient and allows good control over the temperature. To the molten aluminum magnesium is added in solid form. The melt should be stirred from time to time. When all the magnesium has melted, the melt is allowed to solidify. It is then easily crushed up in smaller chunks with an heavy hammer. These chunks are crushed further and sieved. It can also be ball milled into a fine powder using steel media but this can be dangerous since the metal powder can become pyrophoric.
Magnesium
Formula: Mg
Description: Magnesium powder is used in a wide variety of compositions, both for spark effects and 'normal' fuel purposes. Relatively coarse magnalium is used for spark effects. In flares and some bright colored star compositions it functions as a normal fuel. It is superior to aluminum in color compositions since MgCl2 and MgO are more easily vaporised than the corresponding aluminum compounds. This reduces the amount of black-body radiation and improves the color purity.
Hazards: Magnesium dust is harmfull and a dust mask should be worn when handling fine dust. Mixtures containing nitrates and magnesium sometimes heat up and may ignite spontaneously, especially when moist. This can usually be prevented by treating the magnesium with potassium dichromate. This is done by boiling the magnalium in a 5% potassium dichromate solution. The magnesium will turn brown when this is done. Adding fine potassium dichromate powder to such compositions may also help.
Sources: Making magnesium at home is very difficult. Magnesium can be bought in boating supply stores. It is used to prevent corrosion of a ships hull. For that purpose it is welded to the hull. The lower position of magnesium in the electrochemical series will make the magnesium corrode before the steel will. Making such a block of magnesium into a fine powder will not be easy. Filing or cutting and ball milling may be tried. Ball milling of metals can be dangerous however since the metal can become pyrophoric.
Nitric acid
Formula: HNO3
Description: Nitric acid is not used in pyrotechnic compositions but it can be used to prepare a variety of usefull nitrates from carbonates, hydroxides, oxides or free elements. It is used in the explosives industry in the preparation of a lot of commonly used explosives (eg TNT, RDX, PETN, nitrocellulose). Most high explosives have no use in fireworks, though nitrocellulose is used in some fireworks compositions as an acetone soluble binder.
Hazards: Nitric acid is corrosive. The fumes are dangerous to the lungs, eyes and skin. Skin will be stained yellow upon contact. Avoid all contact with both liquid and fumes. Wear eye and skin protection (lab apron, gloves, safety glasses, etc). In some reactions (especially those with metals) a brown gas will develop: nitrogen dioxide. It is very toxic, corrosive and will attack your lungs badly. Only work with nitric acid with adequate ventilation and proper protective clothing. Don't use any solutions more concentrated than 60%. Don't try to prepare high explosives at home and don't allow any organic material to contact nitric acid accidentially because that may result in the formation of dangerously explosive and/or sensitive materials.
Sources: It is possible to prepare nitric acid in several ways. It can also be bought at some drug stores. Here (in the Netherlands) it is sold under it's Latin name, 'acidum nitricum'. Other places where it is sold is at professional gardening suppliers and at welding shops (it is used to passivate stainless steel after welding). One way to prepare it is by distilling a mixture of sulphuric acid and sodium nitrate. This process is dangerous and requires some equipment. This method is probably too dangerous for the average amateur pyro. Another possible method is by precipitating barium sulphate from a barium nitrate solution by adding sulphuric acid. What remains is a nitric acid solution. It should be possible to prepare quite concentrated solutions by using concentrated sulphuric acid and a saturated (-not- hot!) barium nitrate solution. It is important that the sulphuric acid is added to the barium nitrate solution and not the other way around. The mixing of the liquids will produce heat and if the barium nitrate solution is added to the sulphuric acid it could cause sudden boiling and splatting. Therefore, add the sulphuric acid slowly to the barium nitrate while constantly stirring. Allow the mixture to cool from time to time if it gets too hot. A white precipitate of barium sulphate should form. The mixture is then filtered through a sintered glass filter to obtain clear solution of nitric acid.