Fuel and oxidizer chemicals are used in three different ways. The fuse used to ignite the miniature rocket is made of very fine powder, which allows the wick to burn at a very controllable rate. This allows people who light fireworks to stay away for a while. Then, the burning fuse will ignite the larger powder particles at the bottom of the firework. The explosion caused the rocket to lift off.
The formation of fireworks can be roughly divided into two stages. The first stage is that the ignited fuse burns to the gunpowder part, ignites the gunpowder that is tightly packed in the explosive tube, discharges a large amount of hot gas, and pushes the firework to the sky;
The second stage is that as the fuel continues to burn inside the firework and the temperature rises, the functional additives in it are ignited to produce various colors, shapes and effects.
Fireworks require a lot of oxygen to promote combustion, which is the birthplace of oxidants. The oxidant almost sounds like a chemical substance rich in oxygen. The oxidant will release excess oxygen, which will explode better. The most commonly used oxidants are nitrate, chlorate and perchlorate. Today, a typical firework mixture includes fuel, an oxidizer that provides the oxygen required for combustion, and metal chlorides, which contain chloride ions that help color formation. Various chemical elements will produce a variety of colors. The principle is the same as that of spectrum generation on our instruments. The core is electronic transition, such as:
1. Sodium, if found in table salt, causes a strong yellow color
2. Copper produces blue
3. Lithium and strontium produce red
4. Barium is used to make green
5. Elemental calcium produces orange
John Conklin said that fireworks are an application of chemistry and engineering: you need good chemistry to rise in the air, and good engineering skills to ensure that they reach the right height and explode at the right time.
Fireworks shows last 15 to 20 minutes on average, but the planning and preparation required to produce these shows can take up to two years. Designers need enough time to determine the correct colors and shapes they want to use, and to determine the timing of the explosion and the soundtrack.