Carbide of aluminum has chemical formula Al4C3, externally represents itself crystals of yellowish color. Treats to the first group of carbides which composition corresponds to typical valencies of metals (there is an exception – beryllium carbide with a formula Be2C). How to receive aluminum carbide?
Instruction
1. Easily reacts with the diluted acids and water, forming methane and, respectively, either salt, or a hydroxide. By the way, influence by water on aluminum carbide – one of the easiest ways of receiving methane in vitro (at chemistry lessons, for example). Reaction goes as follows: Al4C3 + 12H2O = 4Al (OH)3 + 3CH4
2. At strong heating, carbide of aluminum can react with hydrogen (being restored to pure aluminum and forming methane) and oxygen (forming the main oxide of aluminum and carbon dioxide). Reacts with the strong bases, forming complex salts of aluminum.
3. The main way of receiving this substance in the industry – reaction of aluminum with carbon in the arc electric furnace. It proceeds thus: 4Al + 3C = Al4C3
4. Also carbide of aluminum is formed by production of pure aluminum as the blanket of graphite electrodes at high temperatures (about 1500 - 1700 degrees) reacts with the melted product. Reaction course the same: 4Al + 3C = Al4C3
5. Aluminum begins to interact with graphite already at temperatures about 650 degrees and when temperature reaches about 1400 degrees, reaction proceeds much more vigorously. The greatest number of carbide of aluminum is formed if as raw materials serves aluminum oxide (unlike the silicon dioxide having ability to decompose the formed carbides). In this case, the mix consisting of metal aluminum (60 — 80% on weight), carbide of aluminum of 20 — 35% and oxide of aluminum of 3 — 5% turns out.
6. There is still a way of receiving – by calcinating of the main oxide of aluminum (Al2O3) with coke (C). Reaction goes at very high temperature (about 1800 degrees), the next way: 2Al2O3 + 9C = Al4C3 + 6CO