Calcium carbide industrial products are dark gray, tan or black gray, and those with high calcium carbide are blue purple. Its original section has gloss, and it absorbs water in the gas in dark gray or gray white. It can conduct heat. The higher the purity, the better the heat conduction. It can absorb water in gas. Add water to convert into acetylene and calcium hydroxide. It is converted into calcium cyanamide by reaction with nitrogen. Calcium carbide is one of the basic raw materials for chemical synthesis and chemical industry. It is the key raw material of acetylene chemical plant. Acetylene made from calcium carbide is widely used in metal welding and cutting.
Although calcium carbide has only appeared in the high school curriculum, it has been particularly favored by the question makers because of its diversity of structure and properties, making it one of the hot spots and famous star substances in the chemistry questions of the college entrance examination in recent years. The angle of its questions is not only novel, but also shows some regularity or characteristics. Calcium carbide is converted into acetylene and calcium hydroxide by solid-state and water chemical reaction, which is the only chemical reaction learned in middle school to produce acetylene by solid-state and water chemical reaction.
Acetylene ignites to produce a bright flame, accompanied by a large amount of thick smoke. Calcium hydroxide is a slightly soluble substance, which is easy to form a milky white suspension. The chemical reaction between calcium chloride solid state and water is a very strong chemical reaction, and the converted Ca (OH) 2 is easy to form a paste and block the holes of the plastic plate, so this chemical reaction can not be carried out in the Qipu generator, but can be carried out in a simple device that no longer contains the orifice plate.
Calcium carbide, the main component of calcium carbide, is inorganic compound, white crystal, industrial supplies are black gray blocks, and the section is blue purple or dark gray. In case of water, a violent chemical reaction occurs immediately, which is converted into acetylene and gives off heat. Calcium carbide is a key basic chemical raw material, which is mainly used to produce acetylene gas. It is also used in chemical synthesis, oxyacetylene welding, etc.
Store in a cool, dry warehouse with good natural ventilation. Eliminate kindling and heat sources. The air humidity shall be kept below 75%. The package must be sealed and protected from moisture. It should be stored separately from acids, alcohols, etc., and should not be mixed. The storage area should be equipped with suitable materials to contain leakage.
Heating furnace smelting method and oxygen heating method are generally used in industry. Heating furnace smelting method is to place coke and calcium oxide (molecular formula Cao) in a heating furnace at about 2200 ℃ for smelting and convert them into calcium carbide (molecular formula CaC2). Oxygen heating method: that is, smelting CaC2 (calcium carbide) with oxygen enriched oxygen heating method in blast furnace, obtaining carbon from limestone, and high temperature bottom pressure gas producer.
