What is calcium carbide? calcium carbide in life
Calcium carbide is the chemical name of calcium carbide and the molecular formula is CaC2. It is the basic raw material of organic synthesis chemical industry. Using calcium carbide as raw material can synthesize a series of organic compounds and provide raw materials for industry, agriculture and medicine. The main component of industrial calcium carbide is calcium carbide, and the rest are free calcium oxide, carbon andsiliconCompounds of magnesium, iron, aluminum and a small amount of phosphide and sulfide. The purity of industrial calcium carbide is about 70% -80%, the impurity CaO accounts for about 24%, and carbon, silicon, iron, calcium phosphide and calcium sulfide account for about 6%. Its newly created cross-section is shiny, and the appearance is gray, brown, purple or black depending on the content of calcium carbide. The one with higher calcium carbide is purple. Industrial product density 2.22g/cm3 (18 ° C), melting point 2300 ° C, can conduct electricity. The higher the purity, the easier the conduction.
The chemical properties of calcium carbide are very active. It decomposes violently in contact with water to produce acetylene gas and calcium hydroxide, and emits a lot of heat. It interacts with nitrogen to form calcium cyanamide. The main component of industrial calcium carbide is calcium carbide, and the rest are free calcium oxide, carbon, silicon, magnesium, iron, aluminum compounds and a small amount of phosphide and sulfide. Its newly created section is shiny, and its appearance is gray, brown, purple or black depending on the content of calcium carbide. The higher the purity of calcium carbide, the easier it is to conduct electricity.
The use of calcium carbide
(1) The acetylene formed by the reaction of calcium carbide with water can synthesize many organic compounds. For example: synthetic rubber, artificial resin, acetone, enone, carbon black, etc.; at the same time, acetylene-oxygen flame is widely used in welding and cutting of metals. (2) When heating powdered calcium carbide and nitrogen, the reaction generates calcium cyanamide, that is, lime nitrogen. When heating lime nitrogen, the cyanide melt formed by the reaction with table salt is used in gold mining and non-ferrous metal industries. (3) Calcium carbide itself can be used as a desulfurizer in the iron and steel industry. (4) To produce polyvinyl chloride (PVC), the calcium carbide method is used to produce polyvinyl chloride. The calcium carbide (CaC2) is used to generate acetylene (C2H2) in contact with water. The acetylene and hydrogen chloride (HCl) are synthesized to produce vinyl chloride monomer (CH2CHCl), and then the vinyl chloride is synthesized into polyvinyl chloride through polymerization reaction - [CH CHCI] n - The chemical reaction method. (5) In the old days, miners went into the mine and put calcium carbide into iron cans to use the generated acetylene (C2H2) to make calcium carbide lamps.
Production method of calcium carbide
In industry, electric furnace smelting method and oxythermal method are generally used. The electric furnace smelting method is to smelt coke and calcium oxide (molecular formula CaO) in an electric furnace at about 2200 ° C to generate calcium carbide (molecular formula CaC2). Oxythermal method: namely: blast furnace oxygen-enriched oxythermal smelting CaC2 (calcium carbide), carbon extraction from limestone, high temperature and low pressure gas generator. This third furnace uses process technology to make comprehensive use of the waste heat and coal ash in the coal gasification process. After the coal ash is melted with ingredients, CaC2 and ferrosilicon are generated (when purifying CaC2); "high temperature and low pressure" gas generator, so that the production (development) of gas is naturalized. For each ton of 80% CaC2 smelted, about 168kg of pure carbon is extracted from limestone to produce gas (CO at 55% - 95%) 6000 - 2600 m3, which can produce about 4.5 tons of methanol. Oxygen enrichment not only increases the furnace temperature but also improves the CO quality of gas. Oxygen is especially dual-purpose. The gas after the utilization of coal thermal energy is used for coal chemical industry or clean power generation. This process is energy-free and pollution-free CaC2 production and gas production. Closed operation, full ventilation. Operators must undergo special training and strictly abide by the operating procedures. It is recommended that operators wear self-priming filter dust masks, chemical safety protective glasses, chemical protective clothing, and rubber gloves. Avoid generating dust. Avoid contact with acids and alcohols. Special care should be taken to avoid contact with water. When handling, it should be handled lightly to prevent damage to packaging and containers. Equipped with spill emergency treatment equipment. Empty containers may remain harmful.
