Technological method for preparing zirconium tetrachloride by-product silicon tetrachloride by chlorinating zircon sand

Abstract

The invention discloses a technological method for preparing zirconium tetrachloride by-product silicon tetrachloride by chlorinating zircon sand. The technological method is characterized by comprising the following steps: (1) crushing: dry crushing zircon sand; (2) drying: drying the crushed zircon sand; (3) chlorination: adding the dry zircon sand into a boiling chlorination furnace, and addingCCl4 at that bottom of the furnace for chlorination; and (4) preparation: after the reaction, carrying out the gas-solid separation for ZrCl 4 and SiCl 4 gases generated in a fluidized bed by virtueof a dust collector at the top of the chlorination furnace, returning the collected dust to the furnace to continuously react, and washing and spraying the separated gases by virtue of molten salt. The technological method of the invention has the following advantages: the byproduct CCl4 of methyl chloride industry is converted into ZrCl 4 and SiCl 4 by utilizing the reaction process of zircon sand and CCl4, and the technological method is a pollution-free reaction process and has remarkable economic and environmental protection values; and by adopting the chemical reaction of solid and gas, the reaction temperature is low, the reaction speed is high, and the production capacity is high. The reacted exhaust gas carbon dioxide gas is liquefied and sold as a byproduct.

Description

Technical field [0001] The invention relates to the technical field of preparation of zirconium tetrachloride, in particular to a process method for preparing zirconium tetrachloride by-product silicon tetrachloride by chlorination of zircon sand. Background technique [0002] Crush the zircon sand to 200-325 mesh, and crush the petroleum coke to 100-200 mesh. The zircon sand and petroleum coke are fully mixed and dried in a ratio of 100:20-28, and then added to the boiling chlorination furnace at a uniform speed. The heating element in the chlorination furnace uses a graphite cylinder, and the external power supply of the chlorination furnace uses an intermediate frequency or power frequency induction coil to heat the graphite in the boiling chlorination furnace to supplement the heat required for the chlorination reaction. The reaction temperature is controlled at 1100 -1200℃, chlorine gas is introduced at the bottom, the generated silicon tetrachloride and zirconium tetrachlor...

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Problems solved by technology

[0004] 1. The particle size of zircon sand and petroleum coke is not easy to match, and stratification is easy to occur, forming a "dead furnace" and frequent slag discharge

[0005] 2. The particle size of the material is small, and it will continue to become smaller during the reaction process, and it will flow out of the chlorination furnace and enter the dust collector, which will reduce the metal recovery rate

[0006] 3. The reaction temperature is high, and the service life of the equipment is reduced under the condition of excessive chlorine gas

[0007] 4. This reaction is a chemical reaction of solid + solid + gas, and the reaction speed is slow, resulting in low production capacity per unit area

[0008] 5. The product quality is low. After zirconium tetrachloride and silicon tetrachloride are condensed by the first, second, and third series condensers, the product quality is inconsistent, and they are all crude zirconium tetrachloride. The grade of silicon tetrachloride collected is Also only about 80%, can not be commercially available

[0009] 6. The addition of heat replenishing agent will increase the output of silicon tetrachloride, but the benefit will not increase, because the price of zirconium tetrachloride is more than 10 times that of silicon tetrachloride

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