Method and device for producing high-purity boron tribromide

Abstract

The invention provides a method and device for preparing high-purity boron tribromide (BBr3) from boron carbide used as a raw material. The method comprises the following steps: vaporizing industrial grade liquid bromine through a vaporization kettle, introducing the bromine vapor into a drying chamber under the guidance action of a trace of nitrogen gas, removing moisture by means of anhydrous calcium chloride, feeding into a reaction furnace, and reacting with boron carbide particles at a reaction temperature of 650-850 DEG C to obtain boron tribromide containing impurities, dust and colors; performing ash removal on the boron tribromide through an ash blocker, removing residual bromine and iron ions by means of naphthol in a distillation kettle, and distilling to obtain white boron tribromide; and rectifying through a rectification tower, and removing high boiling point and low boiling point impurities to obtain a boron tribromide product of which the purity is greater than 5N, wherein the boron tribromide rectifying temperature is 120 DEG C, and the reflux ratio is 2-3.The high-purity boron tribromide preparation device provided by the invention is composed of the vaporization kettle, a dryer, the reaction furnace, the ash blocker, a condenser, the distillation kettle (for iron and bromine removal), the rectification tower and a finished product kettle. The purity of the boron tribromide produced by the invention can be up to 5N or above; and the method and device are low in cost and high in efficiency, and can realize industrial continuous production.

Description

technical field [0001] The invention relates to a production method and device of high-purity boron tribromide, belonging to the technical field of chemical materials. Background technique [0002] Boron tribromide is a colorless or slightly yellow fuming liquid with pungent odor at normal temperature and pressure, which is toxic and highly corrosive. Easily decomposed by water and alcohol, slowly decomposed by exposure to light or heat. High-purity boron tribromide is used in electronic industries such as integrated circuits, solar cells, semiconductors, etc. as a P-type doping source. At the same time, boron tribromide is an excellent demethylation or dealkylation reagent, which can be used as a catalyst, bromination agent, intermediate for polymerization, alkylation and acylation reactions, and as a methyl ether dehydroxylation protection to generate phenolic hydroxyl groups. Secondly, boron tribromide can also be used to produce high-purity ultra-fine boron powder thr...

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Problems solved by technology

Similarly, boron carbide also contains impurities such as Fe, iron oxide, and boron oxide, as well as free carbon and boron. During the reaction, iron bromide, unreacted residual bromine, and water that cannot be completely dried will react with boron tribromide. The boric acid dust and boron oxide dust produced will make the product poor in quality and light yellow to red in color, failing to meet high purity requirements

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