Method and device for preparing high-purity yellow phosphorus industrially and continuously

Abstract

The invention relates to a method for preparing high-purity yellow phosphorus industrially and continuously. The method comprises the steps that nitrogen is used for purging a rectifying tower at first so as to make the inert environment, and then a vacuum pump is used for vacuumizing a rectification system; an acid solution and liquid yellow phosphorus heated to 70-80 DEG C are mixed through a liquid mixer and then added into a tower kettle of the rectifying tower, yellow phosphorus flowing back from the tower top and yellow phosphorus steam ascending from the tower bottom make sufficient contact inside the tower to be subjected to gas-liquid exchange, and high-purity yellow phosphorus is extracted. A device comprises the tower kettle. The rectifying tower is arranged on the tower kettle. An integrated tower top cooler is arranged on the top of the rectifying tower. A vacuum skid mounted device is arranged on the integrated tower top cooler. A gravity type backflow extraction device is arranged at the upper portion of the rectifying tower and the lower portion of the integrated tower top cooler through guide pipes. Due to rectification, the content of arsenic in a tower top product is smaller than 30 ppb, and the content of antimony in the tower top product is smaller than 100 ppb.

Description

technical field [0001] The invention relates to a method and equipment for preparing high-purity yellow phosphorus, in particular to an acid-adding rectification method for industrially and continuously preparing high-purity yellow phosphorus. Background technique [0002] Electronic-grade phosphoric acid is an ultra-high-purity chemical reagent used in the electronics industry. It is widely used in microelectronics industries such as ultra-large-scale integrated circuits and large-screen liquid crystal displays. It is mainly used for wet cleaning and wet etching of chips. With the development of the electronic information industry, the semiconductor industry has higher and higher requirements for electronic grade phosphoric acid. High-purity yellow phosphorus is the main raw material for preparing electronic-grade phosphoric acid. Therefore, the content of impurities must be controlled from the raw material. The purity of yellow phosphorus must be above 5N, the content of a...

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Problems solved by technology

U.S. Patent UP4483746 discloses a kind of physical yellow phosphorus purification process, which adopts simple distillation to purify yellow phosphorus, and the yellow phosphorus arsenic content is about 1.0ppm through refining and separation, and the total impurity metal ion is 100ppm; Document (Inorganic Salt Chemical Industry , 2004, 36(2): 24~28) studied the method of purifying and separating yellow phosphorus by using oxidant and then extracting and adsorbing in the laboratory stage; literature (ChemicalIngTech, 1964, 26: 957-959) studied The method of purifying industrial yellow phosphorus by regional melting method, but its purification efficiency is low; some scholars have studied the method of refining yellow phosphorus by using electromagnetic purification method. The method does not need to add chemical reagents and consumes less energy, but its research is in its infancy. Not yet ready for industrial application

[0004] At present, the existing domestic technology for preparing high-purity yellow phosphorus cannot meet the requirements for preparing electronic-grade phosphoric acid. The present invention mainly provides a method for industrially and continuously preparing high-purity yellow phosphorus, aiming at solving this problem from raw materials for producing electronic-grade phosphoric acid. problem

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