A method for preparing low-arsenic yellow phosphorus using a microchannel reactor

Abstract

The invention discloses a method for preparing low arsenic yellow phosphorus by using a microchannel reactor, comprising the following steps: heating and melting industrial yellow phosphorus; using ultrapure water to prepare an oxidizing agent into an oxidant solution with the mass concentration of 5% to 20%; conveying the oxidant solution and the molten industrial yellow phosphorus at a volume flow ratio of (1 to 9):1 to the microchannel reactor I by a metering pump, and reacting at 50 to 90 DEG C for 5s to 60s to obtain the arsenic-removed yellow phosphorus; respectively pumping ultrapure water and the arsenic-removed yellow phosphorus at a volume flow ratio of (1-9):1 into the microchannel reactor II through a metering pump, and performing countercurrent washing at a temperature of 50 to 90 DEG C for 5s to 60s to obtain the low arsenic yellow phosphorus, wherein the oxidizing agent is nitric acid, hydrogen peroxide or hypochlorous acid. The method has the advantages of high arsenicremoval rate, high phosphorus yield and good safety.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, and specifically relates to a method for preparing low-arsenic yellow phosphorus by using a microchannel reactor. Background technique [0002] Yellow phosphorus is an important chemical raw material. In some specific application fields (such as electronic materials such as pharmaceutical intermediates indium phosphide and gallium phosphide), the purity requirements for yellow phosphorus are high, and strict requirements are put forward for the impurity content in yellow phosphorus. requirements, wherein the arsenic content must be less than 20ppm. Arsenic mainly exists in phosphate rock in the form of arsenate. Since phosphorus and arsenic belong to two adjacent elements of the same main group, many physical and chemical properties are similar. Reduction, the two are condensed in the yellow phosphorus product at the same time, arsenic exists in the eutectic form of arsenic phosphide, ...

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Problems solved by technology

[0004] Existing documents such as Japanese Patent Laid-Open No. 5-116916, Japanese Showa 54-93692, WO99 / 62819, CN1257040, CN102107859A, CN1311756A, etc. have reported some methods for removing arsenic by aqueous phase oxidation, but there are some or low arsenic removal efficiency in the implementation process , or low yield of yellow phosphorus, or low safety, or complex process, or high production cost, poor economy and other defects