Method for purifying yellow phosphorus by using methods of activated carbon adsorption together with dilute nitric acid rinsing

Abstract

The invention discloses a method for purifying yellow phosphorus by adopting methods of activated carbon adsorption together with dilute nitric acid rinsing. Firstly, activated carbon and molten industrial yellow phosphorus are mixed and stirred in a refining kettle, and after the adsorption is completed, the activated carbon is separated from the yellow phosphorus by a filter machine; then the processed yellow phosphorus is circularly rinsed with dilute nitric acid in an acid pickling tower; residual organic matters, arsenic and low-price metal ions in the yellow phosphorus, which are not adsorbed by the activated carbon, are oxidized by utilizing the oxidizability of the dilute nitric acid; and afterwards, the yellow phosphorus is circularly rinsed in a water washing tower by using deionized water, thereby completing yellow phosphorus purification. The invention adopts a process with treatment methods of activated carbon adsorption, dilute nitric acid rinsing and deionized water rinsing, and integrates the advantages of various methods; and the content of arsenic in the acquired yellow phosphorus is reduced to below 20 ppm, so that high-purity yellow phosphorus satisfying the requirement for producing electronic grade phosphoric acid can be acquired, and the hidden danger of explosion caused by using high concentration nitric acid is avoided.

Description

technical field [0001] The invention belongs to the technical field of yellow phosphorus production, and in particular relates to a method for producing high-purity yellow phosphorus for producing electronic-grade phosphoric acid by using active carbon adsorption combined with nitric acid rinsing to purify industrial yellow phosphorus. Background technique [0002] High-purity yellow phosphorus is the main basis for the production of various industrial grades, food grades, pharmaceutical grades, reagent grades and other high value-added fine phosphorus products. At present, the yellow phosphorus produced by the electric furnace method needs to be purified to meet its downstream production requirements. Quality requirements for high value-added fine phosphorus products. [0003] The purification of yellow phosphorus mainly removes impurities such as arsenic, silicon, and organic carbon. At present, the methods for purifying and purifying yellow phosphorus mainly include pick...

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Problems solved by technology

[0004] The pickling method is to use sulfuric acid or nitric acid to oxidize and remove impurities in yellow phosphorus. However, in order to obtain high-quality yellow phosphorus, a high-concentration acid must be used, but there is a great safety hazard during the operation. In the past, There have been case reports of explosions in yellow phosphorus rinsed with concentrated acid; the activated carbon adsorption method uses the high specific surface area of ​​activated carbon to absorb dust particles, organic matter and some arsenic and other impurities in yellow phosphorus, but the obtained yellow phosphorus has a high metal ion content; Distillation needs to be used in combination with other methods, and is mainly used to produce ultra-high-purity yellow phosphorus. The process is complicated, the investment cost is high, and it is difficult to realize industrial production.