Deep purification method for oxidizing and alkali-washing yellow phosphorus tail gas

Abstract

The invention discloses a deep purification method for oxidizing and alkali-washing yellow phosphorus tail gas. The method comprises the following steps: washing yellow phosphorus tail gas generated from a yellow phosphorus industry for removing dust; alkali-washing the washed tail gas by using an NaOH solution; oxidizing and alkali-washing the tail gas subjected to alkali-washing by adopting a sodium hypochlorite solution, so as to obtain purified yellow phosphorus tail gas; enabling a washing waste liquor generated after oxidizing and alkali-washing to react with CaO, filtering away precipitates, enabling the obtained filtrate to enter a sodium hypochlorite generator to generate a sodium hypochlorite solution, returning the sodium hypochlorite solution to the oxidizing and alkali-washing step for reuse. According to the method, sodium hypochlorite can be recycled, so that the use amount of the sodium hypochlorite can be greatly reduced, and the corrosion on equipment can be lightened. The content of phosphorus and hydrogen phosphide in discharged tail gas washed by adopting the method is not larger than 100 mg / m<3>, and the water content of discharged tail gas is not larger than 20 g / m<3>, so that the requirement that the content of sulfur and phosphorus impurities in a fuel is required to be lower than 100 mg / m<3>, can be met.

Description

technical field [0001] The invention belongs to the technical field of chemical engineering and environmental protection, and in particular relates to a method for deep purification of yellow phosphorus by oxidizing alkali washing. Background technique [0002] At present, domestic yellow phosphorus production enterprises not only use yellow phosphorus tail gas as heat source gas for raw material drying and supporting phosphate plant, but also generally as heat source for phosphorus bleaching hot water preparation. This part of the yellow phosphorus tail gas does not need to be strictly purified, and it is the most common way of comprehensive utilization of tail gas used by domestic yellow phosphorus production enterprises. But this part of the yellow phosphorus tail gas consumption only accounts for 40-50% of the available amount, and there is still a large amount of tail gas being burned in vain, which wastes energy and pollutes the environment. How to make effective ther...

AI Technical Summary

Problems solved by technology

[0008] The purpose of the present invention is to overcome the defects of the prior art, aiming at the problems of high impurity content when yellow phosphorus tail gas is used as fuel, unsatisfactory removal effect of existing methods, high production cost, etc., to provide a deep purification of yellow phosphorus tail gas by oxidative alkali washing Methods

Images