Yellow Phosphorus Tail Gas Of Harmful Impurities In The Boiler Materials

In recent years, the global yellow phosphorus production center has been transferred to China. The productivity of phosphorus enterprise in China have been enlarged day by day. Rational utilization of yellow phosphorus tail gas and enviroment protection have became an important task. Yellow phosphorus tail gas which contains a lot of CO can be used as fuel. However, because of its strong corrosion behavior in high temperature yellow phosphorus tail gas cannot been utilized as boiler fuel. How to use yellow phosphorus tail gas as boiler fuel has been preliminary studied.(1) Yellow phosphorus tail gas which comes from the process of yellow phosphorus production have been comprehensive analysed and tested. In the papers, CO, O, CO₂, total phosphorus, PH₃, H₂S, COS, SO, CS₂, As and HF in the yellow phosphorus tail gas have been tested at the scene. According to the relevant references, the corrosion behavior of some of them have been summarized and analysed.(2) The corrosion behavior of yellow phosphorus tail gas has been preliminary studied and analysed in the papers through the testing corrosion failure tube by SEM and EDS, corrosion of spalling by XPS and the corrosion test. According to the analysis of the testing corrosion failure tube by SEM and EDS, corrosion of spalling by XPS and the corrosion test can be drawn that the content of P, S is increased but Fe is significantly reduced, binary and ternary eutectic phosphorus was formed on the surface of the sample after the corrosion, the mechanical properties of the sample after the corrosion is reduced. In order to keep boiler normal operation the content of PH₃ and H₂S should be less than 24.9 mg/Nm³ and 3.3 mg/Nm³ which is estimated in the paper.(3) The corroding of yellow phosphorus tail gas is caused by phosphorus, phosphorus compounds, sulfur and sulfur compounds. Removing corrosive substances from yellow phosphorus tail gas is one of the methods to solve the problem of corroding of yellow phosphorus tail gas.(4) The feasibility of using purified yellow phosphorus tail gas by caustic washing and catalytic oxidation process which is achievement of our group as fuel have been discussed in the papers.