Nitrogen oxide waste gas treatment equipment project

　　This project was formally put into operation in April 2021, and is used to treat the tail gas of silver refining and platinum-palladium refining in the first workshop of Guixi Smelter, including the high concentration of nitrogen oxides produced by silver dissolving in nitric acid and the alkaline exhaust gas produced by platinum-palladium complexing kettle. For the high concentration of nitrogen oxides generated from nitric acid silver dissolution, the project adopts two-stage bubble absorption + three-stage jet absorption + two-stage venturi treatment + two-stage alkali spraying for treatment, and for the alkaline exhaust gas generated from platinum-palladium complexing, it adopts one-stage venturi treatment + one-stage acid spraying for treatment. The acidic exhaust gas in the workshop is summed up and then enters the two-stage lye spray tower for treatment, and the alkaline exhaust gas is summed up and then enters the first-stage acid spray tower for treatment, and the treated exhaust gas is then discharged from the chimney, and the project requires the nitrogen oxide exhaust gas emission concentration to be lower than 100mg/m3 and the ammonia concentration to be lower than 5mg/m3.

　　The project was formally put into operation in April 2021, with online monitoring system. The concentration of nitrogen oxide produced by the workshop is 30,000mg/Nm, ammonia concentration is 4,000mg/Nm, hydrochloric acid, nitric acid and sulfur dioxide concentration is 400mg/Nm, and the emission of nitrogen oxide exhaust gas concentration is 40mg/m3, ammonia concentration emission concentration is 1mg/m3, hydrochloric acid, Nitric acid, sulfur dioxide and other acidic waste gas treatment emissions were not detected. The overall operation of the project is good and there is no equipment failure.

　　After the project was awarded (September 2020), Jiangxi Copper Jiujiang Lead and Zinc Smelter signed an agreement with the Company to rectify the waste gas from the rare and precious workshop to deal with the high concentration of nitrogen oxides produced by its nitric acid silver dissolution, and the Company adopted two-stage bubble absorption + four-stage jet absorption + one-stage lye spraying for treatment. The NOx emission concentration is 40mg/m3, which is much lower than the requirement of 100mg/m3 signed in the agreement, and the project has been strongly affirmed by the owner.