Suppressing SO3formation in copper smelting flue gas by ejecting pyrite into flue

SO(3)in the copper smelting flue gas not only causes serious corrosion in heat exchange and dust collection equipment but also increases the amount of sewage acid (waste acid or polluted acid from copper smelting). In this study, we attempted to reduce the damage by ejecting pyrite into the flue to suppress SO(3)formation in the flue. First, the Gibbs free energy for the chemical reactions between the substances was obtained after ejecting pyrite. Subsequently, the thermodynamic study of SO2-O-2-H2O-N-2-CO2-CO system was performed. Then, a kinetic study on the decomposition and oxidation behaviour of pyrite in the flue system was performed through thermogravimetric experiments. Results show that pyrite decomposition and oxidation in the flue system have a very strong oxygen consumption capacity. The SO(3)formation in the copper smelting flue gas is suppressed by the consumption of oxygen in the flue to control the reaction direction of 2SO(2)+ O-2 2SO(3)and the partial pressure of SO3.

Automated summary

In this study, pyrite was ejected into the copper smelting flue gas to suppress the formation of SO(3), which causes serious corrosion in equipment and increases the amount of sewage acid. The thermogravimetric experiments revealed that pyrite in the flue system has a strong oxygen consumption capacity, which in turn suppresses the formation of SO(3).