# Generation and Inhibition of SO\({}_{3}\) in Lead Smelting Flue Gas
## 3 Results and Discussion
### Generation of SO\({}_{3}\) in Simulated Lead Smelting Flue Gas
#### 3.1.2 The Effect of Initial SO\({}_{2}\) Content on SO\({}_{3}\) Generation
By comparing and analyzing the data in the high-temperature region (T \(>\) 783 \({}^{\circ}\)C) of Figure 2c,d, it can be found that the influence of oxygen concentration regulation on SO\({}_{3}\) formation exhibits a significant temperature dependence. Above the thermodynamic decomposition temperature, even if the O\({}_{2}\) concentration is decreased from 5% to 1%, the SO\({}_{3}\) concentration decreases from 3.6% to 1.2%, which is mainly attributed to the enhanced effect of the spontaneous decomposition of SO\({}_{3}\) under high-temperature conditions. At this time, the sulfur components in the system mainly follow the dynamic equilibrium of 2 SO\({}_{3}\)\(\leftrightarrow\)2 SO\({}_{2}\) + O\({}_{2}\). Although the change in oxygen concentration can still affect the equilibrium shift according to [PERSON]'s principle, its regulatory efficiency is significantly weakened compared to that in the low-temperature region. 3.1.4. The Effect of Initial CO\({}_{2}\), CO, SO\({}_{3}\), and H\({}_{2}\)O Contents on SO\({}_{3}\) Generation  
Additional equilibrium simulations were conducted at fixed temperatures (200 \({}^{\circ}\)C, 400 \({}^{\circ}\)C, 900 \({}^{\circ}\)C, 1300 \({}^{\circ}\)C) to evaluate the effects of initial CO\({}_{2}\) (0-15%), CO (0-5%), SO\({}_{3}\) (0-5%), and H\({}_{2}\)O (0-10%) concentrations on final equilibrium compositions. As these  
Figure 3: Effect of initial oxygen content on content of final-gas-phase components, X: O\({}_{2}\) content, mol%; Y: content of component at equilibrium: (a) 200 \({}^{\circ}\)C; (b) 400 \({}^{\circ}\)C; (c) 900 \({}^{\circ}\)C; (d) 1300 \({}^{\circ}\)C.  
parameters demonstrated a limited influence on SO\({}_{3}\) generation with minimal graphical variations, the key findings related to these parameters are summarized below:  
CO\({}_{2}\) Influence: Variations in the initial CO\({}_{2}\) concentration showed a negligible impact (<0.5% deviation) on the equilibrium component distributions across all temperatures. The practical implications are that CO\({}_{2}\) injection primarily alters flue pressure and SO\({}_{3}\) partial pressure rather than chemical equilibria. CO Effects: CO concentrations >2% significantly suppress SO\({}_{3}\) formation via O\({}_{2}\) depletion (\(\Delta\)SO\({}_{3}\)\(\leq-\)34% at 200 \({}^{\circ}\)C) when temperatures are <400 \({}^{\circ}\)C. Minimal SO\({}_{3}\) inhibition (\(\Delta\)SO\({}_{3}\) < 3%) is observed due to thermal decomposition dominance at elevated temperatures (>900 \({}^{\circ}\)C). H\({}_{2}\)O Interactions: A high H\({}_{2}\)O content (>6%) induces sulfuric acid condensation below 250 \({}^{\circ}\)C, exacerbating flue corrosion risks. Moisture control strategies should focus on maintaining a feedstock humidity of <5% and preventing ambient moisture ingress during processing. SO\({}_{3}\) Feedstock Analysis: The initial SO\({}_{3}\) concentration is strongly correlated with the final equilibrium SO\({}_{3}\) concentration in low-temperature systems (200-400 \({}^{\circ}\)C). SO\({}_{3}\) decomposes into SO\({}_{2}\) and O\({}_{2}\) (up to 89% conversion) in high-temperature systems (>900 \({}^{\circ}\)C). This systematic analysis quantifies secondary parameter influences, enabling optimized gas composition control in pyrometallurgical operations [23; 24; 25].