Steel smelting plant: The coated PTFE filter bag used has excellent high temperature resistance and can work stably for a long time in the high temperature environment of steel smelting, preventing material aging, deformation or failure due to high temperature. Its excellent chemical stability can resist various corrosive gases and particulate matter generated during the steel smelting process, extend the service life of filter bags, reduce replacement frequency and costs, while ensuring dust removal effect, improving the environmental protection level and production efficiency of the smelting process.