Abstract:The waste heat boiler of oxygen-enriched side-blown furnace in a lead smelter has serious fouling and coking, the flue gas channel becomes smaller, and a large amount of flue gas overflows, resulting in the system unable to produce normally. This paper mainly analyzed the main components, formation mechanism and causes of ash deposition and coking, and put forward measures to reduce coking and prevent coking. The fouling and coking of waste heat boiler are mainly affected by secondary air volume, furnace charge, side-blown furnace process control, negative pressure and other factors. By reasonably controlling the secondary air volume of the side-blown furnace, reducing the sulfur content of the high-lead slag in the bottom-blown furnace, controlling the input ratio of harmful elements, and reasonably controlling the reducing atmosphere and negative pressure of the side-blown furnace, the problem of ash deposition and coking in the waste heat boiler of the side-blown furnace was basically solved. The cleaning time was greatly reduced, from the original 90h to 15h, and the monthly operation rate of the side-blown furnace was increased from 89% to 94%.