Abstract: In response to the problem of nodule in the converter dry de-dusting flue, the characteristics of nodule were analyzed by XRF, XRD, SEM and other equipment, and the formation mechanism of nodule was analyzed in combination with thermodynamic calculation. The study shows that the nodule phenomenon in the converter dry de-dusting flue is mainly concentrated in the flue hood, the sloping area of the vaporization cooling flue, the end of the vaporization cooling flue, the evaporative cooler interior and banana bend area, and the reasons for the nodule include physical nodule and chemical nodule. Metal splashing in the initial stage of blowing is the main cause of nodule on the flue hood. The presence of a large amount of CaO and the basic oxides Fe?O? in the dust undergoes high-temperature reactions to form CaFe?O?, which is the primary cause of the formation of nodule in the sloping area of the vaporization cooling flue. The high-temperature reaction of ZnO with Fe?O? in the fly ash to form ZnFe?O? is the main reason for nodule at the end of the flue and inside the evaporative cooler, and CaO in the dust reacts with CO? in flue gas to form CaCO?, which will aggravate the nodule inside the evaporative cooler. The flue gas contains a large amount of NaCl and KCl, which are low-melting substances that can cause the size of the nodule in the flue to increase and their strength to augment.

Key words: converter dry de-dusting; flue; characteristics of nodule; formation mechanism of nodule