Study on passivation technology of zinc-containing dust metallized pellets
Rotary hearth furnace process is one of the main processes for treating zinc-containing dust in iron and steel works.The passivation technology of metallized pellets with zinc dust was studied in view of the problems that zinc-containing dust metallized pellets produced by rotary hearth furnace are easy to heat and spontaneous combustion during stacking,which seriously affect the storage,transportation and use of products.The results show that during the cooling and storage of metal pellets,the highly active sponge iron reacts with water to produce hydrogen.Meanwhile,one main reason for autoignition and calorification of metallized pellets is that the galvanic battery reaction occurs to generate the hydrogen,and much heat releases from oxidation of metallized iron within pellets.Compared with natural passivation,spraying CaCl2,lime water and other solutions,the use of MgCl2 solution(5 wt.％)to spray zinc dust metallized pellets,cooling and passivation,has a better effect.After storage of the treated metal pellets for 360 h,oxidation weight gain rate is only 1.42％,the metallization rate of pellets decreased by less than 12％.The expanded experiment proves the feasibility of the passivation technology in actual production,which provides a new solution for the safe storage of zinc-containing dust metallized pellets produced by the rotating hearth furnace process.
万方数据
维普
