還元ペレツト法による鉄鋼製錬ダストの処理

抄録

The mechanism of volatilization removing of Pb and Zn from electric furnace dust by reducing pellet process was clarified and the behavior of volatilization of Cl and F was studied. When the dust pellets without carbon were roasted in air or water vapor atmospher, Pb in the dust was changed to PbCl₂ by coexisting NaCl and was volatilized above 90% at 1000°C. Pb compound, Pb (OH) Cl in the dust was decomposed to PbO and PbCl₂ at lower temperature, then PbCl₂ was removed. But, when NaCl content, was a little, sintering phenomena of the pellets by decomposition products PbO were observed and the fraction of volatilization of Pb was reduced at 1000°C. Cl-bearing compound was completely removed at 1100°Cin either roasting atmospher, but Zn was showed the fraction of volatilization of less than 20%. On the reducing treatment of pellets with carbon, Pb, Cl and Zn were entirely volatilized from the pellets above 1000°C. Iron contents in the pellets roasted above 1100°C were greater than 55% and it makes clear to use these pellets as iron ore.