Influence of adding Sewage Sludge instead of Coal Powder in the sintering process

摘要

Adding Sewage Sludge (SS) in sintering process may provide an alternative for disposal of SS. Therefore, the combustion characteristics of SS and Coal Powder (CP) mixed with the sinter were compared by Thermogravimetric Analysis (TGA) and the effects of adding SS on metallurgical properties of sinter were investigated by sintering pot tests in this paper. TGA results show that the combustion characteristics of SS (5%)-Sinter are better than CP (5%)-Sinter at the same heating rate. Besides, it is beneficial to decrease the ignition temperature by adding more SS into the sinter. The results of sintering pot tests indicate that increasing SS from 0% to 9% in the sintering process can increase the tumbler strength from 62% to 68% and the shatter strength from 63% to 67.4%, and reduce the abrasion index from 4.5% to 3.8%. In addition, the S content in the sinter from sintering pot tests, obtained via X-Ray Fluorescence, decreases from 0.223% to 0.197% and the P content increases from 0.201% to 0.276%; however, these changes are acceptable for the sinter. All these imply that SS is not only a good fuel for sintering, but that adding SS in the sintering process is appropriate as it could improve the metallurgical properties of the sinter to some extent. This will provide a good basis for the practical use of SS in the sintering process of the steel plant.