Effect of organic binders on the activation and properties of indurated magnetite pellets

Abstract

In the ironmaking process, the addition of an organic binder to replace a portion of bentonite has the potential to improve the performance of pellets. The interaction between original bentonite (OB) and organic binder was investigated. Results indicated that the micromorphology of organic composite bentonite (OCB) became porous and the infrared difference spectrum exhibited a curved shape. In addition, the residual burning rates of OB and organic binder were determined to be 82.72% and 2.30%, respectively. Finally, the influence of OCB on the properties of pellets was investigated. The compressive strength of OCB-added green pellets (14.7 N per pellet) was better than that of OB-added pellets (10.3 N per pellet). Moreover, the range of melting temperature of OCB-added green pellets (173°C) was narrower than that of OB-added pellets (198°C). The compressive strength of OCB-added green pellets increased from 2156 to 3156 N per pellet with the increase in roasting temperature from 1200 to 1250°C.

Keywords

pellets / organic composite bentonite / softening-melting property / interaction behavior

References

[1] Zhang H Q, Fu J T. Oxidation behavior of artificial magnetite pellets. Int. J. Miner. Metall. Mater., 2017, 24(6): 603.

[2] Chen J, Jiao Y, Wang X. Thermodynamic studies on gas-based reduction of vanadium titano-magnetite pellets. Int. J. Miner. Metall. Mater., 2019, 26(7): 822.

[3] Eisele TC, Kawatra SK. A review of binders in iron ore pelletization. Miner. Process. Extr. Metall. Rev., 2003, 24(1): 1.

[4] Srivastava U, Kawatra SK, Eisele TC. Study of organic and inorganic binders on strength of iron oxide pellets. Metall. Mater. Trans. B, 2013, 44(4): 1000.

[5] Cheng GJ, Gao ZX, Yang H, Xue XX. Effect of diboron trioxide on the crushing strength and smelting mechanism of high-chromium vanadium-titanium magnetite pellets. Int. J. Miner. Metall. Mater., 2017, 24(11): 1228.

[6] Kotta AB, Patra A, Kumar M, Karak SK. Effect of molasses binder on the physical and mechanical properties of iron ore pellets. Int. J. Miner. Metall. Mater., 2019, 26(1): 41.

[7] Kawatra SK, Ripke SJ. Laboratory studies for improving green ball strength in bentonite-bonded magnetite concentrate pellets. Int. J. Miner. Process., 2003, 72(1): 429.

[8] Liu H, Xie B, Qin YL, Alba MD. Effect of Bentonite on the pelleting properties of iron concentrate. J. Chem., 2017, 2017, 1.

[9] Zhou YL, Kawatra SK. Humic substance-based binder in iron ore pelletization: A review. Miner. Process. Extr. Metall. Rev., 2017, 38(5): 321.

[10] Bhuiyan IU, Mouzon J, Schröppel B, Kaech A, Dobryden I, Forsmo SP, Hedlund J. Microstructure of bentonite in iron ore green pellets. Microsc. Microanal., 2014, 20(1): 33.

[11] Wang RR, Zhang JL, Liu YR, Zheng AY, Liu ZJ, Liu XL, Li ZG. Thermal performance and reduction kinetic analysis of cold-bonded pellets with CO and H₂ mixtures. Int. J. Miner. Metall. Mater., 2018, 25(7): 752.

[12] Zhang YB, Zhou YL, Liu BB, Li GH, Jiang T. Roasting characteristics of specularite pellets with modified humic acid based (MHA) binder under different oxygen atmospheres. Powder Technol., 2014, 261, 279.

[13] Linhares FM, Victor CCF, Lemos LR, Bagatini MC. Effect of three different binders and pellet feed on granulation behaviour of sintering mixtures. Ironmaking Steelmaking, 2020, 47(9): 911.

[14] Yang YB, Huang GX, Jiang T, Huang ZC, Luo Y, Huang YL. Application of organic binder as substitutes for bentonite in pellet preparation. J. Cent. South Univ. Sci. Technol., 2007, 38(5): 850.

[15] Qiu GZ, Jiang T, Huang ZC, Zhu DQ, Fan XH. Characterization of preparing cold bonded pellets for direct reduction using an organic binder. ISIJ Int., 2003, 43(1): 20.

[16] Ammasi A, Pal J. Replacement of bentonite in hematite ore pelletisation using a combination of sodium lignosulphonate and copper smelting slag. Ironmaking Steelmaking, 2016, 43(3): 203.

[17] Sivrikaya O, Arol AI, Eisele T, Kawatra SK. The effect of calcined colemanite addition on the mechanical strength of magnetite pellets produced with organic binders. Miner. Process. Extr. Metall. Rev., 2013, 34(4): 210.

[18] Kawatra S K, Halt J A. Binding effects in hematite and magnetite concentrates. Int. J. Miner. Process., 2011, 99(1): 39.

[19] Fan XH, Wang Y, Gan M, Yuan LS, Dai LQ, Zhao GG. Strength enhancement of oxide pellet with organic binder. J. Iron Steel Res., 2008, 20(5): 5.

[20] Zhu DQ, Mendes V, Chun T, Pan J, Li QH, Li J, Qiu GZ. Direct reduction behaviors of composite binder magnetite pellets in coal-based grate-rotary kiln process. ISIJ Int., 2011, 51(2): 214.

[21] Ridha FN, Manovic V, Anthony EJ, MacChi A. The morphology of limestone-based pellets prepared with kaolin-based binders. Mater. Chem. Phys., 2013, 138(1): 78.

[22] Y.B. Zhang, M.M. Lu, Z.J. Su, J. Wang, Y.K. Tu, X.J. Chen, C.T. Cao, F.Q. Gu, S. Liu, and T. Jiang, Interfacial reaction between humic acid and Ca-Montmorillonite: Application in the preparation of a novel pellet binder, Appl. Clay Sci., 180(2019), No. 6, art. No. 105177.

[23] De Moraes SL, De Lima JRB, Neto JBF, Fredericci C, Saccoccio EM. Binding mechanism in green iron ore pellets with an organic binder. Miner. Process. Extr. Metall. Rev., 2020, 41(4): 247.

[24] Zhu DQ, Xiong SA, Pan J, Zhou XL. Improving pelletization of magnetite concentrate by organic complex bentonite and its industrial application. J. Cent. South Univ. Sci. Technol., 2011, 42(2): 279.

[25] Kumar S, Suman S. Compressive strength of fired pellets using organic binder: response surface approach for analyzing the performance. Trans. Indian Inst. Met., 2018, 71(7): 1629.

[26] Zhou YL, Kawatra SK. Pelletization using humic substance-based binder. Miner. Process. Extr. Metall. Rev., 2017, 38(2): 83.

[27] Ivanova BB, Tsalev DL, Arnaudov MG. Validation of reducing-difference procedure for the interpretation of non-polarized infrared spectra of n-component solid mixtures. Talanta, 2006, 69(4): 822.