Effects of calcium compounds on the carbothermic reduction of vanadium titanomagnetite concentrate

Abstract

Effects of calcium compounds on the carbothermic reduction of vanadium titanomagnetite concentrate (VTC) were investigated. It was found that calcium compounds had great effects on the metallization rate of the reduction product, the order of the metallization rate of reduction product being CaCO₃ > no additive > CaSO₄ > CaCl₂, which indicated that the addition of CaCO₃ was more conducive to promoting the reduction of iron than other calcium compounds. Gas analysis showed that there were mainly two processes in the carbothermic reduction of VTC, a solid-solid and a solid-gas reaction. The concentrations of CO and CO₂ were highest when CaCO₃ was added, while that in a roasting system decreased the most when CaCl₂ was added. X-ray diffraction (XRD) analysis showed that calcium compounds could change the reduction process of ilmenite in VTC. The phase compositions of the reduction products were changed from metallic iron (Fe) and anosovite (FeTi₂O₅) to metallic iron (Fe) and perovekite (CaTiO₃) when calcium compounds were added. Additionally, CaSO₄ and CaCl₂ could significantly promote the growth of metallic iron particles, though the existence of Fe-bearing Mg₂TiO₄ in reduction products was not conducive to the reduction of iron. The formation of FeS would further hinder the reduction of iron after adding CaSO₄.

Keywords

vanadium titanomagnetite concentrate / calcium compounds / carbothermic reduction / metallic iron / perovekite

References

[1] Pan F, Du Z, Zhang MJ, Sun HY. Relationship between the phases, structure, MgO migration and the reduction performance of the pre-oxidized vanadium-titanium magnetite ore in a fluidized bed. ISIJ Int., 2017, 57(3): 413.

[2] Imtiaz M, Rizwan M, Xiong SL, Li HL, Ashraf M, Shahzad S, Shahzad M, Rizwan M, Tua SX. Vanadium, recent advancements and research prospects: a review. Environ. Int., 2015, 80, 79.

[3] Xue YZ, Wang XF, Wang HJ, Li WC. On comprehensive utilization of vanadium-titanium magnetite resources in panzhihua region of sichuan province. Nat. Resour. Econ. China, 2017, 30(4): 9

[4] Mao HX, Zhang RD, Lv XL, Bai CG, Huang XB. Effect of surface properties of iron ores on their granulation behavior. ISIJ Int., 2013, 53(9): 1491.

[5] Zhang L, Zhang LN, Wang MY, Li GQ, Sui ZT. Recovery of titanium compounds from molten Ti-bearing blast furnace slag under the dynamic oxidation condition. Miner. Eng., 2007, 20(7): 684.

[6] Li ZH, Wang ZC, Li G. Preparation of nano-titanium dioxide from ilmenite using sulfuric acid-decomposition by liquid phase method. Powder Technol., 2016, 287, 256.

[7] Sun Y, Zheng HY, Dong Y, Jiang X, Shen YS, Shen FM. Melting and separation behavior of slag and metal phases in metallized pellets obtained from the direct-reduction process of vanadium-bearing titanomagnetite. Int. J. Miner. Process., 2015, 142, 119.

[8] Yang FL, Hlavacek V. Effective extraction of titanium from rutile by a low-temperature chloride process. AIChE J., 2000, 46(2): 355.

[9] Li W, Wang N, Fu GQ, Chu MS, Zhu MY. Influence of roasting characteristics on gas-based direct reduction behavior of Hongge vanadium titanomagnetite pellet with simulated shaft furnace gases. Powder Technol., 2017, 310, 343.

[10] Zhao W, Chu MS, Wang HT, Liu ZG, Tang J, Ying ZW. Reduction behavior of vanadium-titanium magnetite carbon composite hot briquette in blast furnace process. Powder Technol., 2019, 342, 214.

[11] Jena BC, Dresler W, Reilly LG. Extraction of titanium, vanadium and iron from titanomagnetite deposits at pipestone lake, Manitoba, Canada. Miner. Eng, 1995, 8(1–2): 159.

[12] Hu TY, Sun TC, Kou J, Geng C, Wang XQ, Chen C. Recovering titanium and iron by co-reduction roasting of seaside titanomagnetite and blast furnace dust. Int. J. Miner. Process., 2017, 165, 28.

[13] Samanta S, Goswami M, Baidya TK, Mukherjee S, Dey R. Mineralogy and carbothermal reduction behavior of vanadium-bearing titaniferous magnetite ore in Eastern India. Int. J. Miner. Metall. Mater., 2013, 20(10): 917.

[14] Zhang GM, Feng KQ, Yue HF. Theoretical analyses and experimental investigations of selective carbothermal reactions of vanadium-bearing titanomagnetite concentrates for preparation of iron-based wear-resistant material. JOM, 2016, 68(9): 2525.

[15] Yu W, Sun TC, Cui Q, Xu CY, Kou J. Effect of coal type on the reduction and magnetic separation of a high-phosphorus oolitic hematite ore. ISIJ Int, 2015, 55(3): 536.

[16] Chen SY, Chu MS. Metalizing reduction and magnetic separation of vanadium titano-magnetite based on hot briquetting. Int. J. Miner. Metall. Mater, 2014, 21(3): 225.

[17] Man Y, Feng JX, Li FJ, Ge Q, Chen YM, Zhou JZ. Influence of temperature and time on reduction behavior in iron ore-coal composite pellets. Powder Technol., 2014, 256, 361.

[18] Zhao YQ, Sun TC, Zhao HY, Chen C, Wang XP. Effect of reductant type on the embedding direct reduction of beach titanomagnetite concentrate. Int. J. Miner. Metall. Mater., 2019, 26(2): 152.

[19] Lv C, Yang K, Wen SM, Bai SJ, Feng QC. A new technique for preparation of high-grade titanium slag from titanomagnetite concentrate by reduction-melting-magnetic separation processing. JOM., 2017, 69(10): 1801.

[20] Yi LY, Huang ZC, Jiang T. Sticking of iron ore pellets during reduction with hydrogen and carbon monoxide mixtures: Behavior and mechanism. Powder Technol., 2013, 235, 1001.

[21] Chen DS, Song B, Wang LN, Qi T, Wang Y, Wang WJ. Solid state reduction of Panzhihua titanomagnetite concentrates with pulverized coal. Miner. Eng., 2011, 24(8): 864.

[22] Zhang JH, Zhang W, Zhang L, Gu SQ. Mechanism of vanadium slag roasting with calcium oxide. Int. J. Miner. Process., 2015, 138, 20.

[23] Jiang T, Wang S, Guo YF, Chen F, Zheng FQ. Effects of basicity and MgO in slag on the behaviors of smelting vanadium titanomagnetite in the direct reduction-electric furnace process. Metals, 2016, 6(5): 107.

[24] Liu ZG, Chu MS, Wang HT, Zhao W, Xue XX. Effect of MgO content in sinter on the softening-melting behavior of mixed burden made from chromium-bearing vanadium-titanium magnetite. Int. J. Miner. Metall. Mater., 2016, 23(1): 25.

[25] Chen C, Sun TC, Wang XP, Hu TY. Effects of MgO on the reduction of vanadium titanomagnetite concentrates with char. JOM, 2017, 69(10): 1759.

[26] Chen C, Sun TC, Kou J, Zhao YQ. Carbothermic reduction of vanadium titanomagnetite concentrate with magnesium compounds. Chin. J. Rare Met., 2018, 42(7): 765

[27] Zhou LH. Effects of CaO as an additive on the reduction of the vanadic-titanomagnetite-coal mixed pellets. J. Mater. Sci. Eng., 2010, 3(3): 345

[28] Jiang T, Xu J, Guan SF, Xue XX. Study on coal-based direct reduction of high-chromium vanadium-titanium magnetite. J. Northeast. Univ. Nat. Sci., 2015, 36(1): 77

[29] Jung SM. Effects of CaO/CaCO₃ on the carbothermic reduction of titanomagnetite ores. Metall. Mater. Trans. B, 2015, 46(3): 1162.

[30] Zhao YQ, Sun TC, Zhao HY, Li XH, Wang XP. Effects of CaCO3 as additive on coal-based reduction of high-phosphorus oolitic hematite ore. ISIJ Int, 2018, 58(10): 1768.