碱度对富矿粉厚料层烧结固相反应及矿物生成的影响  

Influence of basicity on solid phase reaction and mineral formation in high feed sintering of ore-rich

作　　者：郄亚娜 李宇壮 白诗皓 王建芳 刘鹏 刘然 QIE Ya-na;LI Yu-zhuang;BAI Shi-hao;WANG Jian-fang;LIU Peng;LIU Ran(College of Metallurgy and Energy,North China University of Technology,Tangshan 063009,Hebei,China;Delong Iron and Steel Group,Xingtai 054400,Hebei,China)

机构地区：[1]华北理工大学冶金与能源学院,河北唐山063009 [2]德龙钢铁有限责任公司,河北邢台054400

出　　处：《中国冶金》2023年第2期38-46,共9页China Metallurgy

基　　金：邢台市科技计划资助项目(2020ZC045);河北省自然科学基金资助项目(E2020209208,E2021209023);国家自然科学基金资助项目(52104328)。

摘　　要：富矿粉具有铁品位高、杂质少的优点,但粒度较大,其配比增大后会使混合料平均粒度增加,易导致垂直烧结速度过快,不利于烧结过程的液相生成和冷凝固结,从而影响烧结矿质量和强度。碱度和料层厚度是影响烧结过程固相反应、液相生成的关键因素,通过热力学计算及试验,研究了二元碱度对富矿粉厚料层烧结固相反应及矿物生成的影响机理,解析了烧结过程固相反应及液相生成过程,并计算了烧结理论配碳量,分析了碱度对烧结矿相组成和冶金性能的影响。研究结果表明,随二元碱度的增加,熔剂中CaO有利于固相反应,使CAF3、CAF1等铁酸钙相增加,促进液相的生成与发展;也使硅灰石(Bredigite)相生成温度逐渐降低、数量逐渐增多,而尖晶石(Spinel)、黄长石(Melilite)逐渐减少,均有利于黏结相生成和固结。另外,通过对900mm厚料层烧结杯试验后的烧结矿进行矿相分析发现,当二元碱度从1.9增加到2.1时,烧结矿中铁酸钙含量增加,原始和再生赤铁矿减少,在低温还原时产生的应力减少,使其低温还原粉化指标得到改善,烧结矿的还原性提高;但当碱度继续增加时,烧结矿中形成了更多硅酸钙相,尤其是β-C2S相的增加降低了烧结矿的强度和冶金性能。Ore-rich powder has the advantages of high iron grade and few impurities.However,particle size of orerich powder is large,and the average particle size of granulating pellets increases after its proportion increasing.It easily leads to the rapid vertical sintering speed,and is not conducive to the liquid phase generation and condensation consolidation in the sintering process,which will affect the quality and strength of sinter.Basicity and layer thickness are the key factors affecting the solid phase reaction and liquid phase formation in sintering process.The influence mechanism of binary basicity on solid phase reaction and mineral formation in high feed sitering of ore-rich was studied by thermodynamic calculation and experiment,the solid phase reaction and liquid phase formation process were analyzed,the theoretical carbon content of sintering was calculated,and the influence of basicity on sinter phase composition and metallurgical properties was analyzed.The results show that with the increase of binary basicity,the CaO in the flux is beneficial to the solid phase reaction,which increases CAF3,CAF1and other calcium ferrite phases,and promotes the generation and development of liquid phase.It also reduces the generation temperature of Bredigite phase and increases the number of Bredigite phase,while Spinel and Melilite decrease gradually.It is favorable for bonding phase formation and consolidation.Through the mineral phase analysis of sinter after the sinter cup test with 900mm thick material layer,it is found that when the binary basicity increases from 1.9to 2.1,the content of calcium ferrite in sinter increases,the original and regenerated hematite decreases,and the stress generated during low temperature reduction decreases,so that the low temperature reduction degradation index is improved and the reducibility of sinter is improved.However,when the basicity continues to increase,more calcium silicate phases are formed in sinter,especially the increase ofβ-C2S phase reduces the strength and metallurgi

关 键 词：碱度 固相反应 液相生成 矿物结构 铁酸钙 

分 类 号：TF046.4[冶金工程—冶金物理化学]