铁矿粉烧结复合铁酸钙形成机理研究

发布时间：2018-06-06 23:32

  本文选题：烧结 + 复合铁酸钙　； 参考：《华北理工大学》2017年硕士论文

【摘要】：研究Al_2O_3、MgO含量对CaO-Fe_2O_3二元系铁酸钙生成的影响,分析Al_2O_3、MgO在烧结中的作用;通过对不同温度下烧结矿相组成、含量分析,研究烧结过程中矿相种类、含量变化,以及Al_2O_3、MgO在矿相中扩散路径,阐明复合铁酸钙生成机理。研究主要结论如下:1)在CaO-Fe_2O_3二元系中,MgO含量由0.5%增加至1.5%,利于铁酸钙生成,MgFe_2O_4与铁酸钙反应生成镁复合铁酸钙;MgO含量超过1.5%之后,磁铁矿含量增多,抑制铁酸钙生成。Al_2O_3含量由1.5%增加到3.5%时,烧结矿矿相由铁酸钙向复合铁酸钙转变,促进复合铁酸钙生成。2)CFA生成过程中,首先生成C_2F和CA_2,CA_2与C_2F形成CA_2/C_2F界面,温度升高至800℃左右,C_2F/CA_2界面转变为CF/CA_2界面,CF、CA_2与Fe_2O_3反应生成CFA(850℃-900℃);C_2F、Al_2O_3与Fe_2O_3可直接生成CFA(900℃-950℃),CA_2核的反应是CFA生成的限制环节。3)复合铁酸钙的生成是矿相中CFA反应、消失的过程。Al_2O_3颗粒周围形成CA_2、CFA层,低温时CFA主要与Fe_2O_3、MgFe_2O_4及少量钙镁硅酸盐生成SFCA,较高温度时CFA主要与Fe_2O_3、钙镁硅酸盐及少量MgFe_2O_4生成SFCA;温度1250℃时,不含CA_2区域SFCA易分解生成磁铁矿,含区CA_2域SFCA未发现分解。低SiO_2含量利于CFA反应,促进复合铁酸钙生成。
[Abstract]:The effect of Al2O3MgO content on the formation of calcium ferrate in CaO-Fe_2O_3 binary system was studied, and the role of Al2O3MgO in sintering process was analyzed. By analyzing the composition and content of sinter phases at different temperatures, the types and contents of mineral phases in the sintering process were studied. The diffusion path of Al2O3MgO in ore phase was also discussed, and the formation mechanism of composite calcium ferrate was explained. The main conclusions are as follows: (1) in CaO-Fe_2O_3 binary system, the content of MgO increases from 0.5% to 1.5%, which is beneficial to the formation of MgFe2O4 from calcium ferrate to calcium ferrate, and the content of magnetite increases when the content of MgFe2O4 reacts with calcium ferrate to form more than 1.5% MgO. When inhibiting the formation of calcium ferrate from 1.5% to 3.5%, the sinter phase changes from calcium ferrate to calcium ferrate compound, and during the process of promoting the formation of calcium ferrate, the CA_2/C_2F interface between C2F and CA2CTAS2 and C2F is first formed. When the temperature rises to about 800 鈩，

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