电渣重熔过程中渣成分变化的研究

采用热重-差热分析法对AH6(70%CaF₂)、M-1(42%CaF₂)、L-3(15%CaF₂)和F-2(无CaF₂)4种重熔渣进行热重-差热分析,利用X-射线衍射(XRD)技术对高温熔炼渣结构进行检测。结果表明,CaF₂与渣中其他氧化物发生反应生成的氟化物气体导致渣系失重,并造成初始渣成分和终点渣池的渣成分存在明显差异;随初始渣CaF₂含量的增加,氟化物失重率增大,1 500℃时AH-6、M-1、L-3和F-2渣的失重率分别为11.92%、7.84%、4.87%和0.38%。XRD检测高温熔炼渣发现渣池中出现结构复杂、熔点较高的2CaO·SiO₂(2 130℃)、3Al₂O₃·2SiO₂(1 750℃)、CaO·6Al₂O₃(1860℃)和11CaO·7Al₂O₃·CaF₂(1577℃)等物质,导致渣皮形成过程中发生成分偏析,使电渣重熔全过程中渣池的化学组成和渣壳相组成无法始终保持恒定。 

A Study on Variations of Slag Ingredient during Electroslag Remelting Process

The thermogravimetry (TG) -differential scanning calorimetry ( DSC) analyses on 4 kinds of electroslag for remelting- AH-6 (70% CaF₂), M-l (42%CaF₂), L-3 (15% CaF2) and F-2 (free CaF₂) have been carried out by using TG and DSC, the structure of melting slag at elevated temperature is measured by using X-ray diffraction (XRD) method. Results show that the gas-phase fluoride is forming by reaction between CaF₂ and other oxides in slag led to weight loss of slag and there is obvious difference between initial ingredient of slag and end ingredient of slag in slag pool； with increasing CaF₂ content in initial slag, the weight loss rate of fluoride increases, and at 1 500 ℃ the weight loss rate of slag AH-6, M- 1, L-3 and F-2 is respectively 11. 92% , 7. 84% , 4. 87% and 0. 38%. It is found to measure high temperature melting slag by XRD that the complex structure and higher melting point materials such as 2CaO ? SiO₂ (2 130 ℃ ) , 3Al₂O₃ ?2SiO₂ (1 750 ℃ ) , CaO ,6Al₂O₃ ( 1 860 ℃ ) and 11CaO?7Al₂O₃ , CaF₂ ( 1 577 °C ) occur in slag pool led to the ingredient segregation in formation of slag skin and the ingredient of slag pool and slag skin being no-constant in whole ESR process.