不同FeO比例對FeO-CaO-SiO_2-Al_2O_3-MgO渣系高溫特性影響之研究

Effects of FeO Content on High-temperature Properties in FeO-CaO-SiO_2-Al_2O_3-MgO System

林啟明(C.M. Lin) ； 蘇育瑯(Y.L. Su) ； 尤正維(C.W. Yu) ； 吳威德(W. Wu)

《鑛冶：中國鑛冶工程學會會刊》 62卷4期 (2018/12) Pp. 84-96

https://doi.org/10.30069/MM.201812_62(4).0007

摘要

本研究透過Thermo-Calc模擬之預測結果設計出不同CaO/SiO_2與FeO比例之FeO-CaO-SiO_2-5%MgO-5%Al_2O_3五元渣配方，接著進行WDS-XRF成份分析與XRD結晶相鑑定，確認其配方組成。高溫特性分析以DVIIIRV黏度計進行高溫黏度測量，且對樣品進行流動影像觀察，探討不同配方對熔化與流動性能之影響，結合Thermo-Calc預測熔點，定義出脫磷與發泡的適用範圍。由結晶相分析結果顯示，本研究渣系之組成相皆由FeO、Ca_2SiO_4與CaMoO_4所構成。由黏度分析中發現，熔渣的黏度受Ca_2SiO_4固相顆粒的影響，且黏度隨CaO/SiO_2提升與FeO含量的減少而上升，故C/S=2.1-9.9%FeO與C/S=2.6-20.6%FeO有較高的黏度特性。高溫發泡量測結果顯示，黏度在25cP∼1810cP之間，發泡指數與黏度值呈線性正比關係，且C/S=2.6-20.6%FeO在1560℃時發泡指數高達109.7%，為發泡性能最好之配方。脫磷能力評估方面，經熱力學經驗式計算得知，高CaO/SiO_2且適當的FeO含量之脫磷劑能有效提升脫磷能力，而透過實際脫磷試驗結果發現C/S=2.1-20.0%FeO在1530-1550℃時脫磷率高達89.2%。

關鍵字

不同CaO/SiO_2與FeO含量 ； FeO-based氧化渣 ； 黏度特性 ； 發泡特性 ； 脫磷能力

並列摘要

In this investigation, we used Thermo-Calc thermodynamics simulation analysis to formulate FeO-CaO- SiO_2-5%MgO-5%Al_2O_3 slag systems with different CaO/SiO_2 and FeO ratio. The actual composition of slag was conf irmed by WDS-XRF analysis, the Fe chemical titration, and XRD phase identification. We utilized DV III RV viscometer measurements, high temperature optical image observation, and pre-thermodynamics simulation to investigate the softening, melting and flow properties. We conducted the dephosphorization test and foaming height analysis to determine the optimum composition range of dephosphorization agent and foaming agent in FeO-CaO-SiO_2- 5%MgO-5%Al_2O_3 slag system. XRD results revealed that the FeO-based oxidative slag with different CaO/SiO_2 and FeO content were composed of FeO, Ca_2SiO_4 and CaMoO_4. The viscosity of the slags was affected by the Ca_2SiO_4 solid particles; the viscosity increased with increasing CaO/SiO_2 (or decreasing of FeO content), thus CaO/SiO_2=2.1-9.9%FeO and CaO/SiO_2=2.6-20.6%FeO had a higher viscosity. Foaming test results indicated that the viscosity between 25 cP and 1810 cP, was linearly proportional to the foaming index and CaO/ SiO_2=2.6-20.6%FeO had the best foaming index of 109.7% in all conditions at 1,560 °C. Dephosphorization capacity assessment showed that in the high basicity and the appropriate FeO content of the dephosphorization agent can effectively improve the ability of dephosphorization. Dephosphorization test results showed that the dephosphorization ability of CaO/ SiO_2=2.1-20.0%FeO was up to 89.2% at temperature between 1,530-1,550°C.

並列關鍵字

Different CaO/SiO_2 and FeO content ； FeO-based oxidative slag ； Viscosity property ； Foaming characteristic ； Dephosphorization capacity