摘要
以高温氧化性炉渣为电解质,工业MgO-C砖为阴极,钼丝为阳极,研究外电场作用下耐火材料在CaO-SiO^2-FeO三元氧化性渣中的侵蚀行为。结果表明:在CaO-SiO2-FeO渣中,Si的还原电位约为-5.85V,Fe的还原电位约为-1.25V;当外加电压小于炉渣中离子还原电位时,电压趋使炉渣中离子(Fe^2+,Ca^2+)向阴极作定向移动,而SiO4^2-由于离子半径大,移动速度较慢,大部分滞留在阴极区域,使得阴极附近熔渣粘度不断增加,有效降低了炉渣渗透深度;当阴极电位低于炉渣中离子还原电位时,炉渣中Fe^2+和SiO4^2-将发生电化学还原,Fe和Si的析出促使熔渣组成发生变化,诱导高熔点相硅酸二钙沉积层的形成。高熔点沉积层有效阻断炉渣与耐火材料直接接触,使得熔渣在耐火材料中的渗透深度显著降低,提高了耐火材料抗渣侵能力。
Corrosion behavior of MgO-C refractory in molten oxide slag was investigated under applied voltage,during which MgO-C brick worked as the cathode and molybdenum as anode,..The results show that the reduction potential of SiO4^2-and Fe^2+ are about-5.85 and-1.25 Vin the CaO-SiO2-FeO system,respectively.When the voltage is applied,ions(Ca^2+ and Fe^2+)move to the cathode and aggregate around the cathode.Meanwhile,SiO4^2-ions move to the anode relatively slowly because of their big radius,which results in the retention of SiO4^2-anions at the cathode range.If the applied voltage is less than the reduction potential of the slag,the aggregated ions can lead to viscosity increase of slag around the cathode,which hinders s the diffusion of slag into the MgO-C refractory and thus leads to the decrease in penetration depth.When the applied voltage is lower than the reduction potential of Fe^2+ and SiO4^2-,metallic Si or Fe is formed,which induces a shift of slag composition toward the high melting products(Ca2SiO4).The high melting product layer is responsible for the good physical and chemical protection of the refractory because it blocks the direct contact between the slag and the refractory.
作者
蒋坤
王蝉娜
屈天鹏
田俊
王慧华
王德永
JIANG Kun;WANG Channa;QU Tianpeng;TIAN Jun;WANG Huihua;WANG Deyong(Shagang School of Iron and Steel,Soochow University,Suzhou 215021,China)
出处
《材料科学与工程学报》
CAS
CSCD
北大核心
2019年第3期392-396,共5页
Journal of Materials Science and Engineering
基金
国家自然科学基金资助项目(51604179,51674172,51774208,51704200)
江苏省青年科学基金资助项目(BK20140346,BK20150334,BK20150336)
关键词
外电场
镁碳耐火材料
渗透深度
电化学沉积
applied voltage
MgO-C refractory
penetration depth
electro-deposit
