外电场作用下熔渣对MgO-C耐火材料的侵蚀行为

发布时间：2018-04-29 08:45

本文选题：外电场 + 镁碳耐火材料　；参考：《材料导报》2017年20期

【摘要】：以高温炉渣为电解质,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炉渣中的腐蚀行为。研究结果表明,在CaO-SiO_2-Al_2O_3渣系中,单质硅的析出电位约为-6.1V;在CaO-SiO_2-Fe_2O_3渣系中,单质铁的析出电位约为-1.25V,硅的析出电位为-5.85V。当外加电压小于炉渣分解压时,电压趋使炉渣中离子(Fe~(2+),SiO_4~(2-))定向移动,阴极附近熔渣粘度不断增加,熔渣在耐火材料中扩散速度下降,导致炉渣渗透深度减小。当外加电压高于炉渣分解压时,电压加速炉渣的电化学分解,单质Si和Fe的析出是诱发熔渣组成发生偏移的驱动力,加速高熔点沉积层的形成,而高熔点沉积层有效阻断炉渣与耐火材料直接接触,导致渗透深度显著下降。高熔点沉积层组成与熔渣组成密切相关,在CaO-SiO_2-Al_2O_3渣系中主要由Ca_2SiO_4组成,在CaO-SiO_2-Al_2O_3-MgO渣系中主要由MgAl_2O_4组成。
[Abstract]:Using high temperature slag as electrolyte, industrial MgO-C brick as cathode and molybdenum wire as anode, the corrosion behavior of refractory in slag under external electric field is studied. The results show that the precipitation potential of silicon is about -6.1V in the CaO-SiO_2-Al_2O_3 slag system, and the precipitation potential of mono iron is about -1.25V in the CaO-SiO_2-Fe_2O_3 slag system and the precipitation of silicon in the slag system. When the applied voltage is less than the decomposition pressure of the slag, the voltage leads to the directional movement of the ions (Fe~ (2+), SiO_4~ (2-)) in the slag, the viscosity of the slag in the vicinity of the cathode is increasing, the diffusion speed of the slag in the refractory is reduced, and the depth of the slag penetration decreases. When the applied voltage is higher than the decomposition pressure of the slag, the voltage acceleration of the slag is accelerated. Solution, the precipitation of Si and Fe is the driving force that induces the migration of the slag composition, accelerates the formation of the high melting point sedimentary layer, and the high melting point deposition layer effectively blocks the direct contact between the slag and the refractory material, which leads to a significant decrease in the penetration depth. The composition of the high melting point deposit is closely related to the slag composition, and is mainly composed of Ca_2S in the CaO-SiO_2-Al_2O_3 slag system. The composition of iO_4 is mainly composed of MgAl_2O_4 in CaO-SiO_2-Al_2O_3-MgO slag system.

【作者单位】：苏州大学沙钢钢铁学院;
【基金】：国家自然科学基金(51674172;51604179) 江苏省青年科学基金(BK20140346;BK20150334)
【分类号】：TQ175.1

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