cr2o3 高温反应研究 high temp action and research
BaF2 熔点： 1368℃CaF2 熔点： 1318℃Cr熔点1857±20℃，沸点2672℃。铬的化学性质不活泼，常温下对氧和水汽都是稳定的，铬在高于600℃时开始和氧发生反应，但当表面生成氧化膜以后，反应便缓慢，当加热到1200℃时，氧化膜被破坏，反应重新变快。在1000℃下也能被一氧化碳所氧化。在高温下，铬与氮起反应并为熔融的碱金属所侵蚀，具有很高的耐腐蚀性，在空气中，即便是在赤热的状态下，氧化也很慢。Cr2O3的 溶点:1857 沸点:2672 理论上他们之间除Cr与O2、空气中的水分子、氮气、一氧化碳等发生反应外，其余均比较稳定，不发生反应。
各种耐火材料氧化物在熔融煤渣中的溶解度：Cr2O3 在煤气化炉渣(SiO2 -CaO系)及各种玻璃熔体中的溶解度比其他氧化物材料的溶解度要小得多。因而Cr2O3 或含Cr2O3 的耐火材料具有良好的抗钢渣、有色冶炼渣、煤气化炉渣、油气化炉渣和各种玻璃熔体熔蚀能力。Cr2O3 熔体或Cr2O3 与炉渣反应生成的液相粘度比其他低熔物粘度大, 这就阻止了熔渣沿毛细气孔向砖体内部渗透, 避免形成变质层而产生结构剥落。
不同Cr2O3 含量的铬刚玉砖与刚玉砖被玻璃熔渣侵蚀的深度不同。试验表明:Cr2O3 <17 %时, 砖中Cr2O3 含量愈高, 玻璃熔渣侵入的深度愈浅。
为了更进一步弄清气化炉熔渣对刚玉砖和铬刚玉砖的侵蚀情况, 以坩埚法用气化炉渣样在1500 ℃下进行的抗渣试验表明:刚玉砖被熔渣严重侵蚀, 炉渣全部渗入砖中, 并沿砖内部气孔渗透到表面, 砖变成褐色, 几乎没有渣残留;铬刚玉砖几乎不被熔渣侵蚀, 渣与砖表面没有明显的化学反应, 内孔边缘与残渣界限分明, 渣向砖内渗透很少,砖孔周围只形成约5 ～ 10 mm 厚的变质层, 大量熔渣残存于坩埚孔内。
BaF2 melting point: 1368℃CaF2 melting point: 1318℃Cr melting point 1857 ± 20℃, boiling point 2672℃.The chemistry of chromium is not lively, stable to oxygen and water vapor at room temperature, chromium begins to react with oxygen above 600℃, but when the surface generates the reaction slowly, when heated to 1200℃, the film is destroyed and the reaction becomes faster.It can also be oxidized by carbon monoxide at 1,000℃.At high temperatures, chromium reacts with nitrogen and is eroded by the molten alkali metal, with high corrosion resistance and slow oxidation in the air, even in red-hot states.Cr2O3 dissolution point: 1857 boiling point: 2672 Theoretically, except water molecules in Cr and O2, air, nitrogen, carbon monoxide, and no reaction.
Solubility of various refractory oxides in molten cinders: The solubility of Cr2O3 in gasification slag (line SiO2-CaO line) and various glass melts is much less than that of other oxide materials.Therefore, Cr2O3 or refractory material containing Cr2O3 has good resistance to steel slag, non-ferrous smelting slag, coal gasification slag, oil and gas slag and various glass melt melting capacity.The liquid phase viscosity generated by the Cr2O3 melt or Cr2O3 reaction with the slag is greater than other low melts, which prevents slag penetration along the capillary pores into the brick body, avoiding a metamorphic layer and creating structural peeling.
The depth of chrome corcte bricks with different Cr2O3 content is different from that of corct brick eroded by glass slag.The test showed that at the Cr2O3 <17%, the higher the Cr2O3 content in the brick, the lighter the glass slag intrusion.
To further understand the erosion of cornedum and chromium cornedum bricks in the gasifier, the slag resistance test with crucible slag samples at 1500℃ showed that the cornedum brick is badly eroded by the slag, all the slag into the brick, into the surface along the air hole inside the brick, the brick becomes brown, almost no residue; chrome cornedum brick is almost not eroded by the slag, no obvious chemical reaction, the surface of the inner hole and the residue edge into the brick, only about 5 ~ 10 mm thick, a large amount of slag remains in the crucible hole.
