高硫石油焦用于气化，可实现石油焦的高效清洁利用。煤与石油焦气流床共气化是石油焦气化应用的主要技术路线。石油与煤相比V元素含量较高，V元素易造成耐火材料的侵蚀，目前耐火材料正向无铬方向发展，含V熔渣对新型耐火材料的侵蚀研究还较少。选用一种典型气化用煤的煤灰，配入V2O5模拟石油焦与煤共气化灰，对具有广泛应用前景的刚玉耐火材料进行侵蚀试验，考察气化操作温度、V元素含量和侵蚀时间等因素对侵蚀程度的影响，利用XRD分析含V熔渣高温侵蚀过程中的矿物质变化，利用SEM表征含V熔渣和刚玉材料侵蚀过程中形貌表面变化，阐明含V熔渣侵蚀刚玉材料机理。研究表明：熔渣V元素在刚玉界面处形成钒铝尖晶石，熔渣中V元素与Al元素相互取代，形成相互反应层侵蚀材料表面，破坏了刚玉材料的表面致密性，导致熔渣中低黏度液相渗透加剧。随反应温度增加，V元素与刚玉中Al2O3反应加剧，熔渣与刚玉材料界面处形成的尖晶石颗粒变大，反应层致密性降低，加剧低黏度液相熔渣向刚玉材料渗透，导致刚玉材料侵蚀程度增加。V含量增加时，熔渣与刚玉材料的反应层厚度增加，相互作用界面更加不规则，导致刚玉材料侵蚀程度明显增加。相互作用时间增加，液相熔渣渗透加剧，刚玉材料侵蚀程度明显增加。V含量是决定侵蚀程度的最关键因素，当熔渣中V2O5质量分数为10%、反应温度高于流动温度200 ℃时，刚玉材料侵蚀最严重。石油焦与煤共气化时，应严格控制灰渣中的V含量和操作温度，避免造成耐火材料的侵蚀加剧。

High-sulfur petroleum coke is used for gasification, which can realize the efficient and clean utilization of petroleum coke. The entrained flow co-gasification of coal and petroleum coke is the common technical route of petroleum coke gasification. Compared with coal, the content of V element in petroleum is higher, which is easy to cause the corrosion of refractory materials. The refractory materials of chromium-free are developing at present, there is few researches on the erosion of slag containing V on new type refractory materials. A typical gasification coal ash was selected, which was mixed with V2O5 to simulate co-gasification ash of petroleum coke and coal. The corundum refractories with broad application prospects were used for corrosion test. The influences of V element content, reaction temperature and reaction time on the degree of erosion were investigated. XRD was used to analyze the evolution of minerals in slag containing vanadium at the high temperature process. The changes of morphology and surface during the corrosion process of V containing slag and corundum materials were analyzed by SEM. The erosion mechanism of slag containing V to corundum materials was clarified. The resultsshow that the V element in the slag forms vanadium aluminum spinel at the interface of corundum materials. The mutual substitution of V element and Al element in the slag forms an interactive reaction layer that erodes the surface of the material, which weakens the compactness of the corundum material surface. The penetration of the low viscosity liquid slag in corundum is intensified. With the reaction temperature increasing, the reaction between V element and Al2O3 of corundum is intensified, the size of crystalline spinel particles at the interface of corundum material increases, and the compactness of the reaction layer decreases, which accelerates the liquid slag with low viscosity penetrating into the corundum material, resulting in the erosion of corundum material aggravating. When the V content increases, the thickness of the reaction layer between the slag and corundum material increases, and the interaction interface becomes more irregular, resulting in a significant increase in the corrosion degree of corundum material. The penetration of liquid slag intensifies as the reaction time increases, This leads to the significant increase of the erosion degree of corundum material. The corrosion degree of corundum material also increases obviously with the reaction time increasing, as the penetration degree of liquid slag increases. V content is the most critical factor to determine the degree of corrosion. When the mass fraction of V2O5 in slag is 10%, and the reaction temperature is 200 ℃ higher than the flow temperature, the corundum material is most seriously eroded. When petroleum coke is gasified with coal, the V content and the operating temperature should be strictly controlled to avoid aggravating the erosion of refractory materials.

0 引言

1 试验

   1.1 试验材料

   1.2 试验方法

2 试验结果与讨论

   2.1 含V灰的熔融温度变化

   2.2 相互作用温度对侵蚀行为影响

   2.3 V质量分数对侵蚀行为影响

   2.4 相互作用时间对侵蚀行为影响

3 结论