侵蚀温度和煤渣脱碳对高铬材料抗侵蚀性的影响

Effect of corrosion temperature and decarbonization of coal slag on corrosion resistance of high chrome refractories

为了研究侵蚀温度和煤渣脱碳对水煤浆气化炉用高铬材料抗侵蚀性的影响,取含碳和脱碳两种煤渣,采用静态坩埚法,在埋炭气氛中分别于1 450和1 600℃保温5 h对高铬材料进行侵蚀试验,检测试验后高铬材料的侵蚀渗透深度、脱锆层厚度,以及原砖层的气孔率和孔径分布情况,并分析了试验条件下熔渣系统的氧势。结果表明:1)随着侵蚀温度的升高,侵蚀后坩埚渣-埚界面坩埚侧表面的尖晶石层变薄,坩埚原砖层中气孔增多,孔径增大,抗煤渣侵蚀性下降。2)含碳煤渣对高铬材料的侵蚀较强,侵蚀后残渣中有金属相;脱碳煤渣对高铬材料的侵蚀较弱,侵蚀后残渣中没有出现金属相。3)经热力学分析,当采用脱碳煤渣时,试验过程中熔渣内部的氧势在10^(-9.25)MPa以上;当采用含碳煤渣时,熔渣内部的氧势为10^(-13)~10^(-15)MPa。

Effects of corrosion temperature,and original and decarbonized coal slag on corrosion resistance of high chrome refractories were researched. The static crucible slag tests of high chrome refractories were conducted at 1450 or 1 600℃ for .5 h under carbon embedded condition. Then,the penetration depth,the de-zirconia layer thickness, and the porosity and the pore size distribution in the original layer were measured,and the oxygen potential of the slag system was analyzed. The results show that： （1）with the increase of the corrosion temperature,the thickness of the spinel layer in the crucible surface contacting the slag decreases ,the pore size and quantity increase in the original layer, consequently the slag resistance is deteriorated;（2）the original coal slag containing carbon has stronger corrosion to high chrome refractories and the metal phase deposits in the residual coal slag,while for the decarbonized coal slag,the corrosion is weaker and no metal phase is detected;（3）based on the thermodynamic analysis,the oxygen potential inside the decarbonized coal slag is above 10-925 MPa,while that in the original coal slag is between 10-13 and 10-15 MPa.