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系统地研究了Ba改性Al2 O3 在 115 0℃焙烧 5h后的高温热稳定性及影响因素 .用BET方法、N2 吸附 脱附等温线和粉末X光衍射表征了拟薄水铝石的凝胶处理、高温热处理气氛以及Ba的量对氧化铝的表面积、孔结构和晶相的影响 .结果表明 ,BaO的存在抑制了Al2 O3 晶粒的生长和α相变 ,并与Al2 O3 高温固相作用生成BaO·6Al2 O3 ,随x(BaO) :x(Al2 O3 )的增加 ,BaO的高温稳定作用加强 ,当x(BaO) :x(Al2 O3 )到达 0 0 3时 ,Al2 O3表面积趋于平缓 ,BaO的量进一步提高时其稳定作用降低 .水蒸汽和拟薄水铝石的凝胶化处理加速了Al2 O3 的烧结 ,并且削弱了BaO的高温稳定作用 .
The high-temperature thermal stability and influencing factors of Ba-modified Al 2 O 3 calcined at 115 ℃ for 5h were systematically studied.The BET method, N2 adsorption-desorption isotherm and X-ray powder diffraction were used to characterize the pseudoboehmite gel The effect of BaO on the surface area, pore structure and crystal phase of alumina was investigated by means of the high-temperature heat treatment atmosphere and the amount of Ba. The results show that BaO can inhibit the growth and α phase transformation of Al 2 O 3 grains and solid-phase with Al 2 O 3 With the increase of x (BaO) x (Al 2 O 3), BaO becomes more stable at high temperature. When x (BaO) x (Al 2 O 3) reaches 0 0 3, the surface area of Al 2 O 3 tends to be gentle , The stability of BaO decreases with the increase of BaO.The gelation of water vapor and pseudoboehmite accelerates the sintering of Al 2 O 3 and weakens the high temperature stability of BaO.