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Silica-alumina microspheres prodn. by oil-drop method - includes forming a silica sol by acidifying an alkali metal silicate soln. with a strong mineral acid and a weak organic acid
Silica-alumina microspheres prodn. by oil-drop method - includes forming a silica sol by acidifying an alkali metal silicate soln. with a strong mineral acid and a weak organic acid
SiO2-Al2O3 microspheres are prepd. by (a) acidifying an aq. alkali metal silicate soln. with a strong mineral acid (I) and a weak organic acid (II), concn. of (I) being such as to provide an acid/alkali metal ratio of 0.75-1.0 and concn. of (II) being such as to increase this ratio by a factor of 1.3-2, (b) mixing with an acidic Al2O3 sol. and sufficient urea to effect 150-250% neutralisation of the acid anion content on hydrolysis of the urea to NH3, (c) dispersing the mixt. as droplets in a hot oil bath to form spheroidal hydrogel particles, (d) ageing the particles in the hot oil and (e) washing, drying and calcining. For use as a catalyst (support) in a fixed bed-type operation. Method ensures that firm hydrogel particles are formed which will retain their structural integrity during further processing.
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机译:制备了SiO2-Al2O3微球。通过(a)酸化水溶液碱金属硅酸盐溶液。含有强无机酸(I)和弱有机酸(II)的concn。 (I)中的酸/碱金属的酸/碱金属比为0.75-1.0且浓。 (b)与酸性Al 2 O 3溶胶混合,以使该比率增加1.3-2倍。以及足够的尿素,以在尿素水解为NH3时中和酸阴离子含量的150-250%中和,(c)分散混合物。在热油浴中以液滴形式形成球形水凝胶颗粒,(d)在热油中使颗粒老化,以及(e)洗涤,干燥和煅烧。在固定床型操作中用作催化剂(载体)。该方法确保形成牢固的水凝胶颗粒,该颗粒将在进一步加工期间保持其结构完整性。
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