Abstract

The paper highlights the issues of thermal decomposition of aluminum chloride hexahydrate which is applied to the integrated technology of ash processing from the combustion of Ekibastuz coal. To solve this problem the possibility of using thermal decomposition of AlCl₃·6H₂O crystals in a static state and in a fluidized bed is considered. This approach allowed conducting a comparative assessment and selection of the most rational method for the thermal decomposition of ACH from a technological and economic point of view. It was found that under the conditions of thermal decomposition of ACH in a static state, its maximum decomposition to Al₂O₃ is achieved at a temperature of 400°C. The residual chlorine content in alumina is 1.09%, and aluminum in the form of AlCl₃ is 0.5% of the total aluminum content. At a temperature of 500°C, the residual chlorine content in alumina is 0.71%, and AlCl₃ is practically not detected. It was found that crystals of AlCl₃·6H₂O almost completely decompose in a fluidized bed at a temperature of 500°C (residual chlorine content 0.75%). In this case, the degree of decomposition of AlCl₃·6H₂O crystals was 87% at 300°C and 95% at 400°C. After calcining the samples obtained at 900°C, the residual chlorine content in them decreased to 0.27%, and after calcining at temperatures above 1000°C, no chlorine was detected in the samples at all. The specific surface area of alumina obtained after thermal decomposition at 400°C was 169.6 m²/g. After additional roasting of the sample at a temperature of 1200°C, the specific surface area of alumina decreased to 7.8 m²/g.

中文翻译：

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六水氯化铝热分解生成氧化铝

摘要

本文重点介绍了六水氯化铝的热分解问题，并将其应用于埃基巴斯图兹煤燃烧灰分处理的集成技术。为了解决这个问题，考虑在静态和流化床中使用AlCl ₃ ·6H ₂ O晶体的热分解的可能性。该方法可以从技术和经济的角度进行比较评估并选择最合理的 ACH 热分解方法。结果发现，ACH在静态热分解条件下，在400℃时最大分解为Al ₂ O _{3 。氧化铝中的残余氯含量为1.09％，AlCl 3}形式的铝占总铝含量的0.5％。在500℃的温度下，氧化铝中的残余氯含量为0.71％，并且实际上检测不到AlCl _{3 。}发现AlCl ₃ ·6H ₂ O晶体在流化床中在500℃温度下几乎完全分解(残余氯含量0.75％)。此时，AlCl ₃ ·6H ₂ O晶体的分解度在300℃下为87％，在400℃下为95％。所得样品经900℃煅烧后，残留氯含量降至0.27%，经1000℃以上煅烧后，样品中完全检测不到氯。400℃热分解后得到的氧化铝的比表面积为169.6m ² /g。样品在1200℃的温度下额外焙烧后，氧化铝的比表面积降低至7.8m ² /g。