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采用共沉淀法制备活性强的碳酸铝铵.研究了pH值等因素对合成碳酸铝铵的影响.结果表明:碳酸氢铵混合溶液浓度为2mol/L,pH值为9~10.铝盐溶液浓度为0.2mo1/L,pH值为3~4之间.采用反向滴定缓慢加入的方法,可以得到纯相的碳酸铝铵. 相似文献
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粉煤灰中含有丰富的铝,从粉煤灰中提取铝对于节约资源、改善环境、实现可持续发展都具有重要的意义.研究了以燃煤电厂所产高铝粉煤灰为原料制取氧化铝的工艺过程.高铝粉煤灰与氧化钙混合后在高温下煅烧生成自粉化料,使粉煤灰中的铝活化.将自粉化料与硫酸反应使铝从固相转移至液相得到硫酸铝粗液.研究了硫酸溶液用量、硫酸浓度、酸溶时间以及酸溶温度对铝回收率的影响.采用有机溶液萃取法脱除硫酸铝粗液中的铁离子,使硫酸铝粗液得到精制.然后用氨水与精制硫酸铝溶液反应得到铝铵矾结晶.最后将铝铵矾晶体在高温下煅烧得到氧化铝.采用此法可使粉煤灰中铝的回收率达到77%. 相似文献
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以硝酸铝为原料,用碳酸氢铵和氨水作混合沉淀剂,采用反向滴定共沉淀工艺,在一定的条件下可以得到物相单一、性能优良的氧化铝前驱体-碳酸铝铵。 相似文献
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Muhammad Abdullah Jamil Ahmad Mazhar Mehmood Mujtaba-ul-Hasan Hideki Maekawa 《Ceramics International》2011,37(7):2621-2624
Enhanced mechanical properties of yttria-stabilized zirconia based composites were obtained by introducing alumina whiskers as reinforcement. The alumina whiskers were formed in situ by decomposition of ammonium aluminum carbonate hydroxide (AACH) whiskers during calcination. The whiskers thus formed were amorphous and were converted to α-alumina during sintering at 1450 °C. The AACH whiskers were produced by hydrothermal treatment of an aqueous solution of urea and aluminum nitrate at 120 °C for 24 h. The Vickers hardness of the sintered composite sample increased with an increase in the alumina content up to 10 wt% and then decreased. The maximum hardness achieved at 10 wt% of alumina whiskers was 13.8 GPa, which further increased to 14.4 GPa with the addition of 1.0 wt% of cetyl-trimethyl-ammonium bromide (CTAB). The improved mechanical strength of the composites was attributed to the enhanced dispersion of alumina whiskers due to four times volume decrease during transformation of AACH to alumina and relatively lower aspect ratio of AACH whiskers as well as the deflocculating effect of CTAB. 相似文献
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采用均匀沉淀法,以硫酸铝铵为原料,研究了不同沉淀剂(尿素和碳酸铵)制备的氧化铝粉。采用透射电镜、X射线衍射仪、热分析仪等,对采用不同沉淀剂制得的前驱体和氧化铝粉末的结构和形貌进行了表征。结果表明,以尿素为沉淀剂制得的前驱体氢氧化铝和氧化铝粉末在分散性以及颗粒大小和形状方面都优于以碳酸铵为沉淀剂的产品。此外,以尿素为沉淀剂制得的前驱体氢氧化铝在1 200 ℃煅烧2 h得到了结晶度较好的纯相α-氧化铝,而以碳酸铵为沉淀剂制得的前驱体碳酸铝铵在1 200 ℃煅烧2 h得到θ-氧化铝和α-氧化铝的混合相。 相似文献
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abstract The further development of the extraction of alumina that is produced in the calcination process of ammonium sulfate mixed with fly ash was limited because of the lack of systematic theoretica... 相似文献
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3D urchins like ammonium aluminum carbonate hydroxide (AACH) nanostructures with nano-spikes of dia. 20–30 nm were synthesized by a simple, single step hydrothermal technique by using aluminum nitrate and urea as precursor materials. It was found that morphology of the produced structure strongly depends upon the urea concentration. With increasing the amount of urea, the AACH particles having embedded rods like surface features transformed into 3D urchins. The added urea decomposed during hydrothermal treatment and increased the pH of the solution, which affected the morphology of the produced nanostructures. SEM, XRD, FTIR and TGA were employed to characterize the produced structures. On heating, the volatile ingredients of AACH were removed, leaving behind the alumina urchins. 相似文献
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以粉煤灰为原料制备的硫酸铝溶液萃取除铁研究 总被引:1,自引:0,他引:1
以粉煤灰为原料制备的硫酸铝中含有大量的铁,产品质量达不到标准。实验用P204做萃取剂,用磺化煤油做稀释剂。研究了萃取温度、萃取级数和振荡时间对硫酸铝中含铁量的影响。并进行了反萃实验。在最佳条件下,产品中铁含量可达无铁硫酸铝要求。 相似文献
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《中国化学工程学报》2014,22(11-12):1363-1367
A new developed technology for extracting alumina from coal fly ash was studied in this paper. In this technology, coal fly ash is first sintered with ammonium sulfate, forming ammonium aluminum sulfate in the resultant product, where alumina can be easily leached without using any strong acid or alkali. The products obtained under different sintering conditions were characterized by X-ray diffractometry. Alumina extraction efficiency of these products was also investigated. The results show that the sintering temperature and time substantially influence the phase composition and alumina extraction efficiency of sintered products, while the heating rate has little influence. The optimal sintering condition is 400 °C for 3 h in air with a heating rate of 6 °C·min− 1. Under the optimal sintering condition, the alumina extraction efficiency from as-sintered coal fly ash can reach 85% or more. 相似文献