Preparation of Purity Al₂O₃ for LED Sapphire Materials by Ammonium Aluminum Sulfate and its Performance

Abstract:

The preparation of aluminium sulfate adopting the sulfuric acid heating method with Al (OH)₃ as raw material, and join the β complexing agent in aluminium sulfate solution to remove impurities; ammonium aluminum sulfat is prepared by the reaction of the ammonium solution and aluminum sulfate, and purify ammonium aluminum sulfate to get high purity ammonium aluminum sulfate crystals containing crystal water. Purify the crystallization of ammonium aluminum sulfate with containing water treated at 1250 °C for 3 h. Then the high purity alumina was prepared. Break the high purity alumina to press, and then again process in 3 h under 1650 °C, get Al₂0₃ which is craw materials of sapphire crystal LED. The samples were characterized by atomic absorption spectrum (AAS), differential thermal analysis (TG/DTA), scanning electron microscopy, XRD and chemical analysis. The purity of high purity alumina is 99.991%, which will be applied to the LED manufacturers on sapphire artificial sapphire growth test.

• Periodical: Advanced Materials Research (Volume 1053)
• Pages: 50-55
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1053.50
• Online since: October 2014
• Authors: Ting Yi Chen*, Wen Lu, Wei Liu, Ya Dian Xie, Ye Qi Fu
• Keywords: Ammonium Aluminum Sulfate, High Purity Alumina, LED Sapphire Materials, Performance

References

[1] Youn Sug Yoo, Kyun Young Park, Kyeong Youl Jung, Sung Baek Cho, Preparation of α-alumina nanoparticles via vapor-phase hydrolysis of AlCl3[J], Materials Letters, 63 (2009) 1844–1846.

DOI: 10.1016/j.matlet.2009.05.050

[2] No-Kuk Park, Hee-YoungChoi, Do-HyeongKim, TaeJinLee, MisookKang, Won GunLee, HeunDukKim, JoonWooPark, Purification of Al(OH)3 synthesized by Bayer process for preparation of high purity alumina as sapphire raw material[J], Journal of Crystal Growth 373 (2013).

DOI: 10.1016/j.jcrysgro.2012.12.004

[3] Hu J H. METHOD FOR PREPARING HIGH-PURITY ALUMINA: U.S. Patent, 124[P]. 013-2-28.

[4] Ma J J, Wu B L. Preparation of High-Purity α-Alumina by Oil-in-Water Microemulsion[J]. Advanced Materials Research, 2012, 399: 673-676.

DOI: 10.4028/www.scientific.net/amr.399-401.673

[5] Zaraska L, Sulka G D, Szeremeta J, et al. Porous anodic alumina formed by anodization of aluminum alloy (AA1050) and high purity aluminum[J]. Electrochimica Acta, 2010, 55(14): 4377-4386.

DOI: 10.1016/j.electacta.2009.12.054

[6] Xia H, Wu A, Fan Y, et al. Effects of ion implantation on the brazing properties of high purity alumina[J]. Surface and Coatings Technology, 2012, 206(8): 2098-2104.

DOI: 10.1016/j.surfcoat.2011.09.034

[7] Li F, Jiang J Q, Wu S, et al. Preparation and performance of a high purity poly-aluminum chloride[J]. Chemical Engineering Journal, 2010, 156(1): 64-69.

DOI: 10.1016/j.cej.2009.09.034

[8] HU J H. METHOD FOR PREPARING HIGH-PURITY ALUMINA: WIPO Patent 2011129658[P]. 2011-10-21.

[9] Arnaboldi C, Brofferio C, Bryant A, et al. Production of high purity TeO< sub> 2</sub> single crystals for the study of neutrinoless double beta decay[J]. Journal of Crystal Growth, 2010, 312(20): 2999-3008.

[10] D. Panias, I. Paspaliaris, A. Amanatidis, H.W. Schmidt, A.I. Hollnagel, Boehmite process: an alternative technology in alumina production, Light Metals (2001) 97–103.

[11] D. Panias, I. Paspaliaris, Boehmite process: a new approach in alumina production, Erzmetall 56 (2) (2003) 75–80.

[12] Ralston K D, Fabijanic D, Birbilis N. Effect of grain size on corrosion of high purity aluminium[J]. Electrochimica acta, 2011, 56(4): 1729-1736.

DOI: 10.1016/j.electacta.2010.09.023