Phase Transformations of α-Alumina Made from Waste Aluminum via a Precipitation Technique

Abstract

We report on a recycling project in which α-Al2O3 was produced from aluminum cans because no such work has been reported in literature. Heated aluminum cans were mixed with 8.0 M of H2SO4 solution to form an Al2(SO4)3 solution. The Al2(SO4)3 salt was contained in a white semi-liquid solution with excess H2SO4; some unreacted aluminum pieces were also present. The solution was filtered and mixed with ethanol in a ratio of 2:3, to form a white solid of Al2(SO4)3·18H2O. The Al2(SO4)3·18H2O was calcined in an electrical furnace for 3 h at temperatures of 400–1400 °C. The heating and cooling rates were 10 °C/min. XRD was used to investigate the phase changes at different temperatures and XRF was used to determine the elemental composition in the alumina produced. A series of different alumina compositions, made by repeated dehydration and desulfonation of the Al2(SO4)3·18H2O, is reported. All transitional alumina phases produced at low temperatures were converted to α-Al2O3 at high temperatures. The X-ray diffraction results indicated that the α-Al2O3 phase was realized when the calcination temperature was at 1200 °C or higher.

Recycling of NdFeB Magnets Using Sulfation, Selective Roasting, and Water Leaching

“…Increasing the roasting temperature to 850°C, almost completely removes these metals, while only for Al and Cu still longer durations or higher temperatures are required. Matori et al reported that Al sulfate might survive temperatures up to 900°C without complete decomposition [53], but Cu sulfate must have completely decomposed to at least its oxysulfate form ( Table 2). This minor dissolution of Cu is due to partial solubility of its oxysulfate.…”

Synthesis, characterizations, antibacterial and photoluminescence studies of solution combustion-derived α-Al2O3nanoparticles

“…Naskar has synthesized the alumina nanoparticles from hydrothermal process at 170 • C for 6 h using glucose and other water-based precursor materials [24]. Khamirul Amin Matori et al have reported on a recycling project in which ␣-Al 2 O 3 was produced from aluminium cans with sulphuric acid at 1200 • C [25]. Sourav Ghose et al have studied the role of tetramethyl urea on the formation of mesoporous alumina from hydrothermal method at 150 • C for 6-24 h [26].…”

Proses hidrolisis larutan natrium aluminat dengan menggunakan biang aluminium hidroksida

“…Untuk mengetahui pengaruh dari ekses NaOH yang digunakan dalam proses hidrolisis ini, dilakukan percobaan hidrolisis kedua dengan menambah jumlah ekses NaOH dan dengan variasi pengambilan percontoh yang berbeda yaitu setiap 3 jam. (Matori et al, 2012). Persen hidrolisis pada percobaan kedua lebih rendah dibandingkan dengan percobaan pertama.…”