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Yi Zhang – One of the best experts on this subject based on the ideXlab platform.
crystallization of Aluminium Hydroxide from the reactive naal oh 4 nahco3 solution experiment and modelingChemical Engineering Science, 2010Co-Authors: Yifei Zhang, Chao Yang, Libin Chen, Yi ZhangAbstract:
The crystallization kinetics of Aluminium Hydroxide from the sodium aluminate solution reacted with sodium bicarbonate were systematically investigated in a steady-state MSMPR (mixed-suspension mixed-product removal) crystallizer for the first time, and the expressions of the nucleation rate, growth rate and the agglomeration kernel of Aluminium Hydroxide were successfully regressed. The Aluminium Hydroxide particles precipitated from the reactive system are identified as gibbsite by XRD and SEM examinations. The volume growth rate order of gibbsite with respect to the relative supersaturation of the solution is above the linear growth rate order, and the spiral growth mechanism for the growth of the basal face of gibbsite in the reactive system was further identified by the growth rate, morphology analysis as well as the calculated surface entropy factor. The secondary nucleation rate of gibbsite from the reactive system is three to four orders of magnitude larger than that from seeded process reported in the only available literature reference. The agglomeration kernel of gibbsite in the reactive system increases linearly with growth rate and residence time, and the positive order about 0.55 of magma density is thoroughly different from the negative order of magma density for gibbsite agglomeration in seeded process presented in the literature.
Precipitating sandy Aluminium Hydroxide from sodium aluminate solution by the neutralization of sodium bicarbonateHydrometallurgy, 2009Co-Authors: Yifei Zhang, Chao Yang, Yi ZhangAbstract:
In the sinter process for alumina production, it is still difficult to produce sandy Aluminium Hydroxide by the carbonation of sodium aluminate solution. Therefore, a precisely controllable and feasible process for the precipitation of sandy Aluminium Hydroxide from the supersaturated sodium aluminate solution neutralized by sodium bicarbonate aqueous solution is proposed for the first time, in which the neutralization reagent (NaHCO(3)) can be efficiently recycled by the carbonation of the produced sodium carbonate aqueous solution. The influencing factors of the precipitation, i.e. the pH value, the initial NaOH concentration, the temperature and the addition rate of neutralization agent, were investigated. All the Aluminium Hydroxides precipitated in the research were identified as gibbsite type. The gibbsite products had regular globular morphology and narrow size distribution whose minimum residue on a 44 mu m mesh was 92-94%. (C) 2009 Elsevier B.V. All rights reserved.
Francois Authier – One of the best experts on this subject based on the ideXlab platform.
macrophagic myofasciitis lesions assess long term persistence of vaccine derived Aluminium Hydroxide in muscleBrain, 2001Co-Authors: Riccardo Gherardi, Marie Coquet, Patrick Cherin, Laurent Bélec, Ph Moretto, Patrick A Dreyfus, Jean-françois Pellissier, Patrick Chariot, Francois AuthierAbstract:
Macrophagic myofasciitis (MMF) is an emerging condition of unknown cause, detected in patients with diffuse arthromyalgias and fatigue, and characterized by muscle infiltration by granular periodic acid-Schiff’s reagent-positive macrophages and lymphocytes. Intracytoplasmic inclusions have been observed in macrophages of some patients. To assess their significance, electron microscopy was performed in 40 consecutive cases and chemical analysis was done by microanalysis and atomic absorption spectrometry. Inclusions were constantly detected and corresponded to Aluminium Hydroxide, an immunostimulatory compound frequently used as a vaccine adjuvant. A lymphocytic component was constantly observed in MMF lesions. Serological tests were compatible with exposure to Aluminium Hydroxide-containing vaccines. History analysis revealed that 50 out of 50 patients had received vaccines against hepatitis B virus (86%), hepatitis A virus (19%) or tetanus toxoid (58%), 3-96 months (median 36 months) before biopsy. Diffuse myalgias were more frequent in patients with than without an MMF lesion at deltoid muscle biopsy (P < 0.0001). Myalgia onset was subsequent to the vaccination (median 11 months) in 94% of patients. MMF lesion was experimentally reproduced in rats. We conclude that the MMF lesion is secondary to intramuscular injection of Aluminium Hydroxide-containing vaccines, shows both long-term persistence of Aluminium Hydroxide and an ongoing local immune reaction, and is detected in patients with systemic symptoms which appeared subsequently to vaccination.
Tomohiro Akiyama – One of the best experts on this subject based on the ideXlab platform.
exergetic life cycle assessment of new waste Aluminium treatment system with co production of pressurized hydrogen and Aluminium HydroxideInternational Journal of Hydrogen Energy, 2009Co-Authors: Takehito Hiraki, Tomohiro AkiyamaAbstract:
Abstract A new system is proposed for the treatment of waste Aluminium. The total exergy loss (EXL) in the system for the co-production of 1 kg of hydrogen at 30 MPa and 26 kg of Aluminium Hydroxide is evaluated from the viewpoint of life cycle assessment (LCA) by comparison with the EXLs in conventional systems. The exergy flow diagram reveals that the exergy of waste Aluminium, which contains only 15 mass% metal, is still large, while that of pure Aluminium Hydroxide is relatively small. Therefore, the EXL in the proposed system (150.9 MJ) is 55% less than that in the conventional system (337.7 MJ) in which the gas compressor and production of Aluminium Hydroxide consume significantly more exergy. The results also indicate that exergy analysis should be applied to the LCA as a critical measure for practical use, in addition to the conventional LCA of carbon dioxide emission.