Aluminium hydroxide

About: Aluminium hydroxide is a research topic. Over the lifetime, 2043 publications have been published within this topic receiving 22032 citations. The topic is also known as: Al(OH)3 & Amphojel.

Aluminium hydro(oxide)-based (AO) adsorbent for defluoridation of drinking water: Optimisation, performance comparison, and field testing

Abstract: In this study, the performance of different aluminium hydroxide.based adsorbents was compared in terms of fluoride adsorption capacity, potential for repetitive regeneration, surface acidity and surface site concentrations. The adsorbents were aluminium hydro(oxide) (AO), activated alumina (AA), and pseudoboehmite (PB). The AO adsorbent was synthesised at different OH:Al ratios to optimise the fluoride adsorption capacity. The AO was pilot tested in a rural community in the Ethiopian Rift Valley where groundwaters are heavily enriched with fluoride. The maximum fluoride uptake was achieved for the AO adsorbent synthesised at OH:Al ratios between 2.5 and 2.7. The fluoride adsorption capacity of the adsorbents determined from mini-column studies was found to be 10.6, 1.9, and 2.4 mg/g for AO, AA, and PB, respectively. This significant difference in fluoride adsorption capacity is strongly related to the surface acidity and surface site concentration. The surface acidity (1.57 meq/g) and surface site concentration (0.74 meq/g) for AO is higher than that for AA and PB. The elemental composition analysis showed that AO has a lower % Al2O3 content than AA and PB, but higher sulphate (19.4%) and iron (2.2%) content. High resolution 27Al Magic Angle Spinning Nuclear Magnetic Resonance (27Al MAS NMR) spectra of AO, AA, and PB were recorded, to analyse the coordination geometry of solid Al species and the results showed that aluminium is coordinated octahedrally and tetrahedrally in all cases. Regeneration experiments showed that AA and PB can be regenerated for more than 3 cycles, whereas the potential for regeneration of AO for more than 3 cycles is limited. The results from a community defluoridation plant showed that fluoride in the feed water (8.10 mg/.) is removed below 0.1 mg/.. The average adsorption capacity was determined to be 2.11 mg/g based on continuous field monitoring results obtained until the fluoride content in the treated water exceeded the breakthrough value of 1.5 mg/.. No major operational problems and complaints from the beneficiaries were experienced during operation. Keywords : fluoride, adsorption, surface acidity, regeneration, defluoridation, Ethiopia

Process and equipment for preparing aluminium polychloride

Abstract: A process for preparing aluminium polychloride from hydrochloric acid and aluminium hydroxide includes such steps as blowing appropriate quantity of chlorine gas into the mixed solution of hydrochloric acid and aluminium hydroxide, reaction of chlorine gas on water in the solution to generate hydrochloric acid and hypochlorous acid as catalyst for next reaction, and reaction of hydrochloric acid on aluminium hydroxide to generate aluminium hydroxychloride. Its advantages are simple process and equipment, short period, and high sterilizing, seaweed-killing and decolouring function. The productis an efficient water deaner.

Nano inorganic composite fire-resisting agent for macromolecular material

Abstract: The present invention relates to a nano inorganic composite fire-retardant for macromolecular material. It is composed of nano aluminium hydroxide, nano structure modified aluminium hydroxide or nano magnesium hydroxide and micro-size magnesium hydroxide and auxiliary fire retardant, in which the average grain size of nano aluminium hydroxide is less than or equal to 100 nano, the average grain size of nano structure modified aluminium hydroxide is less than or equal to 150 nano, the average grain size of nano magnesium hydroxide is less than or equal to 100 nano, the average grain size of micro-size magnesium hydroxide is 1-10 microns, and the mass ratio of nano-size inorganic fire retardant and micro-size magnesium hydroxide is 80:20 to 10:90, and the mas ratio of nano-size inorganic fire-retardant and micro-size magnesium hydroxide and auxiliary fire retardant is 100:10 to 100:30. It can be used in the fire-retarding composite materials of PE, PP, ABS, nylon, PC, PVC, EVA and polyester, etc.

Influence of the source of silicon and aluminium in the hydrothermal synthesis of sodalite

Abstract: The synthesis of sodalite from aluminium hydroxide, aluminium isopropoxide and pseudo-boehmite (Catapal alumina) as the source of Al, and fumed silica and sodium silicoglycolate (Na-SiV) as the source of Si has been monitored by solid-state NMR, X-ray diffraction (XRD) and IR spectroscopy. The use of Na-SiV does not affect the crystallization time, but considerably shortens the preparation of the synthesis gel. Aluminium is not significantly incorporated into the sodalite structure when Al(OH)3 is used. Pseudo-boehmite gives multi-phasic products in which purely siliceous sodalite is always accompanied by (Si,Al)-sodalites. Some of the Al occupies non-framework positions, and parent gels with Si : Al = 5.0, 2.0 and 1.0 gave solids with AlIV : AlVI= 0.73, 1.3 and 3.0, respectively. Only aluminium isopropoxide leads to phase-pure products in which all the AI is four-coordinate and Si : Al = 3.49 and 3.13 with fumed silica and Na-SiV, respectively. The formula NAI= 51.855 – 0.0465vas(Si—O—T) allows the Si : Al ratio to be calculated directly from the FTIR spectrum. With the exception of the material with Si : Al = 1.0 and a0= 8.94 ± 0.1 A, the unit cell parameter of sodalites is 8.83 ± 0.1A irrespective of the Al content.