III International Conference

PP-II-48PROPERTIES OF ALUMINA FORMED FROM HYDRATED UNDER MILDCONDITION TSEFLAR TM TREATED GIBBSITEKharina I.V., Isupova L.A., Moroz E.M., Litvak G.S., Rudina N.A., Budneva A.A.,Paukshtis E.A., Tanashev Yu.Yu., Parmon V.N.Boreskov Institute of Catalysis SB RAS, Novosibirsk, RussiaE-mail: Kharina@catalysis.nsk.suPhysical, chemical and mechanical properties of alumina, made from rehydration productof the TSEFLAR TM -treated gibbsite/hydrargillite (CTA HG), were studied with X-rayanalysis, TA, EM, BET and IRS. Alumina granules were prepared by extrusion of plasticpaste prepared from as prepared hydroxides after calcination at 550 o C/4 hours. Aluminaformed from rehydration product of the TSEFLAR TM -treated hydrargillite (CTA HG) wasnearly totally γ-alumina (hydration in acid media), and nearly totally ŋ-alumina (hydration inammonia solution and water). Granules characterized with mono, bi or three size poredistribution (depending on hydration conditions), rather good strength, high specific surfacearea and moisture capacity were prepared.Thermal activation of gibbsite (HG) is known to be a method for production of highlyreactive amorphous Al 2 O 3 x nH 2 O. Hydration of such product is a basis of wastelessmanufacturing the pseudoboehmite-structured hydroxide. Thermal decomposition of HGusing a TSEFLAR TM installation is a new way to implement the thermal decompositionprocess [1]. Product obtained is hydrated at room temperature and atmospheric pressure inwater and aqueous ammonia to form eventually the stable bayerite-like hydroxide structure[2]. In an acid solution at room temperature and atmospheric pressure, amorphous andpseudoboehmite-like hydroxides are formed [3]. Hence TSEFLAR TM is a new wasteless andenergy saving method for preparation of different hydroxides under mild conditions and,consequently, different alumina oxides.The main goal of this paper is the investigation of physical and chemical properties ofaluminas formed from different hydroxides including properties of alumina granules.The samples were characterized using such techniques as XRD (including the mode withthe synchrotron radiation-SR), DTA, BET, IRS, SEM and TEM.Ŋ, γ or γ +ŋ aluminas with X-ray particle size 3-4 nm were revealed by XRD in thesamples prepared by decomposition of hydroxides at 550 o C, 4 h. According to X-rayanalysis, alumina formed from amorphous hydroxide (hydration in acid media) was nearlytotally γ-alumina, and alumina formed from bayerite - like hydroxide (hydration in ammoniasolution and water) was nearly totally ŋ-alumina. The cell parameters of the prepared250