Microsilica, or silica fume, is an amorphous type of silica mostly collected as byproduct of the silicon and ferrosilicon alloy production. In this work, low shrinkage alumina-mullite ceramic composites were prepared from mixtures of calcined alumina, silica fume and aluminum metal powder and sintered at 1550 o C for 2 hrs. The influence of silica fume and aluminum powder on the densification p...

In this paper, mesoporous alumina with different pore sizes and wall crystalline structures was synthesized at calcination temperatures over 550 degrees C. The characterization of the samples calcined at 550, 800, 1100, and 1300 degrees C, respectively, was performed using TEM, XRD, FTIR, TG/DTA, and N2 adsorption/desorption techniques. The correlation between pore size and wall crystalline str...

alumina-supported cs3[re(c2o4)3] precursor has been synthesized  for preparation of re-cs/g-al2o3 catalyst. cs3[re(c2o4)3]  has been prepared from the reaction of recl3 with  h2c2o4.2h2o and cscl in water. the complex has been characterized by elemental analysis and various spectroscopy techniques such as ft-ir, uv-vis and 13c-nmr. the complex was supported on γ-al2o3 by column chromatography. ...

The paper reports on a current research on fluidised bed gasification of biomass and coals. The focus is on the bed material agglomeration and fragmentation phenomena that are well known to affect the reliability and the efficiency of fluidized bed combustion processes. Preliminary results of dedicated tests at high temperature are reported and discussed in the paper. On the whole, agglomeratio...

BACKGROUND Methanol to dimethyl ether (MTD) is considered one of the main routes for the production of clean bio-fuel. The effect of copper loading on the catalytic performance of different phases of alumina that formed by calcination at two different temperatures was examined for the dehydration of methanol to dimethyl ether (DME). RESULTS A range of Cu loadings of (1, 2, 4, 6, 10 and 15% Cu...

Studies were conducted to determine the effects of a panel of seven nanomaterials (NMs), namely: α-alumina, γ-alumina, precipitated silica; silica fume, calcined silica fume, colloidal antimony pentoxide (Sb(2)O(5)), and superfine amorphous ferric oxide (Fe(2)O(3)), on sediment dwelling invertebrates Chironomus tentans under controlled laboratory conditions. Percentage survival, enzyme activiti...

a basic alumina-spinel low cement castable (lcc) composed of sintered bauxite, reactive alumina, calcined alumina, calcined magnesia, microsilica, and high alumina refractory cement was prepared (castable a) to which 5% sodium hexa-meta phosphate was later added (castable b) to prepare samples for heat treatment at 110ºc, 900ºc, and 1400ºc. bulk density (bd), apparent porosity (ap), and cold cr...

nowadays, magnesia carbon refractories are very important for the iron and steel industries. it is dueto their unique properties, such as low wet ability with melt iron and steel. therefore, it is importantto extend the life of the refractory. in this research, the effect of calcined alumina and nano carbon onmechanical strength and corrosion resistance against slag in magnesia carbon refractor...

The role of iron in two modes of integration into alumina catalysts was studied at 0.39 wt% Fe and tested in trichloroethylene combustion. One modified alumina was synthesized using the sol-gel method with Fe added in situ during hydrolysis; another modification was performed using calcined alumina, prepared using the sol-gel method and impregnated with Fe. Several characterization techniques w...