Showing papers on "Activated alumina published in 1969"

High-porous activated alumina and method

Abstract: THIS INVENTION IS ADDRESSED TO THE PREPARATION OF AGGLOMERATES OF ACTIVATED ALUMINA HAVING A HIGH DEGREE OF POROSITY AND MECHANICAL STRENGTH AND IN WHICH THE POROUS VOLUME IS WITHIN THE RANGE OF 50-100 CM. 3/100 GRAMS WITH A LARGE NUMBER OF PORES HAVING A DIAMETER GREATER THAN 0.1 MICRON IN WHICH DEHYDRATED ALUMINA IS REDUCED TO A PARTICLE SIZE WITHIN THE RANGE OF 1 TO 25 MICRONS AND IMPREGNATED WITH WATER, WITH OR WITHOUT MIXTURE WITH AN ORGANIC NAPHTHALENE TYPE MATERIAL AND IN WHICH THE AMOUNT OF WATER IS LIMITED TO AN AMOUNT WHICH DOES NOT EXCEED THE POROUS VOLUME OF THE PARTICLES BY MORE THAN 8 PERCENT. THE IMPREGNATED PARTICLES ARE MOLDED INTO AGGLOMERATES, AGED AND THEN REACTIVATED BY CALCINATION AT ELEVATED TEMPERATURES.

Process for producing fine particle size alumina hydrates

Abstract: FINE PARTICLE SIZE ALUMINA HYDRATES, CONSISTING ESSENTIALLY OF A MIXTURE OF NORDSTRANDITE AND BAYERITE, ARE MADE. THE MIXTURE IS OBTAINED BY SUBJECTING A SODIUM ALUMINATE SOLUTION OF HIGH ALUMINA AND SODIUM HYDROXIDE CONCENTRATION TO DILUTION UNDER CONTROLLED CONDITIONS. THE PRECIPITATED ALUMINA HYDRATES CONSIST ESSENTIALLY OF A MIXTURE OF NORDSTRANDITE BAYERITE WHICH, DUE TO THE FINE PARTICLE SIZE DISTRIBUTION AND HIGH SURFACE AREA, PROVIDE AN EXCELLENT CATALYST BASE UPON CALCINATION. THERMAL TREATMENT OF THE MIXTURE AT ELEVATED TEMPERATURES RESULTS IN AN ACTIVATED ALUMINA OF ESSENTIALLY ETA STRUCTURE.

Ammonia synthetsis iron-alkali metal-carrier- - catalyst

Abstract: The catalyst contains 5-25 wt.% of reduced Fe, deposited on an activated alumina or silica carrier containing 3-30 atoms of alkali metal promotor (spec. Cs or K) per 100 molecules of carrier. These catalysts have very even activity, even with varying particle size or temp. they are very suitable for the first bed where high temp. rises can occur.

Electrical Appliance with a Gaseous Filling Consisting at least Partly of Sulphur Hexafluoride

Abstract: 1,152,754 Gas analysis; indicating apparatus BROWN, BOVERI & CO Ltd Oct9, 1967 [Oct10, 1966], No46101/67 Headings G1B and G1J [Also in Division G4] An electrical appliance, the interior of which is filled with a gas consisting at least partly of sulphur hexafluoride, includes a device for indicating the presence of gaseous contaminants produced by decomposition of the sulphur hexafluoride The device consists of a housing 8a containing a contaminant absorbing material 21 exposed to the gas and comprising a granular material containing OH ions such as activated alumina The granular material is dyed with an indicator, the colour of which changes in the presence of the gaseous contaminants The housing 8a is sealed to a flange 18 in a wall 2 of the appliance by a gasket 20 and screws 44 A wire grid 22 is situated at one end of the housing whilst the other end of the housing is sealed by an inspection glass 29 and gaskets 27, 28 A cover 31, having a colour comparison table 32, protects the indicator dye from fading under the action of light To remove the housing 8a without losing the gas in the appliance, screws 35, 37 are loosened so that a gasket 41 of a cover 38 seals against the inside of the flange 18 due to the excess pressure in the appliance The table 32 may be replaced by a manometer fitted to the inside of the inspection glass A ring 52 showing the colours that the dye undergoes rotates with the manometer needle 50 which indicates the pressure in the appliance A further ring 54 indicating the percentage by volume of the contaminants surrounds the coloured ring so that at a given pressure of the gas in the appliance, the percentage of contaminants may be read off at the position on the outer ring corresponding to the existing colour of the dye