Contribution to the Study of the Production and Properties of Finely Divided Solids, Prepared in a Flame Reactor; CONTRIBUTION A L'ETUDE DE PROCEDES D'OBTENTION ET DES PROPRIETES DES SOLIDES FINEMENT DIVISES ELABORES DANS UN REACTEUR A FLAMME
Thesis submitted to the Univ. of Paris. Sufficiently fine particles cannot be obtained by the grinding of crystals. It is therefore logical to adopt a method whereby the solid is formed from a compound in the vapor phase. Notable amongst such compounds are certain organic derivatives of metals and the metallic halogenides which are volatile at moderate temperatures. Formation of the solid from its gaseous denivative should be possible by hydrolysis or oxidation without the dispersion of the reaction medium being modified. The simplest method seems to be to obtain the reaction in an oxyhydrogen blow-pipe. When the gases in the blow-pipe contain a volatile metallic compound, precipitation of finely divided solid in the form of oxide is produced in the flame at high temperature. Alumimum, titanium, iron and zirconium oxides and silica, the particles of which are spherical and homogeneous in diameter, were prepared in this way. The specific surfaces calculated from the diameters on electron microscope photographs are in agreement with those measured by adsorption of nitrogen at - 195 deg C. The oxides thus prepared are therefore not intensely porous. The properties and size of the oxide particles are studied as a function of various operationnl parameters, such as flame temperature and concentration of volatile metal derivative in the reactive gases. When the blow-pipe is supplied with oxide particles of small diameter, a very marked increase in size is observed. The properties of these preparations are also examined. (auth)
- Research Organization:
- France. Commissariat a l'Energie Atomique. Centre d'Etudes Nucleaires, Saclay
- NSA Number:
- NSA-15-013304
- OSTI ID:
- 4059150
- Report Number(s):
- CEA-1669
- Country of Publication:
- France
- Language:
- English
Similar Records
Contribution to the Study of the Structure and Properties of Silica Gel; CONTRIBUTION A L'ETUDE DE LA STRUCTURE ET DES PROPRIETES DES GELS DE SILICE
Contribution to the Study of the Niobium-Aluminum System; CONTRIBUTION A L'ETUDE DU SYSTEME NIOBIUM/ALUMINIUM