Rhone-poulenc Chimie

Rhone-poulenc Specialites Chimiques

Aluminium Pechiney

Francoise Seon

Claire David

Bernard Boudot

Yves Bertaud

Philippe Nataf

Rene Perrier De La Bathie

Gerard Picard

Paul Michel

Michel Ries

Bernard Tremillon

Ghislaine Barthole

Novel rare earth oxides having a large specific surface of at least 40 m.sup.2 /g, well adapted for catalysis, are prepared (i) by reacting at least one rare earth salt with a strong base in the presence of carboxylate ions, or by reacting at least one rare earth carboxylate with a strong base, to produce a true rare earth hydroxide, (ii) separating the precipitate thus produced, and then (iii) washing and (iv) calcining such precipitate.

Rare earth oxides

Morphologically improved ceric oxide particulates having a grain size distribution such that the mean diameter of the aggregates thereof ranges from 0.2 to 1 .mu.m, are conveniently prepared by (i) hydrolyzing an aqueous solution of a cerium (IV) salt in an acid medium, in the presence of an aqueous colloidal dispersion of a cerium (IV) compound, (ii) separating the resulting precipitate, and (iii) heat treating said separated precipitate, advantageously by calcination at elevated temperatures.

Morphologically improved ceric oxide particulates

The rare earth metals, or alloys thereof, are prepared in high yields in a specially designed electrolytic cell, by electrolyzing a melt comprising (i) at least one chloride of at least one rare earth, or at least one such chloride and at least one chloride of at least one transition metal, (ii) at least one alkali or alkaline earth metal chloride, and (iii) at least one alkali or alkaline earth metal fluoride.

Electrolytic production of rare earth metals/alloys thereof

Phosphates, e.g., the polyphosphates and halophosphates, are prepared in high purity by melt thermocondensing corresponding precursors thereof, e.g., salts of orthophosphoric, pyrophosphoric or metaphosphoric acid, via electromagnetic induction heating, for example in an auto-crucible furnace.

Preparation of phosphates by induction melting

The alkaline earth metal titanates, well adopted for electronics applications, e.g., homogeneous powders of barium or strontium titanate, are prepared by directly reacting, in a molten salt bath medium, (a) at least one titanium compound, with (b) at least one compound A reactive therewith to generate the species TiO.sub.3.sup.2-, and (c) at least one alkaline earth metal nitrate.

Preparation of alkaline earth metal titanates

Morphologically improved ceric oxide particulates having a grain size distribution such that the mean diameter of the aggregates thereof ranges from 0.2 to 1 .mu.m, are conveniently prepared by (i) hydrolyzing an aqueous solution of a cerium (IV) salt in an acid medium, (ii) adding an aqueous colloidal dispersion of a cerium (IV) compound to the product of step (i), (iii) separating the precipitate from step (ii), and then (IV) heat treating said separated precipitate, advantageously by calcination at elevated temperatures.

Process for producing morphologically improved ceric oxide particulates

Vanadium values useful for catalyst regeneration are recovered from compositions/materials comprised thereof, typically spent V.sub.2 O.sub.5 catalysts, by intimately contacting an aqueous suspension of such a material with a gaseous admixture of sulfur dioxide and oxygen, whereby a phase separation thus results, and recovering an aqueous phase constituting a solution of vanadium values.

Recovery of vanadium values

The metals of Groups (IV)(B) or (V)(B) of the Periodic Table, or of the lanthanide series, e.g., titanium metal, are conveniently produced, notably in powder form, by reducing a salt of such a metal by contacting same with liquid admixture comprising lithium metal maintained dispersed in a bath of molten salts.

Production of metals by metallothermia

Novel alloys comprising neodymium, iron and optionally another rare earth metal are facilely prepared by reducing a neodymium/rare earth halide with a reducing metal, in the presence of iron.

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Montreuil, France

Francoise Seon