Rhone-poulenc Specialites Chimiques

Rhone-poulenc Chimie De Base

Rhone-poulenc Specialties Chimiques

Andre Lambert

Jean-Paul Tognet

Bernard Boudot

Frederic Fabre

Georges Nury

Jean Fava

The rare earth hydroxides are improvedly prepared by (i) treating a rare earth phosphate mineral, e.g., monazite or xenotime, with an aqueous solution of an alkali metal hydroxide, (ii) separating therefrom rare earth hydroxide solids and a liquid phase essentially consisting of alkali metal phosphate and alkali metal hydroxide, (iii) crystallizing alkali metal phosphate from said liquid phase, (iv) separating the mother liquor of crystallization therefrom which contains said alkali metal hydroxide, (v) adding calcium oxide or hydroxide to the mother liquor thus separated to form a precipitate therein, (vi) separating said formed precipitate, and (vii) recycling the mother liquor of separation to said treatment step (i).

Production of rare earth hydroxides from phosphate ores

The uranium, yttrium, thorium and rare earth values contained in a phosphate rock are essentially totally recovered therefrom by, during the wet-process preparation of phosphoric acid from said phosphate rock, acidulating same in the presence of aluminum and/or iron, and optionally silica, and thence recovering said values from the phosphoric acid thus produced.

Essentially complete recovery of uranium, yttrium, thorium and rare

Additive composition for an acid copper electroplating bath, which bath being well adapted for the copper plating of printed circuits, is comprised of (1) the sodium salt of .omega.-sulfo-n-propyl N,N-diethyldithiocarbamate, (2) polyethylene glycol having an average molecular weight ranging from about 6,000 to 20,000, (3) crystal violet, and (4) sulfuric acid.

Additive composition, bath and process for acid copper electroplating

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Louvres, France

Andre Lambert