Abstract: Olefin polymerisation uses catalysts based in pi-arene complexes of lanthanide metals in particular such catalysts supported on hydrophobic or hydroxylic surfaces particularly of alumina or silica halide surfaces particularly magnesium chloride. Such catalysts will polymerise ethylene and also propylene to give a largely isotactic polymer without using an electron donor to enhance stereo regularity. They also do not require co-catalysts to activate polymeriscation.

Abstract: A method for the recovery of the bromine content of methyl bromide as bromine or hydrogen bromide comprises oxidizing the methyl bromide over a noble metal catalyst. The production of hydrogen bromide is favored by the inclusion of a source of hydrogen.

Abstract: Heavy metal values are recovered from mother liquors remaining from oxidations to mono- or poly- carboxylic acids in aliphatic monocarboxylic acids in presence of catalyst heavy metals and bromides by (1) concentrating, (2) precipitating and (3) separating heavy metals as sulphates and (4) recovering aliphatic monocarboxylic acid and H Br by distillation, (5) dissolving sulphates in water, (6) adsorbing heavy metals on a cation exchange resin and (7) desorbing them, preferably with the solution from Step 4.

Abstract: Cobalt catalyst values are recovered from mother liquors remaining from oxidations to mono- or polycarboxylic acids in lower aliphatic monocarboxylic acids in presence of catalysts comprising cobalt and bromide ions by (1) if necessary, adjusting the cobalt and bromide concentrations so that they are within specified limits (2) adsorbing cobalt and bromide ions (differentially with respect to extraneous ions) on a strongly basic anion exchange resin and (3) desorbing cobalt and bromide ions with lower aliphatic monocarboxylic acid containing more than 10% by weight of water.