Abstract: Purification of aqueous hydrogen peroxide solutions using conventional ion-exchange techniques can result in the hydrogen peroxide decomposing explosively. Much safer processes are obtained by restricting the contact between the resin bed and the hydrogen peroxide solution to a very short contact time, by employing a treatment chamber that is vented to the atmosphere and also by slurrying the resin bed. The bed is conveniently retained on a mesh that acts as a filter (13) preferably conical having an aperture (17) at its apex through which is introduced a small fraction of the solution countercurrent (10) to the main solution flow (9) in order to slurry the bed (19). The solution can be recycled through the same bed or a plurality of beds. Very high purification can be achieved and combined with improved safety of operation.

Abstract: The electronics industry demands that hydrogen peroxide for use therein be purified to very low levels of impurities, currently at the level of a few ppb for some impurities, or even lower. However, existing methods are either inherently unsafe because they bring concentrated hydrogen peroxide into contact with a concentrate of transition metal decomposition agents for peroxide and a purification resin which acts as a source of carbon, or are unable to attain the desired impurity level. The instant purification process first makes a concentrated suspension of stannic oxide particles in an aqueous medium, which can include aqueous hydrogen peroxide, by subjecting the mixture to high shear mixing, introducing an effective amount of the dispersion into the peroxide solution and filtering the mixture so as to remove the stannic oxide particles that now are loaded with ionic impurities, and particularly with transition metal ions.

Abstract: Concentrated solutions of hydrogen peroxide tend to decompose on storage, thereby losing their effectiveness, amongst other reasons by virtue of interaction with contaminating transition metals.Peroxygen compounds are stabilized by contact with a stabilizing amount of compound of general formula: ##STR1## in which X represents a methylene phosphonic acid group of formula --CH.sub.2 --(--PO.sub.3 H.sub.2) or salt thereof, R represents a tetra methylene diradical, optionally alkyl-substituted, that completes a cyclo-aliphatic ring and thereby establishes the two NX.sub.2 groups in a substantially fixed configuration and Y represents a hydrogen or lower alkyl group.Preferably, the solutions contain additionally one or more co-stabilizers, including stannate, phosphates, hydroxybenzoic acid, citric acid and nitrate.The stabilizer system can enable the solution to be diluted, even with municipal water.

Abstract: A racemate may be resolved into its enantiomers by stereoselective adsorption on a crystalline molecular sieve having an assymetric crystal structure for example zeolite ZSM11. The resolution may be assisted by the presence of an enantiomer of a compound separable from that of the racemate either preadsorbed on the molecular sieve or included in a polar solvent solution of the racemate to be treated. Resolution of an alkyl aryl sulphoxide racemate is exemplified.

Abstract: Crystalline molecular sieve materials such as high silica zeolites are manufactured using an organic template comprising an optically active enantiomer such as an enantiomer of 3(.+-.) methyl piperidine -N,N-dimethyl bromide.A new zeolite materials is identified.