Abstract: Absorbent granules comprising an intimate mixture of particles of alumina trihydrate, 0.5 to 2 parts by weight of particles of a sodium component selected from the group consisting of sodium carbonate, sodium bicarbonate and mixtures thereof per part by weight of said alumina trihydrate and from 5 to 20% by weight of a binder, said alumina trihydrate, sodium component and binder being present in such proportions that, after ignition of a sample of the granules at 900.degree. C., the sample has a sodium oxide, Na.sub.2 O, content of at least 20% by weight. Processes for manufacturing such absorbent granules and for using such absorbent granules for the removal of acidic gases are also disclosed.

Abstract: Absorbents, suitable for absorbing sulphur compounds such as hydrogen sulphide from gases and liquids, in the form of shaped units having an average size within the range 1-10 mm and containing at least 75% by weight of an absorbent material comprising copper carbonate, basic copper carbonate, and/or copper hydroxide. The units preferably have a bulk density of at least 0.9 kg/l, especially at least 1.2 kg/l. The units are preferably agglomerates containing a small amount of a binder such as a cement and may also contain a proportion of alumina to catalyse hydrolysis of carbon-containing sulphur compounds such as carbonyl sulphide or carbon disulphide.

Abstract: A coating composition suitable for application to the internal surfaces of ovens to render these self cleaning comprising a milled self-matting devitrifying enamel frit and antimony trioxide or a precursor thereof, preferably together with an oxidation catalyst comprising an oxide of copper, manganese or cobalt. The coating adheres directly to metal surfaces and avoids the necessity for first applying a ground coat.

Abstract: A self-cleaning catalytic coating for cooking oven walls comprises a mutually sintered matrix of hard catalyst particles and binder particles.The coating is preferably made by forming large hard catalyst particles, such as compressed pellets, milling them to the required size range, typically averaging above 2 microns, then incorporating them with a binder and applying the mixture to a substrate.