Uranous sulphide

Uranium Oxysulphide, U3O2S4 or UO3.2US2, is formed when uranous oxide, urano-uranic oxide, or ammonium uranate is heated in a stream of hydrogen sulphide or carbon disulphide vapour when one of the oxides is heated with a mixture of ammonium chloride and sulphur or when uranyl sulphate is heated in hydrogen or with potassium pentasulphide. It is a greyish-black powder, which is decomposed by nitric acid %vith deposition of sulphur. 

Ammonium sulphide gives a brown precipitate of uranyl sulphide, which on prolonged heating decomposes with separation of sulphur and hydrated uranous oxide. 

Precipitation with ammonium sulphide is best performed at 80° C. in presence of ammonium chloride. Some ammonium uranate is always formed, and complete separation from the alkali metals is only obtained by repeating the precipitation. The results obtained by this method are liable to be high owing to some sulphide being oxidised to sulphate during ignition. ... 

The structures of the metal, hydrides, and carbides are described in other chapters, as also are the halides MX3, MX4, and MX5. Here we devote sections to certain halide structures peculiar to U, complex fluorides of Th and U, oxides of U, uranyl compounds and uranates, nitrides and related compounds, and conclude with a note on the sulphides of U, Th, and Ce. 

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