Studies in chemical phase analysis. Part II. Determination of the solubilities of carbides, nitrides, oxides and sulphides in certain organic solvent-bromine mixtures

Abstract

As part of a study on the quantitative separation of carbide, nitride, oxide and sulphide inclusions from metals, the solubilities of five carbides, seven nitrides, sixteen oxides and eleven sulphides have been determined at 25 °C in methyl acetate-and acetonitrile-bromine mixtures (10 + 1 V/V) both after shaking at room temperature and after refluxing. Aluminium nitride and the carbides and nitrides of chromium, niobium, titanium and vanadium have low or very low solubilities, particularly in methyl acetate-bromine at room temperature, but iron carbide and iron and manganese nitrides are extensively decomposed, with the iron and manganese passing into solution. None of the oxides is more than sparingly soluble but most of the sulphides are appreciably soluble. Appropriate conditions are suggested for achieving a clean separation of oxides and stable carbides and nitrides from metals.