Abstract: Process of flotation of minerals, which consists of introducing the flotation collector into the mineral pulp to be treated in the form of a microemulsifiable composition. In general, the collector agents are organic compounds containing sulphur, particularly mercaptans, thioethers or polysulphides, which generally are very slightly soluble in water. This process is particularly suitable for minerals based on oxides and sulphides.

Abstract: Process of flotation of minerals, which consists of introducing the flotation collector into the mineral pulp to be treated in the form of a microemulsifiable composition. In general, the collector agents are organic compounds containing sulphur, particularly mercaptans, thioethers or polysulphides, which generally are very slightly soluble in water. This process is particularly suitable for minerals based on oxides and sulphides.

Abstract: An improved method of producing dialkyl-sulfoxides by oxidizing corresponding dialkyl-sulfides with hydrogen peroxide in aqueous acidic medium. It remedies the drawback of the similar prior art as concerns the separation of the sulfoxide formed from its reaction medium. The new method permits of easily recovering the sulfoxides in the state of good purity.The improvement consists in mixing the reaction medium with a large proportion of a solvent capable of yielding an azeotropic mixture with water. Then, after oxidization, the water is removed by distillation as azeotropic mixture. Preferably solvents are used which dissolve the dialkyl-sulfide but do not dissolve the sulfoxide formed; heptane is a particularly useful solvent. When an excess of the solvent is used, there is obtained, after distilling off the azeotropic mixture, a slurry of sulfoxide and solvent, easy to separate.