The first tentative experiments on the production of carboxylic acids and their derivatives from balkhashite and Barzas sapromixites by oxidation for use as flotation reagents were carried out in 1932. These experiments, naturally, led to the idea of applying oxidation reactions to obtain these products to sapropel material. Results of the work: 1. The easy oxidability of sapropel material has been established, with a large yield (from 30 to 60%) of oxidation products extracted with organic solvents and alkalis. 2. The oxidation products of sapropel material (a mixture of carboxylic acids and their saponified derivatives) are characterized by high molecular weights and saponification numbers, low hydrogen content and insignificant iodine numbers. 3. The formation of acids soluble in petroleum ether has been established during the secondary oxidation of compounds soluble in sulfuric ether and a mixture of alcohol-benzene, which in their chemical properties are close to the acids of the petroleum fraction of primary oxidation. 4. The most effective oxidizing agent at this stage of work is nitric acid. 5. It has been established that the oxidation products of sapropels are flotation active, especially substances of primary and secondary oxidation, soluble in petroleum ether.
The article sets out a reasonable hypothesis of the causes of mineral flotation. Its main principles are as follows: Insignificant flotation of “sulfide” minerals is due to the formation of halogen oxidation products on their surface, which react with collectors to form stable oriented films of the corresponding organic sulfide compounds of heavy metals, which are inseparable from the substance of the minerals. Cleavage of complete collection products from the surface is possible due to oxidation or as a result of intramolecular rearrangements, especially in the presence of excess collector. The reason for the strong floating of “oxide” minerals is the formation on their surface of unstable reaction intermediates between substances in the mineral and the reservoir. The effectiveness of sulfidization of oxidized minerals is due to the transformation of their surface into the corresponding hemisulfides, which are able to react with reservoirs. The article compares and discusses modern theories of the flotation ability of minerals.
