Development of the coagulant obtaining technology from substandard bauxite of Kazakhstan for wastewater treatment

One of the important environmental problems of Kazakhstan is the insufficient quality of natural and wastewater treatment, the reason for which is the lack of the main, mandatory reagent in water purification technology – coagulant. Aluminum-containing natural and man-made raw materials can be comprehensively processed in order to obtain modified mixed reagents-coagulants. One of the promising types of raw materials on the territory of Kazakhstan for the production of coagulants are substandard bauxites of the Krasnooktyabrsky deposit. This article presents a fundamentally new approach to the development of a technology for producing an effective coagulant with high coagulating properties in a wide pH range – a mixed sulfate aluminum-iron-silica coagulant (MSAISC) – when decomposing Red October bauxite with sulfuric acid with maximum extraction of aluminum, iron and silicon into a paste-like phase. Such a composition of the coagulant, called by us MSAISC (mixed sulfate aluminum-iron-silica coagulant) allows you to expand the range of action both in temperature and pH of the medium. In this sense, silicon coagulant, as well as modern aluminum polyoxychlorides, can be used without flocculant. The simultaneous presence of aluminum, iron and silicon salts in the composition of the coagulant makes it possible to combine the properties of «three in one».