The interaction of molted slag with solid phase of red sludge

Nowadays the most urgent task of non-ferrous metallurgy is the replacement of ecologically dangerous storage of red mud (RM), the withdrawal of alumina production from bauxite, by its complete processing. It is necessary to search for appropriate industrial technologies. This work has demonstrated that one of them is the use of RM for granulation of molten slags. The large amounts of granulated slag are regularly used in the production of cements, in road construction, agriculture and other fields of engineering and technology. The characteristic of the process for obtaining granulated slag is the active interaction of molten metallurgical slag with a cooling liquid. The slag solidifies and its mass breaks up in the atmosphere of the hot steam into small particles because of the emerging critical stresses. These two processes happen simultaneously and instantly. The problem is that during the granulation of slag, which usually contains sulfur, a large amount of harmful substances is released into the atmosphere, such as, sulfur oxides and, mainly, hydrogen sulfide. Its concentration on the working sites of the granulation sections is much higher than the TLV. To combat this phenomenon, fine-dispersed lime or limestone, which are characterized by their sorption properties, are usually added into the cooling liquid composition, bur it results in high expenditures. This paper examines similar properties of finely dispersed red mud. Laboratory and industrial tests have been carried out. It is found that with the help of red mud the concentration of sulfur gases on the granulation working sites can be reduced by 2 orders of magnitude. It is important that the new granulated slag, called in this case “slurry” is not inferior to the usual one according to its basic technological properties.