Characterization and applications of industrial wastes with highcontent of gypsum

Abstract

The recycling of inorganic wastes generated by different industrial processes is a research field of high interest because the minimization of waste disposal, avoiding its potential release into the environment, can generate environmental and economical benefits for these industries and the general population. The appropriate treatment of industrial wastes could even lead to the generation of co-products of economic value and broad application. Obviously, the environmental and health impact of these co-products should comply with existing regulations.In this direction, the present study describes first the used raw materials ilmenite (ILM) and slag (SLAG) and a wasteknown as ―red gypsum‖ (RG) coming from a titanium dioxide industrial facility located at the province of Huelva (Spain), in terms of their elemental composition, radioactive contents,granulometry, mineralogy, microscopic morphology and physical composition. The main goal was to obtain basic information for future potential applications of the RG waste in construction, civil engineering, etc. One of these applications has been studied in the second part of our study: we have analysed the main properties of cements produced with different proportions of red gypsum, and their obtained improvements, in relation to Ordinary Portland Cements (OPC). In the produced RG cements, it has been also demonstrated that the levels of pollutants associated always remain within safety limits.