X-ray diffraction and SEM analysis of waste sulfur modification for use in concretes

Secondary sulfur obtained as a by-product in the oil refining process is a major problem as an environmental pollutant. One of the possibilities of environmental protection is the use of sulfur obtained in this way as a component of sulfur concrete. Mixing of sulfur with suitable additives can provide longer working lifetime of sulfur concrete, as well as maintenance of the former physical, chemical and mechanical characteristics of concrete. Such mixtures are usually called modified sulfur or sulfur cement. Secondary sulfur produced in the oil refining process by the Klaus process (approval of crude oil) cannot be used in this form. In order to be ready for the use of sulfur concrete and asphalt, it is necessary to modify elemental sulfur from cyclic to chain form, obtaining of modified sulfur whose application is as a binding agent in a concrete instead of portland cement is described in this paper. Influence of dicyclopentadien, an organic additive, on sulfur modification has been studied in this research. Microstructure and mineral analysis of modified and unmodified sulfur cement binding are realized using polarized and scanning electron microscopes and X-ray diffraction spectrometer.