Using phosphogypsum in roadbuilding: the potential and problems

Abstract

Introduction. This article discusses the global environmental problem of phosphogypsum and its storage. Phosphogypsum is waste generated in the course of making mineral fertilizers. In Russia, the amount of this material in waste piles is about 300 million tons. It is more rational to use large areas, occupied by these dumps, for other purposes. The solution is its largescale use in highway construction, that will solve the problem of shortage of roadbuilding construction materials in Russia.
 
 Materials and methods. Our task was to analyze the current research into the applicability of phosphogypsum. Towards this end, a brief review and analysis of literary sources, published over the past 45 years, was performed, and conclusions were drawn about the prospects for using this material.
 
 Results. As a result it was found that phosphogypsum is used in construction, and its applicability is confirmed by its practical application. The data obtained as part of the review confirm that stabilized phosphogypsum is widely used to reclaim quarries, fill landfills, and construct embankments. Besides, phosphogypsum, with an inorganic binder added, is used to build reinforced foundations of roadbeds.
 
 Conclusions. It is necessary to improve formulations of phosphogypsum binders (mainly to improve their water and frost resistance) to use them in the climate zones having the most severe climatic conditions. Numerical modeling of structures, made of phosphogypsum dihydrate, is needed, and phosphogypsum dihydrate stabilization methods are to be developed.