Composite Building Materials with the Use of Phosphogypsum

Nowadays waste dumps of phosphogypsum take about 1500 hectares of fertile land and amount to 300 mln tonnes. Existing methods of processing are too labour-and energy-consuming, what didn’t lead to widespread use of phosphogypsum. Phosphogypsum waste continue to be stored in waste dumps, disperse on the wind and create ecological problem in the regions of storage. Authors of this article have developed non-burning technology of production of composite building materials based on phosphogypsum. Basic technology steps include: mixing of dry components in the temperature above 60°C, adding slacked lime, hydro-mechanical-and-chemical activation in the laboratory mixer in the temperature above 60°C, shaping and pressing under pressure. Economic efficiency of this technology is conditioned by usage of inexpensive raw materials (the basic component is phosphogypsum, which is finely dispersed bulk waste of chemical industry), reduction of energy and labour costs of building materials production. Currently in the Yu.M. Borisov’s VGTU center were conducted laboratory research of building materials based on phosphogypsum, completed work on technology parameters, and started tests for obtaining first industrial samples from composite materials with a usage of phosphogypsum.