Phosphogypsum is a large-scale solid waste from the production of phosphoric acid by the extraction method. The volume of accumulated waste in the world amounts to hundreds of millions of tons, and their disposal is becoming increasingly important. The article provides a brief overview of recent research on the use of phosphogypsum as a component of building materials. A list of the main factors of the negative impact of phosphogypsum waste on the environment is given, as well as the main impurities in its composition that reduce the quality of the resulting materials and methods for eliminating these impurities. It is shown that of the many products that can be obtained using phosphogypsum, the most widespread are construction and road materials, in which it is proposed to be used as a replacement for natural gypsum and sand.
Keywords: phosphogypsum, environment, building materials, road coverings, modifying additives
The article presents the technological aspects of obtaining solid synthetic hydrocarbons (paraffins) used to obtain and improve building materials. It is shown that a promising alternative to petroleum paraffins is the production of synthetic hydrocarbons from non-oil, including renewable carbon-containing raw materials. The main reaction conditions, synthesis catalysts, promoters that contribute to the maximum yield of a solid product, the prospects for the use of biomass, carbon-containing wastes, and carbon dioxide in the technology for producing synthetic hydrocarbons are considered.
Keywords: synthetic hydrocarbons, catalysts, promoters, building materials, modifiers
The effect of a zeolite support on the physicochemical properties of cobalt catalysts prepared by the precipitation method and calcined at 400°C was studied. The values of the specific surface of the catalysts, the degree of cobalt reduction, and the dispersion of the metal were determined, and the presence of functional groups on the surface of the catalysts was determined by BET, TPV, TPD-H2, and IR spectroscopy.
Keywords: catalyst, cobalt oxide, hydrocarbons, dispersion, active surface
The article presents the results of studying the effect of the loading of active metal on the physicochemical properties of cobalt catalysts for the Fischer-Tropsch synthesis on a silicate support, promoted with aluminum. Using the BET, XRF, TPR, TPD-H2 methods, it has been established that the optimum cobalt content is 15‒18 wt. %.
Keywords: Fischer-Tropsch synthesis, catalyst, cobalt, active component, loading