A study was conducted on the development of filler compositions based on heat-treated phosphogypsum for the production of paints and varnishes with luminescent ability. In the course of the study, it was revealed that the reduced phosphogypsum, which exhibits the properties of an ultraviolet pigment, can be used to produce paints and varnishes based on colorless varnish XB-784. When using a colorless varnish and synthesized ultraviolet pigment, paint and varnish materials can be obtained that form almost transparent coatings and have a luminescent ability. The introduction of unreconstructed phosphogypsum as a filler increases the covering capacity of paint coatings. Non-reduced heat-treated phosphogypsum as a filler does not give a luminescent glow under the influence of UV irradiation, however, it increases the hiding power of the material and enhances the luminescent ability of the UV pigment.
Keywords: filler compositions, colorless varnish, ultraviolet pigments, phosphogypsum, waste recycling
The paper investigates the possibility of obtaining a luminescent material by heat treatment of phosphogypsum at a temperature of 800 degrees Celsius. It is shown that it is not enough to achieve the result of heating the system to a given temperature, the luminosity of the samples is practically absent.For phosphogypsum subjected to heat treatment at a temperature of 800 degrees Celsius for 60 minutes, it was found that images obtained in the presence of 50-150% moles of citric acid showed the most pronounced luminosity. The luminosity of samples with starch in the amount of 50-75 mol% was worse (by about 50%). The use of coal as a reducing agent under given conditions led to the formation of samples with the lowest luminosity. An extreme change in the dependence of luminosity on the amount of the introduced reducing agent with maxima of 25-75% (mol.) was revealed. It is suggested that the luminescent ability of the reduced phosphogypsum is associated with the formation of the composite material calcium sulfate/sulfide.
Keywords: heat treatment mode, luminescent material, phosphogypsum recycling, reducing