Colored thermolith sands based on gaize (opoka-like) rocks

Nowadays, more and more attention is being paid to improving the aesthetic appeal of ceramic face bricks. It is the variety of appearance that influences a consumer’s choice of a face brick particular type. Different variations of the ceramic wall materials face surface are achieved by three main technological methods, which can be easily combined in one product: relief creation on the face surface --> coloring --> shotcreting. The technology of the first two techniques is well developed, but shotcrete causes certain difficulties. The problem is the lack of colored mineral chips. Natural quartz sand, which is white or grayish in color, and some industrial waste, which is gray and black in color, is often used for shotcrete for ceramic bricks. The authors propose to produce textured colored sands on the base of opal-cristobalite rocks – gaizes by saturating them with elements-chromophores salts solutions of different concentrations with the mineralizers introduction and subsequent burning. The gaizes microporous structure promotes gaize grains coloring throughout the entire volume during firing, while the salts and mineralizers introduction promotes intensive sintering. The conducted experiments allowed to obtain colored thermolite sands of different color and grain composition, which can be used not only for ceramic bricks texturing, but also for concrete products shotcreting, decorative plaster mixtures production, mosaic polymer floors, etc.