Ceramic pigments on the base of technogenic silica-containing material—waste vanadium catalyst were obtained in this work. Corundum is identified along with the predominant mullite phase in the composition of pigments. The ions of nickel, chromium, and iron are embedded in the structure if the concentration of the corresponding oxide in the initial mixture does not exceed 10 wt.%. In this case, the oxide is not identified in a free form according to the results of X-ray diffraction analysis. Spinel CoAl2O4is formed in cobalt pigments. The developed pigments keep the firing temperature up to 1200°C. The obtained pigments may be recommended for ceramic paints and colored glazes for building materials.

The reactions synthesizing diopside ceramic pigments using natural minerals -talc and wollastonite -have been investigated. For the initial components taken in a nonstoichiometric ratio the yield of the main reaction product -diopside -increases in two of the three reactions studied, while in the third reaction a change of the stoichiometry of the input components results in a lower content of diopside. It is found that for a small deviation from stoichiometry the dominant crystal structure of the pigment changes, which in turn fundamentally changes the color of the pigment.

The possibility of ceramic pigments synthesis using industrial waste is studied. These raw materials will lower production costs of ceramic pigments. The synthesized pigments can be recommended for obtaining on-glaze ceramic paints and volume coloring of ceramic pastes in the manufacture of construction materials.

The mineralizing effect of sodium fluoride, boric acid, and a natural fluorine-bearing mineral (topaz concentrate) on the synthesis from talc of ceramic pigments with magnesium metasilicate, forsterite, and diopside structures is investigated. It is shown that NaF is the most active mineralizer. It is noted that NaF has a positive effect not only on the synthesis of crystalline structure but also on the chromaticity of the pigments. The pigment compositions developed can be widely used to tint ceramic pastes, glazes and glasses, in the manufacture of building materials, and to make paints.Substances that accelerate phase-formation reactionsmineralizers -are often used to obtain ceramic pigments under industrial and laboratory conditions. The effectiveness of mineralizers depends on their nature, quantity, and degree of dispersion in the reagent being activated [1].The following possibilities for the action of mineralizers are known: protection from resorption of a mineral, creation of artificial rudimentary crystalline grains, action similar to that of a catalyst, formation of solid solutions, and action similar to fluxes.To intensify many reactions in the solid phase, the content of an added mineralizer must be not exceed 1 -3% of the total mass of the mixture. Boron, fluorine, and alkali-metal compounds are used as mineralizers to make ceramic pigments.The mineralizing action of fluorine ions is explained by the fact that they cannot participate in the formation of "bridges" between the silicon-oxygen tetrahedra. When fluorine ions are introduced into the initial mix, the fraction of oxygen atoms which are bound in the space lattice between one another via silicon atoms, changes, i.e., a fluorine ion breaks chemical bonds in a crystal lattice.Boron compounds are often used as mineralizing additions in the synthesis of pigments. It has been observed that B 2 O 3 lowers the sintering temperature of many crystalline materials, since B 3+ has a large charge and a small ionic radius (0.02 nm). Consequently, the polarization power is more strongly expressed for boron than for singly charged alkali-metal ions; B 3+ has a greater effect on decreasing the stability of the crystal lattice. It is also observed that B 2 O 3 has a positive effect on the chromophoric properties of pigments [1].Currently, a promising direction of research is to study the possibility of obtaining ceramic pigments using natural mineral raw materials. The structures of many pigments which are conventionally synthesized from pure oxides and salts of various elements can be obtained from chemically pure natural raw materials, for example, diopside, wollastonite, and others [2]. But, a structural deficiency of natural minerals is their organic capability of incorporating tinting ions. The introduction of mineralizers can loosen their crystal lattice, increase the "ionic capacity" of natural minerals, and improve the color characteristics of ceramic pigments based on natural mineral raw materials [3].We investigated the effect of different mineraliz...

Ceramic pigments with mullite structure were obtained using waste vanadium catalyst. The ion-chromophores were introduced to the initial mixture in the quantity of 5-15 wt. % in the form of nickel, chromium, iron, and cobalt oxides. It was established that the phase composition of the obtained pigments was complex and consisted of mullite and corundum. But it does not effect on the properties of the obtained pigments, in particular, on heat resistance.