An innovative chemical quantitative mineral analysis (CQMA) was successfully tested on a cordierite-based clay ceramic sample to quantify crystalline and amorphous components. The accuracy of this method was demonstrated on an added module to the CQMA program that used oxide formulas of amorphous phases obtained by energy dispersive X-ray spectroscopy (EDS) microprobe chemical analysis. This CQMA method was tested for three variants calculated using chemical analysis, i.e., X-ray diffraction (XRD) identification of crystalline (cordierite and enstatite) and amorphous phases by scanning electron microscopy (SEM)/EDS texture and microanalyses. The test results from CQMA suggest their application possibilities as well as the limits of their utilization.

This study is focused on the treatment of waste sludge from a zinc chloride production in order to prepare iron-rich pigments usable for a production of glazes. In galvanizing plants, yellow waste sludge containing significant amount of ZnO, Cl, and Fe₂O₃, is formed. This raw waste sludge cannot be used as a pigment in glaze. Therefore, three methods of treating this material were proposed: (a) washing with H₂O, (b) calcination at 180 °C and washing by H₂O, and (c) calcination at 900 °C and washing by H₂O. These methods helped to reduce Zn and Cl content up to 97%. According to X-ray fluorescence analysis percentage of Fe₂O₃ increased from ~41% to ~98%. X-ray power diffraction analysis confirmed the formation of α-Fe₂O₃ (hematite) in the pigment prepared. Scanning electron microscopy with Energy dispersive X-ray analysis showed clusters of rounded particles, and also the change in size of particles after calcination was observed. Particle size, specific surface area, and density measurements together with thermogravimetric and differential thermal analyses were performed. Pigments prepared from the waste sludge were added to transparent glaze in amounts of 1, 5, 10, and 15 wt.%. Pigment-containing glazes were applied by spraying on fired ceramic tiles and then fired at 1060 °C. Color of glazes was determined by (Commission Internationale de l’Eclairage) CIE L*a*b* coordinates as colorless, light brown shades, brown-red, brown-yellow, and deep red-brown. Comparison with colors of glazes prepared using commercial pigments was also performed. Waste sludge can be used to prepare pigments and glazes containing pigments as an alternative to commercial products.

This study is focused on the evaluation of the re-utilizability of scale originated during the steel casting and steel rolling processes as a pigment for glazes. Non-oiled scale with Fe₃O₄ as the major phase were used as a coloring component of transparent glaze matrix in: (i) as received state, (ii) thermally pre-treated at 700 and 900 °C, (iii) mechanically treated in planetary ball mill (60, 120 and 240 min) and (iv) mechanically treated in vibratory disc mill (60 and 120 min). Prepared glazes were applied on the surface of ceramic tiles prepared from a commercially available white ceramic slurry. The resulting tiles with given glaze were thermally treated at 800, 900 and 1060 °C. The pigments were characterized by X-ray powder diffraction method (XRD), X-ray fluorescence spectroscopy (XRF), granulometry (PSD), thermogravimetric analysis (TG) and differential thermal analysis (DTA), scanning electron microscopy (SEM/EDAX). The color of the samples was described by the coordinates L*a*b* from CIELAB color space. The results showed that the non-oiled scale is suitable as the pigment for ceramic glazes. Careful control of the scale treatment process (mechanical as well as thermal) together with the temperature of final glaze firing is necessary to obtain the glaze of desired color and quality.

Metakaolin (MK) prepared by the calcination of kaolin at 550 °C and fly ash (FA) from the combustion of black coal in a granulating boiler were used to prepare unfired ceramic bonding systems via the alkali activation process. A long-term stability of the mechanical properties of the prepared samples similar to the unfired ceramic systems was observed. The optimal metakaolin and fly ash ratio, the type of the activator (NaOH or water glass) and its concentration were evaluated after the hydration in: a) laboratory conditions; b) hydration box; and c) under the hydrothermal activation. Raw materials and the samples prepared by alkali activation process were characterized by XRD, XRF, TG/DTA, and FTIR methods. The mechanical properties of the prepared samples were tested using a compressive strength test after 2, 28 and 56 days of hydration. The compressive strengths of 16 and 24 MPa after 28 days of hydration were reached for FA samples activated with water glass. The alkali activation of MK was successful in the NaOH solution of the molar concentration above 5 M. The compressive strength values of metakaolin, activated hydrothermally and hydrated at laboratory conditions, reached 11.2 and 5.5 MPa, respectively, for 5 M activator of NaOH.