Alternative technological approach for synthesis of ceramic pigments by waste materials recycling

AbstractAlternative technological approach is proposed enabling utilization of raw materials from an oil refinery, such as waste guard layers from reactors. Reagent grade and purified MgO, Cr2O3, Fe2O3, and nitric acid (HNO3), were used as additional precursors. The homogeneous mixtures obtained were formed into pellets and sintered at different temperatures. The main phase was proved by X-ray phase analysis (XRD) and compared to ICPDS database. The main phase in the ceramics synthesized was solid solution of spinel MgAl2O4 and magnesiochromite. These minerals are classified as chromspinelide MgCr1.2Al0.4Fe0.4O4 and alumochromite MgCr1.6Al0.4O4. Additional SEM observations, combined with EDX analysis were performed, evincing agglomeration at lower temperatures, followed by agglomerate crumbling, at elevated calcination temperature.The complete transformation of initial precursors into the final ceramic compounds was found to occur at 800°C – 1h. The ceramic samples synthesized had high density of 1.72–1.93g/cm3 and large absorption area – 32.93% which is probably due to the high porosity of the sample

Synthesis of Ceramics in Different Colors from Industrial Waste

The synthesis of arsenic-free ceramics from industrial waste is studied. Samples of waste containing siliceous material passed the exploitation leap-guard layer shift reactor whose main oxide is -Al2O3 and, with the addition of natural raw materials and pure oxide, arsenic-free ceramics were synthesized with thermal and electrical properties related to the main phase of spinel group minerals; solid solutions were also formed in the process of synthesis. Insulating properties were established by successive heating and cooling of the specimen for six cycles. Electrical insulating properties were established by the method of resistance to arcing. The relative density was determined by hydrostatic method and diffusion lines of molecules at the main phase were characterized by X-ray diffraction analysis. The experimental procedures followed in this study allowed mixing on a molecular level due to the small dimensions of the crystallite which in turn explains the relatively high density