Abstract In this study, porous silicon carbide ceramics were prepared by using silicon carbide as the main material and sodium carboxymethyl cellulose (CMC) as the pore-forming agent. SiO2-Y2O3-Al2O3 and SiO2-kaolin were used as the builders respectively. This study is about the effect of SiO2-Y2O3-Al2O3 and SiO2-kaolin content on the structure and mechanical properties of porous silicon carbide.   SiO2-Y2O3-Al2O3 and SiO2-kaolin affect the porosity, hardness and flexural strength of silicon carbide porous ceramics. In this experiment, the porosity of porous ceramics was measured by Archimedes method. The hardness was measured by Rockwell hardness tester. The flexural strength was measured by universal testing machine. The results show that the properties of silicon carbide porous ceramics prepared by SiO2-Y2O3-Al2O3 are better than that of SiO2-kaolinite when the SiO2 -Y2O3-Al2O3 content is 20%. With SiO2-Y2O3-Al2O3 as the combustion agent, porous ceramic with better performance can be prepared at 1500 ℃. When the SiO2-Y2O3-Al2O3 content is 20%, the prepared silicon carbide porous ceramics has a large porosity and excellent mechanical properties, the opening porosity of 23.73%, hardness and flexural strength of 62 and 15.47MPa, from the fracture can be seen more porous and evenly distributed.

Abstract In this paper, three kinds of iron tailings samples were selected as the main research object, and an iron tailings porous ceramic material was prepared by adding pore forming agent. The crystal structure, surface morphology and microstructure of the composites were observed by XRD and SEM. Finally, the effects of porous ceramics on water pH, conductivity and surface tension were studied. By adjusting the recipe, the final finding of a better formula for firing: iron tailings (1 #): cellulose = 15: 2.57. The interior of the ceramic formed a denser pore structure, and the pores were more uniform, the aperture was more consistent. And the pH value of the water can be weakly alkaline, the conductivity increased by 58.75% and the surface tension decreased by 0.37%. The results provide the basis for the application of the tailings porous ceramic materials in the biological field.

Abstract Titanium oxide has the advantages of high activity, good stability, non-toxic and low cost cost effective. It is one of the most widely studied photocatalysts and the most promising material for photocatalytic ceramics. In this paper, the photocatalytic mechanism of TiO2, the influence factors of photocatalytic activity, the preparation of nano-TiO2, the phase change of nano-TiO2, the application of TiO2 photocatalytic materials and the research progress of photocatalytic ceramics were reviewed.