Prospects of generation of high technologies of recycling of ash-and-slag waste of thermal power stations
The aim of our investigation was definition of the high technology directions of processing and recycling of ash waste and slags of thermal power stations. As a result of research compoundings of preparation are developed and experimental samples of ceramics (including porous ceramics), protectively-decorative coverings, glazes, enamels and engobes, porous ceramics, refractories, facing tiles are received.
High infrared radiance glass-ceramics obtained from fly ash and titanium slag.
A new glass-ceramic was synthesized by crystal growth from a homogenous glass obtained by melting a mixture of fly ash collected from a power plant in Hebei province of China, titanium slag collected from a titanium factory in Sichuan province of China, and MgCO(3) as an additive. According to the measurement results of differential thermal analysis, a thermal treatment of nucleating at 850 degrees C for 2h and crystallizing at 985 degrees C for 1.5h was used to obtain the crystallized glass. X-ray diffraction and scanning electron microscopy measurements showed that the main crystalline phase of this material was iron-ion substituted cordierite, (Mg,Fe)(2)Al(4)Si(5)O(18), which is homogeneously dispersed within the parent glass matrix. The infrared radiance and thermal expansion coefficient of this material have been examined, and the results demonstrate that this glass-ceramic material has potential for application in a wide range of infrared heating and drying materials.
Microstructure of the solder-casting zone in bridges of dental gold alloys.
The composition and structure were studied in the cast and in the solder of bridges which had failed clinically. Both materials were gold alloys but with different contents of Pt, Ag and Zn. The metallographic investigation revealed defects mostly in the solder, situated in the subsurface layer. SEM studied of the fracture surface revealed large porosites and a structure of dense parallel lines--striations--, indicating that the material had failed from fatigue. The materials in the fractured bridges were identified by micro-probe measurements. It was stated that cast material and solder material used together, were of different composition.