The element and mineral composition and the physical characteristics of fly ash from circulating fluidized bed boiler, are different to the other kinds of boilers. The aim of the study was to discuss the distinctive feature between the fly ash from CFB and the fly ash from pulverized coal fire boiler. The experiments show that the change of element composition from CFB and PC boiler has the some rule with the change of granularity. The carbon content of residua from CFB is higher than the content from PC boiler obviously. The SiO2 dioxide content decreases with the granularity of residua fining, while the content of Al2O3, CaO, MgO has the reverse rule in despite of CFB or PC boiler. The content of TFeO of residua increases in CFB while the content decreases in PC boiler with the granularity of residua fining. And the component form of TFeO in CFB is mainly Fe2O3 while the component in PC boiler is mainly Fe3O4. The higher the content of carbon was, the lower the special resistance was.

SiC-coated multi-walled carbon nanotubes (SiC-coated MWNTs) made by RF magnetron sputtering were introduced into the SiC suspensions to enhance the mechanical behaviors of reaction bonded silicon carbide ceramics. The composites were prepared by the epoxy resin curing and liquid silicon infiltration at 1550°Cfor 60min. The distribution, morphology, and reinforcing behaviors of MWNTs were investigated. X-ray diffraction (XRD) reveals that the MWNTs were reserved during the reaction sintering. The flexural strength and fracture toughness increase with MWNTs ranging from 0wt% to 0.5wt%, reaching the peaks value of 347MPa and 4.3MPam1/2 respectively at the MWNTs fraction of 0.5 wt%. This improvement derives from the MWNTs pullout. The consequent decline at MWNTs fraction of 1wt% is resulted from the corrosion of agglomerated MWNTs and the increase of residual silicon.

The rigid seals currently being used for the ash unloading device with the impeller under the hopper of the electrostatic precipitator are easy targets of wear and tear. In addition, the airproof capability of these seals is not perfect. In this light, an advanced powder magnetic seal design which installs permanent magnets at the top of the vane and utilizes the magnetism of Fe3O4 in fly ash to seal the space between two vanes is discussed in this paper. In the self-designed device, three categories of permanent magnet parameters and four kinds of powders with respective with respective magnetic powder mass fractions of 7%, 9%, 12%, and 15% were chosen. The airproof capability was also measured. The results show that this device has excellent airproof capability, can withstand wear and tear, and has a low replacement frequency.