Low-temperature SCR DeNOx process is considered to be a potential technique to meet the stringent environment regulations. It can avoid the problem such as blocking and eroding often generated in medium temperature, polluting and poisoning caused by alkali elements and so on. In this paper, a review of DeNOx catalysts about noble metals, molecular sieve, carbon-based and metal oxides catalyst was presented. The affecting factors of the low-temperature activation were comprehensively expounded, such as precursor introduction method, preparation method, supporter pretreatment and catalyst structure. Then mechanism of SO2 poisoning and effect of active compositions were analyzed. The dual effect of SO2 on the activity of low temperature catalysts mainly results from the formation of certain sulfur-containing species on catalyst surface. Water vapor decreased the number of available active sites attributed to competitive adsorption among H2O and other reactants. Moreover, the co-existence of H2O and SO2 resulted in the decrease of activity obviously. So the way to improve resistance of SO2 and H2O poisoning was summed up. Finally, future research and development directions in the developing low-temperature SCR for removal of NOx technology were proposed.

Failure form and erosion-corrosive mechanism of desulfurization slurry circulating pump were analyzed comprehensively, its protection status and HVOF spraying protection technology research were discussed, the technical characteristics and good prospects of HVOF applied in the slurry circulating pump were pointed out in this paper.Keywords: Desulfurization, Slurry circulating pump, Erosion, Corrosion, HVOF

The FeMnCrNi/Cr3C2 inter metallic composite coatings are prepared by high velocity arc spraying (HVAS) technology on 20G steel. The properties, such as the microstructure, micro hardness, binding strength, high temperature oxidation, thermal shock resistance, and erosion in high temperature, are studied based on methods such as analysis of optical microscope, micro hardness, field emission scanning electron microscope (FESEM), and spectrum analysis. The result shows that FeMnCrNiAl/Cr3 C2 coatings, compared with 20G steel substrate, present higher micro hardness, binding strength and more excellent high temperature properties, which will be improved if added with rare-earth Alloy.

The common form of vanadium-based catalyst and characteristics of plate-type catalyst are described in this paper. The catalytic mechanism of vanadium-based catalysts about Hg0-oxidation and De-PCCD/Fs is intensivly analyzed. The influencing factors of V2O5-WO3(MoO3)/TiO2in mercury removal and PCCD/Fs decomposition are expounded.

Failure mode of coal mill roller was comprehensively analyzed and current situation of mill roller repair was elaborated. Process characteristic and application effect of metal cerement and high chromium cast iron building-up materials were expounded in the article. Owing to excellent wear resistant and low cost, high chromium cast iron building-up materials have been applied widely. The current research situation of self-shielded flux-cored wire with high chromium cast iron was summarized and the existing problem and probable solution were pointed. Key word: Coal mill roller, Abrasive wear, Flux-cored wire, Resurfacing welding