Roller mill is a kind of grinding equipment of the grinding equipment for 80 years. It has been widely used in cement, electric power, metallurgy, chemical industry, and nonmetallic mine etc. Since the 1960 s, roller mill was used in cement industry, due to its remarkable effect of energy saving, soon it attracted people's attention and interest. Nowadays, the usage proportion of raw material, slag , coal grinding roller are greatly more than the ball mill, and 30% of cement clinker are roller mill too. According to the cement grinding technology and material bed grinding mechanism analysis, the conclusion is that roller grinding mill system will be further developed in China's cement industry. Finally, it presents that it should strengthen the grinding mechanism and the roller mill's research contents.

It was studied in the paper by XRD and SEM that the new two stages treatment processing technology of sulfur chemicals wastewater by marble polishing powder and lime, and the effect of the properties of by-product gypsum from the processing as the retarder of cement. The results showed that:The marble polishing powder was the first neutralizer.It's proper that the lime or carbide slag was the second neutralizer. The strength of ordinary Portland cement mixed by- product gypsum as retarder was higher than that of the ordinary Portland cement using dihydrate gypsum as retarder, because the calcium carbonate in the by-product gypsum would participate in the hydration reaction and form the calcium aluminum oxide carbonate hydrate, which was helpful to improve the cement strength during the cement hydrated reaction.

This paper studied the thermal decomposition characteristics of aluminous cement and Portland cement raw meal using thermal analysis and some other test methods. The decomposition heat of aluminous cement raw meal is 703.3kJ/kg and the heat of Portland cement raw meal is 901.2 kJ/kg. It was also researched that the decomposition activation energy(Ea) calculation of limestone and diasporite in two cement raw meal has also been calculated using the shrinking cylinder mechanism with surface reaction rate controlling, random into nuclear and the growth mechanism.