稀土对水泥熟料矿物形成的作用

The Effect of Rare Earth Elements on Cement Clinker Formation

稀土元素氧化物于０．２～２．０×１０－４的微量范围内可改善水泥生料的易烧性，降低熟料中游离氧化钙含量，增加阿利特含量。在该微量范围内，随着稀土含量增加，其作用相应增强；但超过２．０×１０－４后，即使稀土元素氧化物含量增至１．０×１０－３，其作用增幅亦不大。煅烧温度于１３００℃以下，稀土的作用甚弱，而于１３５０℃至１４００℃时其作用较显著。不同种类的稀土元素对水泥熟料矿物形成的作用有差别，镧系元素的作用优于非镧系元素的稀土元素；稀土元素富集于熟料中间相。

Rare earth elements in a micro range of 0.2～2.0×10 -4 are totally capable of improving the burnability of portland cement, reducing the f CaO and increasing the alite content in the clinker. While the rare earth content varies in this micro range, the effect gets stronger clearly with increasing proportion of rare earth elements. Yet, after that, even their content is increased to 10×10 -4 its effect of benefit does not grow much. The effect of rare earth elements would be still faint when the calcination temperature is lower than 1300℃, but that will get obvious at 1350℃～1400℃. There are differences in the effects on cement clinker formation due to various types of rare earth elements. Lanthanide prevails over rare earth elements of non lanthanide. The rare earth elements are distributed mainly over interstitial phases of clinker.