C_2S-C_2A_xF_(1-x)二元体系低钙节能水泥的试验研究

Production of C_2S-C_2A_x_F_(1-x) Cement with Low-grade Pyrite Cinder

以硫铁矿烧渣为原料,研究了C2S-C2Ax F1-x体系水泥的煅烧制度,通过X射线衍射(XRD)、扫描电镜(SEM)及矿物定量,对水泥熟料矿物相组成、形貌进行了分析。同时研究了石膏掺量对水泥凝结时间,抗压强度及水化产物的影响。结果表明,最佳煅烧制度为1 280℃煅烧30 min,其中水泥熟料矿物组成比例为C2S 50.19%,C2Ax F1-x45.30%;水泥的凝结时间随着石膏掺量的增加而增加;抗压强度也随着石膏掺量的增加而增大,综合考虑,最佳石膏掺量为20%;当石膏掺量为0%和5%时,28d水化产物以C2S和C3(A,F)H6为主,当石膏掺量超过10%时,28d水化产物是C-S-H和AFt。

The manufacturing technique for binary rich C2S and C2 AxF1-x clinker system utilizing of pyrite cinders as raw materials was preliminarily studied. The mineral composition of the resulting cement clinker and micro-structure of the cement were investigated using X-ray powder diffraction （XRD）, scanning electron microscope （SEM）, respectively. The results showed that the clinker with high quality was obtained by firing at 1 280℃ for 30 min and the optimal mix proportion of pyrite cinder in the raw materials was 31% and the percentage of C2 S and C2 AxF1-x in the clinker reached 50. 19%, 45.30%, respectively. Effect of nature gypsum content on the performances of the cement, such as compres- sive strength, setting time and hydration products of the cement slurry in the hydration process, etc, was also investigated. The setting time can be delayed by NG content. It shows that the effect of NG conte＇nt on compressive strength law of development is different. NG content also has an important implication on hydration products.