稀土尾矿配料煅烧硅酸盐水泥熟料的实验研究

Experimental Study on Calcination of Portland Cement Clinker with Rare Earth Tailings

针对稀土尾矿堆存量大、难以利用的问题,提出将其用于配烧硅酸盐水泥熟料的利用技术路线。通过同步热分析和易烧性实验研究稀土尾矿对水泥熟料烧制的影响,根据XRD、SEM和物理性能检测研究水泥熟料的物相组成、微观形貌和技术指标。结果显示,稀土尾矿具有促进碳酸钙分解和降低水泥熟料矿物形成温度的作用;煅烧温度为1400℃时稀土尾矿配烧的水泥熟料游离氧化钙含量低,主要矿物为硅酸三钙、β-硅酸二钙和铁铝酸四钙,与典型硅酸盐水泥熟料组成和结构特征一致,而且主要物理性能符合GB/T 21372-2008规定的技术指标要求,表明稀土尾矿可以作为原料制备硅酸盐水泥熟料。

Aiming at the problem of large stock of rare earth tailings and difficult utilization,the technical route of preparing Portland cement clinker using rare earth tailings is put forward in this paper.Effect of rare earth tailing on cement clinker firing was studied by means of synchronous thermal analysis and burnability test.The phase composition,microstructure and technical indexes of cement clinker were studied by XRD,SEM and physical properties test.The results show that the rare earth tailings can promote the decomposition of calcium carbonate and reduce the formation temperature of cement clinker.The cement clinker mixed with rare earth tailings at 140℃ of calcination temperature has low free calcium oxide content and are composed of tricalcium silicate,β-dicalcium silicate and tetracalcium ferroaluminate,which are consistent with the composition and structural characteristics of typical Portland cement clinker.Moreover,the physical properties meet the technical requirements in GB/T 21372-2008,indicating that the rare earth tailings can be used as raw materials to prepare Portland cement clinker.