中文摘要：

众多研究表明，提高反应物起始原料的均匀混合程度、添加适量的添加剂是改善碳热还原法制备碳化硅超细粉体的有效途径。由于稀土元素对众多的化学反应都能起到有效的促进作用，于是，以纳米二氧化硅和活性炭为起始原料，以稀土镧为添加剂，采用碳热还原法制备碳化硅超细粉体，并借助X射线衍射仪和激光粒度仪分别对合成的粉体进行物相和粒度分析，实验结果表明：添加一定量的稀土镧有助于降低碳化硅超细粉的合成温度及粉体粒度。

英文摘要：

Many researches indicated that improving the homogeneous mixing extent of the starting materials and adding appropriate additives were effective ways to improve the preparation of ultrafine SiC by carbothermal reduction reaction. Be- cause rare earth elements can play an effective role in promoting a large number of chemical reactions, ultrafine SiC powder was prepared by carbonthermal reduction method with nano-sized SiO2 and activated carbon as starting materials and with rare earth lanthanum as additive. Phase and particle size of the prepared powder were analyzed by XRD and ZetaPALS. Experiment results showed that the reaction temperature and particle size were both reduced by adding some rare earth lanthanum to the mixture of SiOz and activated carbon.