中文摘要：

以同时含有碳源和硅源的稻壳制备碳化稻壳,采用镁热法还原其中的SiO2,借助XRD对还原产物进行分析,探讨了镁热还原工艺对产物组成的影响.结果表明：碳化稻壳中的SiO2在490℃可以发生镁热还原反应,当还原温度低于700℃时,还原产物是Si或Mg2Si;当还原温度超过700℃时,还原产物中形成SiC;当还原温度高于800℃时,产物中有Mg2SiO4生成.镁热还原温度在600～700℃之间时,通过控制Mg与碳化稻壳中的SiO2的质量配比,可以制备出Si/C复合材料.

英文摘要：

SiO2 in carbonized rice husks （CRHs） which were synthesized from rice huskes（RHs） containing mainly both carbon and silicon sources, was thermally reduced by magnesium. The reaction products was characterized by XRD, the effect of the reduction parameters on the phase composition of the product was investigated. The results show that, SiO2 in the CRHs can be reduced at temperature as low as 490 ℃ ; when the reduction temperature was be- low 700 ℃, the reduction product was Si or Mg2 Si; SiC forms when the reduction temperature was higher than 700 ℃ ;when the reduction temperature exceeded 800 ℃, Mge SiO4 forms in the products. With the mass ratio of Mg and SiO2 in the CRHs being controlled among the reduction temperature of 600-- 700 ℃, Si/C composite could be pre- pared.