酸处理方式对稻壳制备硅酸钠和白炭黑的影响

Effect of acid treatment on preparation of sodium silicate and silica from ice husk

以稻壳为原料,通过预处理-煅烧的工艺,选择电炉和微波两种不同的酸处理方式,对稻壳进行热解,得到高纯的SiO2,然后与不同w(NaOH)溶液反应得到硅酸钠溶液,测定其模数,并制得了固体硅酸钠和白炭黑。采用FTIR、XRD、SEM、TG-DTA等测试手段,对所得稻壳灰、硅酸钠和白炭黑的结构和微观形貌进行表征。结果表明,经微波酸处理的稻壳在焙烧过程中结构的破坏程度相对最小,未经酸处理的稻壳在焙烧过程中结构的破坏程度相对最大;提取SiO2使用的NaOH最佳含量为w(NaOH)=10%。

Electric furnace and microwave were selected as two acid treatment methods to preprocess rise husk.Then the rice husk was pyrolyzed to obtain high purity silicon dioxide which is used as raw material reacting with different concentrations of NaOH solutions to prepare sodium silicate solution. Its modulus was determined and used as raw material to gain sodium silicate and silica. The micro structure and morphology of rice husk ash, SiOs and Na2 SiO3 were characterized by FTIR, XRD, SEM and TG-DTA.The results indicate that the damage degree of the structure of rice husk treated with microwave acid was relatively minimal during calcination.The structure of rice husk without acid treat ment is the most damaged during calcination.The optimum concentration of NaOH for SiO2 extraction was w（NaOH）=10%.