以高硅水镁石为原料、氢氧化钠为钠化剂,研究了高硅水镁石钠化焙烧除硅过程中氢氧化钠用量、焙烧温度、焙烧时间等对焙烧水洗产物中硅含量的影响,对不同温度条件下的焙烧产物和焙烧后水洗产物的结构和谱学特征进行分析和表征,以揭示高硅水镁石钠化焙烧除硅机理。结果表明：在焙烧温度为650 ℃、氢氧化钠用量为理论量3倍、焙烧时间为3 h的最优条件下,钠化焙烧过程中Na⁺会与蛇纹石热分解产物Mg₂SiO₄中的Mg²⁺发生置换反应,最终形成可溶性盐Na₄SiO₄,从而水洗除去,水洗产物中硅质量分数为1.89%,硅提取率达90.1%。

A sodium-roasting process was employed for removing silicon from high-silicon brucite as raw material,using NaOH as sodium treatment reagent.The effects of NaOH content,roasting temperature and roasting time etc.on Si content of the water-washed roasting products were investigated,respectively.The structure and spectroscopic characteristics of roasting products and the water-washed residues in different roasting temperature were analyzed.The mechanism of removing silicon from high-silicon brucite by sodium-roasting process was revealed.The results indicated that optimal processing parameters were roasting temperature of 650 ℃,3 times theoretical amount of NaOH and roasting time of 3 h.Under these conditions,Na⁺ substituted Mg²⁺ of Mg₂SiO₄ obtained by serpentine decomposition,and the final products were Na₄SiO₄.The mass fraction of Si in water washed roasting products reached 1.89% and the extraction ratio of Si reached 90.1%.