(1. 遼寧科技大學(xué) 材料與冶金學(xué)院，鞍山 114051；
2. 東北大學(xué) 材料與冶金學(xué)院，沈陽 110004)
摘 要: 根據(jù)硅鎂型紅土鎳礦中鎂硅酸鹽存在形式，采用化學(xué)沉淀法合成MgSiO3，通過正交實(shí)驗(yàn)考察反應(yīng)溫度、反應(yīng)時(shí)間、液固比和NaOH濃度對(duì)MgSiO3在NaOH亞熔鹽體系中的浸出過程的影響，得出優(yōu)化實(shí)驗(yàn)條件為：反應(yīng)溫度為210 ℃，反應(yīng)時(shí)間為180min，液固比為6:1，NaOH濃度為80%。在優(yōu)化實(shí)驗(yàn)的基礎(chǔ)上，采用Raman光譜對(duì)反應(yīng)過程進(jìn)行在線檢測(cè)，利用XRD和IR光譜分析反應(yīng)后的水浸渣結(jié)構(gòu)變化，解析MgSiO3在NaOH亞熔鹽體系中的反應(yīng)機(jī)理。結(jié)果表明：在反應(yīng)過程中，SiO4中的Si—O被破壞，NaOH介入硅酸鹽晶格中，其中間產(chǎn)物為Mg2SiO4和Na2MgSiO4，Mg2+經(jīng)過堿浸過程可以脫離SiO4陣列，以Mg(OH)2形式從其硅酸鹽中得以釋放。
關(guān)鍵字: MgSiO3；拉曼光譜；亞熔鹽；浸出反應(yīng)機(jī)理
（1. School of Materials and Metallurgy, University of Science and Technology Liaoning, Anshan 114051, China
2. School of Materials and Metallurgy, Northeastern University, Shenyang 110004, China）
Abstract:Based on the existence form of MgSiO3 in garnierite, MgSiO3 was synthetized through chemical precipitation method. Through the orthogonal experimentation, the effects of reaction temperature, reaction time, liquid-to-solid ratio and concentration of NaOH on the leaching process of MgSiO3 in NaOH sub-molten salt system were observed, and the optimal experimental conditions include reaction temperature of 210 ℃, reaction time of 180 min, liquid-to-solid ratio of 6:1, and concentration of NaOH of 80%. Based on the optimized experiment, on-line detection for the reaction process was made by using Raman spectroscopy, XRD and IR were used to analyze the structural change of water leaching residue and explore the reaction mechanism of MgSiO3 in NaOH sub-molten salt system. The results show that, during the reaction process, the Si—O bond in the SiO4 is destroyed and the NaOH inserts itself into the silicate lattice, producing intermediate Mg2SiO4 and Na2MgSiO4 products. After the alkali leaching process, Mg2+ can be separated from SiO4 array, which can be released out of the silicate in the form of Mg(OH)2.
Key words: MgSiO3; Raman spectroscopy; alkali melting; leaching reaction mechanism
