(東北大學(xué) 材料冶金學(xué)院，沈陽 110004)
摘 要: 研究常壓下高濃度氫氧化鈉浸取紅土鎳礦的預(yù)脫硅過程，考察攪拌強(qiáng)度、液固比、氫氧化鈉濃度、反應(yīng)溫度和原礦粒徑對紅土鎳礦中硅的反應(yīng)率的影響。結(jié)果表明：二氧化硅的反應(yīng)率受克−金−布產(chǎn)物層固膜擴(kuò)散控制, 并由阿累尼烏斯方程得到反應(yīng)的表觀活化能為53.74 kJ/mol。結(jié)合動力學(xué)實(shí)驗結(jié)果和電子掃描電鏡(SEM)及X射線能譜(EDAX)分析，證明在反應(yīng)過程中通過固相產(chǎn)物層的內(nèi)擴(kuò)散為反應(yīng)過程的控制步驟。
關(guān)鍵字: 紅土鎳礦；預(yù)脫硅；亞熔熱體系；浸出；氫氧化鈉
（School of Materials and Metallurgy, Northeastern University, Shenyang 110004, China）
Abstract: The leaching mechanism of silicon dioxide from a laterite by concentrated NaOH under the atmosphere pressure was studied. The effects of stirring speed, mass ratio of alkali-to-ore, initial NaOH concentration, reaction temperature and particle size on the reaction rate of silicon dioxide were reported. The results show that the experimental data of the reaction rate are fit to the Crank-Ginsting-Braunshtein’s diffusion-through-layer-reaction-control-model. According to the Arrhenius expression, the apparent activation energy for the leaching reaction is 53.74 kJ/mol. The results of the kinetic experiment and SEM and EDAX analysis prove that the internal diffusion on the solid product layer is the rate-controlling step in the leaching process.
Key words: laterite; pre-desiliconization; sub-molten salt system; leaching; sodium hydroxide
