(中南大學(xué) 冶金科學(xué)與工程學(xué)院 難冶有色金屬資源高效利用國家工程實(shí)驗(yàn)室，長沙 410083)
摘 要: 在對黃鐵礦與鋁酸鈉溶液反應(yīng)熱力學(xué)分析的基礎(chǔ)上，利用接觸角、X射線衍射、紅外光譜和SEM-EDS等分析手段研究溶出溫度和鋁酸鈉溶液組成對黃鐵礦反應(yīng)行為的影響，并探討黃鐵礦的分解過程。結(jié)果表明，黃鐵礦的反應(yīng)速度隨溶液溫度及游離堿濃度的升高而加快，最終產(chǎn)物主要為Fe2O3、S2-和SO42-；拜耳法溶出條件下，反應(yīng)1 h黃鐵礦中硫溶出率高達(dá)90%；反應(yīng)初始階段黃鐵礦表面的Fe2+優(yōu)先與溶液中的OH-結(jié)合生成鐵羥基化合物從表面脫落，導(dǎo)致富硫?qū)拥男纬桑S著反應(yīng)的進(jìn)行，硫最終以S2-和SO42-形式進(jìn)入溶液。
關(guān)鍵字: 黃鐵礦；鋁酸鈉；拜耳法；反應(yīng)行為；機(jī)理；溶出
（National Engineering Laboratory for Efficient Utilization of Refractory Nonferrous Metals Resources,
School of Metallurgical Science and Engineering, Central South University, Changsha 410083, Ch）
Abstract:Based on the thermodynamic analysis of the reaction between pyrite and sodium aluminate solution, the effects of digestion temperature and composition of the sodium aluminate solution on the reaction behavior of pyrite were investigated by the analysis of contact angle, X-ray diffraction, infrared spectrum and scanning electron microscope- energy dispersive spectrum. The decomposition process of pyrite was also discussed. The results show that the reaction rate of pyrite increases with the increase of the temperature and the free caustics concentration in aluninate solution to produce Fe2O3, S2- and SO42- as the main final products. The sulfur dissolution percentage reaches above 90% after reaction of 1 h under the Bayer process. The iron-hydroxyl complexes are generated firstly by the reaction of OH- of sodium aluminate solution and Fe2+ of the pyrite surface, then the complexes detach from the surface of pyrite, which leads to a layer of sulfur-rich compounds. Finally, the sulfur enters into the solution in the form of S2- and SO42-.
Key words: pyrite; sodium aluminate; Bayer process; reaction behavior; mechanism; digestion
