本文選題：氫氧化鋁 + 沉淀法　； 參考：《化工進(jìn)展》2017年03期

【摘要】：以十八水硫酸鋁[Al_2(SO_4)_3·18H_2O]為沉淀前驅(qū)劑,碳酸鈉(Na_2CO_3)為沉淀劑制備氫氧化鋁,采用X射線衍射(XRD)、傅里葉變換紅外光譜(FTIR)、熱重分析(TGA)和掃描電子顯微鏡(SEM)探究硫酸鋁水解反應(yīng)機(jī)理。研究結(jié)果表明,75℃下0.02 mol/L的硫酸鋁溶液在pH=2.50時水解率為1.98%,pH=3.80時水解率為100%。XRD、FTIR、TG-DTG和SEM結(jié)果表明,在Al_2(SO_4)_3溶液中滴加Na_2CO_3沉淀劑制備氫氧化鋁的過程中,pH起著重要作用。當(dāng)溶液pH3時,Al~(3+)以[Al(OH_2)_6]~(3+)形式存在,隨著溶液pH的增加,[Al(OH_2)_6]~(3+)水解生成[Al(OH)_4(OH_2)_2]~ ,[Al(OH)_4(OH_2)_2]~ 在水化作用下脫水縮合為[Al_2(OH)_8(OH_2)_2]~(2 ),堿性增強(qiáng),[Al_2(OH)_8(OH_2)_2]~(2 )轉(zhuǎn)化為[Al_2O(OH)_6]~(2 ),最終形成氫氧化鋁沉淀。pH=3、5、7時,Al_2(SO_4)_3水解所得產(chǎn)物為無規(guī)則團(tuán)聚的非晶態(tài)氫氧化鋁;pH=9、11時,氫氧化鋁從非晶態(tài)轉(zhuǎn)變?yōu)榫B(tài)的勃姆石(γ-AlOOH)及少量拜爾石[α-Al(OH)_3],且pH=11時硫酸鋁水解所得氫氧化鋁結(jié)晶晶型較p H=9時好。
[Abstract]:Aluminum hydroxide was prepared by using Al_2(SO_4)_3 18H_2O as the precursor of precipitation, and so on as precipitation agent. The mechanism of hydrolysis of aluminum sulfate was investigated by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM).The results showed that the hydrolysis rate of aluminum sulfate solution with 0.02 mol/L at 75 鈩，

本文編號：1739732