發(fā)布時(shí)間：2018-05-31 20:11

  本文選題：煤矸石 + α-Fe_2O_3��； 參考：《昆明理工大學(xué)》2017年碩士論文

【摘要】：煤矸石是煤炭開采中的副產(chǎn)固廢物,其大量堆存不僅污染環(huán)境,而且占用大量土地造成資源浪費(fèi)。根據(jù)煤矸石的化學(xué)組成,提取其有效成分開發(fā)環(huán)境友好型技術(shù)工藝,對提高煤矸石資源化綜合利用具有重要意義。為解決在煤矸石多金屬提取中試研究中氧化鐵紅產(chǎn)品純度不高以及機(jī)理不清等問題,本文以硫酸亞鐵FeSO4·7H2O為原料,碳酸鈉Na2CO3為沉淀劑,對Fe2+-CO32--H2O體系進(jìn)行熱力學(xué)分析,并借助X射線衍射儀、傅里葉變換紅外光譜儀、掃描電鏡、熱分析儀等儀器綜合分析氧化鐵紅中間產(chǎn)物α-FeOOH形成機(jī)理以及α-FeOOH熱處理制備鐵紅α-Fe2O3機(jī)理;在此基礎(chǔ)上,考察Na2CO3濃度、反應(yīng)溫度和Fe(Ⅱ)濃度等對煤矸石酸浸分離液制備氧化鐵紅的影響,為煤矸石酸溶物制備氧化鐵紅工藝提供一定的理論基礎(chǔ)。在Fe2+-CO32--H2O體系中,α-FeOOH是由Fe2+-CO32--H2O體系沉淀產(chǎn)物Fe(OH)2氧化形成。體系反應(yīng)過程中,pH對α-FeOOH的顏色、微觀形貌及Fe(Ⅱ)氧化速率有很大的影響,pH在5.0～5.5范圍,α-FeOOH質(zhì)量較好。α-FeOOH的TG-DTG分析和固相反應(yīng)動力學(xué)模型計(jì)算表明:α-FeOOH熱解轉(zhuǎn)化為α-Fe2O3,其反應(yīng)機(jī)理模型為隨機(jī)成核生長機(jī)理,熱解動力學(xué)模型函數(shù)為-ln(1-x),其反應(yīng)活化能Ea=140.49kJ·mol-1,反應(yīng)級數(shù)為0.98。α-FeOOH的熱解反應(yīng)分兩步進(jìn)行,第一步脫去連接晶體之間的水;第二步脫去晶體內(nèi)部結(jié)構(gòu)水,最后轉(zhuǎn)化為α-Fe2O3晶粒。α-FeOOH形貌變化為:隨著熱處理的溫度提高,片狀的α-FeOOH逐漸裂解變成小片狀直至片狀形貌消失形成粉末狀晶體,溫度繼續(xù)升高,其細(xì)小粉末顆粒開始團(tuán)聚結(jié)晶,到700℃時(shí)形成均勻的球狀α-Fe2O3晶粒。響應(yīng)曲面法優(yōu)化煤矸石酸溶物制備氧化鐵紅工藝研究,確定出最佳工藝條件為:Na2CO3濃度107g/L、反應(yīng)溫度43℃、Fe(Ⅱ)濃度0.26mol/L。在此工藝下,進(jìn)行放大實(shí)驗(yàn),所得氧化鐵紅產(chǎn)品質(zhì)量達(dá)到標(biāo)準(zhǔn)GB/T1863-2008《氧化鐵顏料》中優(yōu)等產(chǎn)品要求。
[Abstract]:Coal gangue is a by-product solid waste in coal mining, which not only pollutes the environment, but also occupies a large amount of land to cause waste of resources. According to the chemical composition of coal gangue, it is of great significance to extract its active components and develop environment-friendly technology to improve the comprehensive utilization of coal gangue. In order to solve the problems of low purity and unclear mechanism of iron oxide red product in the pilot-scale study of polymetallic extraction of coal gangue, the system of Fe2 CO32--H2O was thermodynamically analyzed using ferrous sulfate FeSO4 7H2O as raw material and sodium carbonate Na2CO3 as precipitant. The formation mechanism of the intermediate product 偽 -FeOOH of iron oxide and the mechanism of preparing iron red 偽 -Fe _ 2O _ 3 by heat treatment of 偽 -FeOOH were analyzed by means of X-ray diffractometer, Fourier transform infrared spectrometer, scanning electron microscope, thermal analyzer, etc. On this basis, the concentration of Na2CO3 was investigated. The effect of reaction temperature and Fe (鈪，

本文編號：1961132