基于石灰苛化法研究CaO在含草酸盐稀铝酸钠溶液中的反应动力学与机理（英文）
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摘要
基于草酸盐石灰苛化法研究水合铝酸三钙和草酸钙分别在稀铝酸钠溶液和草酸钠溶液中的反应动力学和机理,并获得铝酸钠溶液去除草酸盐的最佳条件及其去除机理。水合铝酸三钙和草酸钙的生成分别受化学反应控制和内扩散控制,分别计算其反应速率方程和表观活化能。在含草酸盐的稀铝酸钠溶液中能够形成具有空间交错片状结构的水铝钙石相,其通过吸附大幅度降低溶液中草酸盐杂质。随着反应时间的延长,生成的草酸钙能够转化为水合铝酸三钙。在反应温度为50℃、搅拌速度为200r/min下,草酸盐苛化效率达到90%以上,氧化铝损失率在31%以下。
The formation kinetics and mechanism of tricalcium aluminate hydrate and calcium oxalate in dilute sodium aluminate solution and sodium oxalate solution were studied respectively based on the lime causticization, and the optimal conditions for removing the oxalate in dilute sodium aluminate solution as well as the mechanism were finally obtained.The formation processes of tricalcium aluminate hydrate and calcium oxalate are mainly controlled by the chemical reaction and the inner diffusion respectively,and the corresponding reaction rate equations as well as the apparent activation energy were calculated. The hydrocalumite with a spatially interleaved structure will form in dilute sodium aluminate solution with sodium oxalate, greatly removing the oxalate impurity by absorption. Calcium oxalate can be converted to tricalcium aluminate hydrate with the increasing reaction time. The oxalate causticization efficiency and the alumina loss rate can be over 90% and below 31% respectively when reacted at 50℃ with a stirring rate of 200 r/min.
The formation kinetics and mechanism of tricalcium aluminate hydrate and calcium oxalate in dilute sodium aluminate solution and sodium oxalate solution were studied respectively based on the lime causticization, and the optimal conditions for removing the oxalate in dilute sodium aluminate solution as well as the mechanism were finally obtained.The formation processes of tricalcium aluminate hydrate and calcium oxalate are mainly controlled by the chemical reaction and the inner diffusion respectively,and the corresponding reaction rate equations as well as the apparent activation energy were calculated. The hydrocalumite with a spatially interleaved structure will form in dilute sodium aluminate solution with sodium oxalate, greatly removing the oxalate impurity by absorption. Calcium oxalate can be converted to tricalcium aluminate hydrate with the increasing reaction time. The oxalate causticization efficiency and the alumina loss rate can be over 90% and below 31% respectively when reacted at 50℃ with a stirring rate of 200 r/min.
引文
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[2]MACHOLD T,LAIRD D W,ROWEN C C.Decomposition of Bayer process organics:Phenolates,polyalcohols,and additional carboxylates[J].Hydrometallurgy,2011,107(3-4):68-73.
[3]WELLINGTON M,VALCIN F.Impact of Bayer process liquor impurities on causticization[J].Industrial&Engineering Chemistry Research,2007,46(15):5094-5099.
[4]SMEULDERS D E,WILSON M A,ARMSTRONG L.Insoluble organic compounds in the Bayer process[J].Industrial&Engineering Chemistry Research,2001,40(10):2243-2251.
[5]BUSETTI F,BERWICK L,MCDONALD S.Physicochemical characterization of organic matters in Bayer liquor[J].Industrial&Engineering Chemistry Research,2014,53(15):6544-6553.
[6]POWER G,LOH J S,VERNON C.Organic compounds in the processing of lateritic bauxites to alumina.Part 2:Effects of organics in the Bayer process[J].Hydrometallurgy,2012,127-128:125-149.
[7]POWER G,LOH J.Organic compounds in the processing of lateritic bauxites to alumina.Part 1:Origins and chemistry of organics in the Bayer process[J].Hydrometallurgy,2010,105(1-2):1-29.
[8]WANG Meng,HU Hui-ping,LIU Jin-wen.Negative effects of dissolved organic compounds on settling performance of goethite in Bayer red mud[J].Transaction of Nonferrous Metals Society of China,2017,27(2):429-439.
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[10]ARNSWALD W,KALTENBERG H G,GUHL E.Removal of organic carbon from Bayer liquor by wet oxidation in tube digesters[C]//Light Metals.New Orleans,LA:TMS,1991:23-27.
[11]TARDIO J,BHARGAVA S,EYER S.Interactions between specific organic compounds during catalytic wet oxidation of Bayer liquor[J].Industrial&Engineering Chemistry Research,2004,43(4):847-851.
[12]LOH J S C,BRODIE G M,POWER G.Wet oxidation of precipitation yield inhibitors in sodium aluminate solutions:Effects and proposed degradation mechanisms[J].Hydrometallurgy,2010,104(2):278-289.
[13]HIND A R,BHARGAVA S K,GROCOTT S C.The surface chemistry of Bayer process solids:A review[J].Colloids Surface A:Physicochemical&Engineering Aspects,1999,146(1):359-374.
[14]PERROTTA A J,WILLIAMS F.Hydrocalumite formation in Bayer liquor and its promotional effect on oxalate precipitation[C]//Light Metals.Warrendale,Pennsylvania:TMS,1995:77-87.
[15]ROSENBERG S P,TICHBON W,WILSON D J,HEATH C A.Process for the removal of oxalate and/or sulphate from Bayer liquors:US6743403[P].2004-06-01.
[16]ROSENBERG S P,WILSON D J,HEATH C A.Inhibiting the formation of TCA in a Bayer causticisation process:US7767190[P].2010-08-03.
[17]ROSENBERG S P,WILSON D J,HEATH C A.Some aspects of calcium chemistry in the Bayer process[C]//Light Metals.New Orleans,LA:TMS,2001:19-24.
[18]LIU Gui-hua,DONG Wen-bo,QI Tian-gui.Behavior of calcium oxalate in sodium aluminate solutions[J].Transactions of Nonferrous Metals Society of China,2017,27(8):1878-1887.
[19]ROSENBERG S P,ARMSTRONG L.Layered double hydroxides in the Bayer process:past,present and future[C]//Light Metals.San Francisco,CA:TMS,2005:157-161.
[20]PERROTTA A J,WILLIAMS F.Layered double hydroxide formation in Bayer liquor and its promotional effect on oxalate precipitation[C]//Light Metals.Anaheim,CA:TMS,1996:17-28.
[21]PEROTTA A J,WILLIAMS F S,STONEHOUSE L.Layered double hydroxides for treatment of Bayer process lake water[C]//Light Metals.Orlando,FL:TMS,1997:37-48.
[22]PAN Xiao-lin,YU Hai-yan,TU Gan-feng,BI Shi-wen.Effects of precipitation activity of desilication products(DSPs)on stability of sodium aluminate solution[J].Hydrometallurgy,2016,165:261-269.
[23]WU Xiao-ling.The method of measuring sodium oxalate by ceric sulfate[J].Journal of Xinjiang Medical University,1999,22(2):148-149.(in Chinese)
[24]YANG Hui-bin,PAN Xiao-lin,YU Hai-yan.Dissolution kinetics and mechanism of gibbsitic bauxite and pure gibbsite in sodium hydroxide solution under atmospheric pressure[J].Transactions of Nonferrous Metals Society of China,2015,25(12):4151-4159.
[25]WHITTINGTON B I,CARDILE C M.The chemistry of tricalcium aluminate hexahydrate relating to the Bayer industry[J].International Journal of Mineral Processing,1996,48:21-38.
[26]SALIMI R,VAUGHAN J,PENG H.Solubility of tricalcium aluminate in synthetic spent Bayer liquor[J].Industrial&Engineering Chemistry Research,2014,53:17499-17505.
[2]MACHOLD T,LAIRD D W,ROWEN C C.Decomposition of Bayer process organics:Phenolates,polyalcohols,and additional carboxylates[J].Hydrometallurgy,2011,107(3-4):68-73.
[3]WELLINGTON M,VALCIN F.Impact of Bayer process liquor impurities on causticization[J].Industrial&Engineering Chemistry Research,2007,46(15):5094-5099.
[4]SMEULDERS D E,WILSON M A,ARMSTRONG L.Insoluble organic compounds in the Bayer process[J].Industrial&Engineering Chemistry Research,2001,40(10):2243-2251.
[5]BUSETTI F,BERWICK L,MCDONALD S.Physicochemical characterization of organic matters in Bayer liquor[J].Industrial&Engineering Chemistry Research,2014,53(15):6544-6553.
[6]POWER G,LOH J S,VERNON C.Organic compounds in the processing of lateritic bauxites to alumina.Part 2:Effects of organics in the Bayer process[J].Hydrometallurgy,2012,127-128:125-149.
[7]POWER G,LOH J.Organic compounds in the processing of lateritic bauxites to alumina.Part 1:Origins and chemistry of organics in the Bayer process[J].Hydrometallurgy,2010,105(1-2):1-29.
[8]WANG Meng,HU Hui-ping,LIU Jin-wen.Negative effects of dissolved organic compounds on settling performance of goethite in Bayer red mud[J].Transaction of Nonferrous Metals Society of China,2017,27(2):429-439.
[9]THE P J,BUSH J F.Solubility of sodium oxalate in Bayer liquor and a method of control[C]//Light Metals.Denver,CO:TMS,1987:5-10.
[10]ARNSWALD W,KALTENBERG H G,GUHL E.Removal of organic carbon from Bayer liquor by wet oxidation in tube digesters[C]//Light Metals.New Orleans,LA:TMS,1991:23-27.
[11]TARDIO J,BHARGAVA S,EYER S.Interactions between specific organic compounds during catalytic wet oxidation of Bayer liquor[J].Industrial&Engineering Chemistry Research,2004,43(4):847-851.
[12]LOH J S C,BRODIE G M,POWER G.Wet oxidation of precipitation yield inhibitors in sodium aluminate solutions:Effects and proposed degradation mechanisms[J].Hydrometallurgy,2010,104(2):278-289.
[13]HIND A R,BHARGAVA S K,GROCOTT S C.The surface chemistry of Bayer process solids:A review[J].Colloids Surface A:Physicochemical&Engineering Aspects,1999,146(1):359-374.
[14]PERROTTA A J,WILLIAMS F.Hydrocalumite formation in Bayer liquor and its promotional effect on oxalate precipitation[C]//Light Metals.Warrendale,Pennsylvania:TMS,1995:77-87.
[15]ROSENBERG S P,TICHBON W,WILSON D J,HEATH C A.Process for the removal of oxalate and/or sulphate from Bayer liquors:US6743403[P].2004-06-01.
[16]ROSENBERG S P,WILSON D J,HEATH C A.Inhibiting the formation of TCA in a Bayer causticisation process:US7767190[P].2010-08-03.
[17]ROSENBERG S P,WILSON D J,HEATH C A.Some aspects of calcium chemistry in the Bayer process[C]//Light Metals.New Orleans,LA:TMS,2001:19-24.
[18]LIU Gui-hua,DONG Wen-bo,QI Tian-gui.Behavior of calcium oxalate in sodium aluminate solutions[J].Transactions of Nonferrous Metals Society of China,2017,27(8):1878-1887.
[19]ROSENBERG S P,ARMSTRONG L.Layered double hydroxides in the Bayer process:past,present and future[C]//Light Metals.San Francisco,CA:TMS,2005:157-161.
[20]PERROTTA A J,WILLIAMS F.Layered double hydroxide formation in Bayer liquor and its promotional effect on oxalate precipitation[C]//Light Metals.Anaheim,CA:TMS,1996:17-28.
[21]PEROTTA A J,WILLIAMS F S,STONEHOUSE L.Layered double hydroxides for treatment of Bayer process lake water[C]//Light Metals.Orlando,FL:TMS,1997:37-48.
[22]PAN Xiao-lin,YU Hai-yan,TU Gan-feng,BI Shi-wen.Effects of precipitation activity of desilication products(DSPs)on stability of sodium aluminate solution[J].Hydrometallurgy,2016,165:261-269.
[23]WU Xiao-ling.The method of measuring sodium oxalate by ceric sulfate[J].Journal of Xinjiang Medical University,1999,22(2):148-149.(in Chinese)
[24]YANG Hui-bin,PAN Xiao-lin,YU Hai-yan.Dissolution kinetics and mechanism of gibbsitic bauxite and pure gibbsite in sodium hydroxide solution under atmospheric pressure[J].Transactions of Nonferrous Metals Society of China,2015,25(12):4151-4159.
[25]WHITTINGTON B I,CARDILE C M.The chemistry of tricalcium aluminate hexahydrate relating to the Bayer industry[J].International Journal of Mineral Processing,1996,48:21-38.
[26]SALIMI R,VAUGHAN J,PENG H.Solubility of tricalcium aluminate in synthetic spent Bayer liquor[J].Industrial&Engineering Chemistry Research,2014,53:17499-17505.