用户名: 密码: 验证码:
熟料溶出浆液流态化分离洗涤及其对二次反应的影响
详细信息    本馆镜像全文|  推荐本文 |  |   获取CNKI官网全文
摘要
烧结法生产氧化铝工艺中,熟料溶出后的赤泥浆液要经过分离和洗涤。目前氧化铝厂一般采用沉降槽工艺分离和洗涤赤泥。经沉降槽分离后得到的粗液浓度为120-130g/L,分离后底流一般需经过6-8次反向沉降洗涤,分离洗涤时间长(约20个小时),二次反应损失严重。烧结法生产的发展趋势是提高湿法系统浓度,以提高生产的经济技术指标,关键在于采取有效的工艺措施,实现高浓度浆液的快速分离,以减轻二次反应的发生。然而目前工业采用的沉降槽方案无法分离高浓度的溶出浆液。科研人员一直在寻找一种能实现快速分离洗涤的新型赤泥分离洗涤工艺。本文将流态化技术引入到熟料溶出浆液的分离洗涤工艺中,利用流态化分离洗涤设备分别对中低浓度和高浓度溶出浆液的分离洗涤进行了实验,系统研究了此过程中的洗涤效果和二次反应,得出以下结论:
     (1)采用流态化技术处理Na20浓度为120-180g/L、液固比为9-12.5的熟料溶出浆液时,控制洗水流量为15-22L/h,可以将分离洗涤过程一步完成,并且能获得Na20浓度为85-140g/L的溢流(粗液),底流液固比为2.5-3,底流附液Na2O浓度为0.5-10g/L,平均分离洗涤效率在99%以上;采用流态化分离洗涤处理Na2O浓度为210-240g/L, A12O3为240-270g/L的熟料高浓度溶出浆液时,通过调节料浆流量为22.86-28.42L/h,洗水流量12-15L/h,能一步获得A1203浓度为160-240g/L的溢流(高浓度粗液),同时得到附液Na20浓度为5-20g/L,液固比为2.5-3的底流,平均分离洗涤效率在99%左右。
     (2)采用流态化技术处理熟料高浓度溶出浆液,平均初溶出率为92.69%,经过流态化分离洗涤后的平均净溶出率为92.53%,二次反应损失平均仅为0.16%。
     (3)建立了熟料溶出浆液流态化分离洗涤的数学模型,模型可以预测流态化分离洗涤所得溢流(粗液)浓度、底流附液浓度及压缩层内赤泥附液的轴向浓度分布。三个主要的模型公式为:
     式(1)可预测熟料溶出浆液流态化分离洗涤过程中溢流(粗液)的Na2O和Al2O3浓度。
     式(2)可预测熟料溶出浆液流态化分离洗涤过程中底流附液的Na20和Al2O3浓度。
     式(3)可预测熟料溶出浆液流态化分离洗涤过程中压缩层内赤泥附液的Na2O和Al2O3浓度。
     (4)流态化分离洗涤能一次实现熟料溶出浆液的分离和洗涤,具有单位面积处理量大、能处理高浓度溶出浆液、分离洗涤效果好和二次反应损失小等优点,工业应用前景良好。
In the sintering process of producing alumina, the slurry after sinter leaching must be separated and washed. Nowadays, settling tank is widely used in the process of separating slurry and washing red mud. A12O3 concentration of the green liquor is 120-130g/L, and the underflow should be washed for 6 to 8 times. It needs about 20 hours, so the secondary reaction loss is serious. An efficient means for reducing energy consumption is to increase A12O3 concentration of wet method system, its pivotal technique involves the process of the rapid separation of solid and liquid which can reduce the secondary reaction loss. However, settling tank process can not be used to separate high Al2O3 concentration slurry. Researchers have been looking for a better technology which can meet rapid separation and washing. In this study, fluidization technology is introduced into the processes of slurry separation and red mud washing. The effect of fluidization separation-washing and secondary reaction loss have been studied systematically in the dissertation. The main research contents and conclusions of the paper are as follows:
     (1) The fluidization separating-washing of leached slurry was studied. The results show that:Na2O concentration and mass ratio of liquid to solid in the underflow can reach 0.5-10g/L and 2.5-3, respectively, and Na2O concentration of the overflow is 85-140g/L, when the Na2O concentration of the leached slurry is 120-180g/L; Na2O concentration and mass ratio of liquid to solid in the underflow can reach 5-20g/L and 2.5-3.5, respectively, and A12O3 concentration of the overflow is 160-220g/L, when the A12O3 concentration of the leached slurry is 240-270g/L. The efficiency of separating-washing is more than 99%.
     (2) The separating-washing of high alumina concentration leached slurry was studied based on the fluidization. The results show that the average secondary loss is 0.16%.
     (3) Mathematical model of slurry fluidized separation-washing is established. The model can predict the overflow concentration and underflow concentration, especially the axial concentration distribution in the solution.
     Equation (1) can predict the alkali concentration in the overflow.
     Equation (2) can predict the alkali concentration in the underflow.
     Equation (3) can predict the axial concentration distribution in the procedure.
     (4) The fluidization separation-washing has many advantages such as higher handling capacity per unit area, good separating-washing effect, capacity of handing high concentration slurry and less secondary reaction loss.
引文
[1]中国产业研究报告网.2011年1月世界原铝产量报告[EB/OL]. (2011-03-25) [2011-5-02]. http://www.chinairr.org/view/V02/201103/25-71380.html.
    [2]中铝网.2010年第四季度世界氧化铝产量报告[EB/OL]. (2011-03-02) [2011-05-02].http://market.cnal.com/statistics/2011/03-02/1299052971216236.sh tml.
    [3]中铝网.2010年中国氧化铝产量数据[EB/OL]. (2011-01-27) [2011-5-02]. http://market.cnal.com/analysis/2011/01-27/1296110104213174.shtml.
    [4]杨重愚.氧化铝生产工艺学,第三版[M].北京:冶金工业出版社,1993.1-280.
    [5]李启津,侯正洪.中国铝土矿床[M].桂林:《矿山地质》编辑部,1989:7-12.
    [6]陈祺,关慧勤,熊慧.世界铝工业资源—铝土矿一氧化铝开发利用情况[J].矿业与投资,2007,(1):27-33.
    [7]曹异生,唐健.氧化铝工业现状和前景分析[J].世界有色金属,,2003,12:11-14.
    [8]申慧.世界铝土矿和氧化铝的发展趋势[J].有色金属工业,2003,8:24-28.
    [9]Guan Shuren. Measures for saving energy in alumina production[J]. Light Metals, 1990:1011-1014.
    [10]Zheng Shangguan. Improvements of hydrometallurgical flowsheet in soda-lime sintering process [J]. Light Metals,1999:77-83.
    [11]Yan D O, Li H L. Discussion on heat consumption in the manufacture of alumina by soda-lime sintering process [J]. Light Metals,1990:157-160.
    [12]周国宝.略论发展我国氧化铝工业战略取向[J].世界有色金属,,2004,1,25-30.
    [13]方启学,钮因健,黄国智.我国铝土矿资源综合分析[J].世界有色金属(增刊),2000,26(1):9-12.
    [14]钮因健.对我国铝土矿资源和氧化铝工业的认识[J].轻金属,2003(3):3-7.
    [15]管永诗,张云.我国铝土矿资源及氧化铝工业现状[J].矿产保护与利用,1998,6:43-44.
    [16]赵恒勤,李劫,王立卓,等.中国铝土矿资源及氧化铝生产技术状况透析[J].矿产保护与利用,2001,5:38-42.
    [17]刑东生,管永诗.我国铝土矿资源及氧化铝工业的现状与分析[J].采矿技术,2001,6:53-55.
    [18]李小斌,张宝琦,程裕国,等.强化烧结法氧化铝生产工艺[P].中国专利:ZL99109697,,2002,12,4.
    [19]毕诗文.氧化铝生产工艺[M].北京:化学工业出版社,2006:222-245.
    [20]Liu Guihua, Li Xiaobin, Peng Zhihong, et al. Behavior of calcium silicate in leaching process [J]. Transactions of Nonferrous Metals Society of China,2003, 13(1):213-216.
    [21]Zhao Qingjie, Chen Qiyuan, Yang Qiaofang. The trends of Chinese alumina production with combined process[J]. Light Metals,2004:127-130.
    [22]陈滨.熟料溶出过程二次反应与高浓度粗液制备技术[D].长沙:中南大学,2008:4-8.
    [23]孙建峰.强化烧结熟料溶出中赤泥的快速分离[J].轻金属,2005,(5):17-20.
    [24]赵福辉.翻盘式真空过滤机在烧结法赤泥分离中的应用研究[J].技术与装备,2006,(9):21-23.
    [25]王永红.卧螺离心机在烧结法粗液分离中的应用研究[J].有色设备,2003,(5):18-20.
    [26]《有色金属冶炼设备》编委会.有色金属冶炼设备第二卷湿法冶炼设备[M].北京:冶金工业出版社,1993.
    [27]余国琮.化工机械[M].天津:天津大学出版社,1998:23-113.
    [28]高慎琴.化工机械[M].北京:化学工业出版社,1998:27-236.
    [29]海军,李培增.选矿-拜耳法赤泥分离洗涤新工艺的研究与应用[J].轻金属,2006(8):33-36.
    [30]韩安玲.拜耳法赤泥分离洗涤三种流程的比选[J].轻金属,2005(3):10-13.
    [31]金涌,祝京旭,汪展文,等.流态化工程原理[M].北京:清华大学出版社,2001:1-19.
    [32]国井大藏,列文斯比尔,华东石油学院上海化工设计院等译.流态化工程[M].北京:石油化学工业出版社,1977:1-56.
    [33]Wilhelm R M, Kwauk M. Fluidization of Solids Particles[J]. Chemical Engineering Progress,1948,44(9):201-218.
    [34]Liang W G, Zhu J X. A Core-Annulus Model for the Radial Flow Structure in a Liquid-Solid Circulating Fluidized Bed [J]. Chemical Engineering,1997, 68(1):51-62.
    [35]Liang W G, Zhu J X. Effect of Radial Flow Non-uniformity on the Alkylation Reaction in a Liquid-Solid Circulating Fluidized Bed Reactor[J]. Industrial and Engineering Chemistry Research,1996,36(11):4651-4658.
    [36]Zheng Y, Zhu J-Z, Martin S, et al. The Axial Hydrodynamic Behavior in a Liquid-Solid Circulating Fluidized Bed [J]. Chemical Engineering,1999,77(2): 284-290.
    [37]《化学工程手册》编辑委员会.化学工程手册(第20篇):流态化[M].北京:化学工业出版社.1987:10-31.
    [38]Kunii D, Leverspiel. Fluidization Engineering[M]. New York:Butterworth Heineman press,1991:9-64.
    [39]黎强,邱宽嵘,丁玉等.流态化原理及其应用[M].徐州:中国矿业大学出版社,1994:1-24.
    [40]吴占松,马润田,汪展文.流态化技术基础及应用[M].北京:化学化工出版社,2006:5-6.
    [41]郭慕孙.流态化浸取和洗涤[M].北京:科学出版社,1979:10-59.
    [42]李建德.流态化洗涤(液固分离)的工业性试验研究[J].化学工程,1981,(2):20-24.
    [43]郭慕孙.化工冶金中的散式流态化[J].中国科学A辑,1973,(3):298-311.
    [44]姜方卫,邹懋森,管秀瑛.流态化技术在铀湿法冶金中的应用—碱浸铀矿浆流态化洗涤试验研究[J].铀矿冶,1986,5(1):30-36.
    [45]肖连生,张启修,龚柏藩.密实移动床-流化床离子交换技术从钨酸盐溶液中除钼试验研究[J].矿冶工程,,2001,21(3):66-68.
    [46]李小斌,李斌,彭志宏,等.赤泥流态化洗涤[J].过程工程学报,2010,10(3):445-450.
    [47]Dale L Keairns. Fluidization Technology[M]. New York:Hemisphere Publishing Corporation,1976,519-544.
    [48]易江林,金涌,俞芷青等.MSB树脂的流化床干燥[A].见:中国化工学会.第五届全国干燥技术交流会议论文集[C].上海:化工出版社,1995:316-319.
    [49]Ralph S, Carsten V, Oachim W, et al. Fluidized bed coating at super critical fluidized conditions[J]. The Journal of Supercritical Fluids,2002,2(24):137-151.
    [50]崔玉斌,魏飞,金涌等.气固逆、并流多级旋流干燥的流体力学行为研究[J].化工冶金,1996,17(3):248-253.
    [51]童景山.流态化干燥技术[M].北京:科学出版社,1996:50.
    [52]时钧,汪家鼎,余国琼,等.化学工程手册[M].北京:化学工业出版社,1996:25-129.
    [53]Lothar Reh. The circulating fluid bed reactor-its main features [J]. Chemical Engineering and Processing:Process Intensification,1986,20(3):117-127.
    [54]孙克萍,先晋聪,宋强.循环流态化焙烧技术在氧化铝业的应用研讨[J].新疆有色金属,2003,26(4):27-28.
    [55]Zhu J-X, Bi H-T. Distinctions between low density and high density circulating fluidized beds[J]. Chemical Engineering,1995,73(5):644-649.
    [56]Squires A M. Story of fluid catalytic cracking:the first circulating fluid bed [J]. Circulating fluidized bed technology,1986:1-19.
    [57]Bai D-R, Zhu J-X, Jin-Y, et al. Novel designs and simulations of FCC riser regenerator [J]. Industrial and Engineering Chemistry Research,1997,36(11): 4543-4548.
    [58]Shingles T, McDonald A F. Commercial experience with synthol CFB reactors [J]. Circulating fluidized bed technology,1988,23(3):43-50.
    [59]杨贵林,黄哲,陈大保等.快速流化床H-98催化剂丁烯氧化脱氢制丁二烯[J].石油化工,1988,16(10):680-685.
    [60]Covezzi M, Mei G. The multizone circulating reactor technology[J]. Chemical Engineering Science,2001,56(13):4059-4067.
    [61]D Santana, J M Rodriguez. A Macias-Machin.Modelling fluidized bed elutriation of fine particles [J]. Power Technology,1999,106(1-2):110-118.
    [62]李秋生.烧结法赤泥快速分离科研与产业化探索[J].轻金属,2009,(10):14-17.
    [63]张哲新,尹周澜,温金德,等.高效沉降槽在烧结法氧化铝生产中的应用[J].山东冶金,2005,27(5):20-22.
    [64]Klimesch D S, Ray A. Hydrogamet formation during autoclaving at 180℃ in unstirred metakaolin-lime-quartz slurries [J]. Cement and Concrete Research, 1998,8(28):1109-1117.
    [65]Bhatty M S Y, Greening N R. Interaction of Alkaline with Hydrating and Hydrated Calcium Silicates in Proceedings of the 4th Conference on the Effects in Cement and Concrete [J]. Purdue University, West Lafayette,1978:87-111.
    [66]Lan G Richardson, Adrian R Brough, Rik Brydson, et al. Location of Aluminum in Substituted Calcium Silicate Hydrate(C-S-H)Gels as Determined by Si and Al NMR and EELS[J]. Am Ceram Soc,1993,76 (9):85-88.
    [67]Danielle S, Klimesch, AbhiRay. DYA-TGA evaluations of the CaO-Al2O3-SiO2-H2O system treated hydrothermally [J]. Thermochimica Acta, 1999,334:115-122.
    [68]Liu Guihua, Li Xiaobin, Peng Zhihong, et al. Stability of calcium silicate in basic solution[J]. Transactions of Nonferrous Metals Society of China,2003,13(5): 1235-1238.
    [69]刘桂华,唐时健,李小斌,等.氧化铝生产中水合硅酸钙的研究进展[J].矿业工程,2005,3(25):54-56.
    [70]Xiaodong Cong. Si NMR study of the structure of calcium silicate hydrate [J]. Advn Com Bas Mat,1996,(3):144-150.
    [71]刘祥民,刘桂华,李小斌.水化石榴石渣湿法处理的研究[J].轻金属,1999(12):12-14.
    [72]孙建峰.强化烧结法熟料溶出中赤泥的快速分离[J].轻金属,2005,(5):17-20.
    [73]李晓斌,徐华军,刘桂华,等.氧化铝熟料溶出过程中Si02的行为[J].过程工程学报,2006,6(3):431-434.
    [74]郭琴珍,王军.二次反应对熟料中氧化铝溶出率的影响[J].轻金属,2003(12):10-12.
    [75]张建.碱石灰铝土矿熟料高浓度溶出过程中二次反应的研究[D].长沙:中南大学,2008:37-47.
    [76]周宗科.浅析二次反应对氧化铝生产熟料溶出的影响[J].世界有色金属,2002,(9):35-38.
    [77]陈红武,周宗科.烧结法熟料溶出条件对二次反应影响分析[J].轻金属,2001,(8):14-16.
    [78]徐华军.氧化铝熟料溶出过程中二次反应的研究[D].长沙:中南大学,2006:8-12.
    [79]李太昌.二次反应抑制剂及其添加工艺技术研究[J].有色金属(冶炼部分),2002,(1):26-28.
    [80]李小斌,张建,刘桂华,等.原硅酸钙在铝酸钠溶液中的反应行为[J].中南大学学报(自然科学版),2009,40(2):275-281.
    [81]Klimesch D S, Ray A. DTA-TG study of the CaO-SiO2-H2O and CaO-Al2O3-SiO2-H2O systems under hydrothermal conditions[J]. Journal of Thermal Analysis and Calorimetry,1999,1(56):24-25.
    [82]Lewis W K, Whitman W G. Absorption symposium[J]. Industrial and Engineering Chemistry,1924,16(12):1215-1220.
    [83]Whitman W G. A preliminary experimental confirmation of the two-film theory of gas absorption[J]. Chemical Materials Engineering,1923,29(4):146-148.
    [84]Higbie R. The rate of adsorption of a pure gas into a still liquid during short periods of exposure[J]. Transaction of American Institute of Chemical Engineers, 1935,31(2):355-360.
    [85]Danckwerts P V. Significance of liquid-Film coefficients in gas absorption [J]. Industrial and Engineering Chemistry,1951,43(6):1460-1467.
    [86]Danckwerts P V. Gas absorption accompanied by chemical reaction [J]. American Institute of Chemical Engineers Journal,1955,1 (4):456-463.
    [87]Toor H L, Marchello J M. Film-penetration model for mass and heat transfer[J]. American Institute of Chemical Engineers Journal,1958,4(1):97-103.
    [88]Ergun S. Fluid Flow through Packed Columns [J].Chemical Engineering Progress, 1952,48(1):89-94.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700