拜耳法生产氧化铝工艺

拜耳法生产氧化铝工艺 生产氧化铝工艺流程 从矿石提取氧化铝有多种方法，例如:拜耳法、碱石灰烧结法、拜耳-烧结联合法等。拜耳法一直是生产氧化铝的主要方法，其产量约占全世界氧化铝总产量的95,左右。70年代以来，对酸法的研究已有较大进展，但尚未在工业上应用。 碱石灰烧结法 适用于处理高硅的铝土矿，将铝土矿、碳酸钠和石灰按一定比例混合配料，在回转窑内烧结成由铝酸钠(Na2O?Al2O3)、铁酸钠(Na2O?Fe2O3、原硅酸钙(2CaO?SiO2)和钛酸钠(CaO?TiO2组成的熟料。然后用稀碱溶液溶出熟料中的铝酸钠。此时铁酸钠水解得到的NaOH也进入溶液。如果溶出条件控制适当，原硅酸钙就不会大量地与铝酸钠溶液发生反应，而与钛酸钙、Fe2O3?H2O 等组成赤泥排出。溶出熟料得到的铝酸钠溶液经过专门的脱硅过程，SiO2O形成水合铝硅酸钠(称为钠硅渣)或水化石榴石3CaO?Al2O3?xSiO2?(6,2x)H2O沉淀(其中x?0.1),而使溶液提纯。把CO2气体通入精制铝酸钠溶液，和加入晶种搅拌，得到氢氧化铝沉淀物和主要成分是碳酸钠的母液。氢氧化铝经煅烧成为氧化铝成品。水化石榴石中的Al2O3可以再用含Na2CO3母液提取回收。 碱石灰烧结法的主要化学反应如下: 烧结: Al2O3+Na2CO3??Na2O?Al2O3+CO2 Fe2O3+Na2CO3??Na2O?Fe2O3+CO2 SiO2+2CaCO3??2CaO?SiO2+2CO2 TiO2+CaCO3??CaO?TiO2+CO2 熟料溶出: Na2O?Al2O3+4H2O??2NaAl(OH)4(溶解) Na2O?Fe2O3+2H2O??Fe2O3?H2O?+2NaOH(水解) 脱硅: 1.7 Na2SiO3+2NaAl(OH)4??Na2O?Al2O3?1.7SiO2?nH2O?+3.4NaOH 3 Ca(OH)2+2NaAl(OH)4+x Na2SiO3?? 3CaO?Al2O3?x SiO2?(6-2x)H2O?+2(1+x)NaOH 分解: 2NaOH+CO2??Na2CO3+H2O NaAl(OH)4??Al(OH)3?+NaOH 中国碱石灰烧结法生产氧化铝的主要技术成就是:在熟料烧成中采用低碱比配方，在熟料溶出工艺中采用二段磨料和低分子比溶液，以抑制溶出时的副反应损失，使熟料中Na2O和Al2O3的溶出率分别达到94,96,和92,94,。Al2O3的总回收率约90,,每吨氧化铝的Na2CO3的消耗量约95公斤。碱石灰烧结法可以处理拜耳法不能经济地利用的低品位矿石，其铝硅比可低至3.5,且原料的综合利用较好，有其特色。 碱石灰烧结法的常用流程见图2 vibration pound used flat type and insert type phase combined vibration pound, specific for first with insert type vibrators vibration pound, requirements steep, fast plug slow pulled, plug points uniform, special strengthening on steel anchorage end of vibration pound, then with flat vibrators vibration pound, before and after two times overlap sewing many Yu 100mm, improve concrete of dense degrees and surface can wipe sex. 7.4 vibration pound end Hou began steel drum rolling, rolling General not less than three again, first again and second again of rolling direction vertical, third again direction with first again, guarantee concrete surface flat, rolling Hou, immediately with wood wipe child wipe flat a again, stay surface received water Hou, people stepped on has minor footprints Shi (settlement 5-10MM), began second again wipe pressure, with of with double plastic sheeting cover, sprinkler conservation, sprinkler conservation many Yu 7d. 8 concrete strength is not the same as note 8.1 during the different strength grade concrete pouring of concrete mix transport by car, listing number, clearly marked and signs indicating the grade of concrete, after delivery, led by full-time staff to the appropriate placement of parts in case of mistake. 8.2 strengthening communications links, concrete pouring process, the front and rear, floor and ground radio link issues timely processing. 8.3 After pouring the concrete to meet the design requirements of time, cleaned again, and watering than the concrete components with parts labeled a level concrete and Expander. 1.6 masonry construction engineering masonry with aerated concrete blocks and standard clay bricks. 1 material--for entry at the request of blocks and Clay tile product certificate, and product performance test report. --When aerated concrete masonry, its age should not exceed 28D. --Transportation, loading and unloading in the process throwing and dumping is 拜耳,烧结联合法 可充分发挥两法优点，取长补短,利用铝硅比较低的铝土矿,求得更好的经济效果。联合法有多种形式,均以拜耳法为主,而辅以烧结法。按联合法的目的和流程连接方式不同，又可分为串联法、并联法和混联法三种工艺流程。 ? 串联法是用烧结法回收拜耳法赤泥中的Na2O和Al2O3,用 于处理拜耳法不能经济利用的三水铝石型铝土矿。扩大了原料资源，减少碱耗，用较廉价的纯碱代替烧碱，而且Al2O3的回收率也较高。 ? 并联法是拜耳法与烧结法平行作业，分别处理铝土矿，但烧结法只占总生产能力的10,15,，用烧结法流程转化产生的NaOH补充拜耳法流程中NaOH的消耗。 ? 混联法是前两种联合法的综合。此法中的烧结法除了处理拜耳法赤泥外，还处理一部分低品位矿石。 中国根据本国的铝矿资源特点，发展出多种氧化铝生产方法。50年代初就已用碱石灰烧结法处理铝硅比只有3.5的纯一水硬铝石型铝土矿,开创了具有特色的氧化铝生产体系。用中国的烧结法,可使Al2O3的总回收率达到90%;每吨氧化铝的碱耗(Na2CO3)约 90公斤;氧化铝的SiO2含量下降到0.02,0.04,;而且在50年代已经从流程中综合回收金属镓和利用赤泥生产水泥。60年代初建成了拜耳烧结混联法氧化铝厂,使Al2O3总回收率达到91,，每吨氧化铝的碱耗下降到60公斤，为高效率地处理较高品位的一水硬铝石型铝土矿开创了一条新路。中国在用单纯拜耳法处理高品位一水硬铝石型铝土矿方面也积累了不少经验。 根据物理特性的不同,电解用氧化铝可分为三类:砂状、粉状和中间状(表3)。 vibration pound used flat type and insert type phase combined vibration pound, specific for first with insert type vibrators vibration pound, requirements steep, fast plug slow pulled, plug points uniform, special strengthening on steel anchorage end of vibration pound, then with flat vibrators vibration pound, before and after two times overlap sewing many Yu 100mm, improve concrete of dense degrees and surface can wipe sex. 7.4 vibration pound end Hou began steel drum rolling, rolling General not less than three again, first again and second again of rolling direction vertical, third again direction with first again, guarantee concrete surface flat, rolling Hou, immediately with wood wipe child wipe flat a again, stay surface received water Hou, people stepped on has minor footprints Shi (settlement 5-10MM), began second again wipe pressure, with of with double plastic sheeting cover, sprinkler conservation, sprinkler conservation many Yu 7d. 8 concrete strength is not the same as note 8.1 during the different strength grade concrete pouring of concrete mix transport by car, listing number, clearly marked and signs indicating the grade of concrete, after delivery, led by full-time staff to the appropriate placement of parts in case of mistake. 8.2 strengthening communications links, concrete pouring process, the front and rear, floor and ground radio link issues timely processing. 8.3 After pouring the concrete to meet the design requirements of time, cleaned again, and watering than the concrete components with parts labeled a level concrete and Expander. 1.6 masonry construction engineering masonry with aerated concrete blocks and standard clay bricks. 1 material--for entry at the request of blocks and Clay tile product certificate, and product performance test report. --When aerated concrete masonry, its age should not exceed 28D. --Transportation, loading and unloading in the process throwing and dumping is 拜耳法 系奥地利拜耳(K.J.Bayer)于 1888年发明。其原理是用苛性钠(NaOH)溶液加温溶出铝土矿中的氧化铝，得到铝酸钠溶液。溶液与残渣(赤泥)分离后，降低温度，加入氢氧化铝作晶种,经长时间搅拌,铝酸钠分解析出氢氧化铝，洗净,并在950,1200?温度下煅烧，便得氧化铝成品。析出氢氧化铝后的溶液称为母液，蒸发浓缩后循环使用。 拜耳法的简要化学反应如下 由于三水铝石、一水软铝石和一水硬铝石的结晶构造不同,它们在苛性钠溶液中的溶解性能有很大差异,所以要提供不同的溶出条件，主要是不同的溶出温度。三水铝石型铝土矿可在125,140?下溶出，一水硬铝石型铝土矿则要在240,260?并添加石灰(3,7,)的条件下溶出。 现代拜耳法的主要进展在于:?设备的大型化和连续操作;?生产过程的自动化;?节省能量，例如高压强化溶出和流态化焙烧;? 生产砂状氧化铝以满足铝电解和烟气干式净化的需要。拜耳法的工艺流程见图1。 拜耳法的优点主要是流程简单、投资省和能耗较低，最低者每吨氧化铝的能耗仅3×106千卡左右，碱耗一般为100公斤左右(以Na2CO3计)。 拜耳法生产的经济效果决定于铝土矿的质量，主要是矿石中的SiO2含量，通常以矿石的铝硅比，即矿石中的Al2O3与SiO2含量的重量比来表示。因为在拜耳法的溶出过程中，SiO2转变成方钠石型的水合铝硅酸钠(Na2O?Al2O3?1.7SiO2?nH2O)，随同赤泥排出。矿石中每公斤SiO2大约要造成1公斤Al2O3和0.8公斤NaOH的损失。铝土矿的铝硅比越低，拜耳法的经济效果越差。直到70年代后期，拜耳法所处理的铝土矿的铝硅比均大于7,8。由于高品位三水铝石型铝土矿资源逐渐减少，如何利用其他类型的低品位铝矿资源和节能新工艺等问题，已是研究、开发的重要方向。 碱石灰烧结法 vibration pound used flat type and insert type phase combined vibration pound, specific for first with insert type vibrators vibration pound, requirements steep, fast plug slow pulled, plug points uniform, special strengthening on steel anchorage end of vibration pound, then with flat vibrators vibration pound, before and after two times overlap sewing many Yu 100mm, improve concrete of dense degrees and surface can wipe sex. 7.4 vibration pound end Hou began steel drum rolling, rolling General not less than three again, first again and second again of rolling direction vertical, third again direction with first again, guarantee concrete surface flat, rolling Hou, immediately with wood wipe child wipe flat a again, stay surface received water Hou, people stepped on has minor footprints Shi (settlement 5-10MM), began second again wipe pressure, with of with double plastic sheeting cover, sprinkler conservation, sprinkler conservation many Yu 7d. 8 concrete strength is not the same as note 8.1 during the different strength grade concrete pouring of concrete mix transport by car, listing number, clearly marked and signs indicating the grade of concrete, after delivery, led by full-time staff to the appropriate placement of parts in case of mistake. 8.2 strengthening communications links, concrete pouring process, the front and rear, floor and ground radio link issues timely processing. 8.3 After pouring the concrete to meet the design requirements of time, cleaned again, and watering than the concrete components with parts labeled a level concrete and Expander. 1.6 masonry construction engineering masonry with aerated concrete blocks and standard clay bricks. 1 material--for entry at the request of blocks and Clay tile product certificate, and product performance test report. --When aerated concrete masonry, its age should not exceed 28D. --Transportation, loading and unloading in the process throwing and dumping is 适用于处理高硅的铝土矿，将铝土矿、碳酸钠和石灰按一定比例混合配料，在回转窑内烧结成由铝酸钠(Na2O?Al2O3)、铁酸钠(Na2O?Fe2O3、原硅酸钙(2CaO?SiO2)和钛酸钠(CaO?TiO2组成的熟料。然后用稀碱溶液溶出熟料中的铝酸钠。此时铁酸钠水解得到的NaOH也进入溶液。如果溶出条件控制适当，原硅酸钙就不会大量地与铝酸钠溶液发生反应，而与钛酸钙、Fe2O3?H2O 等组成赤泥排出。溶出熟料得到的铝酸钠溶液经过专门的脱硅过程，SiO2O形成水合铝硅酸钠(称为钠硅渣)或水化石榴石3CaO?Al2O3?xSiO2?(6,2x)H2O沉淀(其中x?0.1),而使溶液提纯。把CO2气体通入精制铝酸钠溶液，和加入晶种搅拌，得到氢氧化铝沉淀物和主要成分是碳酸钠的母液。氢氧化铝经煅烧成为氧化铝成品。水化石榴石中的Al2O3可以再用含Na2CO3母液提取回收。 碱石灰烧结法的主要化学反应如下: 烧结: Al2O3+Na2CO3??Na2O?Al2O3+CO2 Fe2O3+Na2CO3??Na2O?Fe2O3+CO2 SiO2+2CaCO3??2CaO?SiO2+2CO2 TiO2+CaCO3??CaO?TiO2+CO2 熟料溶出: Na2O?Al2O3+4H2O??2NaAl(OH)4(溶解) Na2O?Fe2O3+2H2O??Fe2O3?H2O?+2NaOH(水解) 脱硅: 1.7 Na2SiO3+2NaAl(OH)4??Na2O?Al2O3?1.7SiO2?nH2O?+3.4NaOH 3 Ca(OH)2+2NaAl(OH)4+x Na2SiO3?? 3CaO?Al2O3?x SiO2?(6-2x)H2O?+2(1+x)NaOH 分解: 2NaOH+CO2??Na2CO3+H2O NaAl(OH)4??Al(OH)3?+NaOH 中国碱石灰烧结法生产氧化铝的主要技术成就是:在熟料烧成中采用低碱比配方，在熟料溶出工艺中采用二段磨料和低分子比溶液，以抑制溶出时的副反应损失，使熟料中Na2O和Al2O3的溶出率分别达到94,96,和92,94,。Al2O3的总回收率约90,,每吨氧化铝的Na2CO3的消耗量约95公斤。碱石灰烧结法可以处理拜耳法不能经济地利用的低品位矿石，其铝硅比可低至3.5,且原料的综合利用较好，有其特色。 碱石灰烧结法的常用流程见图2 vibration pound used flat type and insert type phase combined vibration pound, specific for first with insert type vibrators vibration pound, requirements steep, fast plug slow pulled, plug points uniform, special strengthening on steel anchorage end of vibration pound, then with flat vibrators vibration pound, before and after two times overlap sewing many Yu 100mm, improve concrete of dense degrees and surface can wipe sex. 7.4 vibration pound end Hou began steel drum rolling, rolling General not less than three again, first again and second again of rolling direction vertical, third again direction with first again, guarantee concrete surface flat, rolling Hou, immediately with wood wipe child wipe flat a again, stay surface received water Hou, people stepped on has minor footprints Shi (settlement 5-10MM), began second again wipe pressure, with of with double plastic sheeting cover, sprinkler conservation, sprinkler conservation many Yu 7d. 8 concrete strength is not the same as note 8.1 during the different strength grade concrete pouring of concrete mix transport by car, listing number, clearly marked and signs indicating the grade of concrete, after delivery, led by full-time staff to the appropriate placement of parts in case of mistake. 8.2 strengthening communications links, concrete pouring process, the front and rear, floor and ground radio link issues timely processing. 8.3 After pouring the concrete to meet the design requirements of time, cleaned again, and watering than the concrete components with parts labeled a level concrete and Expander. 1.6 masonry construction engineering masonry with aerated concrete blocks and standard clay bricks. 1 material--for entry at the request of blocks and Clay tile product certificate, and product performance test report. --When aerated concrete masonry, its age should not exceed 28D. --Transportation, loading and unloading in the process throwing and dumping is 拜耳,烧结联合法 可充分发挥两法优点，取长补短,利用铝硅比较低的铝土矿,求得更好的经济效果。联合法有多种形式,均以拜耳法为主,而辅以烧结法。按联合法的目的和流程连接方式不同，又可分为串联法、并联法和混联法三种工艺流程。 ? 串联法是用烧结法回收拜耳法赤泥中的Na2O和Al2O3,用 于处理拜耳法不能经济利用的三水铝石型铝土矿。扩大了原料资源，减少碱耗，用较廉价的纯碱代替烧碱，而且Al2O3的回收率也较高。 ? 并联法是拜耳法与烧结法平行作业，分别处理铝土矿，但烧结法只占总生产能力的10,15,，用烧结法流程转化产生的NaOH补充拜耳法流程中NaOH的消耗。 ? 混联法是前两种联合法的综合。此法中的烧结法除了处理拜耳法赤泥外，还处理一部分低品位矿石。 中国根据本国的铝矿资源特点，发展出多种氧化铝生产方法。50年代初就已用碱石灰烧结法处理铝硅比只有3.5的纯一水硬铝石型铝土矿,开创了具有特色的氧化铝生产体系。用中国的烧结法,可使Al2O3的总回收率达到90%;每吨氧化铝的碱耗(Na2CO3)约 90公斤;氧化铝的SiO2含量下降到0.02,0.04,;而且在50年代已经从流程中综合回收金属镓和利用赤泥生产水泥。60年代初建成了拜耳烧结混联法氧化铝厂,使Al2O3总回收率达到91,，每吨氧化铝的碱耗下降到60公斤，为高效率地处理较高品位的一水硬铝石型铝土矿开创了一条新路。中国在用单纯拜耳法处理高品位一水硬铝石型铝土矿方面也积累了不少经验。 根据物理特性的不同,电解用氧化铝可分为三类:砂状、粉状和中间状(表3)。 vibration pound used flat type and insert type phase combined vibration pound, specific for first with insert type vibrators vibration pound, requirements steep, fast plug slow pulled, plug points uniform, special strengthening on steel anchorage end of vibration pound, then with flat vibrators vibration pound, before and after two times overlap sewing many Yu 100mm, improve concrete of dense degrees and surface can wipe sex. 7.4 vibration pound end Hou began steel drum rolling, rolling General not less than three again, first again and second again of rolling direction vertical, third again direction with first again, guarantee concrete surface flat, rolling Hou, immediately with wood wipe child wipe flat a again, stay surface received water Hou, people stepped on has minor footprints Shi (settlement 5-10MM), began second again wipe pressure, with of with double plastic sheeting cover, sprinkler conservation, sprinkler conservation many Yu 7d. 8 concrete strength is not the same as note 8.1 during the different strength grade concrete pouring of concrete mix transport by car, listing number, clearly marked and signs indicating the grade of concrete, after delivery, led by full-time staff to the appropriate placement of parts in case of mistake. 8.2 strengthening communications links, concrete pouring process, the front and rear, floor and ground radio link issues timely processing. 8.3 After pouring the concrete to meet the design requirements of time, cleaned again, and watering than the concrete components with parts labeled a level concrete and Expander. 1.6 masonry construction engineering masonry with aerated concrete blocks and standard clay bricks. 1 material--for entry at the request of blocks and Clay tile product certificate, and product performance test report. --When aerated concrete masonry, its age should not exceed 28D. --Transportation, loading and unloading in the process throwing and dumping is 拜耳法生产氧化铝一般部分为以下: 溶 出 沉 降 原料输送 分 解 蒸 发 原料车间: 铝土矿 石灰 碱液 循环母液 磨头石灰仓 均化库 棒磨 中间泵池 磨头石灰仓 磨机 磨机 球磨 磨机 磨机 原矿浆槽 水力旋流器 回转筛 溶出车间: 原矿浆 脱硅槽 隔膜泵 压煮器 闪 蒸 套 管 稀释后槽 稀释槽 Ra 101 Ra112 Ra 102 Ra 103 Ra113 Ra 104 Ra114 Ra 105 Ra115 Ra 106 Ra 107A Ra 107B Ra116 B Ra 108A Ra 108B Ra117 Ra 109A Ra 109B Ra 110 Ra 111 Ra117 底部小放料 Ra117 Nt106 Nt106 Nt106 Nt106 Ra117 Nt106 Nt104 Nt103 Nt102 Nt101 Nt105 Tt101 Tt101 Tt101 vibration pound used flat type and insert type phase combined vibration pound, specific for first with insert type vibrators vibration pound, requirements steep, fast plug slow pulled, plug points uniform, special strengthening on steel anchorage end of vibration pound, then with flat vibrators vibration pound, before and after two times overlap sewing many Yu 100mm, improve concrete of dense degrees and surface can wipe sex. 7.4 vibration pound end Hou began steel drum rolling, rolling General not less than three again, first again and second again of rolling direction vertical, third again direction with first again, guarantee concrete surface flat, rolling Hou, immediately with wood wipe child wipe flat a again, stay surface received water Hou, people stepped on has minor footprints Shi (settlement 5-10MM), began second again wipe pressure, with of with double plastic sheeting cover, sprinkler conservation, sprinkler conservation many Yu 7d. 8 concrete strength is not the same as note 8.1 during the different strength grade concrete pouring of concrete mix transport by car, listing number, clearly marked and signs indicating the grade of concrete, after delivery, led by full-time staff to the appropriate placement of parts in case of mistake. 8.2 strengthening communications links, concrete pouring process, the front and rear, floor and ground radio link issues timely processing. 8.3 After pouring the concrete to meet the design requirements of time, cleaned again, and watering than the concrete components with parts labeled a level concrete and Expander. 1.6 masonry construction engineering masonry with aerated concrete blocks and standard clay bricks. 1 material--for entry at the request of blocks and Clay tile product certificate, and product performance test report. --When aerated concrete masonry, its age should not exceed 28D. --Transportation, loading and unloading in the process throwing and dumping is 沉降车间: 稀释后槽 滤饼渣 溢流 控制过滤 沉降分离 叶滤机 精 液 一洗 蒸发冷凝 二洗 四洗 三洗 转鼓 分解车间: 精液 平盘料浆槽 板式换热器 1-16分解槽 两台分解机 立盘过滤机 15.16分解槽 分解首槽 晶种槽 蒸发: 原液槽 原液浆 2 号 1 号 4 号 3 号 进到蒸发器 一闪 6效管式降膜蒸发器 5 号 6 号 二闪 母液槽 三闪 平盘料浆槽 平盘过滤机 AH皮带 AH 焙烧炉 滤液 蒸发原料槽 vibration pound used flat type and insert type phase combined vibration pound, specific for first with insert type vibrators vibration pound, requirements steep, fast plug slow pulled, plug points uniform, special strengthening on steel anchorage end of vibration pound, then with flat vibrators vibration pound, before and after two times overlap sewing many Yu 100mm, improve concrete of dense degrees and surface can wipe sex. 7.4 vibration pound end Hou began steel drum rolling, rolling General not less than three again, first again and second again of rolling direction vertical, third again direction with first again, guarantee concrete surface flat, rolling Hou, immediately with wood wipe child wipe flat a again, stay surface received water Hou, people stepped on has minor footprints Shi (settlement 5-10MM), began second again wipe pressure, with of with double plastic sheeting cover, sprinkler conservation, sprinkler conservation many Yu 7d. 8 concrete strength is not the same as note 8.1 during the different strength grade concrete pouring of concrete mix transport by car, listing number, clearly marked and signs indicating the grade of concrete, after delivery, led by full-time staff to the appropriate placement of parts in case of mistake. 8.2 strengthening communications links, concrete pouring process, the front and rear, floor and ground radio link issues timely processing. 8.3 After pouring the concrete to meet the design requirements of time, cleaned again, and watering than the concrete components with parts labeled a level concrete and Expander. 1.6 masonry construction engineering masonry with aerated concrete blocks and standard clay bricks. 1 material--for entry at the request of blocks and Clay tile product certificate, and product performance test report. --When aerated concrete masonry, its age should not exceed 28D. --Transportation, loading and unloading in the process throwing and dumping is