WO2007009377A1 - A process for preparing powdery alumina from low concentration solution by seed decomposition - Google Patents
A process for preparing powdery alumina from low concentration solution by seed decomposition Download PDFInfo
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- WO2007009377A1 WO2007009377A1 PCT/CN2006/001743 CN2006001743W WO2007009377A1 WO 2007009377 A1 WO2007009377 A1 WO 2007009377A1 CN 2006001743 W CN2006001743 W CN 2006001743W WO 2007009377 A1 WO2007009377 A1 WO 2007009377A1
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- decomposition
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F7/00—Compounds of aluminium
- C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
- C01F7/04—Preparation of alkali metal aluminates; Aluminium oxide or hydroxide therefrom
- C01F7/14—Aluminium oxide or hydroxide from alkali metal aluminates
- C01F7/144—Aluminium oxide or hydroxide from alkali metal aluminates from aqueous aluminate solutions by precipitation due to cooling, e.g. as part of the Bayer process
Definitions
- the present invention relates to a method for producing alumina, and more particularly to a method for producing a powdered alumina by seeding a low concentration solution.
- Seed decomposition is one of the important processes in the Bayer process alumina production process. Its task is to separate the aluminum hydroxide from the supersaturated sodium aluminate solution by controlling the seed material, and decompose the obtained aluminum hydroxide. Subsequent processing.
- the dissolution conditions are different, and the composition of the obtained sodium aluminate solution is also different.
- the domestic processing of diaspore and gibbsite alumina plants the semen alkali concentration and alumina concentration obtained by leaf filtration after dissolution are higher, generally Na 2 0 K concentration 145 ⁇ 172g / l, A1 2 0 3 concentration of 160 ⁇ 195g / l, seed decomposition using high concentration, high seed ratio to produce sand-like alumina.
- the dissolution system adopted is very different from the existing alumina plant. It is dissolved at low temperature and normal pressure, and the alkali concentration of circulating mother liquor is very high. Low, Na 2 0 K concentration is only 140g / l, the composition of the obtained sodium aluminate solution is quite different from the solution obtained by domestic treatment of high grade diaspore and gibbsite; that is, the concentration of sodium aluminate solution is low. And ⁇ ⁇ is higher (semen ⁇ ⁇ value is about 1.85), low concentration is conducive to decomposition, and high ⁇ ⁇ is not conducive to decomposition.
- the object of the present invention is to provide a method for producing powdered alumina by low-concentration solution seeding, so as to solve the problem of the decomposition process of the low-grade high-iron trihydrate bauxite first aluminum post-iron solution.
- the invention is realized as follows: the powdery alumina is produced by one-stage decomposition; the semen sent from the sedimentation workshop is mixed with the aluminum hydroxide seeds from the seed filtration process, and then added into the first two tanks of the decomposition system, wherein the first tank is decomposed
- the temperature is 5 8 ⁇ 61 "C
- the final bath temperature is 46 ⁇ 49 "C
- decomposition time 60 ⁇ 62 hours
- semen concentration is Na 2 0 K concentration 90 ⁇ 100g / l, A1 2 0 3 concentration 80 ⁇ 90g / l
- decomposition of aluminum hydroxide slurry One part goes to the finished product filtration process, and the other part goes to the seed filtration process (the aluminum hydroxide slurry distribution ratio is used to decompose the first groove seed crystal coefficient of 2.0 ⁇ 2.5); the seed filtered filter cake merges with the semen and returns to the decomposition system before 2 In the decomposition slot.
- the decomposition tank adopts a common flat bottom mechanical stirring decomposition tank; the optimum decomposition tank temperature is: 60 ⁇ in the first tank and 47 ⁇ 48 ° C in the last tank.
- the semen decomposition rate can reach 46 ⁇ 48% range, the decomposition yield rate is 41 ⁇ 45kg / m 3 - semen, and the aluminum hydroxide decomposed and produced is calcined to obtain powdery alumina.
- the chemical composition meets the quality requirements of the metallurgical grade first grade in the national standard YS/T274-1998.
- the invention has the beneficial effects that: the method of the invention can solve the problem of the decomposition process of the high-iron trihydrate bauxite first aluminum post-iron solution, and has good economic and social benefits.
- Embodiment 1 of the present invention a powdery alumina is produced by one-stage decomposition, and the decomposition tank adopts a common flat-bottom mechanical stirring decomposition tank; the semen sent from the sedimentation workshop is mixed with the aluminum hydroxide seeds from the seed filtration process and added to the decomposition system. In the first two slots, each slot is 50. /.
- the amount of decomposition the first bath temperature is 60 ⁇ , the final bath temperature is 48 ° C, the seed crystal coefficient is 2.0 ⁇ 2.5, the semen concentration is Na 2 0 K concentration 90 ⁇ 100 g / l, A1 2 0 3 concentration 80 ⁇ 90 g /l; After 61 hours decomposition, the decomposition rate is up to 46%; part of the aluminum hydroxide slurry after decomposition is used as the product of the process to the final product filtration process, and the other part is to the seed filtration process (the distribution of aluminum hydroxide slurry is used to decompose the first tank) The seed crystal coefficient is 2.0 ⁇ 2.5 for the control basis. After the seed filter cake is combined with the semen, it returns to the first two decomposition tanks of the decomposition system.
- Embodiment 2 of the present invention The powdery alumina is produced by one-stage decomposition. If the scale of the factory is large, a large flat-bottom mechanical stirring decomposition tank of 3000 m 3 or more is used. In order to ensure the decomposition reaction speed, the conventional tank can be set in the 4 to 8 tank. Intermediate cooling facility; where the temperature of the first tank is 58. C, the final bath temperature is 46 ⁇ , the seed crystal coefficient is 2.0, the semen concentration is Na 2 0 K concentration 90 g / l, A1 2 0 3 concentration 80 g / l; after 60 hours decomposition, the decomposition rate is 46%.
Abstract
A method for producing powdery alumina from low concentration solution by seed composition, it comprises a one-stage decomposition process. The decomposition tank used is a conventional flat-bottomed one with mechanical agitating means. The refined liquid from the sedimentation department and aluminium hydroxide seeds from the seeds filtration procedure are mixed, and then the mixture is charged into the first two tanks of the decomposition system, wherein the temperature of the first decomposition tank is 58-62 °C, the temperature of the last decomposition tank is 46-49 °C. The seed crystal coefficient is 2.0-2.5, the decomposition time is 60-62 hours, the concentration of the refined liquid is 90-100g/l by Na2Ok, and 80-90g/l by Al2O3. One portion of the decomposed aluminium hydroxide slurry is undergone the final product filtration procedure, and the other portion is undergone the seeds filtration procedure. The filter cake of the seeds filtration is merged with the refined liquid and returns to the first two decomposition tanks of the decomposition system. The method solves the problem of the dissolving procedure for treating high ferro content alumina trihydrate, in the sequence of aluminium and ferro, resulting in a better economical and social efficiency.
Description
低浓度溶液种分生产粉状氧化铝方法 技术领域： Method for producing powdered alumina by low-concentration solution seeding
本发明涉及一种氧化铝生产方法， 特别是一种低浓度溶液种分生 产粉状氧化铝方法。 The present invention relates to a method for producing alumina, and more particularly to a method for producing a powdered alumina by seeding a low concentration solution.
背景技术： Background technique:
种子分解是拜尔法氧化铝生产过程中的重要工序之一， 它的任务 是通过控制种分奈件， 使氢氧化铝从过饱和的铝酸钠溶液中析出， 分 解得到的氢氧化铝供后续工序处理。 Seed decomposition is one of the important processes in the Bayer process alumina production process. Its task is to separate the aluminum hydroxide from the supersaturated sodium aluminate solution by controlling the seed material, and decompose the obtained aluminum hydroxide. Subsequent processing.
由于氧化铝厂处理的铝土矿不同， 溶出条件不一样， 得到的铝酸 钠溶液组成也有差别。 总体来说， 国内处理一水硬铝石、 三水铝石的 氧化铝厂， 溶出后经叶滤得到的精液碱浓度和氧化铝浓度均较高， 一 般为 Na20K浓度 145 ~ 172g/l， A1203浓度 160 ~ 195g/l， 种子分解采用高 浓度、 高种子比生产砂状氧化铝。 Due to the different bauxites treated in the alumina plant, the dissolution conditions are different, and the composition of the obtained sodium aluminate solution is also different. In general, the domestic processing of diaspore and gibbsite alumina plants, the semen alkali concentration and alumina concentration obtained by leaf filtration after dissolution are higher, generally Na 2 0 K concentration 145 ~ 172g / l, A1 2 0 3 concentration of 160 ~ 195g / l, seed decomposition using high concentration, high seed ratio to produce sand-like alumina.
针对高铁三水铝土矿为易溶三水铝石型及氧化铝品位低的特点， 所采取的溶出制度与现有氧化铝厂有很大差别， 为低温常压溶出， 循 环母液碱浓度很低， Na20K浓度仅 140g/l， 得到的铝酸钠溶液组成与国 内处理高品位一水硬铝石和三水铝石所得到的溶液有着较大的差别； 即铝酸钠溶液浓度低、 而 α κ则较高 （精液 α κ值约 1.85左右） ， 浓度 低有利于分解， 而 α κ高则不利于分解。 In view of the characteristics of high-iron trihydrate bauxite mine which is easy to dissolve gibbsite type and low alumina grade, the dissolution system adopted is very different from the existing alumina plant. It is dissolved at low temperature and normal pressure, and the alkali concentration of circulating mother liquor is very high. Low, Na 2 0 K concentration is only 140g / l, the composition of the obtained sodium aluminate solution is quite different from the solution obtained by domestic treatment of high grade diaspore and gibbsite; that is, the concentration of sodium aluminate solution is low. And α κ is higher (semen α κ value is about 1.85), low concentration is conducive to decomposition, and high α κ is not conducive to decomposition.
针对此低浓度溶液的特点， 氧化铝厂现有的分解技术条件不能满 足本低浓度分解的要求。 根据试验研究， 提出一种新的分解工艺技术， 采用低浓度生产粉状氧化铝 (也称为普通状氧化铝）。 之所以生产粉状 氧化铝，主要是考虑到高铁三水铝土矿品位较低。 此种类型的高铁三水 铝土矿目前处于初始开发及工业化研究阶段,初期建厂规模不宜太大， 生产粉状氧化铝产量高一些，技术难度相对较小。 In view of the characteristics of this low concentration solution, the existing decomposition technology conditions of the alumina plant cannot meet the requirements of this low concentration decomposition. According to the experimental research, a new decomposition process technology was proposed to produce powdered alumina (also called ordinary alumina) at a low concentration. The reason for the production of powdered alumina is mainly due to the low grade of high-iron trihydrate bauxite. This type of high-speed rail Sanshui bauxite mine is currently in the initial development and industrialization research stage. The initial plant construction scale should not be too large, the production of powdered alumina is higher, and the technical difficulty is relatively small.
发明内容： Summary of the invention:
本发明的目的在于： 提出一种低浓度溶液种分生产粉状氧化铝的 方法， 以解决低品位高铁三水铝土矿先铝后铁方案分解工序的难题。 The object of the present invention is to provide a method for producing powdered alumina by low-concentration solution seeding, so as to solve the problem of the decomposition process of the low-grade high-iron trihydrate bauxite first aluminum post-iron solution.
本发明是这样实现的： 采用一段分解生产粉状氧化铝； 从沉降车 间送来的精液与种子过滤工序来的氢氧化铝种子混合后一同加进分解 系统前 2个槽中， 其中分解首槽温度为 58 ~ 61 "C， 末槽温度为 46 ~ 49
"C , 晶种系数 2.0 ~ 2.5， 分解时间 60 ~ 62小时， 精液浓度为 Na20K浓度 90 ~ 100g/l, A1203浓度 80 ~ 90g/l; 分解后的氢氧化铝料浆一部分去成 品过滤工序， 另一部分去种子过滤工序 （氢氧化铝料浆分配比例以分 解首槽晶种系数 2.0 ~ 2.5为控制依据） ； 种子过滤的滤饼与精液汇合 后， 返回分解系统前 2个分解槽中。 The invention is realized as follows: the powdery alumina is produced by one-stage decomposition; the semen sent from the sedimentation workshop is mixed with the aluminum hydroxide seeds from the seed filtration process, and then added into the first two tanks of the decomposition system, wherein the first tank is decomposed The temperature is 5 8 ~ 61 "C, the final bath temperature is 46 ~ 49 "C , seed crystal coefficient 2.0 ~ 2.5, decomposition time 60 ~ 62 hours, semen concentration is Na 2 0 K concentration 90 ~ 100g / l, A1 2 0 3 concentration 80 ~ 90g / l; decomposition of aluminum hydroxide slurry One part goes to the finished product filtration process, and the other part goes to the seed filtration process (the aluminum hydroxide slurry distribution ratio is used to decompose the first groove seed crystal coefficient of 2.0 ~ 2.5); the seed filtered filter cake merges with the semen and returns to the decomposition system before 2 In the decomposition slot.
在以上方法中， 分解槽采用普通平底机械搅拌分解槽； 最佳的分 解槽温度为： 首槽 60Ό， 末槽 47 ~ 48°C。 In the above method, the decomposition tank adopts a common flat bottom mechanical stirring decomposition tank; the optimum decomposition tank temperature is: 60 首 in the first tank and 47 ~ 48 ° C in the last tank.
采用以上分解技术和工艺控制条件， 精液分解率可达 46 ~ 48%范 围， 分解产出率 41 ~ 45kg/m3 -精液， 分解产出的氢氧化铝经焙烧后 得到粉状氧化铝， 其化学成分达到国家规定的 YS/T274 - 1998标准中 的冶金级一级品质量要求。 Using the above decomposition technology and process control conditions, the semen decomposition rate can reach 46 ~ 48% range, the decomposition yield rate is 41 ~ 45kg / m 3 - semen, and the aluminum hydroxide decomposed and produced is calcined to obtain powdery alumina. The chemical composition meets the quality requirements of the metallurgical grade first grade in the national standard YS/T274-1998.
本发明的有益效果是： 使用本发明的方法， 能够解决高铁三水铝 土矿先铝后铁方案分解工序的难题， 具有较好的经济效益和社会效 益。 The invention has the beneficial effects that: the method of the invention can solve the problem of the decomposition process of the high-iron trihydrate bauxite first aluminum post-iron solution, and has good economic and social benefits.
具体实施方式： detailed description:
本发明的实施例 1 : 采用一段分解生产粉状氧化铝， 分解槽采用 普通平底机械搅拌分解槽； 从沉降车间送来的精液与种子过滤工序来 的氢氧化铝种子混合后一同加进分解系统前 2个槽中， 每槽各 50。/。的 量， 其中分解首槽温度为 60Ό , 末槽温度为 48°C , 晶种系数 2.0 ~ 2.5， 精液浓度为 Na20K浓度 90 ~ 100g/l， A1203浓度 80 ~ 90g/l; 经 61小时分 解， 分解率达 46%; 分解后的氢氧化铝料浆一部分作为本工序产品去 成品过滤工序， 另一部分去种子过滤工序 （氢氧化铝料浆分配比例以 分解首槽晶种系数 2.0 ~ 2.5为控制依据） ， 种子过滤的滤饼与精液汇 合后， 返回分解系统前 2个分解槽中。 Embodiment 1 of the present invention: a powdery alumina is produced by one-stage decomposition, and the decomposition tank adopts a common flat-bottom mechanical stirring decomposition tank; the semen sent from the sedimentation workshop is mixed with the aluminum hydroxide seeds from the seed filtration process and added to the decomposition system. In the first two slots, each slot is 50. /. The amount of decomposition, the first bath temperature is 60 Ό, the final bath temperature is 48 ° C, the seed crystal coefficient is 2.0 ~ 2.5, the semen concentration is Na 2 0 K concentration 90 ~ 100 g / l, A1 2 0 3 concentration 80 ~ 90 g /l; After 61 hours decomposition, the decomposition rate is up to 46%; part of the aluminum hydroxide slurry after decomposition is used as the product of the process to the final product filtration process, and the other part is to the seed filtration process (the distribution of aluminum hydroxide slurry is used to decompose the first tank) The seed crystal coefficient is 2.0 ~ 2.5 for the control basis. After the seed filter cake is combined with the semen, it returns to the first two decomposition tanks of the decomposition system.
本发明的实施例 2: 采用一段分解生产粉状氧化铝， 若工厂生产 规模大，采用了 3000m3以上大型平底机械搅拌分解槽， 为保证分解反 应速度， 可在 4 ~ 8 号槽设置常规的中间降温设施； 其中分解首槽温 度为 58。C， 末槽温度为 46Ό， 晶种系数 2.0， 精液浓度为 Na20K浓度 90g/l, A1203浓度 80g/l; 经 60小时分解， 分解率达 46%。
Embodiment 2 of the present invention: The powdery alumina is produced by one-stage decomposition. If the scale of the factory is large, a large flat-bottom mechanical stirring decomposition tank of 3000 m 3 or more is used. In order to ensure the decomposition reaction speed, the conventional tank can be set in the 4 to 8 tank. Intermediate cooling facility; where the temperature of the first tank is 58. C, the final bath temperature is 46 Ό, the seed crystal coefficient is 2.0, the semen concentration is Na 2 0 K concentration 90 g / l, A1 2 0 3 concentration 80 g / l; after 60 hours decomposition, the decomposition rate is 46%.
Claims
1. 一种低浓度溶液种分生产粉状氧化铝的方法， 其特征在于： 采 用一段分解生产粉状氧化铝， 从沉降车间送来的精液与种子过滤工序 来的氢氧化铝种子混合后一同加进分解系统前 2个槽中， 其中分解首 槽温度为 58~61 C， 末槽温度为 46~49Π， 晶种系数 2·0~2.5， 分解 时间 60~62小时， 精液浓度为 32(^浓度90~100^1, Α1203浓度 80 ~ 90g/l, 精液 ακ值约 1.82 ~ 1.90, 分解母液 α κ值 3.30 ~ 3.40; 分解后的 氢氧化铝料浆一部分去成品过滤工序， 另一部分去种子过滤工序； 种 子过滤的滤饼与精液汇合后， 返回分解系统前 2个分解槽中。 A method for producing powdered alumina by seeding a low-concentration solution, characterized in that: the powdery alumina is produced by a decomposition process, and the semen sent from the sedimentation workshop is mixed with the aluminum hydroxide seed from the seed filtration process. Add to the first two tanks of the decomposition system, in which the temperature of the first tank is 58~61 C, the temperature of the final tank is 46~49Π, the seed crystal coefficient is 2·0~2.5, the decomposition time is 60~62 hours, and the semen concentration is 3 2 (^ concentration 90~100^1, Α1 2 0 3 concentration 80 ~ 90g/l, semen α κ value about 1.82 ~ 1.90, decomposition mother liquid α κ value 3.30 ~ 3.40; decomposition of the aluminum hydroxide slurry to the finished product filtration In the process, another part is subjected to the seed filtration process; after the seed filtered filter cake is combined with the semen, it is returned to the first two decomposition tanks of the decomposition system.
2. 根据权利要求 1所述的低浓度溶液种分生产粉状氧化铝的方 法， 其特征在于： 分解槽采用普通平底机械搅拌分解槽。 2. The method for producing powdered alumina by seeding a low concentration solution according to claim 1, wherein the decomposition tank is a common flat bottom mechanical stirring decomposition tank.
3. 根据权利要求 1 所述的低浓度溶液种分生产粉状氧化铝的方 法， 其特征在于： 最佳的分解槽温度为： 首槽 60Ό, 末槽 47~48°C。
3. The method of producing powdered alumina by seeding a low concentration solution according to claim 1, wherein: the optimum decomposition tank temperature is: 60 首 in the first tank and 47 to 48 ° C in the last tank.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005102003984A CN100372772C (en) | 2005-07-18 | 2005-07-18 | Method for producing powder form aluminum oxide by low concentration solution seed decomposition |
| CN200510200398.4 | 2005-07-18 |
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| Publication Number | Publication Date |
|---|---|
| WO2007009377A1 true WO2007009377A1 (en) | 2007-01-25 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/CN2006/001743 WO2007009377A1 (en) | 2005-07-18 | 2006-07-18 | A process for preparing powdery alumina from low concentration solution by seed decomposition |
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| CN (1) | CN100372772C (en) |
| WO (1) | WO2007009377A1 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103159241A (en) * | 2011-12-15 | 2013-06-19 | 贵阳铝镁设计研究院有限公司 | Two-section decomposition process for alumina production by Bayer process |
| CN105197970A (en) * | 2014-06-27 | 2015-12-30 | 沈阳铝镁设计研究院有限公司 | Method for improving two-stage decomposition effect |
| CN109592700A (en) * | 2018-12-18 | 2019-04-09 | 广西华银铝业有限公司 | A kind of method of alumina producer decomposing grading production continuous operation |
| CN112225237A (en) * | 2020-10-26 | 2021-01-15 | 洛阳莱茵希德特种材料有限公司 | Preparation method of superfine aluminum hydroxide |
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| CN106986362A (en) * | 2017-04-12 | 2017-07-28 | 柳健康 | A kind of sodium aluminate solution high concentration is low admittedly containing one section of seeded precipitation technique |
| CN111410221B (en) * | 2020-03-26 | 2022-11-08 | 重庆市九龙万博新材料科技有限公司 | Be applicable to crystal seed processing apparatus among sodium aluminate production technology |
| CN112456524A (en) * | 2020-12-10 | 2021-03-09 | 沈阳铝镁设计研究院有限公司 | Method for treating fine seeds by using horizontal tilting disk filter |
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| EP0102403A1 (en) * | 1982-09-02 | 1984-03-14 | Alcoa Chemie GmbH | Process for the production of alumine |
| US4732742A (en) * | 1985-12-17 | 1988-03-22 | Aluminum Pechiney | Process for the production at a high level of productivity of aluminum trihydroxide in a high state of purity and with a median diameter of less than 4 micrometers, which is regulated as required |
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| CN103159241A (en) * | 2011-12-15 | 2013-06-19 | 贵阳铝镁设计研究院有限公司 | Two-section decomposition process for alumina production by Bayer process |
| CN105197970A (en) * | 2014-06-27 | 2015-12-30 | 沈阳铝镁设计研究院有限公司 | Method for improving two-stage decomposition effect |
| CN109592700A (en) * | 2018-12-18 | 2019-04-09 | 广西华银铝业有限公司 | A kind of method of alumina producer decomposing grading production continuous operation |
| CN112225237A (en) * | 2020-10-26 | 2021-01-15 | 洛阳莱茵希德特种材料有限公司 | Preparation method of superfine aluminum hydroxide |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1730398A (en) | 2006-02-08 |
| CN100372772C (en) | 2008-03-05 |
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