CN116462214A - Production system for preparing low-sodium alumina from metallurgical-grade alumina - Google Patents
Production system for preparing low-sodium alumina from metallurgical-grade alumina Download PDFInfo
- Publication number
- CN116462214A CN116462214A CN202310544779.2A CN202310544779A CN116462214A CN 116462214 A CN116462214 A CN 116462214A CN 202310544779 A CN202310544779 A CN 202310544779A CN 116462214 A CN116462214 A CN 116462214A
- Authority
- CN
- China
- Prior art keywords
- alumina
- sodium
- aluminum oxide
- metallurgical
- low
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 title claims abstract description 111
- 229910052708 sodium Inorganic materials 0.000 title claims abstract description 72
- 239000011734 sodium Substances 0.000 title claims abstract description 72
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 34
- 238000005406 washing Methods 0.000 claims abstract description 69
- 238000000034 method Methods 0.000 claims abstract description 57
- 230000008569 process Effects 0.000 claims abstract description 38
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 33
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 claims abstract description 31
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 claims abstract description 27
- 238000001914 filtration Methods 0.000 claims abstract description 25
- KKCBUQHMOMHUOY-UHFFFAOYSA-N sodium oxide Chemical compound [O-2].[Na+].[Na+] KKCBUQHMOMHUOY-UHFFFAOYSA-N 0.000 claims abstract description 23
- 229910001948 sodium oxide Inorganic materials 0.000 claims abstract description 23
- 238000000354 decomposition reaction Methods 0.000 claims abstract description 20
- ANBBXQWFNXMHLD-UHFFFAOYSA-N aluminum;sodium;oxygen(2-) Chemical compound [O-2].[O-2].[Na+].[Al+3] ANBBXQWFNXMHLD-UHFFFAOYSA-N 0.000 claims abstract description 15
- 229910001388 sodium aluminate Inorganic materials 0.000 claims abstract description 15
- 239000000243 solution Substances 0.000 claims abstract description 11
- 238000001035 drying Methods 0.000 claims abstract description 10
- 239000013078 crystal Substances 0.000 claims abstract description 6
- 239000002994 raw material Substances 0.000 claims abstract description 6
- 239000011550 stock solution Substances 0.000 claims abstract description 5
- 238000001816 cooling Methods 0.000 claims abstract 2
- 238000004806 packaging method and process Methods 0.000 claims abstract 2
- 239000000047 product Substances 0.000 claims description 43
- 239000012065 filter cake Substances 0.000 claims description 34
- 239000002002 slurry Substances 0.000 claims description 33
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims description 29
- 239000000706 filtrate Substances 0.000 claims description 27
- 239000007787 solid Substances 0.000 claims description 25
- 210000000582 semen Anatomy 0.000 claims description 22
- 239000003513 alkali Substances 0.000 claims description 19
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 10
- 238000005054 agglomeration Methods 0.000 claims description 10
- 230000002776 aggregation Effects 0.000 claims description 10
- 229910052710 silicon Inorganic materials 0.000 claims description 10
- 239000010703 silicon Substances 0.000 claims description 10
- 239000003518 caustics Substances 0.000 claims description 9
- 238000001704 evaporation Methods 0.000 claims description 9
- 230000008020 evaporation Effects 0.000 claims description 9
- 238000000926 separation method Methods 0.000 claims description 8
- 238000004131 Bayer process Methods 0.000 claims description 5
- 239000000919 ceramic Substances 0.000 claims description 4
- 238000004064 recycling Methods 0.000 claims description 4
- 239000011819 refractory material Substances 0.000 claims description 2
- 239000000758 substrate Substances 0.000 claims description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims 1
- 229910052782 aluminium Inorganic materials 0.000 claims 1
- 230000018044 dehydration Effects 0.000 claims 1
- 238000006297 dehydration reaction Methods 0.000 claims 1
- 239000002245 particle Substances 0.000 claims 1
- 230000009466 transformation Effects 0.000 claims 1
- 239000002253 acid Substances 0.000 abstract description 8
- 230000008901 benefit Effects 0.000 abstract description 5
- 239000007788 liquid Substances 0.000 abstract description 4
- 230000009286 beneficial effect Effects 0.000 abstract description 3
- 238000001354 calcination Methods 0.000 abstract 1
- 239000000463 material Substances 0.000 description 12
- 239000007789 gas Substances 0.000 description 4
- 238000002360 preparation method Methods 0.000 description 4
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 230000000996 additive effect Effects 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 230000002860 competitive effect Effects 0.000 description 1
- 238000005536 corrosion prevention Methods 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000029087 digestion Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000007667 floating Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- 238000004537 pulping Methods 0.000 description 1
- 238000011946 reduction process Methods 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 239000004753 textile Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- 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
- C01F7/30—Preparation of aluminium oxide or hydroxide by thermal decomposition or by hydrolysis or oxidation of aluminium compounds
-
- 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
- C01F7/021—After-treatment of oxides or hydroxides
-
- 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
-
- 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
- C01F7/44—Dehydration of aluminium oxide or hydroxide, i.e. all conversions of one form into another involving a loss of water
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/80—Compositional purity
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Abstract
The invention relates to a production system for preparing low-sodium alumina from metallurgical-grade alumina, which takes sodium aluminate refined liquid after leaf filtration as a decomposition stock solution, adopts a two-stage method seed crystal decomposition process, and obtains aluminum hydroxide after filtering and washing by cooling, adding seed crystal and the like to crystallize and separate out the aluminum hydroxide in the decomposition process of sodium aluminate solution; then calcining by adopting a roasting furnace to remove crystal water in aluminum hydroxide, thereby obtaining metallurgical-grade aluminum oxide; and then, taking metallurgical-grade aluminum oxide as a raw material, adopting a washing treatment process to further remove sodium oxide, and filtering, drying and packaging to finally obtain a low-sodium aluminum oxide product. The method does not add mineralizer, does not use acid washing process, does not have the problem of product pollution, and the prepared low-sodium aluminum oxide product has obvious quality advantage. The invention can simultaneously produce two different kinds of alumina products, and convert metallurgical grade products with low added value into special products with high added value, thereby being beneficial to enriching product structures of enterprises and increasing effective ways.
Description
Technical Field
The invention relates to the technical field of metallurgical-grade aluminum oxide and special aluminum oxide production, in particular to a production system for preparing low-sodium aluminum oxide from metallurgical-grade aluminum oxide.
Background
Low sodium alumina generally refers to alumina having a sodium oxide content of less than 0.1%, which is one of the specialty alumina products. The low-sodium alumina has the characteristics of high melting point, strong chemical inertia, good electrical insulation, high hardness and good wear resistance, can be used for various high-temperature resistant ceramic parts, wear resistant ceramic parts, textile ceramic parts, water valve plates, hair waving plates, electronic substrates, electric vacuum tubes, shaped and unshaped refractory materials and the like, and has very broad application prospects. The preparation methods of the low-sodium alumina are various, the technical route, the production cost and the product quality are different, and the research and development of the low-cost high-quality low-sodium alumina preparation process is always a focus of attention in the special alumina industry. The domestic metallurgical grade alumina has huge energy capacity, and the low-sodium alumina production line grafted on the alumina mass production flow has obvious cost advantages, not only has low energy consumption and less equipment investment, but also can absorb filtrate, does not generate industrial three wastes, and realizes the development of green circulation and low carbon.
Patent No. CN202210667423.3 discloses a low sodium alumina and a method for preparing the same, which comprises pre-roasting aluminum hydroxide, mixing and pulping the roasted alumina and water, and adding CO 2 And introducing neutral gas into the slurry to perform a neutralization reaction to obtain the low-sodium alumina. Patent number CN201010579645.7 proposes a method for reducing sodium oxide in alumina using carbon dioxide, which requires consumption of CO 2 The chemical reaction of the gas involves three phases of gas, liquid and solid, the production process is complex, and the subsequent addition of a sodium removing agent is required, so that the production cost is high, and the product quality is unstable.
Patent number CN202110189284.3 proposes a process for preparing ultra-low sodium alumina and a method for preparing ultra-low sodium alumina, which uses industrial alumina products as raw materials and is prepared by an acid washing treatment process. Acid is required to be added in the production process, so that the tank and the equipment are required to be subjected to acid corrosion prevention treatment, and the production cost is high; in addition, the residual acid also pollutes the product, and limits the application range of the product.
The method does not use CO 2 The gas and the acid solution are not added with any mineralizer and sodium removing agent in the whole production process, so that the production process is simpler, and the equipment investment can be effectively reduced. The low-sodium alumina prepared by the method is a safe and green product without pollution and residue, does not harm the subsequent production process, and is beneficial to improving and improving the quality of the terminal product.
Disclosure of Invention
Aiming at the problems of complex production process, large equipment investment, unstable product quality and the like in the prior method, the invention provides a production system for preparing low-sodium alumina from metallurgical-grade alumina.
The application provides a metallurgical grade aluminum oxide prepares production system of low sodium alumina, include:
s1, firstly, sodium aluminate semen after Bayer process leaf filtration operation is used as decomposition stock solution, and caustic alkali concentration and alpha of the semen are controlled by adjusting washing liquor k Meanwhile, the semen floating matters and the silicon quantity index are required to meet the requirements, and the product quality is strictly controlled from the source;
s2, conveying the sodium aluminate refined solution to a decomposing tank for two-section seed separation, wherein a variable-temperature decomposing system is adopted in the decomposing process, and coarse and fine seed crystals are respectively added to an attaching head tank and a long and large head tank; stirring in the whole process of decomposition to accelerate the decomposition speed; controlling agglomeration and decomposition time, carrying out product classification on decomposed aluminum hydroxide by adopting a cyclone, and conveying the obtained AH finished product slurry to a flat plate washing procedure;
s3, delivering the AH finished product slurry which is decomposed to a flat disc process, washing with water, filtering and washing to obtain an aluminum hydroxide filter cake with less than 0.005% of attached alkali, returning filtrate to an evaporation process, and recycling the filtrate in a Bayer process alumina production flow;
s4, delivering the aluminum hydroxide filter cake to a roasting furnace for roasting to obtain a metallurgical grade aluminum oxide product; then the slurry is sent to a slurry tank for slurry preparation; the pulped slurry is sent to a horizontal belt filter for washing and filtering, sodium oxide is further removed, and the sodium removal effect is ensured by controlling the adding proportion of washing water, so that a low-sodium alumina filter cake is obtained; the washing liquid returns to the aluminum hydroxide washing system and is used as washing water for recycling;
s5, drying the low-sodium alumina filter cake to remove the surface adhesive water, reducing the moisture content, and drying at 100-110 ℃ for 2-3 h; the dried low-sodium alumina is reduced by burning and the sodium oxide is respectively lower than 1 percent and 0.08 percent, and the low-sodium alumina can be sold as a low-sodium alumina product after being packaged.
Specifically, the concentration of caustic alkali in the semen stock solution is 120-140 g/L, alpha k The silicon quantity index is controlled to be 1.30-1.50, the silicon quantity index is required to be more than 200, and the content of suspended matters is less than 0.02g/L.
Specifically, the temperatures of the agglomeration head tank and the long head tank are respectively not lower than 80 ℃ and 65 ℃, and the solid contents are respectively not lower than 120g/L and 500g/L; the agglomeration period and the long period are respectively not less than 10 hours and 40 hours.
Specifically, the aluminum hydroxide with the growth of the decomposition and crystallization is graded by a cyclone, the decomposed finished product slurry is sent to a flat disc process, water washing, filtration and washing are carried out, an aluminum hydroxide filter cake with the alkali less than 0.005% is obtained, and the filtrate is returned to the evaporation process.
Specifically, the aluminum hydroxide is dehydrated in a roasting mode, and the temperature of a main furnace is 980-1050 ℃, so that a metallurgical grade aluminum oxide product with sodium oxide content lower than 0.28% is obtained.
Specifically, the metallurgical grade alumina is further sodium removed by adopting a washing treatment process, firstly, the alumina is prepared into slurry, wherein the temperature of a slurry tank is 50-70 ℃, the solid content is 300-400 g/L, the slurry time is 5-6 h, and the alumina slurry after the slurry preparation is sent to the next working procedure for filtering and washing.
Specifically, a horizontal belt filter is adopted to carry out liquid-solid separation on alumina slurry, the mass ratio of washing water to alumina is 30-60, the washing water temperature is 50-60 ℃, the total alkali alkalinity is less than 0.05g/L, a low-sodium alumina filter cake and filtrate are obtained, and the filtrate is used as metallurgical grade alumina washing water for recycling.
Specifically, the low-sodium alumina filter cake is dehydrated by a dryer, the temperature is 100-110 ℃ and the time is 2-3 hours; the dried low-sodium alumina is reduced by burning and the sodium oxide is respectively lower than 1 percent and 0.08 percent, and the low-sodium alumina is sold in a ton package mode after being packaged.
Compared with the prior art, the invention has the following beneficial effects:
1. the invention prepares metallurgical grade alumina products by taking sodium aluminate seminal fluid after Bayer process leaf filtration as stock solution and adjusting seminal fluid index and optimizing decomposition process, has strong adaptability to digestion process and ore type, and has wide primary raw material sources.
2. The invention uses metallurgical grade alumina as raw material, adopts washing technology to reduce sodium oxide, does not add any additive, does not use acid solution for washing, has lower requirements on equipment, is easy to graft on the Bayer process production flow, can recycle washing liquor, and has competitive advantage in production cost.
3. The invention adopts a physical washing sodium reduction process, does not introduce foreign impurities, does not have additive residues, does not have acid pollution, has stable physical and chemical properties of low-sodium alumina, has obvious product quality advantages, and is suitable for being used as a raw material of middle-high-end products.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the drawings that are needed in the embodiments or the description of the prior art will be briefly described below, it will be obvious that the drawings in the following description are some embodiments of the present invention, and that other drawings can be obtained according to these drawings without inventive effort to a person skilled in the art.
FIG. 1 is a flow chart of a production system for preparing low sodium alumina from metallurgical grade alumina.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
A production system for preparing low sodium alumina from metallurgical grade alumina, the examples being as follows:
example 1:
caustic concentration of sodium aluminate semen 120g/L, alpha k 1.30, silicon number index 200, suspended matters 0.02g/L. Agglomeration and growth time of semen in the decomposition process are respectively 10 hours and 40 hours; the temperature of the first attaching groove and the long first growing groove are respectively 80 ℃ and 65 ℃, and the solid content is respectively 120g/L and 500g/L. The discharged material of the decomposer is graded by a cyclone, and finished product slurry is sent to a flat disc process for washing, filtering and washing to obtain aluminum hydroxide with 0.005 percent of attached alkaliAnd (5) returning the filter cake and the filtrate to the evaporation process. And removing water from the aluminum hydroxide filter cake in a roasting mode, and obtaining a metallurgical grade aluminum oxide product with sodium oxide content of 0.28% at the temperature of 980 ℃ of a main furnace. And (3) further removing sodium from the metallurgical-grade aluminum oxide by adopting washing treatment, wherein the temperature of a slurrying tank is 50 ℃, the solid content is 300g/L, the slurrying time is 5 hours, and the materials are sent to the next working procedure for filtering and washing after slurrying. And (3) carrying out liquid-solid separation on the alumina slurry by adopting a horizontal belt filter, wherein the mass ratio of washing water to alumina is 30, the temperature is 50 ℃, the total alkali alkalinity is 0.5g/L, and a low-sodium alumina filter cake and filtrate are obtained, and the filtrate is recycled as metallurgical grade alumina washing water. And (3) drying the low-sodium alumina filter cake at the temperature of 100 ℃ for 2 hours to obtain a low-sodium alumina product with the sodium oxide content of 0.08%.
Example 2:
caustic concentration of sodium aluminate semen 130g/L, alpha k 1.35, silicon number index 220, suspended matter 0.015g/L. Agglomeration and growth time of semen in the decomposition process are respectively 10 hours and 40 hours; the temperature of the first attaching groove and the long first growing groove are respectively 80 ℃ and 65 ℃, and the solid content is respectively 150g/L and 550g/L. The discharged materials of the decomposer are graded by a cyclone, the finished product slurry is sent to a flat disc process for washing, filtering and washing to obtain an aluminum hydroxide filter cake with 0.005% of attached alkali, and the filtrate is returned to the evaporation process. And removing water from the aluminum hydroxide filter cake in a roasting mode, and obtaining a metallurgical grade aluminum oxide product with sodium oxide content of 0.26% at the temperature of 1000 ℃ of a main furnace. And (3) further removing sodium from the metallurgical-grade aluminum oxide by adopting washing treatment, wherein the temperature of a slurrying tank is 60 ℃, the solid content is 350g/L, the slurrying time is 5 hours, and the materials are sent to the next working procedure for filtering and washing after slurrying. And (3) carrying out liquid-solid separation on the alumina slurry by adopting a horizontal belt filter, wherein the mass ratio of washing water to alumina is 40, the temperature is 60 ℃, the total alkali alkalinity is 0.5g/L, and a low-sodium alumina filter cake and filtrate are obtained, and the filtrate is recycled as metallurgical grade alumina washing water. And (3) drying the low-sodium alumina filter cake at the temperature of 100 ℃ for 2 hours to obtain a low-sodium alumina product with the sodium oxide content of 0.06%.
Example 3:
caustic concentration of sodium aluminate semen 135g/L, alpha k 1.40, silicon number index 250, suspended matters 0.015g/L. Agglomeration and growth time of semen in the decomposition process are respectively 12h and 45h; head attaching groove and long and largeThe first tank temperature is 80 ℃ and 65 ℃ respectively, and the solid content is 120g/L and 500g/L respectively. The discharged materials of the decomposer are graded by a cyclone, the finished product slurry is sent to a flat disc process for washing, filtering and washing to obtain an aluminum hydroxide filter cake with 0.005% of attached alkali, and the filtrate is returned to the evaporation process. And removing water from the aluminum hydroxide filter cake in a roasting mode, and obtaining a metallurgical grade aluminum oxide product with 0.25% of sodium oxide content at the temperature of 1000 ℃ of a main furnace. And (3) further removing sodium from the metallurgical-grade aluminum oxide by adopting washing treatment, wherein the temperature of a slurrying tank is 55 ℃, the solid content is 350g/L, the slurrying time is 6 hours, and the materials are sent to the next working procedure for filtering and washing after slurrying. And (3) carrying out liquid-solid separation on the alumina slurry by adopting a horizontal belt filter, wherein the mass ratio of washing water to alumina is 35, the temperature is 60 ℃, the total alkali alkalinity is 0.5g/L, and a low-sodium alumina filter cake and filtrate are obtained, and the filtrate is recycled as metallurgical grade alumina washing water. And (3) drying the low-sodium alumina filter cake at the temperature of 100 ℃ for 2 hours to obtain a low-sodium alumina product with the sodium oxide content of 0.08%.
Example 4:
caustic concentration of sodium aluminate semen 130g/L, alpha k 1.45, silicon number index 230, suspended matter 0.015g/L. Agglomeration and growth time of semen in the decomposition process are respectively 12h and 45h; the temperature of the first attaching groove and the long first growing groove are 81 ℃ and 65 ℃ respectively, and the solid content is 150g/L and 520g/L respectively. The discharged materials of the decomposer are graded by a cyclone, the finished product slurry is sent to a flat disc process for washing, filtering and washing to obtain an aluminum hydroxide filter cake with 0.005% of attached alkali, and the filtrate is returned to the evaporation process. The water is removed from the aluminum hydroxide filter cake by adopting a roasting mode, and the main furnace temperature is 1050 ℃, so that a metallurgical grade aluminum oxide product with the sodium oxide content of 0.24% is obtained. And (3) further removing sodium from the metallurgical-grade aluminum oxide by adopting washing treatment, wherein the temperature of a slurrying tank is 60 ℃, the solid content is 350g/L, the slurrying time is 5 hours, and the materials are sent to the next working procedure for filtering and washing after slurrying. And (3) carrying out liquid-solid separation on the alumina slurry by adopting a horizontal belt filter, wherein the mass ratio of washing water to alumina is 60, the temperature is 60 ℃, the total alkali alkalinity is 0.5g/L, and a low-sodium alumina filter cake and filtrate are obtained, and the filtrate is recycled as metallurgical grade alumina washing water. And (3) drying the low-sodium alumina filter cake at the temperature of 100 ℃ for 2 hours to obtain a low-sodium alumina product with the sodium oxide content of 0.05%.
Example 5:
caustic concentration of sodium aluminate semen 125g/L, alpha k 1.42, silicon number index 220, suspended matter 0.01g/L. Agglomeration and growth time of semen in the decomposition process are respectively 10h and 45h; the temperature of the first attaching groove and the long first growing groove are respectively 82 ℃ and 68 ℃, and the solid content is respectively 130g/L and 530g/L. The discharged materials of the decomposer are graded by a cyclone, the finished product slurry is sent to a flat disc process for washing, filtering and washing to obtain an aluminum hydroxide filter cake with 0.005% of attached alkali, and the filtrate is returned to the evaporation process. And removing water from the aluminum hydroxide filter cake in a roasting mode, and obtaining a metallurgical grade aluminum oxide product with sodium oxide content of 0.23% at the temperature of 1020 ℃ of a main furnace. And (3) further removing sodium from the metallurgical-grade aluminum oxide by adopting washing treatment, wherein the temperature of a slurrying tank is 55 ℃, the solid content is 330g/L, the slurrying time is 5 hours, and the materials are sent to the next working procedure for filtering and washing after slurrying. And (3) carrying out liquid-solid separation on the alumina slurry by adopting a horizontal belt filter, wherein the mass ratio of washing water to alumina is 55, the temperature is 55 ℃, the total alkali alkalinity is 0.5g/L, and a low-sodium alumina filter cake and filtrate are obtained, and the filtrate is recycled as metallurgical grade alumina washing water. And (3) drying the low-sodium alumina filter cake at the temperature of 100 ℃ for 2 hours to obtain a low-sodium alumina product with the sodium oxide content of 0.05%.
Example 6:
caustic concentration of sodium aluminate semen 140g/L, alpha k 1.45, silicon number index 250, suspended matters 0.02g/L. Agglomeration and growth time of semen in the decomposition process are respectively 12h and 40h; the temperature of the first attaching groove and the long first growing groove are respectively 80 ℃, 65 ℃ and the solid content is respectively 150g/L and 560g/L. The discharged materials of the decomposer are graded by a cyclone, the finished product slurry is sent to a flat disc process for washing, filtering and washing to obtain an aluminum hydroxide filter cake with 0.005% of attached alkali, and the filtrate is returned to the evaporation process. And removing water from the aluminum hydroxide filter cake in a roasting mode, and obtaining a metallurgical grade aluminum oxide product with sodium oxide content of 0.26% at the temperature of 1030 ℃ of the main furnace. And (3) further removing sodium from the metallurgical-grade aluminum oxide by adopting washing treatment, wherein the temperature of a slurrying tank is 65 ℃, the solid content is 380g/L, the slurrying time is 6 hours, and the materials are sent to the next working procedure for filtering and washing after slurrying. Separating liquid and solid of alumina slurry by using a horizontal belt filter, wherein the mass ratio of washing water to alumina is 50, the temperature is 60 ℃, the total alkali alkalinity is 0.5g/L, and obtaining a low-sodium alumina filter cake and filtrate, wherein the filtrate is used as metallurgical grade alumina washing waterRecycling and reusing. And (3) drying the low-sodium alumina filter cake at the temperature of 100 ℃ for 2 hours to obtain a low-sodium alumina product with the sodium oxide content of 0.06%.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. A production system for preparing low-sodium alumina from metallurgical-grade alumina is characterized in that: using sodium aluminate refined solution as a decomposition stock solution, adopting a two-stage seed crystal decomposition process, and obtaining a metallurgical grade alumina product through the working procedures of particle size classification, aluminum hydroxide filtering washing, roasting dehydration and the like; and then, using metallurgical-grade aluminum oxide as a raw material, and carrying out links such as washing treatment process, filtering washing, drying, packaging and the like to prepare a low-sodium aluminum oxide product with sodium oxide content less than 0.08%, thereby realizing product transformation and upgrading.
2. The production system for preparing low sodium alumina from metallurgical grade aluminum oxide of claim 1, wherein: the sodium aluminate semen is the semen after the Bayer process leaf filtration operation, the concentration of caustic alkali in the semen is 120-140 g/L, and alpha is the same as that of the sodium aluminate semen k The silicon quantity index is more than 200 and the content of suspended matters is less than 0.02g/L between 1.30 and 1.50.
3. The production system for preparing low sodium alumina from metallurgical grade aluminum oxide of claim 1, wherein: the sodium aluminate refined solution adopts a two-section seed crystal decomposition process, and the decomposition process adopts a variable temperature decomposition system of rapid cooling of a wide plate heat exchanger; the agglomeration period and the long period are respectively not less than 10 hours and 40 hours; the temperature of the first attaching groove and the long first growing groove is not lower than 80 ℃ and 65 ℃ respectively, and the solid content is not lower than 120g/L and 500g/L respectively.
4. The production system for preparing low sodium alumina from metallurgical grade aluminum oxide of claim 1, wherein: the aluminum hydroxide with the decomposed and crystallized growth is graded by a cyclone, the decomposed finished product slurry is sent to a flat disc process, water washing, filtering and washing are carried out, an aluminum hydroxide filter cake with the attached alkali less than 0.005% is obtained, and the filtrate is returned to the evaporation process.
5. The production system for preparing low sodium alumina from metallurgical grade aluminum oxide of claim 1, wherein: the aluminum hydroxide is roasted to remove water, and the temperature of the main furnace is 980-1050 ℃, so that a metallurgical grade aluminum oxide product with sodium oxide content lower than 0.28% is obtained.
6. The production system for preparing low sodium alumina from metallurgical grade aluminum oxide of claim 1, wherein: the metallurgical grade alumina is further treated by a washing treatment process to remove sodium, firstly, the alumina is prepared into slurry, wherein the temperature of a slurry tank is 50-70 ℃, the solid content of the slurry tank is 300-400 g/L, the slurry time is 5-6 h, and the alumina after the slurry is filtered and washed in the next working procedure.
7. The production system for preparing low sodium alumina from metallurgical grade aluminum oxide of claim 1, wherein: the method adopts a horizontal belt filter to carry out liquid-solid separation on alumina slurry, the mass ratio of washing water to alumina is 30-60, the washing water temperature is 50-60 ℃, the total alkali alkalinity is less than 0.05g/L, a low-sodium alumina filter cake and filtrate are obtained, and the filtrate is used as metallurgical grade alumina washing water for recycling.
8. The production system for preparing low sodium alumina from metallurgical grade aluminum oxide of claim 1, wherein: the low-sodium alumina filter cake is dehydrated by a dryer at the temperature of 100-110 ℃ for 2-3 h.
9. The production system for preparing low sodium alumina from metallurgical grade aluminum oxide of claim 1, wherein: the dried low-sodium alumina is burnt down to be less than 1%, the sodium oxide content is less than 0.08%, and the low-sodium alumina is sold in a ton package mode after being packaged.
10. The production system for preparing low sodium alumina from metallurgical grade aluminum oxide of claim 1, wherein: the metallurgical grade alumina is washed to obtain low sodium special alumina product, and may be used widely in refractory material, automobile spark plug, electronic substrate, wear resistant ceramic and other non-aluminum fields.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310544779.2A CN116462214A (en) | 2023-05-12 | 2023-05-12 | Production system for preparing low-sodium alumina from metallurgical-grade alumina |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310544779.2A CN116462214A (en) | 2023-05-12 | 2023-05-12 | Production system for preparing low-sodium alumina from metallurgical-grade alumina |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116462214A true CN116462214A (en) | 2023-07-21 |
Family
ID=87179017
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310544779.2A Pending CN116462214A (en) | 2023-05-12 | 2023-05-12 | Production system for preparing low-sodium alumina from metallurgical-grade alumina |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116462214A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1020790A (en) * | 1962-06-14 | 1966-02-23 | Kaiser Aluminium Chem Corp | Improvements in or relating to alumina material |
| CN1911810A (en) * | 2005-06-23 | 2007-02-14 | 中国铝业股份有限公司 | Method for producing sandy aluminium oxide by sintering method decomposition |
| CN108751242A (en) * | 2018-08-27 | 2018-11-06 | 三门峡义翔铝业有限公司 | A kind of low sodium alumina decomposition technique and low sodium alumina |
| CN115092947A (en) * | 2022-07-29 | 2022-09-23 | 山东理工大学 | Sodium removing method for high-purity aluminum hydroxide/aluminum oxide |
-
2023
- 2023-05-12 CN CN202310544779.2A patent/CN116462214A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1020790A (en) * | 1962-06-14 | 1966-02-23 | Kaiser Aluminium Chem Corp | Improvements in or relating to alumina material |
| CN1911810A (en) * | 2005-06-23 | 2007-02-14 | 中国铝业股份有限公司 | Method for producing sandy aluminium oxide by sintering method decomposition |
| CN108751242A (en) * | 2018-08-27 | 2018-11-06 | 三门峡义翔铝业有限公司 | A kind of low sodium alumina decomposition technique and low sodium alumina |
| CN115092947A (en) * | 2022-07-29 | 2022-09-23 | 山东理工大学 | Sodium removing method for high-purity aluminum hydroxide/aluminum oxide |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106587116B (en) | A kind of method for extracting lithium carbonate and aluminium hydroxide using lepidolite and flyash | |
| CN103318925B (en) | Method for producing high-purity lithium carbonate by using lithium concentrate | |
| CN104495899B (en) | A kind of carbide slag and flyash work in coordination with the method for recycling | |
| CN103950956B (en) | A kind of triphane concentrate Production By Sulfuric Acid Process Quilonum Retard technique | |
| CN101792187B (en) | Method for producing feed grade ferrous sulfate monohydrate from titanium pigment waste acid condensed slag | |
| CN102249253A (en) | Method for producing aluminum oxide and co-producing active calcium silicate through high-alumina fly ash | |
| CN102897810B (en) | Method for producing aluminum oxide by using fly ash | |
| CN102583477A (en) | Comprehensive utilization method of high-ferrum and low-grade bauxite | |
| CN109824072B (en) | Method for preparing alumina by using industrial waste residues | |
| CN113428882A (en) | Method for preparing battery-grade lithium carbonate from spodumene | |
| CN112320826A (en) | Method for jointly preparing high-purity magnesium oxide and refined ammonium sulfate by using low-grade magnesite | |
| CN106315640B (en) | Handle the high method for steaming mother liquor in alumina producing | |
| CN112813275B (en) | Method for inhibiting reaction loss of metal aluminum in aluminum ash wet-process aluminum extraction process | |
| CN107827131B (en) | Method for producing aluminum oxide by Bayer process | |
| CN106517277A (en) | Method for producing aluminum oxide co-production silicon fertilizer from bauxite | |
| CN116462214A (en) | Production system for preparing low-sodium alumina from metallurgical-grade alumina | |
| CN110775955B (en) | Method for treating anode carbon slag of aluminum electrolysis cell by using NaOH molten salt method | |
| US4031182A (en) | Recovery of aluminum from alunite ore using acid leach to purify the residue for bayer leach | |
| CN1299992C (en) | High purity magnesium oxide cleaning production method | |
| RU2494965C1 (en) | Method of processing bauxites into alumina | |
| CN112520764A (en) | Process for producing lithium hydroxide by mixing salt lake ore and lithium polymer | |
| CN110510645A (en) | A kind of method and system cleaning loop production magnesium hydroxide | |
| CN112760483B (en) | Method for metal smelting separation and co-production of high-purity calcium product and high-purity calcium product prepared by method | |
| US4332778A (en) | Non-evaporative process for the production of aluminum sulfate | |
| CN113716577B (en) | Desiliconization method of kaolin-containing silicon-aluminum-containing raw material |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |