CN113371745A - System and method for producing high-purity alumina by recycling fly ash - Google Patents
System and method for producing high-purity alumina by recycling fly ash Download PDFInfo
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- CN113371745A CN113371745A CN202110427862.2A CN202110427862A CN113371745A CN 113371745 A CN113371745 A CN 113371745A CN 202110427862 A CN202110427862 A CN 202110427862A CN 113371745 A CN113371745 A CN 113371745A
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- reactor
- desiliconization
- fly ash
- purification
- hydroxide
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- 239000010881 fly ash Substances 0.000 title claims abstract description 67
- 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 44
- 238000004064 recycling Methods 0.000 title claims abstract description 18
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 14
- 238000000746 purification Methods 0.000 claims abstract description 76
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 66
- 239000002253 acid Substances 0.000 claims abstract description 55
- 238000002386 leaching Methods 0.000 claims abstract description 53
- 238000001354 calcination Methods 0.000 claims abstract description 47
- 235000014413 iron hydroxide Nutrition 0.000 claims abstract description 47
- NCNCGGDMXMBVIA-UHFFFAOYSA-L iron(ii) hydroxide Chemical compound [OH-].[OH-].[Fe+2] NCNCGGDMXMBVIA-UHFFFAOYSA-L 0.000 claims abstract description 47
- 238000006386 neutralization reaction Methods 0.000 claims abstract description 37
- 230000004913 activation Effects 0.000 claims abstract description 34
- 238000003837 high-temperature calcination Methods 0.000 claims abstract description 25
- 230000003213 activating effect Effects 0.000 claims abstract description 20
- 238000004062 sedimentation Methods 0.000 claims description 57
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 45
- 239000000378 calcium silicate Substances 0.000 claims description 39
- 229910052918 calcium silicate Inorganic materials 0.000 claims description 39
- OYACROKNLOSFPA-UHFFFAOYSA-N calcium;dioxido(oxo)silane Chemical compound [Ca+2].[O-][Si]([O-])=O OYACROKNLOSFPA-UHFFFAOYSA-N 0.000 claims description 39
- 239000002244 precipitate Substances 0.000 claims description 34
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 claims description 30
- 239000006228 supernatant Substances 0.000 claims description 30
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 28
- 238000007599 discharging Methods 0.000 claims description 26
- 239000000047 product Substances 0.000 claims description 25
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 claims description 24
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 claims description 24
- 239000007788 liquid Substances 0.000 claims description 24
- 238000000926 separation method Methods 0.000 claims description 23
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 20
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 claims description 20
- 238000006243 chemical reaction Methods 0.000 claims description 19
- 229960004887 ferric hydroxide Drugs 0.000 claims description 19
- IEECXTSVVFWGSE-UHFFFAOYSA-M iron(3+);oxygen(2-);hydroxide Chemical compound [OH-].[O-2].[Fe+3] IEECXTSVVFWGSE-UHFFFAOYSA-M 0.000 claims description 19
- 230000035484 reaction time Effects 0.000 claims description 19
- 239000000243 solution Substances 0.000 claims description 18
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 claims description 16
- 239000000292 calcium oxide Substances 0.000 claims description 15
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 claims description 15
- 229910000029 sodium carbonate Inorganic materials 0.000 claims description 15
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 15
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 claims description 13
- 239000000843 powder Substances 0.000 claims description 13
- 239000012629 purifying agent Substances 0.000 claims description 12
- 238000000227 grinding Methods 0.000 claims description 11
- 239000002245 particle Substances 0.000 claims description 11
- 235000017550 sodium carbonate Nutrition 0.000 claims description 11
- 230000003472 neutralizing effect Effects 0.000 claims description 9
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 8
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 claims description 8
- 229910017604 nitric acid Inorganic materials 0.000 claims description 8
- 235000006408 oxalic acid Nutrition 0.000 claims description 8
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 claims description 8
- 239000011259 mixed solution Substances 0.000 claims description 7
- 235000021110 pickles Nutrition 0.000 claims description 6
- UIIMBOGNXHQVGW-DEQYMQKBSA-M Sodium bicarbonate-14C Chemical compound [Na+].O[14C]([O-])=O UIIMBOGNXHQVGW-DEQYMQKBSA-M 0.000 claims description 4
- 239000012190 activator Substances 0.000 claims description 4
- 238000004090 dissolution Methods 0.000 claims description 4
- 239000011736 potassium bicarbonate Substances 0.000 claims description 4
- 235000015497 potassium bicarbonate Nutrition 0.000 claims description 4
- 229910000028 potassium bicarbonate Inorganic materials 0.000 claims description 4
- 229910000027 potassium carbonate Inorganic materials 0.000 claims description 4
- 235000011181 potassium carbonates Nutrition 0.000 claims description 4
- TYJJADVDDVDEDZ-UHFFFAOYSA-M potassium hydrogencarbonate Chemical compound [K+].OC([O-])=O TYJJADVDDVDEDZ-UHFFFAOYSA-M 0.000 claims description 4
- 230000001376 precipitating effect Effects 0.000 claims description 4
- 238000007873 sieving Methods 0.000 claims description 4
- 229910000030 sodium bicarbonate Inorganic materials 0.000 claims description 4
- 235000017557 sodium bicarbonate Nutrition 0.000 claims description 4
- 239000007795 chemical reaction product Substances 0.000 claims description 3
- 238000010979 pH adjustment Methods 0.000 claims 1
- 238000000605 extraction Methods 0.000 abstract description 18
- 239000002910 solid waste Substances 0.000 abstract description 5
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 32
- 239000000741 silica gel Substances 0.000 description 16
- 229910002027 silica gel Inorganic materials 0.000 description 16
- 238000000034 method Methods 0.000 description 15
- 230000008569 process Effects 0.000 description 12
- 229910052782 aluminium Inorganic materials 0.000 description 10
- 239000000203 mixture Substances 0.000 description 10
- 239000000126 substance Substances 0.000 description 9
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 8
- 229910052593 corundum Inorganic materials 0.000 description 8
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 8
- 229910052710 silicon Inorganic materials 0.000 description 8
- 239000010703 silicon Substances 0.000 description 8
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 7
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical group [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 7
- 239000000920 calcium hydroxide Substances 0.000 description 7
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 7
- 239000000377 silicon dioxide Substances 0.000 description 7
- 229910001845 yogo sapphire Inorganic materials 0.000 description 7
- KKCBUQHMOMHUOY-UHFFFAOYSA-N Na2O Inorganic materials [O-2].[Na+].[Na+] KKCBUQHMOMHUOY-UHFFFAOYSA-N 0.000 description 5
- 229910052681 coesite Inorganic materials 0.000 description 5
- 229910052906 cristobalite Inorganic materials 0.000 description 5
- 239000002274 desiccant Substances 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000012535 impurity Substances 0.000 description 5
- 238000005259 measurement Methods 0.000 description 5
- 229910052682 stishovite Inorganic materials 0.000 description 5
- 229910052905 tridymite Inorganic materials 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 description 4
- 238000009413 insulation Methods 0.000 description 4
- 229910052863 mullite Inorganic materials 0.000 description 4
- 229910052664 nepheline Inorganic materials 0.000 description 4
- 239000010434 nepheline Substances 0.000 description 4
- 238000004806 packaging method and process Methods 0.000 description 4
- 239000013049 sediment Substances 0.000 description 4
- 235000012239 silicon dioxide Nutrition 0.000 description 4
- 239000003513 alkali Substances 0.000 description 3
- 239000000084 colloidal system Substances 0.000 description 3
- 238000011084 recovery Methods 0.000 description 3
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 3
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- -1 aluminum ions Chemical class 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 239000001110 calcium chloride Substances 0.000 description 2
- 229910001628 calcium chloride Inorganic materials 0.000 description 2
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 2
- 229910001634 calcium fluoride Inorganic materials 0.000 description 2
- 239000003245 coal Substances 0.000 description 2
- 239000010883 coal ash Substances 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000005457 optimization Methods 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 238000010992 reflux Methods 0.000 description 2
- 238000012216 screening Methods 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 238000010183 spectrum analysis Methods 0.000 description 2
- 238000004876 x-ray fluorescence Methods 0.000 description 2
- 229910020489 SiO3 Inorganic materials 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 239000002956 ash Substances 0.000 description 1
- 239000004566 building material Substances 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 159000000007 calcium salts Chemical class 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000010431 corundum Substances 0.000 description 1
- XLYOFNOQVPJJNP-ZSJDYOACSA-N heavy water Substances [2H]O[2H] XLYOFNOQVPJJNP-ZSJDYOACSA-N 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 238000012803 optimization experiment Methods 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229910001483 soda nepheline Inorganic materials 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Images
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
- C01F7/04—Preparation of alkali metal aluminates; Aluminium oxide or hydroxide therefrom
- C01F7/08—Preparation of alkali metal aluminates; Aluminium oxide or hydroxide therefrom by treating aluminous minerals with sodium carbonate, e.g. sinter processes
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/113—Silicon oxides; Hydrates thereof
- C01B33/12—Silica; Hydrates thereof, e.g. lepidoic silicic acid
- C01B33/14—Colloidal silica, e.g. dispersions, gels, sols
- C01B33/141—Preparation of hydrosols or aqueous dispersions
- C01B33/142—Preparation of hydrosols or aqueous dispersions by acidic treatment of silicates
- C01B33/143—Preparation of hydrosols or aqueous dispersions by acidic treatment of silicates of aqueous solutions of silicates
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/20—Silicates
- C01B33/24—Alkaline-earth metal silicates
-
- 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
- C01F7/441—Dehydration of aluminium oxide or hydroxide, i.e. all conversions of one form into another involving a loss of water by calcination
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G49/00—Compounds of iron
- C01G49/02—Oxides; Hydroxides
-
- 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
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Dispersion Chemistry (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
- Processing Of Solid Wastes (AREA)
- Compounds Of Iron (AREA)
Abstract
The invention relates to a system and a method for producing high-purity alumina by recycling fly ash, wherein the system comprises a grinder, a pre-desiliconization reactor, an activation calcination reactor, an acid leaching reactor, an iron hydroxide purification reactor, a neutralization reactor and a high-temperature calcination reactor which are sequentially connected along the direction of extracting alumina, wherein the pre-desiliconization reactor is also connected with a pre-desiliconization agent doser, the activation calcination reactor is also connected with an activating agent doser, the acid leaching reactor is also connected with an acid leaching solution doser, the iron hydroxide purification reactor is also connected with an iron hydroxide purification agent doser, and the neutralization reactor is also connected with a neutralizer doser. Compared with the prior art, the invention realizes the comprehensive utilization of the fly ash, simultaneously realizes the extraction of the high-purity alumina and the fractional purification of impurity-removed products, and really realizes the concept of solid waste recycling.
Description
Technical Field
The invention belongs to the technical field of environmental protection, and relates to a system and a method for producing high-purity alumina by recycling fly ash.
Background
The fly ash is a key point for environmental protection due to complex components and difficult treatment and disposal, but meanwhile, the fly ash is used as a potential resource due to unique physicochemical properties and rich in various valuable metal elements, and therefore reasonable resource utilization is urgently needed. At present, the fly ash is applied to the production fields of building materials, ceramics and the like, but the high-valued utilization rate is low. In recent years, the extraction of valuable elements in fly ash has been taken as a high-value utilization way, and becomes a research hotspot of domestic and foreign scholars. Especially, the extraction of aluminum can not only solve the problem of the accumulation of the fly ash, but also effectively utilize a large amount of aluminum resources in the ash. In the extraction process, because the alumina in the fly ash mainly exists in the form of stable crystalline substances such as mullite, corundum and the like, the SiO in the fly ash is difficult to directly destroy by adopting a common extraction process2-Al2O3Bonds and mullite structure. In addition, the phase composition of the fly ash is extremely complex, so the extraction process is simpleThe impurity removal process is also to be improved.
Disclosure of Invention
The invention aims to provide a system and a method for producing high-purity alumina by recycling fly ash, which realize the extraction of the high-purity alumina and the fractional purification of impurity-removed products while realizing the comprehensive utilization of the fly ash and really realize the concept of recycling solid wastes.
The purpose of the invention can be realized by the following technical scheme:
one of the technical schemes of the invention provides a system for producing high-purity alumina from fly ash resources, which comprises a grinder, a pre-desiliconization reactor, an activation calcination reactor, an acid leaching reactor, an iron hydroxide purification reactor, a neutralization reactor and a high-temperature calcination reactor which are sequentially connected along the direction of extracting alumina, wherein the pre-desiliconization reactor is also connected with a pre-desiliconization agent doser, the activation calcination reactor is also connected with an activating agent doser, the acid leaching reactor is also connected with an acid leaching solution doser, the iron hydroxide purification reactor is also connected with an iron hydroxide purification agent doser, and the neutralization reactor is also connected with a neutralizer doser.
Further, a liquid outlet of the pre-desiliconization reactor is also connected with a calcium silicate purification reactor, the calcium silicate purification reactor is also connected with a silicon removing agent doser, and a liquid outlet of the calcium silicate purification reactor is also connected with the pre-desiliconization reactor in a returning way. Furthermore, a second sedimentation tank is arranged between the calcium silicate purification reactor and the pre-desilication reactor.
Furthermore, a screen machine is arranged between the grinder and the pre-desilication reactor, wherein a coarse powder outlet of the screen machine is also connected with an inlet of the grinder in a returning way.
Further, along the direction of extracting the alumina, a first sedimentation tank is arranged between the pre-desilication reactor and the activation calcination reactor, a third sedimentation tank is arranged between the acid leaching reactor and the ferric hydroxide purification reactor, a fourth sedimentation tank is arranged between the ferric hydroxide purification reactor and the neutralization reactor, and a fifth sedimentation tank is arranged between the neutralization reactor and the high-temperature calcination reactor.
Further, the liquid outlet of the neutralization reactor is also connected with the inlet of the ferric hydroxide purification reactor in a return mode.
The second technical scheme of the invention provides a method for producing high-purity alumina by recycling fly ash, which comprises the following steps:
(1) adding the fly ash to be treated into a grinder for grinding treatment, sieving to obtain fine powder particles, discharging the fine powder particles into a pre-desiliconization reactor, adding a pre-desiliconization agent for pre-desiliconization treatment, and discharging precipitates into an activation calcination reactor after solid-liquid separation of sludge-water mixed liquid after the treatment;
(2) adding an activating agent into the activation calcination reactor, performing activation calcination treatment, and discharging the obtained calcination product into an acid leaching reactor;
(3) adding acid leaching solution into the acid leaching reactor for acid leaching reaction, settling and separating the obtained reaction product, and discharging the supernatant into an iron hydroxide purification reactor;
(4) adding an iron hydroxide purifying agent into the iron hydroxide purifying reactor for purification treatment, precipitating and separating the treated mixed solution, and continuously discharging the obtained supernatant into a neutralization reactor;
(5) adding a neutralizing agent into the neutralization reactor to continuously adjust the pH, then settling and separating to obtain an aluminum hydroxide precipitate, and discharging the aluminum hydroxide precipitate into the high-temperature calcination reactor;
(6) and (3) carrying out high-temperature calcination on the aluminum hydroxide precipitate fed into the high-temperature calcination reactor to obtain the high-purity aluminum oxide.
Further, in the step (1), the reaction time of the pre-desiliconization treatment is 30-1000 min.
Further, in the step (2), the temperature of the activation calcination is 100-1500 ℃, and the time is 10-500 min.
Further, in the step (3), the temperature of the acid dissolution reaction is 25-100 ℃, and the time is 30-600 min.
Further, in the step (4), the time of the purification treatment is 30-500 min.
Further, in the step (6), the temperature of the high-temperature calcination is 400-.
Further, the pre-desiliconization agent is one or more of sodium hydroxide, calcium oxide or potassium hydroxide.
Further, the activating agent is one or more of sodium carbonate, sodium bicarbonate, potassium carbonate or potassium bicarbonate, and the adding amount of the activating agent is 10-300 g/L.
Further, the pickle liquor is one or more of hydrochloric acid, sulfuric acid, nitric acid or oxalic acid.
Further, the iron hydroxide purifying agent is one or more of sodium hydroxide, potassium hydroxide, calcium oxide, sodium bicarbonate or sodium carbonate.
Further, the neutralizing agent is one or more of hydrochloric acid, sulfuric acid, nitric acid or oxalic acid.
Further, in the step (1), the supernatant obtained by carrying out solid-liquid separation on the sludge-water mixed solution is subjected to desiliconization and then returns to the inlet of the pre-desiliconization reactor.
Further, in the step (2), the supernatant obtained after adjusting the pH and settling separation in the neutralization reactor is also refluxed to the inlet of the ferric hydroxide purification reactor.
Compared with the prior art, the invention has the following advantages:
(1) the process has strong universality, can extract alumina by high-value utilization aiming at the circulating fluidized bed fly ash or pulverized coal furnace fly ash, and the extraction rate of the alumina is not lower than 86 percent.
(2) The process realizes the high-efficiency removal, separation and purification of impurities through the processes of pre-desiliconization, deep desiliconization, fractional precipitation and the like, relieves the pressure of treatment and disposal of the solid waste of the coal-fired power plant coal ash, and realizes the complete resource utilization of the coal ash.
(3) The alkali liquor generated by the calcium silicate purification reactor and the neutralization reactor is refluxed, so that the generation of waste liquid is avoided, and the zero emission of the aluminum extraction process of the fly ash is realized.
(4) The calcium silicate, silica gel, ferric hydroxide and other products produced in the extraction process have high purity, the calcium silicate can be recovered as a heat-insulating material, the silica gel can be recovered as a high-activity adsorption material, and the ferric hydroxide can be recovered as a pigment or water purifying agent raw material. And no secondary solid waste is generated in the extraction process of the alumina, so that the high-value utilization of the fly ash is really realized.
Drawings
FIG. 1 is a process flow diagram of the present invention;
FIG. 2 is a diagram of the recovered calcium silicate, silica gel, iron hydroxide and aluminum oxide products of example 2;
FIG. 3 shows the results of optimizing the reaction conditions of the fly ash pre-desilication process and the calcium silicate extraction process;
FIG. 4 shows the results of reaction condition optimization in the pre-desiliconized fly ash activation calcination process and the acid leaching process.
The notation in the figure is:
1-a grinder, 2-a screen machine, 3-a pre-desilication reactor, 4-a first sedimentation tank, 5-a calcium silicate purification reactor, 6-a second sedimentation tank, 7-an activation calcination reactor, 8-an acid leaching reactor, 9-a third sedimentation tank, 10-an iron hydroxide purification reactor, 11-a fourth sedimentation tank, 12-a neutralization reactor, 13-a fifth sedimentation tank, 14-a high-temperature calcination reactor, 15-a pre-desilication agent doser, 16-a desilication agent doser, 17-an activator doser, 18-an acid leaching solution doser, 19-an iron hydroxide purification agent doser and 20-a neutralizer doser.
Detailed Description
The system for producing high-purity alumina by recycling fly ash is explained in detail below.
In the description of the present invention, it should be noted that the terms "first", "second", "third", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In order to truly realize the recycling of solid waste, the invention provides a system for producing high-purity alumina by recycling fly ash, which has a structure shown in figure 1 and comprises a grinding machine 1, a pre-desiliconization reactor 3, an activation calcination reactor 7, an acid leaching reactor 8, an iron hydroxide purification reactor 10, a neutralization reactor 12 and a high-temperature calcination reactor 14 which are sequentially connected along the direction of extracting alumina, wherein the pre-desiliconization reactor 3 is further connected with a pre-desiliconization agent doser 15, the activation calcination reactor 7 is further connected with an activator doser 17, the acid leaching reactor 8 is further connected with an acid leaching solution doser 18, the iron hydroxide purification reactor 10 is further connected with an iron hydroxide purification agent doser 19, and the neutralization reactor 12 is further connected with a neutralizer doser 20.
The grinder 1 of the present invention is a common device for grinding materials in the field, and fine powder particles obtained by sieving after grinding are relatively comparable to "fine" and "coarse" in coarse powder particles, so as to be distinguished, and the specific particle size range is determined according to actual requirements.
In some embodiments, the liquid outlet of the pre-desilication reactor 3 is further connected to a calcium silicate purification reactor 5, the calcium silicate purification reactor 5 is further connected to a desiliconization agent doser 16, and the liquid outlet of the calcium silicate purification reactor 5 is further connected back to the pre-desilication reactor 3. Furthermore, a second sedimentation tank 6 is arranged between the calcium silicate purification reactor 5 and the pre-desilication reactor 3.
In some embodiments, a screen 2 is further disposed between the grinder 1 and the pre-desilication reactor 3, wherein the coarse powder outlet of the screen 2 is also connected back to the inlet of the grinder 1. The mesh number of the screen machine 2 can be designed to be 5-1500 meshes according to practical requirements.
In some embodiments, a first sedimentation tank 4 is further arranged between the pre-desilication reactor 3 and the activation calcination reactor 7, a third sedimentation tank 9 is further arranged between the acid leaching reactor 8 and the ferric hydroxide purification reactor 10, a fourth sedimentation tank 11 is further arranged between the ferric hydroxide purification reactor 10 and the neutralization reactor 12, and a fifth sedimentation tank 13 is further arranged between the neutralization reactor 12 and the high temperature calcination reactor 14 along the direction of extracting alumina.
In some embodiments, the liquid outlet of the neutralization reactor 12 is also connected back to the inlet of the ferric hydroxide purification reactor 10.
The method for producing high-purity alumina by recycling fly ash is continuously analyzed and explained below.
Based on the system, the invention also provides a method for producing high-purity alumina by recycling the fly ash, and a specific flow can be seen in figure 1, and the method comprises the following steps:
(1) adding the fly ash to be treated into a grinder 1 for grinding treatment, sieving to obtain fine powder particles, discharging the fine powder particles into a pre-desiliconization reactor 3, adding a pre-desiliconization agent for pre-desiliconization treatment, and discharging precipitates into an activation calcination reactor 7 after solid-liquid separation of sludge-water mixed liquid after the treatment;
(2) adding an activating agent into the activation and calcination reactor 7, carrying out activation and calcination treatment, and discharging the obtained calcination product into an acid leaching reactor 8;
(3) adding acid leaching solution into the acid leaching reactor 8 for acid leaching reaction, settling and separating the obtained reaction product, and discharging the supernatant into an iron hydroxide purification reactor 10;
(4) adding an iron hydroxide purifying agent into the iron hydroxide purifying reactor 10 for purification treatment, precipitating and separating the treated mixed solution, and continuously discharging the obtained supernatant into a neutralization reactor 12;
(5) adding a neutralizing agent into the neutralization reactor 12 to continuously adjust the pH, then settling and separating to obtain an aluminum hydroxide precipitate, and discharging the aluminum hydroxide precipitate into the high-temperature calcination reactor 14;
(6) and (3) carrying out high-temperature calcination on the aluminum hydroxide precipitate fed into the high-temperature calcination reactor 14 to obtain high-purity aluminum oxide.
In some embodiments, in step (1), the reaction time of the pre-desilication treatment is 30 to 1000 min.
In some embodiments, in step (2), the temperature of the activation calcination is 100-1500 ℃, and the time is 10-500 min.
In some embodiments, in step (3), the temperature of the acid dissolution reaction is 25 to 100 ℃ for 30 to 600 min.
In some embodiments, in step (4), the time of the purification treatment is 30 to 500 min.
In some embodiments, in step (6), the temperature of the high-temperature calcination is 400-1500 ℃, and the time is 10-300 min.
In some embodiments, the pre-desiliconization agent is one or more of sodium hydroxide, calcium oxide or potassium hydroxide, and the pre-desiliconization agent is added in the form of solution or slurry, corresponding to 5-50% by mass, and corresponding to 5-1000g of fly ash, with the addition amount of 100-. The pre-desiliconization agent is preferably calcium hydroxide or sodium hydroxide, mixed with calcium oxide or calcium hydroxide.
In some embodiments, the activating agent is one or more of sodium carbonate, sodium bicarbonate, potassium carbonate or potassium bicarbonate, and the mass ratio of the activating agent to the precipitate obtained after the pre-desilication is 0.5-3.0.
In some embodiments, the acid leaching solution is one or more of hydrochloric acid, sulfuric acid, nitric acid or oxalic acid, the mass percentage is 5% -20%, the amount of the acid leaching solution corresponds to 5-1000g of fly ash, and the addition amount of the fly ash is 100-50000 mL.
In some embodiments, the iron hydroxide purifying agent is one or more of sodium hydroxide, potassium hydroxide, calcium oxide, sodium bicarbonate or sodium carbonate, and the dosage is 5-100g/L, wherein 5-100g of the iron hydroxide purifying agent is added to 1L of the supernatant obtained in the step (3).
In some embodiments, the neutralizing agent is one or more of hydrochloric acid, sulfuric acid, nitric acid or oxalic acid, and the dosage is 5-200 g/L.
In some embodiments, in step (1), the supernatant obtained by subjecting the slurry-water mixed solution to solid-liquid separation is subjected to desiliconization and then returned to the inlet of the pre-desiliconization reactor 3. The treatment time in the silicon removal treatment is 10-500min, the silicon removal agent is one or more of calcium oxide, calcium hydroxide, calcium chloride or calcium fluoride, and the adding amount is 5-200 g/L.
In some embodiments, in step (2), the supernatant obtained after adjusting the pH and settling separation in the neutralization reactor 12 is also refluxed to the inlet of the ferric hydroxide purification reactor 10.
The reaction principle of each part of the invention is as follows:
1) a pre-desilication stage: firstly, primarily removing impurity silicon in the fly ash, dissolving partial silicon dioxide by adding strong alkali, and then adding calcium salt to obtain high-purity calcium silicate. The reaction formulas are shown in (1) to (3).
2) And (3) calcining and activating stage: the mullite in the fly ash can be converted into nepheline by adding the activating agent and calcining at high temperature, so that the activity is greatly improved, the difficulty in subsequent aluminum extraction is reduced, and the extraction rate of aluminum is improved. The reaction formulas are shown in (4) to (8).
3Na2CO3+Al6Si2O13→NaAlSiO4+4NaAlO2+3CO2 (4)
SiO2+Na2CO3→2NaSiO3+CO2↑ (5)
Al2O3+Na2CO3→2NaAlO2+CO2↑ (6)
Fe2O3+Na2CO3→Na2O·Fe2O3+CO2↑ (7)
4Fe3O4+6Na2CO3+O2→6Na2O·Fe2O3+6CO2↑ (8)
3) And (3) silica gel purification stage: the addition of acid dissolves and activates the calcined nepheline and iron oxide, thereby obtaining a silicic acid colloid with higher purity. The reaction formulas are shown in (9) to (11).
2NaAlSiO4+8H+→2H2SiO3↓+2Na++2Al3++2H2O (9)
Na2O·Fe2O3+8H+→2Na++Fe3++4H2O (11)
3) And (3) iron hydroxide purification stage: the addition of alkali can directly convert aluminum ions into metaaluminate ions, and convert iron ions into ferric hydroxide precipitates for recycling.
2Fe3++6OH-→2Fe(OH)3↓ (13)
4) And (3) a neutralization reaction stage: acid is added to the solution to adjust the pH to about 8, which converts the meta-aluminate to an aluminum hydroxide precipitate.
5) And (3) an alumina extraction stage: the aluminum hydroxide precipitate is roasted at high temperature to obtain high-purity aluminum oxide.
2Al(OH)3→Al2O3+3H2O(g) (15)
In order to more clearly illustrate the examples of the present invention or the implementation method in the prior art, the following examples and figures are only some examples of the present invention, and other examples or figures can be obtained by those skilled in the art without inventive labor.
Example 1:
a system and a method for producing high-purity aluminum oxide by recycling fly ash are shown in an extraction flow of figure 1, and comprise a grinder 1, a screen machine 2, a pre-desiliconization reactor 3, a first sedimentation tank 4, a calcium silicate purification reactor 5, a second sedimentation tank 6, an activation calcination reactor 7, an acid leaching reactor 8, a third sedimentation tank 9, an iron hydroxide purification reactor 10, a fourth sedimentation tank 11, a neutralization reactor 12, a fifth sedimentation tank 13 and a high-temperature calcination reactor 14 which are connected in sequence. Wherein, the pre-desiliconization reactor 3 is also connected with a pre-desiliconization agent doser 15, the calcium silicate purification reactor 5 is also connected with a desiliconization agent doser 16, the activation calcination reactor 7 is also connected with an activating agent doser 17, the acid leaching reactor 8 is also connected with an acid leaching solution doser 18, the iron hydroxide purification reactor 10 is also connected with an iron hydroxide purification agent doser 19, and the neutralization reactor 12 is also connected with a neutralizer doser 20.
The method comprises the following specific steps:
(1) adding the fly ash to be treated into a grinder 1 for grinding, then sending the fly ash into a screening machine 2, discharging fine powder particles which are screened and separated by the screening machine into a pre-desiliconization reactor 3, and discharging coarse powder particles back to the grinder 1 for continuous grinding;
(2) adding a pre-desiliconization agent into the pre-desiliconization reactor 3 for pre-desiliconization treatment, performing solid-liquid separation on the treated mud-water mixed liquid in a first sedimentation tank 4, discharging the obtained precipitate into an activation calcination reactor 7 for activation calcination, discharging the supernatant into a calcium silicate purification reactor 5, adding a desiliconization agent, performing precipitation separation in a second sedimentation tank 6, and refluxing the supernatant into the pre-desiliconization reactor 3, wherein the precipitate is calcium silicate solid;
(3) after an activating agent is added into the activation calcining reactor 7, calcining and activating the mixture, converting mullite in the fly ash into nepheline, improving the activity of the nepheline so as to promote the subsequent leaching of aluminum, and discharging the calcined product into an acid leaching reactor 8;
(4) adding acid leaching solution into the acid leaching reactor 8 for acid leaching reaction, settling and separating the acid leaching solution in a third sedimentation tank 9, discharging supernatant into an iron hydroxide purification reactor 10, and obtaining precipitate which is silica gel;
(5) adding an iron hydroxide purifying agent into an iron hydroxide purifying reactor 10 for reaction, and discharging supernatant into a neutralization reactor 12 after settling separation in a fourth settling pond 11, wherein the precipitate is iron hydroxide;
(6) adding a neutralizer into the neutralization reactor 12 to continuously adjust the pH, precipitating and separating through a fifth sedimentation tank 13, refluxing the supernatant to the ferric hydroxide purification reactor 10, discharging the aluminum hydroxide precipitate into a high-temperature calcination reactor 14, and calcining to obtain a high-purity aluminum oxide product.
Example 2:
on the basis of the alumina extraction process of example 1, the operating process parameters of this example are as follows:
TABLE 1 fly ash chemical composition of certain power plant of inner Mongolia
| Chemical composition | Al2O3 | SiO2 | Fe2O3 | CaO | MgO | Na2O | K2O |
| Wt％ | 29.64 | 48.26 | 5.54 | 9.66 | 1.20 | 1.44 | 0.90 |
The fly ash to be treated was taken from a coal fired power plant in inner Mongolia and its chemical composition is shown in Table 1. According to X-ray fluorescence spectrum analysis (XRF), the fly ash belongs to low-aluminum high-calcium fly ash.
In this example, 30g of fly ash treated by a grinder 1 and a screen 2 was weighed, wherein the screen 2 had a mesh size of 200 mesh (80 μm). The reaction time in the pre-desiliconization reactor 3 is 60min, the used pre-desiliconization agent is 600mL of sodium hydroxide with the mass fraction of 20%, the supernatant is discharged into the calcium silicate purification reactor 5 after the sedimentation separation in the second sedimentation tank 4, the reaction time is 30min, the used calcium silicate purification agent is calcium oxide, the adding amount is 20g/L, the supernatant flows back to the inlet of the pre-desiliconization reactor 3 after the sedimentation separation in the second sedimentation tank 6, the obtained calcium silicate precipitate can be recycled as a heat insulation product, and the comparison of each measurement index with the national standard calcium silicate heat insulation product (GB/T10699-.
TABLE 2 calcium silicate insulation articles determination index comparison
| Index (I) | Calcium silicate product | GB/T 10699-2015 |
| Density (kg/m)3) | 213 | ≤240 |
| Average compressive Strength (MPa) | 0.69 | ≥0.65 |
| Average flexural strength (MPa) | 0.37 | ≥0.33 |
| Thermal conductivity (100 ℃, W/(m.K)) | 0.043 | ≤0.065 |
| Mass water content (%) | 2.34 | ≤7.5 |
| Dimensional stability (%) | 0.8 | ≤1.0 |
| Linear shrinkage (%) | 1.7 | ≤2.0 |
The pre-desiliconized fly ash sediment generated in the second sedimentation tank 4 is sent into an activation calcination reactor 7, the reaction time is 120min, the used activating agent is sodium carbonate, and the mass ratio of the added amount of the sodium carbonate to the pre-desiliconized fly ash sediment is 1.2: 1. After calcination, the activated product is fed to an acid bath 8.
TABLE 3 comparison of silica gel desiccant determination indexes for packaging
| Index (I) | Silica gel product | GB 10455-1989 |
| Content (including structural Water,%) | 98.2 | ≥98 |
| pH | 4.3 | 4-8 |
| Specific resistance (omega cm) | 2740 | ≥2000 |
| Loss on drying (%) | 2.3 | ≤2.5 |
The reaction time in the acid leaching tank 8 is 30min, the used acid leaching solution is 200mL of 1mol/L sulfuric acid, the leaching of the sulfuric acid can remove the residual impurity silicon in the form of silicic acid colloid, after the silicon is settled and separated in the third sedimentation tank 9, the supernatant is discharged into the ferric hydroxide purification reactor 10, the obtained silica gel precipitate can be used as silica gel drying agent for resource recovery, and the determination indexes of the silica gel precipitate and the national standard silica gel drying agent for packaging (GB 10455-.
The water discharged from the third sedimentation tank 9 enters an iron hydroxide purification reactor 10, the reaction time is 25min, the used iron hydroxide purification agent is sodium hydroxide, the adding amount is 5g/L, after sedimentation separation in a fourth sedimentation tank 11, the supernatant is discharged into a neutralization reactor 12, and the obtained precipitate is iron hydroxide.
And the effluent of the fourth sedimentation tank 11 enters a neutralization reactor 12, the reaction time is 30min, the used neutralizing agent is hydrochloric acid, the adding amount of the hydrochloric acid is 80g/L, after sedimentation separation in a fifth sedimentation tank 13, the supernatant liquid flows back to an iron hydroxide purification reactor 10, and the obtained precipitate is aluminum hydroxide.
The aluminum hydroxide precipitate generated in the fifth sedimentation tank 13 is discharged into the high-temperature calcination reactor 14, the reaction time is 90min, the calcination temperature is 1200 ℃, the calcination product is high-purity aluminum oxide, and the indexes of the high-purity aluminum oxide precipitate and the comparison of the national standard aluminum oxide (GB/T24487) 2009 in table 4 show.
TABLE 4 comparison of alumina measurement indices
| Chemical composition (wt%) | Alumina product | GB/T 24487-2009 |
| Al2O3 | 98.6 | ≥98.4 |
| SiO2 | 0.04 | ≤0.06 |
| Fe2O3 | 0.01 | ≤0.03 |
| Na2O | 0.59 | ≤0.7 |
| Burn and relieve | 0.9 | ≤1.0 |
FIG. 2 is a diagram of recovered calcium silicate, silica gel, iron hydroxide and alumina products, and it can be seen from the diagram that the quality of each product recovered by the process is excellent, and various other high-value byproducts can be simultaneously extracted on the basis of realizing alumina extraction, so as to realize high-value utilization of fly ash.
Fig. 3 is an experimental result of optimization of a part of reaction conditions in the pre-desilication reactor and the calcium silicate purification reactor, and by optimizing the dosage of the pre-desilication agent (fig. 3(a)), the silica in the fly ash can be primarily dissolved out to the maximum extent, and the loss of aluminum in the pre-desilication process can be reduced, so that the influence of the loss on the subsequent purification process can be reduced. By optimizing the amount of calcium silicate purifying agent to be added (fig. 3(b)), it is possible to extract calcium silicate while ensuring the purity of the silicon product.
Fig. 4 shows the results of an optimization experiment of the reaction conditions in the activation calcination reactor 7 and the acid leaching reactor 8, and the optimal reaction conditions were established by examining the influence of the reaction temperature, the reaction time, and the amount of the added activator on the leaching effect of the subsequent alumina acid leaching (fig. 4 (a)). By examining the influence of the concentration of the pickle liquor, the pickle liquor temperature and the pickle liquor time on the alumina leaching effect (figure 4(b)), the maximum leaching of alumina in the pickle liquor reactor is ensured.
Example 3:
compared to example 2, most of them are the same, except that in this example: fly ash to be treated was taken from a power plant in the Shanghai and its chemical composition is shown in Table 5. According to X-ray fluorescence spectrum analysis (XRF), the fly ash belongs to high-aluminum low-calcium fly ash.
TABLE 5 fly ash chemical composition of certain power plant in Shanghai
| Chemical composition | Al2O3 | SiO2 | Fe2O3 | CaO | MgO | TiO2 | K2O |
| Wt％ | 39.73 | 50.67 | 3.86 | 2.48 | 0.533 | 1.44 | 0.788 |
In this example, 30g of fly ash treated by a grinder 1 and a screen 2 were weighed, wherein the screen 2 had a mesh size of 400 mesh (40 μm). The reaction time in the pre-desiliconization reactor 3 is 50min, the used pre-desiliconization agent is 600mL of sodium hydroxide with the mass fraction of 15%, the supernatant fluid is discharged into the calcium silicate purification reactor 5 after the sedimentation separation in the second sedimentation tank 4, the reaction time is 25min, the used calcium silicate purification agent is calcium hydroxide, the adding amount is 25g/L, the supernatant fluid flows back to the inlet of the pre-desiliconization reactor 3 after the sedimentation separation in the second sedimentation tank 6, the obtained calcium silicate precipitate can be used as an insulating product for resource recovery, and the comparison of each measurement index with the national standard 'insulating calcium silicate product' (GB/T10699-.
TABLE 6 calcium silicate insulation articles determination index comparison
| Index (I) | Calcium silicate product | GB/T 10699-2015 |
| Density (kg/m)3) | 232 | ≤240 |
| Average compressive Strength (MPa) | 0.67 | ≥0.65 |
| Average flexural strength (MPa) | 0.34 | ≥0.33 |
| Thermal conductivity (100 ℃, W/(m.K)) | 0.054 | ≤0.065 |
| Mass water content (%) | 2.56 | ≤7.5 |
| Dimensional stability (%) | 0.9 | ≤1.0 |
| Linear shrinkage (%) | 1.8 | ≤2.0 |
The pre-desiliconized fly ash sediment generated in the second sedimentation tank 4 is sent into an activation calcination reactor 7, the reaction time is 120min, the used activating agent is sodium carbonate, and the mass ratio of the added amount of the sodium carbonate to the pre-desiliconized fly ash sediment is 1.4: 1. After calcination, the activated product is fed to an acid bath 8.
The reaction time in the acid leaching tank 8 is 25min, the used acid leaching solution is 200mL of 1mol/L hydrochloric acid, the residual impurity silicon can be removed in the form of silicic acid colloid by leaching of the hydrochloric acid, after sedimentation separation in the third sedimentation tank 9, the supernatant is discharged into the ferric hydroxide purification reactor 10, the obtained silica gel precipitate can be used as silica gel drying agent for resource recovery, and various measurement indexes of the silica gel drying agent are shown in Table 7 with respect to the national standard silica gel drying agent for packaging (GB 10455-.
TABLE 7 silica gel desiccant determination index comparison for packaging
| Index (I) | Silica gel product | GB 10455-1989 |
| Content (including structural Water,%) | 98.1 | ≥98 |
| pH | 4.1 | 4-8 |
| Specific resistance (omega cm) | 2639 | ≥2000 |
| Loss on drying (%) | 2.4 | ≤2.5 |
The water discharged from the third sedimentation tank 9 enters an iron hydroxide purification reactor 10, the reaction time is 25min, the used iron hydroxide purification agent is sodium hydroxide, the adding amount of the sodium hydroxide is 10g/L, after sedimentation separation in a fourth sedimentation tank 11, the supernatant is discharged into a neutralization reactor 12, and the obtained precipitate is iron hydroxide.
And the effluent of the fourth sedimentation tank 11 enters a neutralization reactor 12, the reaction time is 45min, the used neutralizing agent is hydrochloric acid, the adding amount of the hydrochloric acid is 75g/L, after sedimentation separation in a fifth sedimentation tank 13, the supernatant liquid flows back to an iron hydroxide purification reactor 10, and the obtained precipitate is aluminum hydroxide.
The aluminum hydroxide precipitate generated in the fifth sedimentation tank 13 is discharged into the high-temperature calcination reactor 14, the reaction time is 120min, the calcination temperature is 1100 ℃, the calcination product is high-purity aluminum oxide, and the indexes of the high-purity aluminum oxide are shown in a comparison table 8 with the national standard of aluminum oxide (GB/T24487-2009).
TABLE 8 comparison of alumina measurement indices
| Chemical composition (w)t％) | Alumina product | GB/T 24487-2009 |
| Al2O3 | 98.4 | ≥98.4 |
| SiO2 | 0.05 | ≤0.06 |
| Fe2O3 | 0.02 | ≤0.03 |
| Na2O | 0.65 | ≤0.7 |
| Burn and relieve | 1.0 | ≤1.0 |
In addition, the treatment reagents and the corresponding treatment process conditions used in the above embodiments can be arbitrarily adjusted within the following ranges (i.e., can be adjusted to any end value or any middle value) according to the actual situation:
the reaction time of the pre-desiliconization treatment is 30-1000 min;
the temperature of the activation calcination is 100-1500 ℃, and the time is 10-500 min;
the temperature of the acid dissolution reaction is 25-100 ℃, and the time is 30-600 min;
the time for purifying the ferric hydroxide is 30-500 min.
The high-temperature calcination temperature is 400-1500 ℃, and the time is 10-300 min;
the pre-desiliconization agent is one or more of sodium hydroxide, calcium oxide or potassium hydroxide, the pre-desiliconization agent is added in the form of solution or slurry, the corresponding mass percent is 5-50%, meanwhile, the corresponding mass percent is 5-1000g of fly ash, the addition amount is 100-50000mL, and the pre-desiliconization agent is preferably calcium hydroxide or sodium hydroxide and is mixed with calcium oxide or calcium hydroxide;
the activating agent is one or more of sodium carbonate, sodium bicarbonate, potassium carbonate or potassium bicarbonate, and the mass ratio of the activating agent to the precipitate obtained after the pre-desiliconization is 0.5-3.0;
the acid leaching solution is one or more of hydrochloric acid, sulfuric acid, nitric acid or oxalic acid, the mass percentage is 5-20%, the corresponding mass percentage is 5-1000g of fly ash, and the addition amount of the fly ash is 100-50000 mL;
the iron hydroxide purifying agent is one or more of sodium hydroxide, potassium hydroxide, calcium oxide, sodium bicarbonate or sodium carbonate, the adding amount is 5-100g/L, and 5-100g of the iron hydroxide purifying agent is correspondingly added into every 1L of the supernatant obtained in the step (3);
the neutralizing agent is one or more of hydrochloric acid, sulfuric acid, nitric acid or oxalic acid, and the adding amount is 5-200 g/L;
in the step (1), supernatant obtained by carrying out solid-liquid separation on the sludge-water mixed solution is returned to an inlet of the pre-desiliconization reactor after desiliconization treatment, the treatment time in the desiliconization treatment is 10-500min, the desiliconization agent is one or more of calcium oxide, calcium hydroxide, calcium chloride or calcium fluoride, and the adding amount is 5-200 g/L.
The embodiments described above are described to facilitate an understanding and appreciation of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make modifications and alterations without departing from the scope of the present invention.
Claims (10)
1. The system is characterized by comprising a grinding machine, a pre-desiliconization reactor, an activation calcination reactor, an acid leaching reactor, an iron hydroxide purification reactor, a neutralization reactor and a high-temperature calcination reactor which are sequentially connected along the direction of extracting alumina, wherein the pre-desiliconization reactor is further connected with a pre-desiliconization agent doser, the activation calcination reactor is further connected with an activator doser, the acid leaching reactor is further connected with an acid leaching solution doser, the iron hydroxide purification reactor is further connected with an iron hydroxide purification agent doser, and the neutralization reactor is further connected with a neutralizer doser.
2. The system for producing high-purity aluminum oxide from fly ash as a resource as claimed in claim 1, wherein a liquid outlet of the pre-desiliconization reactor is further connected with a calcium silicate purification reactor, the calcium silicate purification reactor is further connected with a desiliconization agent doser, and a liquid outlet of the calcium silicate purification reactor is further connected with the pre-desiliconization reactor in a return manner.
3. The system for producing high-purity alumina from fly ash as a resource as claimed in claim 2, wherein a second sedimentation tank is further arranged between the calcium silicate purification reactor and the pre-desilication reactor.
4. The system for producing high-purity aluminum oxide by recycling fly ash as claimed in claim 1, wherein a screen machine is further arranged between the grinding machine and the pre-desilication reactor, and a coarse powder outlet of the screen machine is also connected with an inlet of the grinding machine in a return mode.
5. The system for producing high-purity aluminum oxide from fly ash as a resource as claimed in claim 1, wherein a first sedimentation tank is further arranged between the pre-desilication reactor and the activation calcination reactor along the direction of extracting aluminum oxide, a third sedimentation tank is further arranged between the acid leaching reactor and the ferric hydroxide purification reactor, a fourth sedimentation tank is further arranged between the ferric hydroxide purification reactor and the neutralization reactor, and a fifth sedimentation tank is further arranged between the neutralization reactor and the high-temperature calcination reactor.
6. The system for producing high-purity aluminum oxide from fly ash as a resource as claimed in claim 1, wherein the liquid outlet of the neutralization reactor is also connected with the inlet of the ferric hydroxide purification reactor.
7. A method for producing high-purity alumina by recycling fly ash, which is realized based on the system as claimed in any one of claims 1 to 6, and is characterized by comprising the following steps:
(1) adding the fly ash to be treated into a grinder for grinding treatment, sieving to obtain fine powder particles, discharging the fine powder particles into a pre-desiliconization reactor, adding a pre-desiliconization agent for pre-desiliconization treatment, and discharging precipitates into an activation calcination reactor after solid-liquid separation of sludge-water mixed liquid after treatment;
(2) adding an activating agent into the activation and calcination reactor, performing activation and calcination treatment, and discharging the obtained calcination product into an acid leaching reactor;
(3) adding acid leaching solution into the acid leaching reactor for acid leaching reaction, settling and separating the obtained reaction product, and discharging the supernatant into an iron hydroxide purification reactor;
(4) adding an iron hydroxide purifying agent into the iron hydroxide purifying reactor for purification treatment, precipitating and separating the treated mixed solution, and continuously discharging the obtained supernatant into a neutralization reactor;
(5) adding a neutralizing agent into the neutralization reactor to continuously adjust the pH, then settling and separating to obtain an aluminum hydroxide precipitate, and discharging the aluminum hydroxide precipitate into the high-temperature calcination reactor;
(6) and (3) carrying out high-temperature calcination on the aluminum hydroxide precipitate fed into the high-temperature calcination reactor to obtain the high-purity aluminum oxide.
8. The method for producing high-purity alumina as a resource of fly ash according to claim 7, wherein in the step (1), the reaction time of the pre-desilication treatment is 30-1000 min;
in the step (2), the temperature of the activation calcination is 100-1500 ℃, and the time is 10-500 min;
in the step (3), the temperature of the acid dissolution reaction is 25-100 ℃, and the time is 30-600 min;
in the step (4), the purification treatment time is 30-500 min;
in the step (6), the temperature of the high-temperature calcination is 400-1500 ℃, and the time is 10-300 min.
9. The method for producing high-purity aluminum oxide from fly ash as a resource as claimed in claim 7, wherein the pre-desiliconization agent is one or more of sodium hydroxide, calcium oxide and potassium hydroxide;
the activating agent is one or more of sodium carbonate, sodium bicarbonate, potassium carbonate or potassium bicarbonate, and the adding amount of the activating agent is 10-300 g/L;
the pickle liquor is one or more of hydrochloric acid, sulfuric acid, nitric acid or oxalic acid;
the iron hydroxide purifying agent is one or more of sodium hydroxide, potassium hydroxide, calcium oxide, sodium bicarbonate or sodium carbonate;
the neutralizing agent is one or more of hydrochloric acid, sulfuric acid, nitric acid or oxalic acid.
10. The method for producing high-purity aluminum oxide by recycling fly ash as claimed in claim 7, wherein in the step (1), the supernatant obtained by subjecting the slurry-water mixed solution to solid-liquid separation is subjected to desiliconization and then returned to the inlet of the pre-desiliconization reactor;
in the step (2), the supernatant obtained after the pH adjustment and the sedimentation separation in the neutralization reactor is also refluxed to the inlet of the ferric hydroxide purification reactor.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102897810A (en) * | 2012-11-06 | 2013-01-30 | 大唐国际发电股份有限公司 | Method for producing aluminum oxide by using fly ash |
| CN103303952A (en) * | 2012-03-06 | 2013-09-18 | 中国科学院过程工程研究所 | Method for linked preparation of sodium aluminate and production of silica-based material by means of high-alumina fly ash low-temperature liquid-phase alkali dissolving |
| US20130343971A1 (en) * | 2011-05-11 | 2013-12-26 | Inner Mongolia Datang International Recycling Resource Development Co., Ltd. | Method for co-producing alumina and activated calcium silicate from high-alumina fly ash |
| CN108622920A (en) * | 2018-05-30 | 2018-10-09 | 大唐国际发电股份有限公司高铝煤炭资源开发利用研发中心 | A kind of method of aluminous fly-ash extraction aluminium oxide |
| CN110577231A (en) * | 2019-09-06 | 2019-12-17 | 于谦 | method for extracting aluminum oxide and coproducing silicon oxide and ferric oxide from fly ash |
| CN215048708U (en) * | 2021-04-21 | 2021-12-07 | 上海电力大学 | System for fly ash resourceful production high-purity alumina |
-
2021
- 2021-04-21 CN CN202110427862.2A patent/CN113371745B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20130343971A1 (en) * | 2011-05-11 | 2013-12-26 | Inner Mongolia Datang International Recycling Resource Development Co., Ltd. | Method for co-producing alumina and activated calcium silicate from high-alumina fly ash |
| CN103303952A (en) * | 2012-03-06 | 2013-09-18 | 中国科学院过程工程研究所 | Method for linked preparation of sodium aluminate and production of silica-based material by means of high-alumina fly ash low-temperature liquid-phase alkali dissolving |
| CN102897810A (en) * | 2012-11-06 | 2013-01-30 | 大唐国际发电股份有限公司 | Method for producing aluminum oxide by using fly ash |
| CN108622920A (en) * | 2018-05-30 | 2018-10-09 | 大唐国际发电股份有限公司高铝煤炭资源开发利用研发中心 | A kind of method of aluminous fly-ash extraction aluminium oxide |
| CN110577231A (en) * | 2019-09-06 | 2019-12-17 | 于谦 | method for extracting aluminum oxide and coproducing silicon oxide and ferric oxide from fly ash |
| CN215048708U (en) * | 2021-04-21 | 2021-12-07 | 上海电力大学 | System for fly ash resourceful production high-purity alumina |
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