CN114751746A - Treatment method of carbon-containing solid waste in aluminum electrolysis industry - Google Patents
Treatment method of carbon-containing solid waste in aluminum electrolysis industry Download PDFInfo
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- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 77
- 229910052782 aluminium Inorganic materials 0.000 title claims abstract description 65
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 title claims abstract description 64
- 229910052799 carbon Inorganic materials 0.000 title claims abstract description 63
- 238000005868 electrolysis reaction Methods 0.000 title claims abstract description 44
- 238000000034 method Methods 0.000 title claims abstract description 32
- 239000002910 solid waste Substances 0.000 title claims abstract description 31
- 238000009835 boiling Methods 0.000 claims abstract description 50
- 239000003792 electrolyte Substances 0.000 claims abstract description 34
- 239000002699 waste material Substances 0.000 claims abstract description 28
- 239000007789 gas Substances 0.000 claims abstract description 14
- 238000005188 flotation Methods 0.000 claims abstract description 13
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 6
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 6
- 239000001301 oxygen Substances 0.000 claims abstract description 6
- 239000002994 raw material Substances 0.000 claims description 21
- 238000002485 combustion reaction Methods 0.000 claims description 16
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 3
- 229930195733 hydrocarbon Natural products 0.000 claims description 2
- 150000002430 hydrocarbons Chemical class 0.000 claims description 2
- 150000002632 lipids Chemical class 0.000 claims description 2
- 239000000178 monomer Substances 0.000 claims description 2
- 150000007524 organic acids Chemical class 0.000 claims description 2
- 229920000642 polymer Polymers 0.000 claims description 2
- 239000004215 Carbon black (E152) Substances 0.000 claims 1
- 229910001610 cryolite Inorganic materials 0.000 abstract description 9
- 230000003647 oxidation Effects 0.000 abstract description 4
- 238000007254 oxidation reaction Methods 0.000 abstract description 4
- 239000012535 impurity Substances 0.000 abstract description 2
- 239000000047 product Substances 0.000 description 18
- 239000002893 slag Substances 0.000 description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 10
- 150000002222 fluorine compounds Chemical class 0.000 description 8
- 239000000203 mixture Substances 0.000 description 8
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 7
- 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 description 7
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 7
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 7
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 7
- 239000011575 calcium Substances 0.000 description 7
- 229910052791 calcium Inorganic materials 0.000 description 7
- 229910052744 lithium Inorganic materials 0.000 description 7
- 239000011777 magnesium Substances 0.000 description 7
- 229910052749 magnesium Inorganic materials 0.000 description 7
- 239000011591 potassium Substances 0.000 description 7
- 229910052700 potassium Inorganic materials 0.000 description 7
- 239000011734 sodium Substances 0.000 description 7
- 229910052708 sodium Inorganic materials 0.000 description 7
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 description 6
- 238000001354 calcination Methods 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 6
- 239000000463 material Substances 0.000 description 5
- 239000000843 powder Substances 0.000 description 5
- 239000002920 hazardous waste Substances 0.000 description 4
- XFXPMWWXUTWYJX-UHFFFAOYSA-N Cyanide Chemical compound N#[C-] XFXPMWWXUTWYJX-UHFFFAOYSA-N 0.000 description 3
- -1 fluorine ions Chemical class 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 231100000331 toxic Toxicity 0.000 description 3
- 230000002588 toxic effect Effects 0.000 description 3
- KLZUFWVZNOTSEM-UHFFFAOYSA-K Aluminium flouride Chemical compound F[Al](F)F KLZUFWVZNOTSEM-UHFFFAOYSA-K 0.000 description 2
- 241001465754 Metazoa Species 0.000 description 2
- 230000006378 damage Effects 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 230000007774 longterm Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 239000011819 refractory material Substances 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 231100000419 toxicity Toxicity 0.000 description 2
- 230000001988 toxicity Effects 0.000 description 2
- 239000002253 acid Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- AZDRQVAHHNSJOQ-UHFFFAOYSA-N alumane Chemical compound [AlH3] AZDRQVAHHNSJOQ-UHFFFAOYSA-N 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 239000008280 blood Substances 0.000 description 1
- 210000004369 blood Anatomy 0.000 description 1
- 210000000988 bone and bone Anatomy 0.000 description 1
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 1
- 229910001634 calcium fluoride Inorganic materials 0.000 description 1
- 229920003064 carboxyethyl cellulose Polymers 0.000 description 1
- 229910052593 corundum Inorganic materials 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 239000012634 fragment Substances 0.000 description 1
- JMANVNJQNLATNU-UHFFFAOYSA-N glycolonitrile Natural products N#CC#N JMANVNJQNLATNU-UHFFFAOYSA-N 0.000 description 1
- 231100001261 hazardous Toxicity 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- 239000011244 liquid electrolyte Substances 0.000 description 1
- 229910001635 magnesium fluoride Inorganic materials 0.000 description 1
- IOVCWXUNBOPUCH-UHFFFAOYSA-M nitrite group Chemical group N(=O)[O-] IOVCWXUNBOPUCH-UHFFFAOYSA-M 0.000 description 1
- 235000005985 organic acids Nutrition 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 1
- 231100000572 poisoning Toxicity 0.000 description 1
- 230000000607 poisoning effect Effects 0.000 description 1
- 210000002345 respiratory system Anatomy 0.000 description 1
- 231100000444 skin lesion Toxicity 0.000 description 1
- 206010040882 skin lesion Diseases 0.000 description 1
- 239000010802 sludge Substances 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000002352 surface water Substances 0.000 description 1
- 210000001519 tissue Anatomy 0.000 description 1
- 229910001845 yogo sapphire Inorganic materials 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
- C04B35/52—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/62204—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products using waste materials or refuse
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/64—Burning or sintering processes
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
- C25C3/00—Electrolytic production, recovery or refining of metals by electrolysis of melts
- C25C3/06—Electrolytic production, recovery or refining of metals by electrolysis of melts of aluminium
- C25C3/08—Cell construction, e.g. bottoms, walls, cathodes
- C25C3/12—Anodes
- C25C3/125—Anodes based on carbon
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Organic Chemistry (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Inorganic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Metallurgy (AREA)
- Electrolytic Production Of Metals (AREA)
- Processing Of Solid Wastes (AREA)
Abstract
The invention provides a method for treating carbon-containing solid waste in aluminum electrolysis industry, which comprises the following steps: crushing the carbon-containing solid waste, and then adding the crushed carbon-containing solid waste into a fluidized bed furnace for roasting, wherein the boiling gas in the fluidized bed furnace is at least one of preheated air and industrial oxygen, the height of a boiling layer is 10-300 cm, the temperature of the boiling layer is maintained at 500-800 ℃, the roasting time is 0.1-10 hours, and the roasted product is an electrolyte with cryolite as a main component and the carbon content is less than or equal to 1%. The invention carries out boiling oxidation roasting on the waste cathode of the aluminum electrolytic cell, the aluminum electrolytic carbon residue or the electrolyte obtained by flotation of the waste cathode and the aluminum electrolytic carbon residue, the product is purer electrolyte, the carbon content is reduced to below 1 percent, other impurities are not added, the requirement of aluminum electrolysis can be met, and all the electrolyte is recycled.
Description
Technical Field
The invention relates to the technical field of aluminum electrolysis, in particular to a method for treating carbon-containing solid waste in the aluminum electrolysis industry.
Background
The service life of the aluminum electrolytic cell is about 2000-4000 days, and after long-term use, the lining material of the electrolytic cell can deform, wear and break due to physical and chemical actions, so that the electrolytic cell can not continue to produce normally and needs to be overhauled. The essence of the cell overhaul is the replacement of the lining, the lining material that is rejected during the replacement process comprising: waste cathode carbon blocks, waste refractory materials, impermeable materials and the like. These waste cell lining materials are also known as overhaul sludge. Research shows that 20-30kg of aluminum electrolysis waste cell lining is averagely produced every ton of raw aluminum is produced at present, wherein 12-20kg of waste cathode (carbon overhaul residue) is produced.
The waste tank lining contains high-level soluble fluoride and cyanide due to the erosion and penetration of high-temperature electrolyte for a long time. When meeting water (such as rainwater, underground water and surface water), fluorine ions and cyanogen ions are easy to mix into rivers and permeate into the underground, which pollutes water sources and soil for a long time and has great harm to the surrounding ecological environment. The main points are as follows:
1) HCN is extremely toxic, can cause poisoning in small amounts and death in a few seconds (HCN causes death in an amount of 0.05 grams), and can also be poisoned by entering blood from skin lesions or by inhaling HCN through the respiratory tract.
2) The growth of animals and plants is greatly damaged, so that animal bones/plant tissues are blackened and necrotized;
3) influence the agricultural ecological balance and reduce the yield of crops;
4) in humid conditions, toxic and harmful gases are released;
5) after long-term storage and weathering, raise dust is easily formed to pollute the atmosphere.
Typical spent cathode compositions are shown in table 1:
table 1: typical composition table of waste cathode
| Item | C | O | F | Na | Al | Si | Fe | Ca | Others |
| Content (wt.) | 36.1 | 21.08 | 11.25 | 5.31 | 17.65 | 1.23 | 2.67 | 0.52 | 4.19 |
The carbon residue is another harmful solid waste generated in the aluminum electrolysis process and is fragments fallen off by the oxidation of carbon anodes of the electrolytic cell. The electrolyte is required to be periodically fished out because of serious damage to the electrolytic process. On average, about 6-15kg of carbon residue is produced per ton of raw aluminum produced. The carbon residue contains 25-40% of carbon, a large amount of fluoride electrolyte and a small amount of cyanide, and has hidden pollution danger to the environment.
Typical carbon residue composition is shown in table 2:
table 2: typical composition table of aluminium electrolysis carbon slag
| Item | C | Na3AlF6 | AlF3 | CaF2 | MgF2 | LiF | KF | Al2O3 | Others are |
| Content (c) of | 39 | 43.52 | 7.59 | 3.84 | 0.51 | 1.48 | 1.92 | 1.6 | 0.54 |
According to the relevant regulations of the national common people's republic of China solid waste pollution environmental control Law, the national standard hazardous waste identification standard corrosivity identification (GB 5085.1-2007), the hazardous waste identification standard leaching toxicity identification (GB 5085.3-2007) and the national hazardous waste record (No. 39 of the 2016 environmental protection ministry), the aluminum electrolysis cell overhaul slag (waste cell lining) and the aluminum electrolysis carbon slag belong to hazardous waste, the hazardous property is T, the waste category is HW48, and the code is 321-023-48. Therefore, the waste tank lining and the carbon slag are one of the main environmental pollution sources in the electrolytic aluminum industry as industrial solid dangerous wastes. If the treatment is not harmless or the storage and the disposal are not proper, the ecological environment and the human health are seriously influenced.
At present, the harmless treatment to the waste cell lining of the electrolytic cell mainly comprises the following steps:
1) fire method: the carbonaceous and non-carbonaceous mixed overhaul residues are usually treated by adding additives and roasting at high temperature to oxidize and decompose cyanide and convert fluoride into water insoluble substances to eliminate the toxicity. The disadvantages are high cost; the resource utilization of the roasted product is difficult; the solidified fluoride can be activated after still reacting when meeting strong acid and strong base; in the high-temperature roasting process, fluoride is hydrolyzed and volatilized, so that secondary pollution is easily caused, and the like.
2) The carbonaceous waste cathode, the non-carbonaceous refractory material and the impermeable material are treated respectively. Wherein the waste cathode is floated to obtain electrolyte and carbon powder. However, the electrolyte obtained by flotation also contains about 5% of carbon, so that the electrolyte is not suitable for use in an electrolytic cell; carbon powder also contains 10% or more of electrolyte, and the range of use is also affected.
The treatment of carbon residue, which is mainly a flotation method at present, also has similar problems with the waste cathode flotation.
Disclosure of Invention
In order to solve the problems of harmlessness and resource utilization of carbonaceous solid wastes generated in the aluminum electrolysis process, the invention provides a method for treating the carbonaceous solid wastes in the aluminum electrolysis industry, wherein the carbonaceous solid wastes are treated by a boiling oxidation roasting method, the product is relatively pure electrolyte, the carbon content is reduced to below 1 percent, the requirement of the aluminum electrolysis process can be met, and the resource utilization of all fluorides in the carbonaceous solid wastes is realized.
The invention adopts the following technical scheme:
a method for treating carbon-containing solid waste in the aluminum electrolysis industry comprises the following steps:
the method comprises the steps of crushing the carbon-containing solid wastes, then adding the crushed carbon-containing solid wastes into a fluidized bed furnace for roasting, wherein the boiling gas in the fluidized bed furnace is at least one of preheated air and industrial oxygen, the boiling gas is used for forming a boiling layer, the height of the boiling layer is 10-300 cm, the temperature of the boiling layer is maintained at 500-800 ℃, the roasting time is adjusted according to the type of raw materials, the carbon content and the furnace temperature, the roasting time is controlled to be 0.1-10 hours, the carbon content of a roasted product is less than or equal to 1%, the roasted product is an electrolyte mainly comprising cryolite and other fluorides or oxides further comprising elements such as sodium, aluminum, calcium, magnesium, potassium and lithium, and the roasted product can be recycled as a raw material for aluminum electrolysis.
In the whole roasting process, the fluoride electrolyte is in a solid state, so that the phenomenon that the oxidation process is influenced by the carbon particles coated by the formed liquid electrolyte is avoided.
The main reaction in the roasting process is as follows:
C+O2＝CO2
further, the carbon-containing solid waste comprises one or more of aluminum electrolysis cell waste cathodes, aluminum electrolysis cell waste cathode flotation carbon-containing electrolytes, aluminum electrolysis carbon residues and aluminum electrolysis carbon residue flotation carbon-containing electrolytes.
Furthermore, the granularity of the crushed carbon-containing solid waste is less than or equal to 0.5 mm.
Furthermore, the preheating temperature of the boiling gas is 50-800 ℃, and the air inlet temperature is adjusted according to the temperature of the boiling layer, so that the temperature of the boiling layer is maintained at 500-800 ℃.
Furthermore, a heat exchange device is arranged in the boiling layer and used for controlling the temperature of the boiling layer.
Further, the heat exchange device is a tube heat exchanger or a plate heat exchanger, and the heat exchange medium can be water, molten salt, high-temperature heat conduction oil, and the like; the heat exchange medium after heat exchange and heating can be used as a heat source.
Further, in the initial stage of roasting, a combustion improver can be added into the raw materials, and the addition amount of the combustion improver is 0-20% of the mass of the carbon-containing solid waste.
Furthermore, the combustion improver is various organic compounds which do not contain non-combustible components basically and do not contain S, P, benzene rings and the like and can generate toxic or polluting substances, and the ignition point of the combustion improver is 150-500 ℃, such as a monomer or a polymer of organic matters such as hydrocarbons, alcohols, lipids, organic acids and the like.
Compared with the prior art, the invention has the following technical effects:
after boiling, oxidizing and roasting the waste cathode of the aluminum electrolytic cell, the aluminum electrolytic carbon slag or the electrolyte obtained by flotation of the waste cathode and the aluminum electrolytic carbon slag, the product is purer electrolyte, the carbon content is reduced to below 1 percent, other impurities are not added, the requirement of aluminum electrolysis can be met, and all the electrolyte is recycled; the temperature in the roasting process is low, and the energy consumption cost is low; in the whole process, the electrolyte is in a solid state, the electrolyte does not volatilize, the heated gas medium does not contain water, and the electrolyte basically does not hydrolyze, so that secondary pollution is not generated; no waste slag is generated in the whole process.
Detailed Description
The present invention will be further described with reference to the following embodiments.
Example 1:
using 40% carbon-containing aluminum cell waste cathode as raw material, crushing to less than or equal to 0.5 mm; in the initial stage of roasting, 5% of PE powder is added as a combustion improver, and the mixture is added into a fluidized bed furnace after being mixed with raw materials; the boiling gas is air, and the air inflow and the blanking amount are controlled to maintain the height of a boiling layer to be 100 cm; the boiling layer is provided with a horizontally arranged tube heat exchanger, and a heat exchange medium is water; the initial air inlet temperature is 500 ℃, after the combustion improver is combusted, the air inlet temperature and the water flow in the heat exchanger are controlled according to the temperature of a boiling layer, and the temperature of the boiling layer is controlled to be 500-700 ℃; the calcination time was 8 hours. The carbon content of the roasted product is less than or equal to 0.7 percent, the roasted product is an electrolyte with cryolite as the main component, and other fluorides or oxides containing elements such as sodium, aluminum, calcium, magnesium, potassium, lithium and the like can be recycled as the raw materials for aluminum electrolysis.
Example 2:
using 30% carbon-containing aluminum electrolysis carbon slag as a raw material, crushing the aluminum electrolysis carbon slag to be less than or equal to 0.5mm, and adding no combustion improver; the boiling gas is 50% of air and 50% of industrial oxygen, and the air inflow and the blanking amount are controlled to maintain the height of a boiling layer to be 150 cm; the boiling layer is provided with a horizontally arranged tubular heat exchanger with fins, and the heat exchange medium is water; the initial air inlet temperature is 700 ℃, after the reaction starts, the air inlet temperature is controlled according to the temperature of a boiling layer, and the temperature of the boiling layer is controlled to be 600-800 ℃; the calcination time was 3 hours. The carbon content of the roasted product is less than or equal to 0.6 percent, the roasted product is an electrolyte with cryolite as the main component, and other fluorides or oxides containing elements such as sodium, aluminum, calcium, magnesium, potassium, lithium and the like can be recycled as the raw materials for aluminum electrolysis.
Example 3:
the method comprises the following steps of (1) taking aluminum electrolysis carbon slag flotation electrolyte powder as a raw material, wherein the raw material contains 5% of carbon, adding 3-hydroxy-amino acid as a combustion improver in an initial roasting stage, and adding 10% of the combustion improver; the boiling gas is air, and the air inflow and the blanking amount are controlled to maintain the height of a boiling layer to be 30 cm; the boiling layer is provided with a horizontally arranged tube heat exchanger, and a heat exchange medium is nitrite molten salt; the initial air inlet temperature is 700 ℃, after the reaction starts, the air inlet temperature is controlled according to the temperature of a boiling layer, and the temperature of the boiling layer is controlled to be 600-800 ℃; the calcination time was 1 hour. The carbon content of the roasted product is less than or equal to 0.5 percent, the roasted product is an electrolyte with cryolite as the main component, and other fluorides or oxides containing elements such as sodium, aluminum, calcium, magnesium, potassium, lithium and the like can be recycled as the raw materials for aluminum electrolysis.
Example 4:
the method comprises the following steps of (1) taking waste cathode flotation electrolyte powder of an aluminum electrolytic cell as a raw material, wherein the raw material contains 7% of carbon, adding ethyl carboxyethyl cellulose solidified ethanol as a combustion improver at the initial stage of roasting, and adding 15% of the combustion improver; the boiling gas is 70% of air and 30% of industrial oxygen, and the air inflow and the blanking amount are controlled to maintain the height of a boiling layer to be 70 cm; the boiling layer is provided with a horizontally arranged tube heat exchanger, and a heat exchange medium is water; the initial air inlet temperature is 650 ℃, after the reaction starts, the air inlet temperature is controlled according to the temperature of a boiling layer, and the temperature of the boiling layer is controlled to be 600-800 ℃; the calcination time was 0.5 hour. The carbon content of the roasted product is less than or equal to 0.5 percent, the roasted product is an electrolyte with cryolite as the main component, and other fluorides or oxides containing elements such as sodium, aluminum, calcium, magnesium, potassium, lithium and the like can be recycled as the raw materials for aluminum electrolysis.
Example 5:
the mixture of the aluminum electrolysis cell waste cathode flotation electrolyte powder and the aluminum electrolysis carbon residue flotation electrolyte powder is used as a raw material, the raw material contains 6% of carbon, and no combustion improver is added; the boiling gas is air, and the air inflow and the blanking amount are controlled to maintain the height of a boiling layer to be 130 cm; the initial air inlet temperature is 700 ℃, after the reaction starts, the air inlet temperature is controlled according to the temperature of a boiling layer, and the temperature of the boiling layer is controlled to be 600-800 ℃; the calcination time was 0.75 hours. The carbon content of the roasted product is less than or equal to 0.5 percent, the roasted product is an electrolyte mainly comprising cryolite, and other fluorides or oxides containing elements such as sodium, aluminum, calcium, magnesium, potassium, lithium and the like can be recycled as the raw materials for aluminum electrolysis.
Example 6:
the mixture of the waste cathode of the aluminum electrolytic cell and the aluminum electrolytic carbon slag is used as a raw material, the mixture is crushed to be less than or equal to 0.5mm, the raw material contains 30 percent of carbon, and no combustion improver is added; the boiling gas is industrial oxygen, and the air inflow and the blanking amount are controlled to maintain the height of a boiling layer to be 200 cm; the initial air inlet temperature is 700 ℃, after the reaction starts, the air inlet temperature is controlled according to the temperature of a boiling layer, and the temperature of the boiling layer is controlled to be 550-750 ℃; the calcination time was 1.5 hours. The carbon content of the roasted product is less than or equal to 0.5 percent, the roasted product is an electrolyte with cryolite as the main component, and other fluorides or oxides containing elements such as sodium, aluminum, calcium, magnesium, potassium, lithium and the like can be recycled as the raw materials for aluminum electrolysis.
The above-mentioned embodiments are merely preferred embodiments of the present invention, which are merely illustrative and not restrictive, and it should be understood that other embodiments may be easily implemented by those skilled in the art by means of replacement or modification according to the technical contents disclosed in the specification, and therefore, all changes and modifications that come within the spirit and technical conditions of the present invention should be included in the claims of the present invention.
Claims (8)
1. A method for treating carbon-containing solid waste in the aluminum electrolysis industry is characterized by comprising the following steps:
Crushing the carbon-containing solid waste, and then adding the crushed carbon-containing solid waste into a fluidized bed furnace for roasting, wherein the boiling gas in the fluidized bed furnace is at least one of preheated air and industrial oxygen, the height of a boiling layer is 10-300 cm, the temperature of the boiling layer is maintained at 500-800 ℃, the roasting time is 0.1-10 hours, the carbon content of a roasted product is less than or equal to 1%, and the roasted product is recycled as a raw material for aluminum electrolysis.
2. The method for treating the carbon-containing solid waste in the aluminum electrolysis industry according to claim 1, wherein the carbon-containing solid waste comprises one or more of aluminum electrolysis cell waste cathodes, aluminum electrolysis cell waste cathode flotation carbon-containing electrolytes, aluminum electrolysis carbon residues and aluminum electrolysis carbon residue flotation carbon-containing electrolytes.
3. The method for treating the carbon-containing solid waste in the aluminum electrolysis industry according to claim 1, wherein the granularity of the crushed carbon-containing solid waste is less than or equal to 0.5 mm.
4. The method for treating the carbon-containing solid waste in the aluminum electrolysis industry as recited in claim 1, wherein the preheating temperature of the boiling gas is 50-800 ℃.
5. The method for treating the carbon-containing solid waste in the aluminum electrolysis industry as recited in claim 1, wherein a heat exchange device is arranged in the boiling layer for controlling the temperature of the boiling layer.
6. The method for treating the carbon-containing solid waste in the aluminum electrolysis industry according to claim 5, wherein the heat exchange device is a tube heat exchanger or a plate heat exchanger.
7. The method for treating the carbon-containing solid waste in the aluminum electrolysis industry according to claim 1, wherein a combustion improver is added into the carbon-containing solid waste, and the addition amount of the combustion improver is 0-20% of the mass of the carbon-containing solid waste.
8. The method as claimed in claim 7, wherein the combustion improver is one or more of hydrocarbon, alcohol, lipid, and organic acid monomer or polymer.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4021318A (en) * | 1974-12-10 | 1977-05-03 | Sumitomo Chemical Company, Limited | Process for producing aluminum |
| US4053375A (en) * | 1976-07-16 | 1977-10-11 | Dorr-Oliver Incorporated | Process for recovery of alumina-cryolite waste in aluminum production |
| CN1055768A (en) * | 1991-05-22 | 1991-10-30 | 抚顺铝厂 | Fluidized-bed roasting treatment method for aluminium electrolytic flue ash |
| CN107904621A (en) * | 2017-11-09 | 2018-04-13 | 北京科技大学 | A kind of regeneration treating method of waste cathode of aluminum electrolytic cell carbon block |
| CN112499658A (en) * | 2020-12-08 | 2021-03-16 | 矿冶科技集团有限公司 | Treatment method of aluminum electrolysis waste carbon slag and obtained regenerated cryolite |
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2022
- 2022-03-23 CN CN202210288910.9A patent/CN114751746A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4021318A (en) * | 1974-12-10 | 1977-05-03 | Sumitomo Chemical Company, Limited | Process for producing aluminum |
| US4053375A (en) * | 1976-07-16 | 1977-10-11 | Dorr-Oliver Incorporated | Process for recovery of alumina-cryolite waste in aluminum production |
| CN1055768A (en) * | 1991-05-22 | 1991-10-30 | 抚顺铝厂 | Fluidized-bed roasting treatment method for aluminium electrolytic flue ash |
| CN107904621A (en) * | 2017-11-09 | 2018-04-13 | 北京科技大学 | A kind of regeneration treating method of waste cathode of aluminum electrolytic cell carbon block |
| CN112499658A (en) * | 2020-12-08 | 2021-03-16 | 矿冶科技集团有限公司 | Treatment method of aluminum electrolysis waste carbon slag and obtained regenerated cryolite |
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