CA2737182A1 - Novel combined graphitized irregular cathode for aluminum and graphitized cathode stop block thereof - Google Patents
Novel combined graphitized irregular cathode for aluminum and graphitized cathode stop block thereof Download PDFInfo
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- 229910052782 aluminium Inorganic materials 0.000 title claims abstract description 82
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 title claims abstract description 82
- 230000001788 irregular Effects 0.000 title claims abstract description 33
- 239000000654 additive Substances 0.000 claims abstract description 34
- RHZUVFJBSILHOK-UHFFFAOYSA-N anthracen-1-ylmethanolate Chemical compound C1=CC=C2C=C3C(C[O-])=CC=CC3=CC2=C1 RHZUVFJBSILHOK-UHFFFAOYSA-N 0.000 claims abstract description 34
- 239000003830 anthracite Substances 0.000 claims abstract description 34
- 230000000996 additive effect Effects 0.000 claims abstract description 31
- 239000002008 calcined petroleum coke Substances 0.000 claims abstract description 30
- 239000002994 raw material Substances 0.000 claims abstract description 29
- 239000011300 coal pitch Substances 0.000 claims abstract description 19
- 238000005868 electrolysis reaction Methods 0.000 claims abstract description 18
- QYEXBYZXHDUPRC-UHFFFAOYSA-N B#[Ti]#B Chemical compound B#[Ti]#B QYEXBYZXHDUPRC-UHFFFAOYSA-N 0.000 claims abstract description 15
- 229910033181 TiB2 Inorganic materials 0.000 claims abstract description 15
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 4
- 239000000956 alloy Substances 0.000 claims abstract description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 54
- 229910052799 carbon Inorganic materials 0.000 claims description 54
- 239000000463 material Substances 0.000 claims description 32
- 238000004898 kneading Methods 0.000 claims description 21
- 239000000047 product Substances 0.000 claims description 20
- 238000005470 impregnation Methods 0.000 claims description 18
- 239000011265 semifinished product Substances 0.000 claims description 14
- 238000005087 graphitization Methods 0.000 claims description 13
- 238000003754 machining Methods 0.000 claims description 12
- 230000015572 biosynthetic process Effects 0.000 claims description 10
- 238000002156 mixing Methods 0.000 claims description 10
- 238000000034 method Methods 0.000 claims description 8
- 238000012216 screening Methods 0.000 claims description 3
- 230000000694 effects Effects 0.000 abstract description 5
- 230000002787 reinforcement Effects 0.000 abstract description 5
- 239000003792 electrolyte Substances 0.000 description 21
- 238000004519 manufacturing process Methods 0.000 description 15
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 13
- 229910010271 silicon carbide Inorganic materials 0.000 description 13
- 238000005299 abrasion Methods 0.000 description 8
- 238000002360 preparation method Methods 0.000 description 7
- 229910052717 sulfur Inorganic materials 0.000 description 7
- 239000011593 sulfur Substances 0.000 description 7
- 238000005516 engineering process Methods 0.000 description 6
- 239000002006 petroleum coke Substances 0.000 description 6
- 239000000203 mixture Substances 0.000 description 5
- 239000011819 refractory material Substances 0.000 description 5
- 239000011230 binding agent Substances 0.000 description 4
- 239000011329 calcined coke Substances 0.000 description 4
- 230000007547 defect Effects 0.000 description 4
- 239000011317 mixed pitch Substances 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 3
- 238000005265 energy consumption Methods 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 239000011295 pitch Substances 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- 229910021383 artificial graphite Inorganic materials 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 229910001610 cryolite Inorganic materials 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 230000008719 thickening Effects 0.000 description 2
- 239000010936 titanium Substances 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 229910000521 B alloy Inorganic materials 0.000 description 1
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- 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 1
- 229910001295 No alloy Inorganic materials 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 229910001069 Ti alloy Inorganic materials 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- SNAAJJQQZSMGQD-UHFFFAOYSA-N aluminum magnesium Chemical compound [Mg].[Al] SNAAJJQQZSMGQD-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 238000010000 carbonizing Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000005056 compaction Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000000280 densification Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000003487 electrochemical reaction Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 235000021384 green leafy vegetables Nutrition 0.000 description 1
- 239000011339 hard pitch Substances 0.000 description 1
- 238000003837 high-temperature calcination Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 239000012811 non-conductive material Substances 0.000 description 1
- 229910052755 nonmetal Inorganic materials 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 239000011334 petroleum pitch coke Substances 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Electrolytic Production Of Metals (AREA)
Abstract
A novel combined graphitized irregular cathode for aluminum comprises body blocks and graphitized cathode stop blocks; the graphitized cathode stop blocks are prepared from raw materials including: calcined petroleum coke, electrically calcined anthracite, coal pitch, TiB2 alloy additive and SiC additive. According to the invention, the graphitized cathode stop blocks are inlaid at a junction seam of two cathode body blocks in a manner of bridging over the cathode, thus electrode distance of aluminum electrolysis is shortened, cell voltage is lowered by about 0.35 volts to 0.5 volts; the energy per ton aluminum can be saved not less than 1000KWh to achieve prominent effect of energy-saving and consumption-reduction. The invention can avoid grooving in the middle of the body blocks reduces the effective thickness of body blocks to impact on life-span, but implement reinforcement of local structure on the junction seam of body blocks to prolong life-span of electrolytic cell.
Description
NOVEL COMBINED GRAPHITIZED IRREGULAR CATHODE FOR
ALUMINUM AND GRAPHITIZED CATHODE STOP BLOCK THEREOF
FIELD OF THE INVENTION
[00011 The invention belongs to the technical field of aluminum electrolysis, and more particularly relates to an aluminum electrolysis irregular cathode for preparing metal aluminum by fused salt electrolysis process and a graphitized cathode stop block thereof.
BACKGROUND OF THE INVENTION
[00021 Aluminum is prepared by alumina fused salt electrolysis process with the fundamental principal that: electrochemical reaction of molten A12O3 occurs under the action of direct currents between anode and cathode to separate Al/O, Al3+
acquires electrons constantly at cathode to form Al drops which are accumulated to create a large amount of aluminum electrolyte, while 02 loses electrons constantly at anode and is reacted with C to generate a large amount of C02, the chemical equation is expressed as 2A1203+3C=4A1+3CO2, and considerable electric energy is required during this reaction.
Direct current consumption of aluminum electrolysis is determined according to the following formula: direct current consumption = 2980xV/.t (V represents cell voltage that changes along with the change of electrode distance, and represents current effect, the current electrolytic cell has the current effect ranging from 0.93 to 0.95).
Practice has proved that: the distance (electrode distance for short) between the anode and the level of the aluminum electrolyte has a tremendous influence on the current consumption for electrolytic aluminum, and in case that the current common planar cathode is used, the direct current consumption for the production of metal aluminum by fused salt electrolysis process ranges from 13500 to 13800kWh/tAl. As aluminum electrolytic cell is influenced by charging, magnetic field, electric field, anode replacement, anode gaseous escape and other factors, fluctuation of the level of the aluminum electrolyte inside the cell could occur to form `turbulence', which, on one hand, can `stir' electrolyte to further reduce precipitation of electrolytes and favor production, on the other hand, leads to fluctuation of the liquid level so as to result in the increase of the `electrode distance', thereby raising current consumption, meanwhile, the `turbulence' is liable to cause abrasion to cathode to shorten the service life thereof.
[00031 In the aspect of the study and the invention of irregular cathode for aluminum, to reduce current consumption of aluminum electrolysis, traditional method is characterized in that stop block is prepared from the same raw materials as body block and usually integrated with body block, therefore, the service life and other properties of such an aluminum electrolysis cathode are dramatically limited, just as the overseas and domestic publication documents we have searched:
[00041 1. China Patent, Name: Aluminum Electrolytic Cell with Irregular Cathode Carbon Block Structure, Application (Patent) Number: 200710010523.4, Application Date:
2007.3.2, Classification Number: C25C3/08(2006.1) Applicant (Patent Right):
FENG, Naiyang, Abstract: The aluminum electrolytic cell with irregular cathode carbon block structure comprises a groove casing, a refractory heat-preserving material arranged at the bottom, an anode and a cathode, a plurality of raised structures are formed on the surface of a structurally irregular cathode carbon block, the aluminum electrolytic cell with cathode structure according to the invention can lessen flow rate of cathode aluminum electrolyte in the electrolytic cell and reduce fluctuation height of the aluminum electrolyte, in order to enhance the steadiness of the level of the metal aluminum electrolyte in the aluminum electrolytic cell, lower loss caused by aluminum dissolution, raise current efficiency, shorten electrode distance and reduce electric energy consumption for aluminum electrolysis, and mixture or precipitate of thick cryolite melt alumina can be formed between raised walls at the bottom of the cathode in order to prevent the cathode aluminum electrolyte from flowing to the bottom of the electrolytic cell through cracks and gaps at the bottom of the electrolytic cell to melt steel bar, thereby achieving the purpose of prolonging the service life of the electrolytic cell. A raised irregular cathode carbon block of the invention is integrated with body block by means of connection and is made of the same material as the cathode carbon block of traditional electrolytic cells, and the irregular cathode carbon block can be made of anthracite, or made of artificial graphite scrap or mixed material of anthracite and artificial graphite scrap, or be graphitized or semi- graphitized.
ALUMINUM AND GRAPHITIZED CATHODE STOP BLOCK THEREOF
FIELD OF THE INVENTION
[00011 The invention belongs to the technical field of aluminum electrolysis, and more particularly relates to an aluminum electrolysis irregular cathode for preparing metal aluminum by fused salt electrolysis process and a graphitized cathode stop block thereof.
BACKGROUND OF THE INVENTION
[00021 Aluminum is prepared by alumina fused salt electrolysis process with the fundamental principal that: electrochemical reaction of molten A12O3 occurs under the action of direct currents between anode and cathode to separate Al/O, Al3+
acquires electrons constantly at cathode to form Al drops which are accumulated to create a large amount of aluminum electrolyte, while 02 loses electrons constantly at anode and is reacted with C to generate a large amount of C02, the chemical equation is expressed as 2A1203+3C=4A1+3CO2, and considerable electric energy is required during this reaction.
Direct current consumption of aluminum electrolysis is determined according to the following formula: direct current consumption = 2980xV/.t (V represents cell voltage that changes along with the change of electrode distance, and represents current effect, the current electrolytic cell has the current effect ranging from 0.93 to 0.95).
Practice has proved that: the distance (electrode distance for short) between the anode and the level of the aluminum electrolyte has a tremendous influence on the current consumption for electrolytic aluminum, and in case that the current common planar cathode is used, the direct current consumption for the production of metal aluminum by fused salt electrolysis process ranges from 13500 to 13800kWh/tAl. As aluminum electrolytic cell is influenced by charging, magnetic field, electric field, anode replacement, anode gaseous escape and other factors, fluctuation of the level of the aluminum electrolyte inside the cell could occur to form `turbulence', which, on one hand, can `stir' electrolyte to further reduce precipitation of electrolytes and favor production, on the other hand, leads to fluctuation of the liquid level so as to result in the increase of the `electrode distance', thereby raising current consumption, meanwhile, the `turbulence' is liable to cause abrasion to cathode to shorten the service life thereof.
[00031 In the aspect of the study and the invention of irregular cathode for aluminum, to reduce current consumption of aluminum electrolysis, traditional method is characterized in that stop block is prepared from the same raw materials as body block and usually integrated with body block, therefore, the service life and other properties of such an aluminum electrolysis cathode are dramatically limited, just as the overseas and domestic publication documents we have searched:
[00041 1. China Patent, Name: Aluminum Electrolytic Cell with Irregular Cathode Carbon Block Structure, Application (Patent) Number: 200710010523.4, Application Date:
2007.3.2, Classification Number: C25C3/08(2006.1) Applicant (Patent Right):
FENG, Naiyang, Abstract: The aluminum electrolytic cell with irregular cathode carbon block structure comprises a groove casing, a refractory heat-preserving material arranged at the bottom, an anode and a cathode, a plurality of raised structures are formed on the surface of a structurally irregular cathode carbon block, the aluminum electrolytic cell with cathode structure according to the invention can lessen flow rate of cathode aluminum electrolyte in the electrolytic cell and reduce fluctuation height of the aluminum electrolyte, in order to enhance the steadiness of the level of the metal aluminum electrolyte in the aluminum electrolytic cell, lower loss caused by aluminum dissolution, raise current efficiency, shorten electrode distance and reduce electric energy consumption for aluminum electrolysis, and mixture or precipitate of thick cryolite melt alumina can be formed between raised walls at the bottom of the cathode in order to prevent the cathode aluminum electrolyte from flowing to the bottom of the electrolytic cell through cracks and gaps at the bottom of the electrolytic cell to melt steel bar, thereby achieving the purpose of prolonging the service life of the electrolytic cell. A raised irregular cathode carbon block of the invention is integrated with body block by means of connection and is made of the same material as the cathode carbon block of traditional electrolytic cells, and the irregular cathode carbon block can be made of anthracite, or made of artificial graphite scrap or mixed material of anthracite and artificial graphite scrap, or be graphitized or semi- graphitized.
[00051 According to the invention, improvement for the cathode structure of aluminum electrolysis is achieved to facilitate production and operation and obtain beneficial effect to a certain extent; however, the following defects are still present:
[00061 a) The raised part is made of the same material as the body and has the service life shorter than the body owing to large washout of the `turbulence' of the aluminum electrolyte, hence, the power saving effect decreases dramatically as the raised part abrades.
[00071 b) Greens are required to be manufactured to raised structures during the raised formation of surface, industrialization can be realized only after tremendous investment is applied to original production equipment for technological transformation as the current formation equipment, molds and roaster charging are inadaptable.
The raised parts on the surface of cathode are liable to cause cracked rejects even subsequent to the technological transformation.
[00081 c) Structural reinforcement is not implemented on the weak parts of cathode junction.
100091 d) It can be regarded as a misguidance that mixture or precipitate of thick cryolite melt alumina, which can be formed between raised walls at the bottom of cathode, is favorable for prolonging the service life of the electrolytic cell;
instead, this could only increase electric resistivity at the bottom of the electrolytic cell and generates unnecessary power consumption.
[00101 2. China Patent, Name: Novel Cathode-structured Aluminum Electrolytic Cell Capable of Reducing Abrasion of Raised Parts of Cathode, Application (Patent) Number:
200910248884.1, Classification Number: C25C3/08 (2006.1) I Applicant (Patent Right):
FENG, Naiyang, Address: 11-3, Qixiang 2#, Hubei Road, Nanhuwang, Heping District, Shenyang City, Liaoning Province, Abstract: A novel cathode-structured aluminum electrolytic cell capable of reducing the abrasion of raised parts of cathode is characterized in that: a raised structure, known as length-direction raised part, is processed on the edge of each cathode carbon block in the length direction; or a raised structure perpendicular to the length direction of the cathode carbon block, known as width-direction raised part, is processed at the upper part of each cathode carbon block; or the length-direction raised part and the width-direction raised part are simultaneously processed at the upper edge of the cathode carbon block. The middle part of the cathode carbon block is inlaid with a layer of wallboard made of refractory material, the wallboard forms, with the raised parts of the cathode carbon block, an integral raised part having the effect of reducing flow rate of aluminum electrolyte, lessening fluctuation of aluminum electrolyte and enhancing steadiness of the level of the aluminum electrolyte in electrolytic cell, and after the raised parts of the cathode carbon block are abraded, the wallboard made of refractory material can continuously play the role of reducing flow rate of aluminum electrolyte owing to the smaller electrochemical abrasiveness than carbon. Claims: A novel cathode-structured aluminum electrolytic cell capable of reducing the abrasion of raised parts of cathode, characterized in that: a raised structure, known as length-direction raised part, is processed on the edge of each cathode carbon block in the length direction; or a raised structure perpendicular to the length direction of the cathode carbon block, known as width-direction raised part, is processed at the upper part of each cathode carbon block; or the length-direction raised part and the width-direction raised part are simultaneously processed at the upper edge of the cathode carbon block; the three structures are as below:
(1) the length-direction raised part, which has the raised height ranging from 10 to 18 centimeters and the raised width ranging from 5 to 15 centimeters in the length direction, is processed and also positioned on the edge of each cathode carbon block in the length direction, and the horizontal distance between the outer surface of the length-direction raised part and the edge of the cathode carbon block is from 1 to 3 centimeters, a middle seam of two adjacent cathode carbon blocks are in tamped connection with each other through carbon tamping paste which has the height equal to that of the cathode carbon block, a wallboard made of refractory material is laid on the upper surface of the tamping paste of two adjacent cathode carbon blocks, and between every two adjacent cathode carbon blocks, the raised parts on the edge of the two adjacent cathode carbon blocks in the length direction and the wallboard made of refractory material constitute an integral length-direction raised part; (2) the length-direction raised part and the width-direction raised part are simultaneously processed at the upper part of the cathode carbon block with the width-direction raised part being positioned between the two integral length-direction raised parts described above and being integrated with the cathode carbon block, and on each cathode carbon block, the distance between the width-direction raised part and the integral length-direction raised parts adjacent thereto is from 5 to 10 centimeters; and (3) the width-direction raised parts are processed at the upper part of the cathode carbon block, and on each cathode carbon block, the distance between every two width-direction raised parts is from 20 to 40 centimeters, the height and the width of the width-direction raised parts are respectively from 10 to 18 centimeters and from 18 to 30 centimeters, and the length of the width-direction raised parts is consistent with or smaller by 2 to 6 centimeters than the width of the cathode carbon block.
[00111 In addition to the technical problems same as the patent 1, the invention also has the problem that the use of refractory material, i.e. non-conductive material, inevitably leads to the increase of electric resistivity of cell to further increase power consumption, which departs from the energy saving objective.
[00121 3. China Patent, Name: Components of Hard Graphitized Cathode Carbon Block and Manufacturing Method thereof, Application (Patent) Number:
200910210043.1, Application Date: 2009.11.04, Applicant (Patent Right): Luoyang Xin'an Electric Power Group Wanji Graphite Product Co., Ltd., Abstract: The invention discloses components of a hard graphitized cathode carbon block for aluminum electrolytic cell and a manufacturing method thereof: a manufacturing method of the graphitized cathode carbon block, containing 15 to 17% of binder and 83 to 85% of electrically calcined anthracite, comprises the following steps of, smashing-screening-material mixing-kneading-material cooling-vibratory compaction-roasting- graphitization- machining; according to the invention, the abrasiveness of carbon block is reduced owing to the large intensity of carbon block, which is favorable for prolonging the service life of electrolytic cell; and the fracture sensitivity of carbon block is reduced owing to the excellent deformation ability thereof; and in the aspect of electrical properties, lower electric resistivity is achieved to reduce cathode drop, therefore, the purpose of better saving energy and lowering consumption is reached.
[00131 4. China Patent, Name: Abrasion-Resistant Graphitized Cathode Carbon Block for Aluminum Electrolytic Cell and Manufacturing Method thereof, Application (Patent) Number: 200910167718.9 Application Date: 2009.9.23, Applicant (Patent Right):
Sichuan Guanghan Shida Carbon Co., Ltd. Abstract: The invention discloses an abrasion-resistant graphitized cathode carbon block for aluminum electrolytic cell and a manufacturing method thereof, relating to the field of nonmetal material of metallurgical engineering material. According to the invention, high-sulfur petroleum coke with the sulfur content reaching 1 to 3% is used as one of the raw materials for manufacturing the graphitized cathode carbon block, and the proportions of the raw materials are as below:
80 to 85% of high-sulfur petroleum coke with the sulfur content reaching 1 to 3%, and 15 to 20% of modified coal pitch; during working operation, secondary high temperature calcination is adopted to effectively remove the sulfur in the high-sulfur petroleum coke;
the working operations of impregnation and secondary roasting in the prior art are replaced by large vibratory compaction and lengthwise graphitization technologies; the graphitization time of products is reduced by over 50%, thereby reducing energy consumption and cost. The high-sulfur petroleum coke, an inferior raw material which can only be used as fuel or sintering aid originally, is effectively utilized. The manufactured abrasion-resistant graphitized cathode carbon block has high intensity, low porosity and good resistance to washout and abrasion of aluminum electrolyte, enhances the service life of electrolytic cell, and is suitable for the use as cathode lining of large electrolytic cell, and especially for the use in the electrolytic cell with over 400kA.
[00141 5. China Patent, Name: Graphitized Cathode Carbon Block for Aluminum Electrolytic Cell, Application (Patent) Number: 200810068782.7, Application Date:
2008.6.19, Applicant (Patent Right): Aluminum Corporation of China Limited, Abstract:
The invention discloses a graphitized cathode carbon block for aluminum electrolytic cell, which consists of calcined coke and mixed pitch, wherein the calcined coke accounts for 81 to 83% of the total weight of the graphitized cathode carbon block and the mixed pitch accounts for 17 to 19%. The mixed pitch consists of modified pitch and tar with the modified pitch accounting for 78 to 82% of the total weight of the mixed pitch and the tar accounting for 18 to 22%. The grain size of the calcined coke is smaller than 4.6 millimeters, wherein the granular grain size ranging from 4.5 to 3 millimeters accounts for 15.5+2%, the granular grain size ranging from 3 to 1 millimeter accounts for 15 2%, and the granular grain size smaller than 1 millimeter accounts for 21+2%; and powder accounts for 48.5 2%. The grain size of the calcined coke is 200 meshes accounting for 50 3%.
Compared with the prior art, the invention reduces the electric resistivity of cathode carbon block prominently, enhances the electric conductivity of cathode paste and raises sodium corrosion resistance of cathode carbon block, so that the quality of the graphitized cathode carbon block product is remarkably enhanced, the surrounding environment of aluminum electrolysis factory building is improved, the cell voltage is reduced, the service life of aluminum electrolytic cell is prolonged, and energy consumption and manufacturing cost are lowered, etc.
[00151 6. China Patent, Name: Graphitized Cathode Production Technology, Application (Patent) Number: 200410040135.7 Application Date: 2004.7.2, Applicant (Patent Right): Guiyang Aluminum Magnesium Design & Research Institute, Abstract:
The invention discloses a graphitized cathode production technology, which comprises the steps of: selecting and mixing petroleum coke and pitch coke, calcining, smashing and screening the mixture, mixing and then adding hard pitch binder to the mixture, kneading and processing the mixture into a carbon block blank shape of the cathode required by electrolytic cell, and carbonizing the pitch binder by means of fusing to obtain graphitized cathode carbon block. The invention has the advantages of superior mechanical, electrical and thermal properties and is particularly suitable for the use in large electrolytic cell.
[00161 Taken together, the patents 3-6 include the following defects:
[00171 1) Reinforced material and thickening material are not used in formula, so the compactness is inferior and the intensity is low.
[00181 2) Large grain size (4 millimeters at most) of the raw materials in formula leads to low density, poor homogeneousness and inferior abrasion and washout resistances.
[00191 3) Introduction of no alloy additive not only results in the limited reduction of cathode drop in the aspect of electrical properties, but also limits energy saving and consumption reduction.
[00201 4) Since the graphitization temperature is above 2100 C, the optimization for performance indexes and the reduction for defects of the internal structure of product cannot be realized.
SUMMARY OF THE INVENTION
[00211 Given the problems described above, the invention aims at providing a novel combined graphitized irregular cathode for aluminum, which can be prepared by current equipment at low cost, has long service life of stop blocks (as long as electrolytic cell), simultaneously implements structural reinforcement on weak parts of the junction of two cathode body blocks, and solves the technical problem that aluminum electrolyte is liable to leakage from the junction of two cathode body blocks, and further providing a graphitized cathode stop block which is indispensable for constituting the novel combined graphitized irregular cathode for aluminum and has simple modified operation, high density, high intensity and long service life, and a preparation method thereof.
[00221 The invention is implemented in such a manner that:
[00231 A novel combined graphitized irregular cathode for aluminum comprises body blocks and graphitized cathode stop blocks, longitudinal edges of the body blocks are symmetrically provided with two groups of grooves, the graphitized cathode stop blocks made of the material different from the body blocks are inlaid inside the groove combined by the two grooves in a manner of bridging over a junction seam between the two body blocks, and the graphitized cathode stop blocks are tamped on the body blocks through paste, i.e. the stop blocks are inlaid on the junction seam between the two cathode body blocks in a manner of bridging over the cathode. The external dimension of the body blocks and the stop blocks, the inlaying manner and the machining requirement can be determined in accordance with the dimension of electrolytic cell and the installed capacity of transformer.
[00241 The novel combined graphitized irregular cathode for aluminum described above is characterized in that: the body blocks are made of carbon block material for common aluminum electrolysis and the stop blocks are made of graphitized material for aluminum electrolysis.
[00251 The distance between the graphitized cathode stop blocks described above and the transverse outer edge of the body blocks is from 300 to 380 millimeters so that the stop blocks are not damaged or loosened by collision during the operation or the maintenance of the anode of the aluminum electrolytic cell, and the spacing between the two graphitized cathode stop blocks is from 300 to 350 millimeters so as to facilitate the charging of the electrolytic cell.
[00261 The novel combined graphitized irregular cathode for aluminum described above is characterized in that: the junction seam between the body blocks is tamped through paste.
[00271 The novel combined graphitized irregular cathode for aluminum described above is characterized in that: the grooves are 100 to 150 millimeters deep and 80 to 100 millimeters wide.
[00281 The novel combined graphitized irregular cathode for aluminum described above is characterized in that: the graphitized cathode stop blocks have rectangular or convex cross section; and in case of the convex cross section, chamfer angles, from 135 to 175 and 30 to 60 millimeters high, are arranged on the top end of the graphitized cathode stop blocks.
[00291 The graphitized cathode stop block constituting the novel combined graphitized irregular cathode for aluminum is prepared from the following raw materials in parts by weight:
TiB2 alloy additive 1 to 8 parts;
calcined petroleum coke 40 to 85 parts;
Electrically calcined anthracite 1 to 40 parts;
Coal pitch 15 to 25 parts;
SiC additive 1 to 15 parts.
100301 The graphitized cathode stop block described above is characterized in that: the grain size of both the calcined petroleum coke and the electrically calcined anthracite is 0 to 2 millimeters.
[00311 Both the TiB2 (titanium boride) additive and the SiC (silicon carbide) additive described above are selected from commercially pure additives with the grain size smaller than or equal to 40 microns, and these two additives are easily commercially available for the skilled in this art.
[00321 The calcined petroleum coke in raw materials reduces the ash content and enhances the electrical conductivity of product by means of low ash content and easy graphitization property of petroleum coke.
[00331 The electrically calcined anthracite in raw materials enhances the washout resistance, the density and the intensity of product by means of low electric resistivity and high compactness thereof.
[0034] The coal pitch in raw materials is used as binder for binding various materials, in order to form a firm carbon binding grid.
[00351 The SiC (silicon carbide) additive in raw materials is used as reinforcement for pore pinning inside product, in order to enhance the density and the intensity of product.
[00361 The TiB2 (titanium boride) additive in raw materials is capable of stabilizing the fluctuation of aluminum electrolyte owing to the humidification property thereof for molten aluminum electrolyte, and simultaneously realizes lower electric resistivity in the aspect of electrical properties to further lower cathode drop, reduce electrode distance and save power.
[00371 The method for preparing the graphitized cathode stop block comprises the following steps of:
(1) Smashing calcined petroleum coke and electrically calcined anthracite;
(2) Screening the smashed calcined petroleum coke and electrically calcined anthracite according to the requirement of grain size;
(3) material mixing: the electrically calcined anthracite, the calcined petroleum coke, the Pt boron/titanium alloy additive and the SiC additive are put in a kneading ladle according to the proportion of the raw materials thereof;
(4) kneading: dry kneading is implemented for 20 to 40 minutes at the temperature ranging from 40 to 165 C; and wet kneading is implemented for 35 to 50 minutes at the temperature ranging from 150 to 170 C;
[00061 a) The raised part is made of the same material as the body and has the service life shorter than the body owing to large washout of the `turbulence' of the aluminum electrolyte, hence, the power saving effect decreases dramatically as the raised part abrades.
[00071 b) Greens are required to be manufactured to raised structures during the raised formation of surface, industrialization can be realized only after tremendous investment is applied to original production equipment for technological transformation as the current formation equipment, molds and roaster charging are inadaptable.
The raised parts on the surface of cathode are liable to cause cracked rejects even subsequent to the technological transformation.
[00081 c) Structural reinforcement is not implemented on the weak parts of cathode junction.
100091 d) It can be regarded as a misguidance that mixture or precipitate of thick cryolite melt alumina, which can be formed between raised walls at the bottom of cathode, is favorable for prolonging the service life of the electrolytic cell;
instead, this could only increase electric resistivity at the bottom of the electrolytic cell and generates unnecessary power consumption.
[00101 2. China Patent, Name: Novel Cathode-structured Aluminum Electrolytic Cell Capable of Reducing Abrasion of Raised Parts of Cathode, Application (Patent) Number:
200910248884.1, Classification Number: C25C3/08 (2006.1) I Applicant (Patent Right):
FENG, Naiyang, Address: 11-3, Qixiang 2#, Hubei Road, Nanhuwang, Heping District, Shenyang City, Liaoning Province, Abstract: A novel cathode-structured aluminum electrolytic cell capable of reducing the abrasion of raised parts of cathode is characterized in that: a raised structure, known as length-direction raised part, is processed on the edge of each cathode carbon block in the length direction; or a raised structure perpendicular to the length direction of the cathode carbon block, known as width-direction raised part, is processed at the upper part of each cathode carbon block; or the length-direction raised part and the width-direction raised part are simultaneously processed at the upper edge of the cathode carbon block. The middle part of the cathode carbon block is inlaid with a layer of wallboard made of refractory material, the wallboard forms, with the raised parts of the cathode carbon block, an integral raised part having the effect of reducing flow rate of aluminum electrolyte, lessening fluctuation of aluminum electrolyte and enhancing steadiness of the level of the aluminum electrolyte in electrolytic cell, and after the raised parts of the cathode carbon block are abraded, the wallboard made of refractory material can continuously play the role of reducing flow rate of aluminum electrolyte owing to the smaller electrochemical abrasiveness than carbon. Claims: A novel cathode-structured aluminum electrolytic cell capable of reducing the abrasion of raised parts of cathode, characterized in that: a raised structure, known as length-direction raised part, is processed on the edge of each cathode carbon block in the length direction; or a raised structure perpendicular to the length direction of the cathode carbon block, known as width-direction raised part, is processed at the upper part of each cathode carbon block; or the length-direction raised part and the width-direction raised part are simultaneously processed at the upper edge of the cathode carbon block; the three structures are as below:
(1) the length-direction raised part, which has the raised height ranging from 10 to 18 centimeters and the raised width ranging from 5 to 15 centimeters in the length direction, is processed and also positioned on the edge of each cathode carbon block in the length direction, and the horizontal distance between the outer surface of the length-direction raised part and the edge of the cathode carbon block is from 1 to 3 centimeters, a middle seam of two adjacent cathode carbon blocks are in tamped connection with each other through carbon tamping paste which has the height equal to that of the cathode carbon block, a wallboard made of refractory material is laid on the upper surface of the tamping paste of two adjacent cathode carbon blocks, and between every two adjacent cathode carbon blocks, the raised parts on the edge of the two adjacent cathode carbon blocks in the length direction and the wallboard made of refractory material constitute an integral length-direction raised part; (2) the length-direction raised part and the width-direction raised part are simultaneously processed at the upper part of the cathode carbon block with the width-direction raised part being positioned between the two integral length-direction raised parts described above and being integrated with the cathode carbon block, and on each cathode carbon block, the distance between the width-direction raised part and the integral length-direction raised parts adjacent thereto is from 5 to 10 centimeters; and (3) the width-direction raised parts are processed at the upper part of the cathode carbon block, and on each cathode carbon block, the distance between every two width-direction raised parts is from 20 to 40 centimeters, the height and the width of the width-direction raised parts are respectively from 10 to 18 centimeters and from 18 to 30 centimeters, and the length of the width-direction raised parts is consistent with or smaller by 2 to 6 centimeters than the width of the cathode carbon block.
[00111 In addition to the technical problems same as the patent 1, the invention also has the problem that the use of refractory material, i.e. non-conductive material, inevitably leads to the increase of electric resistivity of cell to further increase power consumption, which departs from the energy saving objective.
[00121 3. China Patent, Name: Components of Hard Graphitized Cathode Carbon Block and Manufacturing Method thereof, Application (Patent) Number:
200910210043.1, Application Date: 2009.11.04, Applicant (Patent Right): Luoyang Xin'an Electric Power Group Wanji Graphite Product Co., Ltd., Abstract: The invention discloses components of a hard graphitized cathode carbon block for aluminum electrolytic cell and a manufacturing method thereof: a manufacturing method of the graphitized cathode carbon block, containing 15 to 17% of binder and 83 to 85% of electrically calcined anthracite, comprises the following steps of, smashing-screening-material mixing-kneading-material cooling-vibratory compaction-roasting- graphitization- machining; according to the invention, the abrasiveness of carbon block is reduced owing to the large intensity of carbon block, which is favorable for prolonging the service life of electrolytic cell; and the fracture sensitivity of carbon block is reduced owing to the excellent deformation ability thereof; and in the aspect of electrical properties, lower electric resistivity is achieved to reduce cathode drop, therefore, the purpose of better saving energy and lowering consumption is reached.
[00131 4. China Patent, Name: Abrasion-Resistant Graphitized Cathode Carbon Block for Aluminum Electrolytic Cell and Manufacturing Method thereof, Application (Patent) Number: 200910167718.9 Application Date: 2009.9.23, Applicant (Patent Right):
Sichuan Guanghan Shida Carbon Co., Ltd. Abstract: The invention discloses an abrasion-resistant graphitized cathode carbon block for aluminum electrolytic cell and a manufacturing method thereof, relating to the field of nonmetal material of metallurgical engineering material. According to the invention, high-sulfur petroleum coke with the sulfur content reaching 1 to 3% is used as one of the raw materials for manufacturing the graphitized cathode carbon block, and the proportions of the raw materials are as below:
80 to 85% of high-sulfur petroleum coke with the sulfur content reaching 1 to 3%, and 15 to 20% of modified coal pitch; during working operation, secondary high temperature calcination is adopted to effectively remove the sulfur in the high-sulfur petroleum coke;
the working operations of impregnation and secondary roasting in the prior art are replaced by large vibratory compaction and lengthwise graphitization technologies; the graphitization time of products is reduced by over 50%, thereby reducing energy consumption and cost. The high-sulfur petroleum coke, an inferior raw material which can only be used as fuel or sintering aid originally, is effectively utilized. The manufactured abrasion-resistant graphitized cathode carbon block has high intensity, low porosity and good resistance to washout and abrasion of aluminum electrolyte, enhances the service life of electrolytic cell, and is suitable for the use as cathode lining of large electrolytic cell, and especially for the use in the electrolytic cell with over 400kA.
[00141 5. China Patent, Name: Graphitized Cathode Carbon Block for Aluminum Electrolytic Cell, Application (Patent) Number: 200810068782.7, Application Date:
2008.6.19, Applicant (Patent Right): Aluminum Corporation of China Limited, Abstract:
The invention discloses a graphitized cathode carbon block for aluminum electrolytic cell, which consists of calcined coke and mixed pitch, wherein the calcined coke accounts for 81 to 83% of the total weight of the graphitized cathode carbon block and the mixed pitch accounts for 17 to 19%. The mixed pitch consists of modified pitch and tar with the modified pitch accounting for 78 to 82% of the total weight of the mixed pitch and the tar accounting for 18 to 22%. The grain size of the calcined coke is smaller than 4.6 millimeters, wherein the granular grain size ranging from 4.5 to 3 millimeters accounts for 15.5+2%, the granular grain size ranging from 3 to 1 millimeter accounts for 15 2%, and the granular grain size smaller than 1 millimeter accounts for 21+2%; and powder accounts for 48.5 2%. The grain size of the calcined coke is 200 meshes accounting for 50 3%.
Compared with the prior art, the invention reduces the electric resistivity of cathode carbon block prominently, enhances the electric conductivity of cathode paste and raises sodium corrosion resistance of cathode carbon block, so that the quality of the graphitized cathode carbon block product is remarkably enhanced, the surrounding environment of aluminum electrolysis factory building is improved, the cell voltage is reduced, the service life of aluminum electrolytic cell is prolonged, and energy consumption and manufacturing cost are lowered, etc.
[00151 6. China Patent, Name: Graphitized Cathode Production Technology, Application (Patent) Number: 200410040135.7 Application Date: 2004.7.2, Applicant (Patent Right): Guiyang Aluminum Magnesium Design & Research Institute, Abstract:
The invention discloses a graphitized cathode production technology, which comprises the steps of: selecting and mixing petroleum coke and pitch coke, calcining, smashing and screening the mixture, mixing and then adding hard pitch binder to the mixture, kneading and processing the mixture into a carbon block blank shape of the cathode required by electrolytic cell, and carbonizing the pitch binder by means of fusing to obtain graphitized cathode carbon block. The invention has the advantages of superior mechanical, electrical and thermal properties and is particularly suitable for the use in large electrolytic cell.
[00161 Taken together, the patents 3-6 include the following defects:
[00171 1) Reinforced material and thickening material are not used in formula, so the compactness is inferior and the intensity is low.
[00181 2) Large grain size (4 millimeters at most) of the raw materials in formula leads to low density, poor homogeneousness and inferior abrasion and washout resistances.
[00191 3) Introduction of no alloy additive not only results in the limited reduction of cathode drop in the aspect of electrical properties, but also limits energy saving and consumption reduction.
[00201 4) Since the graphitization temperature is above 2100 C, the optimization for performance indexes and the reduction for defects of the internal structure of product cannot be realized.
SUMMARY OF THE INVENTION
[00211 Given the problems described above, the invention aims at providing a novel combined graphitized irregular cathode for aluminum, which can be prepared by current equipment at low cost, has long service life of stop blocks (as long as electrolytic cell), simultaneously implements structural reinforcement on weak parts of the junction of two cathode body blocks, and solves the technical problem that aluminum electrolyte is liable to leakage from the junction of two cathode body blocks, and further providing a graphitized cathode stop block which is indispensable for constituting the novel combined graphitized irregular cathode for aluminum and has simple modified operation, high density, high intensity and long service life, and a preparation method thereof.
[00221 The invention is implemented in such a manner that:
[00231 A novel combined graphitized irregular cathode for aluminum comprises body blocks and graphitized cathode stop blocks, longitudinal edges of the body blocks are symmetrically provided with two groups of grooves, the graphitized cathode stop blocks made of the material different from the body blocks are inlaid inside the groove combined by the two grooves in a manner of bridging over a junction seam between the two body blocks, and the graphitized cathode stop blocks are tamped on the body blocks through paste, i.e. the stop blocks are inlaid on the junction seam between the two cathode body blocks in a manner of bridging over the cathode. The external dimension of the body blocks and the stop blocks, the inlaying manner and the machining requirement can be determined in accordance with the dimension of electrolytic cell and the installed capacity of transformer.
[00241 The novel combined graphitized irregular cathode for aluminum described above is characterized in that: the body blocks are made of carbon block material for common aluminum electrolysis and the stop blocks are made of graphitized material for aluminum electrolysis.
[00251 The distance between the graphitized cathode stop blocks described above and the transverse outer edge of the body blocks is from 300 to 380 millimeters so that the stop blocks are not damaged or loosened by collision during the operation or the maintenance of the anode of the aluminum electrolytic cell, and the spacing between the two graphitized cathode stop blocks is from 300 to 350 millimeters so as to facilitate the charging of the electrolytic cell.
[00261 The novel combined graphitized irregular cathode for aluminum described above is characterized in that: the junction seam between the body blocks is tamped through paste.
[00271 The novel combined graphitized irregular cathode for aluminum described above is characterized in that: the grooves are 100 to 150 millimeters deep and 80 to 100 millimeters wide.
[00281 The novel combined graphitized irregular cathode for aluminum described above is characterized in that: the graphitized cathode stop blocks have rectangular or convex cross section; and in case of the convex cross section, chamfer angles, from 135 to 175 and 30 to 60 millimeters high, are arranged on the top end of the graphitized cathode stop blocks.
[00291 The graphitized cathode stop block constituting the novel combined graphitized irregular cathode for aluminum is prepared from the following raw materials in parts by weight:
TiB2 alloy additive 1 to 8 parts;
calcined petroleum coke 40 to 85 parts;
Electrically calcined anthracite 1 to 40 parts;
Coal pitch 15 to 25 parts;
SiC additive 1 to 15 parts.
100301 The graphitized cathode stop block described above is characterized in that: the grain size of both the calcined petroleum coke and the electrically calcined anthracite is 0 to 2 millimeters.
[00311 Both the TiB2 (titanium boride) additive and the SiC (silicon carbide) additive described above are selected from commercially pure additives with the grain size smaller than or equal to 40 microns, and these two additives are easily commercially available for the skilled in this art.
[00321 The calcined petroleum coke in raw materials reduces the ash content and enhances the electrical conductivity of product by means of low ash content and easy graphitization property of petroleum coke.
[00331 The electrically calcined anthracite in raw materials enhances the washout resistance, the density and the intensity of product by means of low electric resistivity and high compactness thereof.
[0034] The coal pitch in raw materials is used as binder for binding various materials, in order to form a firm carbon binding grid.
[00351 The SiC (silicon carbide) additive in raw materials is used as reinforcement for pore pinning inside product, in order to enhance the density and the intensity of product.
[00361 The TiB2 (titanium boride) additive in raw materials is capable of stabilizing the fluctuation of aluminum electrolyte owing to the humidification property thereof for molten aluminum electrolyte, and simultaneously realizes lower electric resistivity in the aspect of electrical properties to further lower cathode drop, reduce electrode distance and save power.
[00371 The method for preparing the graphitized cathode stop block comprises the following steps of:
(1) Smashing calcined petroleum coke and electrically calcined anthracite;
(2) Screening the smashed calcined petroleum coke and electrically calcined anthracite according to the requirement of grain size;
(3) material mixing: the electrically calcined anthracite, the calcined petroleum coke, the Pt boron/titanium alloy additive and the SiC additive are put in a kneading ladle according to the proportion of the raw materials thereof;
(4) kneading: dry kneading is implemented for 20 to 40 minutes at the temperature ranging from 40 to 165 C; and wet kneading is implemented for 35 to 50 minutes at the temperature ranging from 150 to 170 C;
(5) Forming: the kneaded raw materials are put in a mold for formation;
(6) roasting: the formed semi-finished product is subjected to primary roasting, then to high pressure impregnation with molten coal pitch and finally to secondary roasting at low temperature ranging from 700 to 850 C; the degree of vacuum of the high pressure impregnation is not less than -0.092MPa and the pressure thereof is not less than 1.5MPa;
(7) low-temperature graphitization: the temperature ranges from 1800 to 2000 C;
(8) Machining: machining is performed according to the dimensional requirement of finished product to obtain the graphitized cathode stop block.
[00381 Compared with the prior art, the novel combined graphitized irregular cathode for aluminum and the graphitized cathode stop block thereof according to the invention have the following advantages of:
(1) the energy-saving graphitized irregular cathode is formed by inlaying stop blocks on a junction seam between two cathode body blocks in a manner of bridging over cathode, and through the raised stop blocks, the cathode can stabilize the level of aluminum electrolyte to shorten the electrode distance by not less than 10 millimeters and reduce cell voltage by about 0.35 to 5V, thus the purpose that the power consumption of electrolysis aluminum per ton is saved by not less than 1000kWh is reached;
(2) inlaying the stop blocks in a manner of bridging over the cathode can not only avoid that grooving in the middle of the body blocks reduces the effective thickness of the body blocks to further impact on the service life thereof, but can also implement reinforcement of local structure on the weak parts (the junction seam) of the body blocks in order to prolong the service life of electrolytic cell;
(3) the productions of the body block and the stop block are performed based on different materials, thereby achieving well-directed quality improvement and simple implementation as well as lowering cost;
(4) No variation is applied to current body equipment, molds, furnace types and the like in the production process of the cathode, and operability is strong;
NlIP002-1 CA
(5) in use, grooving is simple and consistent with current aluminum electrolysis technologies;
(6) The graphitized cathode stop block is prepared based on the formula in which fine grains with the maximal grain size not more than 2 millimeters are adopted, thus the intensity, density, homogeneousness and corrosion and washout resistances of product are enhanced;
(7) By introducing the reinforced and thickening materials (electrically calcined anthracite and SiC additive) into the graphitized cathode stop block, the mechanical properties of product are further enhanced;
(8) with the TiB2 alloy additive added to the graphitized cathode stop block, the fluctuation of aluminum electrolyte can be stabilized owing to the humidification property of TiB2 for molten aluminum electrolyte, and lower electric resistivity in the aspect of electrical properties is simultaneously realized to further lower cathode drop, thus the purpose of saving energy and reducing consumption better is reached;
[00381 Compared with the prior art, the novel combined graphitized irregular cathode for aluminum and the graphitized cathode stop block thereof according to the invention have the following advantages of:
(1) the energy-saving graphitized irregular cathode is formed by inlaying stop blocks on a junction seam between two cathode body blocks in a manner of bridging over cathode, and through the raised stop blocks, the cathode can stabilize the level of aluminum electrolyte to shorten the electrode distance by not less than 10 millimeters and reduce cell voltage by about 0.35 to 5V, thus the purpose that the power consumption of electrolysis aluminum per ton is saved by not less than 1000kWh is reached;
(2) inlaying the stop blocks in a manner of bridging over the cathode can not only avoid that grooving in the middle of the body blocks reduces the effective thickness of the body blocks to further impact on the service life thereof, but can also implement reinforcement of local structure on the weak parts (the junction seam) of the body blocks in order to prolong the service life of electrolytic cell;
(3) the productions of the body block and the stop block are performed based on different materials, thereby achieving well-directed quality improvement and simple implementation as well as lowering cost;
(4) No variation is applied to current body equipment, molds, furnace types and the like in the production process of the cathode, and operability is strong;
NlIP002-1 CA
(5) in use, grooving is simple and consistent with current aluminum electrolysis technologies;
(6) The graphitized cathode stop block is prepared based on the formula in which fine grains with the maximal grain size not more than 2 millimeters are adopted, thus the intensity, density, homogeneousness and corrosion and washout resistances of product are enhanced;
(7) By introducing the reinforced and thickening materials (electrically calcined anthracite and SiC additive) into the graphitized cathode stop block, the mechanical properties of product are further enhanced;
(8) with the TiB2 alloy additive added to the graphitized cathode stop block, the fluctuation of aluminum electrolyte can be stabilized owing to the humidification property of TiB2 for molten aluminum electrolyte, and lower electric resistivity in the aspect of electrical properties is simultaneously realized to further lower cathode drop, thus the purpose of saving energy and reducing consumption better is reached;
(9) The density and the intensity of product are further enhanced by adopting high-pressure impregnation and secondary roasting densification technologies for the graphitized cathode stop block;
(10) low temperature graphitization technology is adopted for the graphitized cathode stop block in order to optimize the mechanical, electrical and thermal properties as well as the performance indexes of product and to reduce the defects of the internal structure of product;
(11) The invention can save energy by more than 1000kWh for more than 2200 days.
BRIEF DESCRIPTION OF THE DRAWINGS
[00391 Figure 1 is a stereogram of the novel combined graphitized irregular cathode for aluminum of the invention;
[00401 Figure 2 is a top view of the Figure 1;
[00411 Figure 3 is a right view of the Figure 1; and [00421 Figure 4 is a process flow diagram of the graphitized cathode stop block.
[00431 In the figures, 1 represents body block, 2 represents junction seam, 3 represents graphitized cathode stop block, 4 represents groove and 5 represents top end chamfer angle.
DETAILED DESCRIPTION OF THE INVENTION
[00441 Embodiment 1:
[00451 The preparation of the graphitized cathode stop block comprises the following steps that: 1 part of calcined anthracite and 40 parts of electrically calcined petroleum coke based on mass proportion are smashed; the smashed electrically calcined anthracite and calcined petroleum coke are screened according to requirement of grain size to obtain grains with the grain size of 0 millimeter; the screened electrically calcined anthracite and calcined petroleum coke, conforming to the requirement, are put in a kneading ladle together with 1 part of 40 microns commercially pure TiB2 additive and 1 part of 40 microns commercially pure SiC additive, followed by material mixing; 15 parts of molten coal pitch and the well-mixed raw materials above are subjected to dry kneading for 20 minutes at 40 C; the kneaded raw materials are put in a mold for formation;
the formed semi-finished product is subjected to primary roasting, then to high pressure impregnation with molten coal pitch and finally to secondary roasting at low temperature of 700 C, wherein the degree of vacuum of the high pressure impregnation is not less than -0.092MPa and the pressure thereof is not less than 1.5MPa; after the secondary roasting, the semi-finished product is subjected to low-temperature graphitization at 1800 C; and the graphitized crude finished product is cooled and then subjected to machining to form the graphitized cathode stop block which is 120 millimeters high and 150 millimeters wide.
[00461 Shown as Figure 1, in the novel combined graphitized irregular cathode for aluminum according to the invention, the external dimension of the body blocks and the length of the stop blocks are determined in accordance with the dimension of electrolytic cell and the installed capacity of transformer; longitudinal edges of the body blocks (1) are symmetrically provided with two groups of grooves (4) which are 100 millimeters deep and 80 millimeters wide, the distance between the grooves (4) and the transverse outer edge of the body blocks is 300 millimeters and the spacing between two grooves (4) at the same side is 300 millimeters; the graphitized cathode stop blocks (3), which are made of the material different from the body blocks, has rectangular cross section and is 120 millimeters high and 150 millimeters wide, are inlaid inside the groove combined by the two grooves (4) in a manner of bridging over a junction seam (2) between the two body blocks (1); and finally, the junction seam (2) between the two body blocks (1) is tamped through paste and the graphitized cathode stop blocks (3) are tamped on the body blocks (1) through paste as well.
[00471 Embodiment 2:
[00481 The preparation of the graphitized cathode stop block comprises the following steps that: 20 part of calcined anthracite and 606 parts of electrically calcined petroleum coke based on mass proportion are smashed; the smashed electrically calcined anthracite and calcined petroleum coke are screened according to requirement of grain size to obtain grains with the grain size of 1 millimeter; the screened electrically calcined anthracite and calcined petroleum coke, conforming to the requirement, are put in a kneading ladle together with 4 part of 30 microns commercially pure TiB2 additive and 7 part of 30 microns commercially pure SiC additive, followed by material mixing; 20 parts of molten coal pitch and the well-mixed raw materials above are subjected to dry kneading for 30 minutes at 100 C; the kneaded raw materials are put in a mold for formation;
the formed semi-finished product is subjected to primary roasting, then to high pressure impregnation with molten coal pitch and finally to secondary roasting at low temperature of 800 C, wherein the degree of vacuum of the high pressure impregnation is not less than -0.092MPa and the pressure thereof is not less than 1.5MPa; after the secondary roasting, the semi-finished product is subjected to low-temperature graphitization at 1900 C; and the graphitized crude finished product is cooled and then subjected to machining to form the graphitized cathode stop block which is 190 millimeters high and 175 millimeters wide.
[00491 Shown as Figure 1, in the novel combined graphitized irregular cathode for aluminum according to the invention, the external dimension of the body blocks and the length of the stop blocks are determined in accordance with the dimension of electrolytic cell and the installed capacity of transformer; longitudinal edges of the body blocks (1) are symmetrically provided with two groups of grooves (4) which are 125 millimeters deep and 90 millimeters wide, the distance between the grooves (4) and the transverse outer edge of the body blocks is 340 millimeters and the spacing between two grooves (4) at the same side is 325 millimeters; the graphitized cathode stop blocks (3), which are made of the material different from the body blocks, has rectangular cross section and is 190 millimeters high and 175 millimeters wide, are inlaid inside the groove combined by the two grooves (4) in a manner of bridging over a junction seam (2) between the two body blocks (1); and finally, the junction seam (2) between the two body blocks (1) is tamped through paste and the graphitized cathode stop blocks (3) are tamped on the body blocks (1) through paste as well.
[00501 Embodiment 3:
[00511 The preparation of the graphitized cathode stop block comprises the following steps that: 40 part of calcined anthracite and 85 parts of electrically calcined petroleum coke based on mass proportion are smashed; the smashed electrically calcined anthracite and calcined petroleum coke are screened according to requirement of grain size to obtain grains with the grain size of 2 millimeter; the screened electrically calcined anthracite and calcined petroleum coke, conforming to the requirement, are put in a kneading ladle together with 8 part of 20 microns commercially pure TiB2 additive and 15 part of 20 microns commercially pure SiC additive, followed by material mixing; 25 parts of molten coal pitch and the well-mixed raw materials above are subjected to dry kneading for 40 minutes at 165 C; the kneaded raw materials are put in a mold for formation;
the formed semi-finished product is subjected to primary roasting, then to high pressure impregnation with molten coal pitch and finally to secondary roasting at low temperature of 850 C, wherein the degree of vacuum of the high pressure impregnation is not less than -0.092MPa and the pressure thereof is not less than 1.5MPa; after the secondary roasting, the semi-finished product is subjected to low-temperature graphitization at 2000 C; The graphitized crude finished product is cooled and then subjected to machining to form the graphitized cathode stop block, which has convex cross section, the overall height of 260 millimeters, the overall width of 200 millimeters, the top end chamfer angles (5) of 135 and the chamfer angle height of 30 millimeters.
[00521 Shown as Figure 1, in the one of novel combined graphitized irregular cathodes for aluminum according to the invention, the external dimension of the body blocks and the length of the stop blocks are determined in accordance with the dimension of electrolytic cell and the installed capacity of transformer; longitudinal edges of the body blocks (1) are symmetrically provided with two groups of grooves (4) which are millimeters deep and 100 millimeters wide, the distance between the grooves (4) and the transverse outer edge of the body blocks is 380 millimeters and the spacing between two grooves (4) at the same side is 350 millimeters; The graphitized cathode stop blocks (3), which are made of the material different from the body blocks and has convex cross section, the overall height of 260 millimeters, the overall width of 200 millimeters, the top end chamfer angles (5) of 135 and the chamfer angle height of 30 millimeters, are inlaid inside the groove combined by the two grooves (4) in a manner of bridging over the junction seam (2) between the two body blocks (1);and finally, the junction seam (2) between the two body blocks (1) is tamped through paste and the graphitized cathode stop blocks (3) are tamped on the body blocks (1) through paste as well.
[00531 Embodiment 4:
[0054] The preparation of the graphitized cathode stop block comprises the following steps that: 10 part of calcined anthracite and 50 parts of electrically calcined petroleum coke based on mass proportion are smashed; the smashed electrically calcined anthracite and calcined petroleum coke are screened according to requirement of grain size to obtain grains with the grain size of 0.5 millimeter; the screened electrically calcined anthracite and calcined petroleum coke, conforming to the requirement, are put in a kneading ladle together with 3 part of 10 microns commercially pure TiB2 additive and 4 part of 10 microns commercially pure SiC additive, followed by material mixing; 18 parts of molten coal pitch and the well-mixed raw materials above are subjected to dry kneading for 35 minutes at 150 C; the kneaded raw materials are put in a mold for formation;
the formed semi-finished product is subjected to primary roasting, then to high pressure impregnation with molten coal pitch and finally to secondary roasting at low temperature of 780 C, wherein the degree of vacuum of the high pressure impregnation is not less than -0.092MPa and the pressure thereof is not less than 1.5MPa; after the secondary roasting, the semi-finished product is subjected to low-temperature graphitization at 1850 C; The graphitized crude finished product is cooled and then subjected to machining to form the graphitized cathode stop block, which has convex cross section, the overall height of 260 millimeters, the overall width of 200 millimeters, the top end chamfer angles (5) of 150 and the chamfer angle height of 45 millimeters.
[0055] Shown as Figure 1, in the one of novel combined graphitized irregular cathodes for aluminum according to the invention, the external dimension of the body blocks and the length of the stop blocks are determined in accordance with the dimension of electrolytic cell and the installed capacity of transformer; longitudinal edges of the body blocks (1) are symmetrically provided with two groups of grooves (4) which are millimeters deep and 100 millimeters wide, the distance between the grooves (4) and the transverse outer edge of the body blocks is 380 millimeters and the spacing between two grooves (4) at the same side is 350 millimeters; The graphitized cathode stop blocks (3), which are made of the material different from the body blocks and has convex cross section, the overall height of 260 millimeters, the overall width of 200 millimeters, the top end chamfer angles (5) of 135 and the chamfer angle height of 30 millimeters, are inlaid inside the groove combined by the two grooves (4) in a manner of bridging over the junction seam (2) between the two body blocks (1);and finally, the junction seam (2) between the two body blocks (1) is tamped through paste and the graphitized cathode stop blocks (3) are tamped on the body blocks (1) through paste as well.
[0056] Embodiment 5:
[0057] The preparation of the graphitized cathode stop block comprises the following steps that: 35 part of calcined anthracite and 75 parts of electrically calcined petroleum coke based on mass proportion are smashed; the smashed electrically calcined anthracite and calcined petroleum coke are screened according to requirement of grain size to obtain grains with the grain size of 1.8 millimeter; the screened electrically calcined anthracite and calcined petroleum coke, conforming to the requirement, are put in a kneading ladle together with 6 part of 25 microns commercially pure TiB2 additive and 12 part of 25 microns commercially pure SiC additive, followed by material mixing; 22 parts of molten coal pitch and the well-mixed raw materials above are subjected to dry kneading for 40 minutes at 160 C; the kneaded raw materials are put in a mold for formation;
the formed semi-finished product is subjected to primary roasting, then to high pressure impregnation with molten coal pitch and finally to secondary roasting at low temperature of 840 C, wherein the degree of vacuum of the high pressure impregnation is not less than -0.092MPa and the pressure thereof is not less than 1.5MPa; after the secondary roasting, the semi-finished product is subjected to low-temperature graphitization at 1820 C; The graphitized crude finished product is cooled and then subjected to machining to form the graphitized cathode stop block, which has convex cross section, the overall height of 260 millimeters, the overall width of 200 millimeters, the top end chamfer angles (5) of 175 and the chamfer angle height of 60 millimeters.
[00581 Shown as Figure 1, in the one of novel combined graphitized irregular cathodes for aluminum according to the invention, the external dimension of the body blocks and the length of the stop blocks are determined in accordance with the dimension of electrolytic cell and the installed capacity of transformer; longitudinal edges of the body blocks (1) are symmetrically provided with two groups of grooves (4) which are millimeters deep and 100 millimeters wide, the distance between the grooves (4) and the transverse outer edge of the body blocks is 380 millimeters and the spacing between two grooves (4) at the same side is 350 millimeters; The graphitized cathode stop blocks (3), which are made of the material different from the body blocks and has convex cross section, the overall height of 260 millimeters, the overall width of 200 millimeters, the top end chamfer angles (5) of 1750 and the chamfer angle height of 60 millimeters, are inlaid inside the groove combined by the two grooves (4) in a manner of bridging over the junction seam (2) between the two body blocks (1); and finally, the junction seam (2) between the two body blocks (1) is tamped through paste and the graphitized cathode stop blocks (3) are tamped on the body blocks (1) through paste as well.
[00591 Embodiment 6:
[00601 The preparation of the graphitized cathode stop block comprises the following steps that: 30 part of calcined anthracite and 70 parts of electrically calcined petroleum coke based on mass proportion are smashed; the smashed electrically calcined anthracite and calcined petroleum coke are screened according to requirement of grain size to obtain grains with the grain size of 1.5 millimeter; the screened electrically calcined anthracite and calcined petroleum coke, conforming to the requirement, are put in a kneading ladle together with 5 part of 35 microns commercially pure TiB2 additive and 10 part of 35 microns commercially pure SiC additive, followed by material mixing; 22 parts of molten coal pitch and the well-mixed raw materials above are subjected to dry kneading for 50 minutes at 170 C; the kneaded raw materials are put in a mold for formation;
the formed semi-finished product is subjected to primary roasting, then to high pressure impregnation with molten coal pitch and finally to secondary roasting at low temperature of 820 C, wherein the degree of vacuum of the high pressure impregnation is not less than -0.092MPa and the pressure thereof is not less than 1.5MPa; after the secondary roasting, the semi-finished product is subjected to low-temperature graphitization at 1950 C; The graphitized crude finished product is cooled and then subjected to machining to form the graphitized cathode stop block, which has convex cross section, the overall height of 260 millimeters, the overall width of 200 millimeters, the top end chamfer angles (5) of 175 and the chamfer angle height of 60 millimeters.
[00611 Shown as Figure 1, in the one of novel combined graphitized irregular cathodes for aluminum according to the invention, the external dimension of the body blocks and the length of the stop blocks are determined in accordance with the dimension of electrolytic cell and the installed capacity of transformer; longitudinal edges of the body blocks (1) are symmetrically provided with two groups of grooves (4) which are millimeters deep and 100 millimeters wide, the distance between the grooves (4) and the transverse outer edge of the body blocks is 380 millimeters and the spacing between two grooves (4) at the same side is 350 millimeters; The graphitized cathode stop blocks (3), which are made of the material different from the body blocks and has convex cross section, the overall height of 260 millimeters, the overall width of 200 millimeters, the top end chamfer angles (5) of 175 and the chamfer angle height of 60 millimeters, are inlaid inside the groove combined by the two grooves (4) in a manner of bridging over the junction seam (2) between the two body blocks (1);and finally, the junction seam (2) between the two body blocks (1) is tamped through paste and the graphitized cathode stop blocks (3) are tamped on the body blocks (1) through paste as well.
BRIEF DESCRIPTION OF THE DRAWINGS
[00391 Figure 1 is a stereogram of the novel combined graphitized irregular cathode for aluminum of the invention;
[00401 Figure 2 is a top view of the Figure 1;
[00411 Figure 3 is a right view of the Figure 1; and [00421 Figure 4 is a process flow diagram of the graphitized cathode stop block.
[00431 In the figures, 1 represents body block, 2 represents junction seam, 3 represents graphitized cathode stop block, 4 represents groove and 5 represents top end chamfer angle.
DETAILED DESCRIPTION OF THE INVENTION
[00441 Embodiment 1:
[00451 The preparation of the graphitized cathode stop block comprises the following steps that: 1 part of calcined anthracite and 40 parts of electrically calcined petroleum coke based on mass proportion are smashed; the smashed electrically calcined anthracite and calcined petroleum coke are screened according to requirement of grain size to obtain grains with the grain size of 0 millimeter; the screened electrically calcined anthracite and calcined petroleum coke, conforming to the requirement, are put in a kneading ladle together with 1 part of 40 microns commercially pure TiB2 additive and 1 part of 40 microns commercially pure SiC additive, followed by material mixing; 15 parts of molten coal pitch and the well-mixed raw materials above are subjected to dry kneading for 20 minutes at 40 C; the kneaded raw materials are put in a mold for formation;
the formed semi-finished product is subjected to primary roasting, then to high pressure impregnation with molten coal pitch and finally to secondary roasting at low temperature of 700 C, wherein the degree of vacuum of the high pressure impregnation is not less than -0.092MPa and the pressure thereof is not less than 1.5MPa; after the secondary roasting, the semi-finished product is subjected to low-temperature graphitization at 1800 C; and the graphitized crude finished product is cooled and then subjected to machining to form the graphitized cathode stop block which is 120 millimeters high and 150 millimeters wide.
[00461 Shown as Figure 1, in the novel combined graphitized irregular cathode for aluminum according to the invention, the external dimension of the body blocks and the length of the stop blocks are determined in accordance with the dimension of electrolytic cell and the installed capacity of transformer; longitudinal edges of the body blocks (1) are symmetrically provided with two groups of grooves (4) which are 100 millimeters deep and 80 millimeters wide, the distance between the grooves (4) and the transverse outer edge of the body blocks is 300 millimeters and the spacing between two grooves (4) at the same side is 300 millimeters; the graphitized cathode stop blocks (3), which are made of the material different from the body blocks, has rectangular cross section and is 120 millimeters high and 150 millimeters wide, are inlaid inside the groove combined by the two grooves (4) in a manner of bridging over a junction seam (2) between the two body blocks (1); and finally, the junction seam (2) between the two body blocks (1) is tamped through paste and the graphitized cathode stop blocks (3) are tamped on the body blocks (1) through paste as well.
[00471 Embodiment 2:
[00481 The preparation of the graphitized cathode stop block comprises the following steps that: 20 part of calcined anthracite and 606 parts of electrically calcined petroleum coke based on mass proportion are smashed; the smashed electrically calcined anthracite and calcined petroleum coke are screened according to requirement of grain size to obtain grains with the grain size of 1 millimeter; the screened electrically calcined anthracite and calcined petroleum coke, conforming to the requirement, are put in a kneading ladle together with 4 part of 30 microns commercially pure TiB2 additive and 7 part of 30 microns commercially pure SiC additive, followed by material mixing; 20 parts of molten coal pitch and the well-mixed raw materials above are subjected to dry kneading for 30 minutes at 100 C; the kneaded raw materials are put in a mold for formation;
the formed semi-finished product is subjected to primary roasting, then to high pressure impregnation with molten coal pitch and finally to secondary roasting at low temperature of 800 C, wherein the degree of vacuum of the high pressure impregnation is not less than -0.092MPa and the pressure thereof is not less than 1.5MPa; after the secondary roasting, the semi-finished product is subjected to low-temperature graphitization at 1900 C; and the graphitized crude finished product is cooled and then subjected to machining to form the graphitized cathode stop block which is 190 millimeters high and 175 millimeters wide.
[00491 Shown as Figure 1, in the novel combined graphitized irregular cathode for aluminum according to the invention, the external dimension of the body blocks and the length of the stop blocks are determined in accordance with the dimension of electrolytic cell and the installed capacity of transformer; longitudinal edges of the body blocks (1) are symmetrically provided with two groups of grooves (4) which are 125 millimeters deep and 90 millimeters wide, the distance between the grooves (4) and the transverse outer edge of the body blocks is 340 millimeters and the spacing between two grooves (4) at the same side is 325 millimeters; the graphitized cathode stop blocks (3), which are made of the material different from the body blocks, has rectangular cross section and is 190 millimeters high and 175 millimeters wide, are inlaid inside the groove combined by the two grooves (4) in a manner of bridging over a junction seam (2) between the two body blocks (1); and finally, the junction seam (2) between the two body blocks (1) is tamped through paste and the graphitized cathode stop blocks (3) are tamped on the body blocks (1) through paste as well.
[00501 Embodiment 3:
[00511 The preparation of the graphitized cathode stop block comprises the following steps that: 40 part of calcined anthracite and 85 parts of electrically calcined petroleum coke based on mass proportion are smashed; the smashed electrically calcined anthracite and calcined petroleum coke are screened according to requirement of grain size to obtain grains with the grain size of 2 millimeter; the screened electrically calcined anthracite and calcined petroleum coke, conforming to the requirement, are put in a kneading ladle together with 8 part of 20 microns commercially pure TiB2 additive and 15 part of 20 microns commercially pure SiC additive, followed by material mixing; 25 parts of molten coal pitch and the well-mixed raw materials above are subjected to dry kneading for 40 minutes at 165 C; the kneaded raw materials are put in a mold for formation;
the formed semi-finished product is subjected to primary roasting, then to high pressure impregnation with molten coal pitch and finally to secondary roasting at low temperature of 850 C, wherein the degree of vacuum of the high pressure impregnation is not less than -0.092MPa and the pressure thereof is not less than 1.5MPa; after the secondary roasting, the semi-finished product is subjected to low-temperature graphitization at 2000 C; The graphitized crude finished product is cooled and then subjected to machining to form the graphitized cathode stop block, which has convex cross section, the overall height of 260 millimeters, the overall width of 200 millimeters, the top end chamfer angles (5) of 135 and the chamfer angle height of 30 millimeters.
[00521 Shown as Figure 1, in the one of novel combined graphitized irregular cathodes for aluminum according to the invention, the external dimension of the body blocks and the length of the stop blocks are determined in accordance with the dimension of electrolytic cell and the installed capacity of transformer; longitudinal edges of the body blocks (1) are symmetrically provided with two groups of grooves (4) which are millimeters deep and 100 millimeters wide, the distance between the grooves (4) and the transverse outer edge of the body blocks is 380 millimeters and the spacing between two grooves (4) at the same side is 350 millimeters; The graphitized cathode stop blocks (3), which are made of the material different from the body blocks and has convex cross section, the overall height of 260 millimeters, the overall width of 200 millimeters, the top end chamfer angles (5) of 135 and the chamfer angle height of 30 millimeters, are inlaid inside the groove combined by the two grooves (4) in a manner of bridging over the junction seam (2) between the two body blocks (1);and finally, the junction seam (2) between the two body blocks (1) is tamped through paste and the graphitized cathode stop blocks (3) are tamped on the body blocks (1) through paste as well.
[00531 Embodiment 4:
[0054] The preparation of the graphitized cathode stop block comprises the following steps that: 10 part of calcined anthracite and 50 parts of electrically calcined petroleum coke based on mass proportion are smashed; the smashed electrically calcined anthracite and calcined petroleum coke are screened according to requirement of grain size to obtain grains with the grain size of 0.5 millimeter; the screened electrically calcined anthracite and calcined petroleum coke, conforming to the requirement, are put in a kneading ladle together with 3 part of 10 microns commercially pure TiB2 additive and 4 part of 10 microns commercially pure SiC additive, followed by material mixing; 18 parts of molten coal pitch and the well-mixed raw materials above are subjected to dry kneading for 35 minutes at 150 C; the kneaded raw materials are put in a mold for formation;
the formed semi-finished product is subjected to primary roasting, then to high pressure impregnation with molten coal pitch and finally to secondary roasting at low temperature of 780 C, wherein the degree of vacuum of the high pressure impregnation is not less than -0.092MPa and the pressure thereof is not less than 1.5MPa; after the secondary roasting, the semi-finished product is subjected to low-temperature graphitization at 1850 C; The graphitized crude finished product is cooled and then subjected to machining to form the graphitized cathode stop block, which has convex cross section, the overall height of 260 millimeters, the overall width of 200 millimeters, the top end chamfer angles (5) of 150 and the chamfer angle height of 45 millimeters.
[0055] Shown as Figure 1, in the one of novel combined graphitized irregular cathodes for aluminum according to the invention, the external dimension of the body blocks and the length of the stop blocks are determined in accordance with the dimension of electrolytic cell and the installed capacity of transformer; longitudinal edges of the body blocks (1) are symmetrically provided with two groups of grooves (4) which are millimeters deep and 100 millimeters wide, the distance between the grooves (4) and the transverse outer edge of the body blocks is 380 millimeters and the spacing between two grooves (4) at the same side is 350 millimeters; The graphitized cathode stop blocks (3), which are made of the material different from the body blocks and has convex cross section, the overall height of 260 millimeters, the overall width of 200 millimeters, the top end chamfer angles (5) of 135 and the chamfer angle height of 30 millimeters, are inlaid inside the groove combined by the two grooves (4) in a manner of bridging over the junction seam (2) between the two body blocks (1);and finally, the junction seam (2) between the two body blocks (1) is tamped through paste and the graphitized cathode stop blocks (3) are tamped on the body blocks (1) through paste as well.
[0056] Embodiment 5:
[0057] The preparation of the graphitized cathode stop block comprises the following steps that: 35 part of calcined anthracite and 75 parts of electrically calcined petroleum coke based on mass proportion are smashed; the smashed electrically calcined anthracite and calcined petroleum coke are screened according to requirement of grain size to obtain grains with the grain size of 1.8 millimeter; the screened electrically calcined anthracite and calcined petroleum coke, conforming to the requirement, are put in a kneading ladle together with 6 part of 25 microns commercially pure TiB2 additive and 12 part of 25 microns commercially pure SiC additive, followed by material mixing; 22 parts of molten coal pitch and the well-mixed raw materials above are subjected to dry kneading for 40 minutes at 160 C; the kneaded raw materials are put in a mold for formation;
the formed semi-finished product is subjected to primary roasting, then to high pressure impregnation with molten coal pitch and finally to secondary roasting at low temperature of 840 C, wherein the degree of vacuum of the high pressure impregnation is not less than -0.092MPa and the pressure thereof is not less than 1.5MPa; after the secondary roasting, the semi-finished product is subjected to low-temperature graphitization at 1820 C; The graphitized crude finished product is cooled and then subjected to machining to form the graphitized cathode stop block, which has convex cross section, the overall height of 260 millimeters, the overall width of 200 millimeters, the top end chamfer angles (5) of 175 and the chamfer angle height of 60 millimeters.
[00581 Shown as Figure 1, in the one of novel combined graphitized irregular cathodes for aluminum according to the invention, the external dimension of the body blocks and the length of the stop blocks are determined in accordance with the dimension of electrolytic cell and the installed capacity of transformer; longitudinal edges of the body blocks (1) are symmetrically provided with two groups of grooves (4) which are millimeters deep and 100 millimeters wide, the distance between the grooves (4) and the transverse outer edge of the body blocks is 380 millimeters and the spacing between two grooves (4) at the same side is 350 millimeters; The graphitized cathode stop blocks (3), which are made of the material different from the body blocks and has convex cross section, the overall height of 260 millimeters, the overall width of 200 millimeters, the top end chamfer angles (5) of 1750 and the chamfer angle height of 60 millimeters, are inlaid inside the groove combined by the two grooves (4) in a manner of bridging over the junction seam (2) between the two body blocks (1); and finally, the junction seam (2) between the two body blocks (1) is tamped through paste and the graphitized cathode stop blocks (3) are tamped on the body blocks (1) through paste as well.
[00591 Embodiment 6:
[00601 The preparation of the graphitized cathode stop block comprises the following steps that: 30 part of calcined anthracite and 70 parts of electrically calcined petroleum coke based on mass proportion are smashed; the smashed electrically calcined anthracite and calcined petroleum coke are screened according to requirement of grain size to obtain grains with the grain size of 1.5 millimeter; the screened electrically calcined anthracite and calcined petroleum coke, conforming to the requirement, are put in a kneading ladle together with 5 part of 35 microns commercially pure TiB2 additive and 10 part of 35 microns commercially pure SiC additive, followed by material mixing; 22 parts of molten coal pitch and the well-mixed raw materials above are subjected to dry kneading for 50 minutes at 170 C; the kneaded raw materials are put in a mold for formation;
the formed semi-finished product is subjected to primary roasting, then to high pressure impregnation with molten coal pitch and finally to secondary roasting at low temperature of 820 C, wherein the degree of vacuum of the high pressure impregnation is not less than -0.092MPa and the pressure thereof is not less than 1.5MPa; after the secondary roasting, the semi-finished product is subjected to low-temperature graphitization at 1950 C; The graphitized crude finished product is cooled and then subjected to machining to form the graphitized cathode stop block, which has convex cross section, the overall height of 260 millimeters, the overall width of 200 millimeters, the top end chamfer angles (5) of 175 and the chamfer angle height of 60 millimeters.
[00611 Shown as Figure 1, in the one of novel combined graphitized irregular cathodes for aluminum according to the invention, the external dimension of the body blocks and the length of the stop blocks are determined in accordance with the dimension of electrolytic cell and the installed capacity of transformer; longitudinal edges of the body blocks (1) are symmetrically provided with two groups of grooves (4) which are millimeters deep and 100 millimeters wide, the distance between the grooves (4) and the transverse outer edge of the body blocks is 380 millimeters and the spacing between two grooves (4) at the same side is 350 millimeters; The graphitized cathode stop blocks (3), which are made of the material different from the body blocks and has convex cross section, the overall height of 260 millimeters, the overall width of 200 millimeters, the top end chamfer angles (5) of 175 and the chamfer angle height of 60 millimeters, are inlaid inside the groove combined by the two grooves (4) in a manner of bridging over the junction seam (2) between the two body blocks (1);and finally, the junction seam (2) between the two body blocks (1) is tamped through paste and the graphitized cathode stop blocks (3) are tamped on the body blocks (1) through paste as well.
Claims (10)
1. A novel combined graphitized irregular cathode for aluminum, comprising body blocks (1) and graphitized cathode stop blocks (3), characterized in that:
longitudinal edges of the body blocks (1) are symmetrically provided with two groups of grooves (4), the graphitized cathode stop blocks (3) are inlaid inside the groove combined by the two grooves (4) in a manner of bridging over a junction seam (2) between the two body blocks (1), and the graphitized cathode stop blocks (3) are tamped on the body blocks (1) through paste.
longitudinal edges of the body blocks (1) are symmetrically provided with two groups of grooves (4), the graphitized cathode stop blocks (3) are inlaid inside the groove combined by the two grooves (4) in a manner of bridging over a junction seam (2) between the two body blocks (1), and the graphitized cathode stop blocks (3) are tamped on the body blocks (1) through paste.
2. The novel combined graphitized irregular cathode for aluminum according to claim 1, characterized in that: the body blocks (1) are made of carbon block material for common aluminum electrolysis and the stop blocks (3) are made of graphitized material for aluminum electrolysis.
3. The novel combined graphitized irregular cathode for aluminum according to claim 1, characterized in that: the distance between the graphitized cathode stop blocks (3) and the transverse outer edge of the body blocks is from 300 to 380 millimeters and the spacing between the two graphitized cathode stop blocks (3) in the same longitudinal direction is from 300 to 350 millimeters.
4. The novel combined graphitized irregular cathode for aluminum according to claim 1, characterized in that: the junction seam (2) between the body blocks (1) is tamped through paste.
5. The novel combined graphitized irregular cathode for aluminum according to claim 1, characterized in that: the grooves are 100 to 150 millimeters deep and 80 to 100 millimeters wide.
6. The novel combined graphitized irregular cathode for aluminum according to claim 1, characterized in that: the graphitized cathode stop blocks (3) have rectangular or convex cross section.
7. A graphitized cathode stop block according to claim 1, characterized in that the graphitized cathode stop block is prepared from the following raw materials in parts by weight:
TiB2 alloy additive 1 to 8 parts;
calcined petroleum coke 40 to 85 parts;
Electrically calcined anthracite 1 to 40 parts;
Coal pitch 15 to 25 parts;
SiC additive 1 to 15 parts.
TiB2 alloy additive 1 to 8 parts;
calcined petroleum coke 40 to 85 parts;
Electrically calcined anthracite 1 to 40 parts;
Coal pitch 15 to 25 parts;
SiC additive 1 to 15 parts.
8. The graphitized cathode stop block according to claim 7, characterized in that: the grain size of both the calcined petroleum coke and the electrically calcined anthracite is 0 to 2 millimeters.
9. The graphitized cathode stop block according to claim 7, characterized in that: both the TiB2 additive and the SiC additive are selected from commercially pure additives with the grain size smaller than or equal to 40 microns.
10. A method for preparing the graphitized cathode stop block according to claims 1 and 7, characterized in that the method comprises the following steps of:
(1) Smashing calcined petroleum coke and electrically calcined anthracite;
(2) Screening the smashed calcined petroleum coke and electrically calcined anthracite according to the requirement of grain size;
(3) Material mixing: the electrically calcined anthracite, the calcined petroleum coke, the TiB2 additive and the SiC additive are put in a kneading ladle according to the proportion of the raw materials thereof;
(4) kneading: dry kneading is implemented for 20 to 40 minutes at the temperature ranging from 40 to 165°C; and wet kneading is implemented for 35 to 50 minutes at the temperature ranging from 150 to 170°C;
(5) Forming: the kneaded raw materials are put in a mold for formation;
(6) Roasting: the formed semi-finished products are subjected to primary roasting, then to high pressure impregnation with molten coal pitch and finally to secondary roasting at low temperature ranging from 700 to 850°C; the degree of vacuum of the high pressure impregnation is not less than -0.092MPa and the pressure thereof is not less than 1.5MPa;
(7) Low-temperature graphitization: the temperature ranges from 1800 to 2000°C;
(8) Machining: machining is performed according to the dimensional requirement of finished product to obtain the graphitized cathode stop block.
(1) Smashing calcined petroleum coke and electrically calcined anthracite;
(2) Screening the smashed calcined petroleum coke and electrically calcined anthracite according to the requirement of grain size;
(3) Material mixing: the electrically calcined anthracite, the calcined petroleum coke, the TiB2 additive and the SiC additive are put in a kneading ladle according to the proportion of the raw materials thereof;
(4) kneading: dry kneading is implemented for 20 to 40 minutes at the temperature ranging from 40 to 165°C; and wet kneading is implemented for 35 to 50 minutes at the temperature ranging from 150 to 170°C;
(5) Forming: the kneaded raw materials are put in a mold for formation;
(6) Roasting: the formed semi-finished products are subjected to primary roasting, then to high pressure impregnation with molten coal pitch and finally to secondary roasting at low temperature ranging from 700 to 850°C; the degree of vacuum of the high pressure impregnation is not less than -0.092MPa and the pressure thereof is not less than 1.5MPa;
(7) Low-temperature graphitization: the temperature ranges from 1800 to 2000°C;
(8) Machining: machining is performed according to the dimensional requirement of finished product to obtain the graphitized cathode stop block.
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| CN201010296859.3 | 2010-09-30 | ||
| CN2010102968593A CN101949035B (en) | 2010-09-30 | 2010-09-30 | Novel composite graphitized deformed cathode for aluminium electrolysis |
| CN201010296856.X | 2010-09-30 | ||
| CN201010296856XA CN101949034B (en) | 2010-09-30 | 2010-09-30 | Cathode graphitizing current stop block for aluminum electrolysis |
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| US4631121A (en) * | 1986-02-06 | 1986-12-23 | Reynolds Metals Company | Alumina reduction cell |
| RU2055943C1 (en) * | 1993-08-06 | 1996-03-10 | Александр Яковлевич Гохштейн | Process of production of aluminium by electrolysis of cryolite-alumina melt and electrolyzer for its implementation |
| CN100480431C (en) | 2004-07-02 | 2009-04-22 | 贵阳铝镁设计研究院 | Production process for graphitized cathode |
| CN100478500C (en) | 2007-03-02 | 2009-04-15 | 冯乃祥 | Abnormal cathode carbon block structure aluminum electrolysis bath |
| CN101260545A (en) * | 2008-04-23 | 2008-09-10 | 云南涌鑫金属加工有限公司 | Energy-saving aluminum electrolysis bath |
| CN101608320A (en) | 2008-06-19 | 2009-12-23 | 中国铝业股份有限公司 | A kind of graphitized cathode carbon block for aluminum cell |
| CN101665957B (en) | 2009-09-23 | 2011-01-12 | 四川广汉士达炭素股份有限公司 | Anti-abrasion graphitization cathode carbon blocks used for aluminum electrolytic cell and manufacturing method thereof |
| CN101694003A (en) | 2009-11-04 | 2010-04-14 | 洛阳新安电力集团万基石墨制品有限公司 | Component of hard graphitizing cathode carbon block and method for producing same |
| CN101724863B (en) | 2009-12-30 | 2012-07-04 | 冯乃祥 | Aluminum electrolytic tank with novel cathode structure capable of reducing protruding abrasion of cathode |
-
2011
- 2011-04-06 DE DE201110001834 patent/DE102011001834A1/en not_active Ceased
- 2011-04-13 CA CA2737182A patent/CA2737182C/en active Active
- 2011-06-22 RU RU2011125377/02A patent/RU2557177C2/en active
Also Published As
| Publication number | Publication date |
|---|---|
| RU2557177C2 (en) | 2015-07-20 |
| DE102011001834A1 (en) | 2012-04-05 |
| CA2737182C (en) | 2014-08-05 |
| RU2011125377A (en) | 2012-12-27 |
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