Graphite electrode yog cov khoom siv graphite uas tiv taus kub siab uas tsim los ntawm roj av sib xyaw, koob coke ua cov khoom sib xyaw thiab thee bitumen ua cov khoom siv khi, uas tau tsim los ntawm ntau yam txheej txheem xws li sib xyaw, molding, roasting, impregnation, graphitization thiab kev ua khoom siv.
Lub graphite electrode yog ib qho khoom siv hluav taws xob kub heev uas siv hluav taws xob ua hlau. Lub graphite electrode siv los muab hluav taws xob rau hauv lub cub hluav taws xob, thiab qhov kub siab uas tsim los ntawm lub arc ntawm qhov kawg ntawm lub electrode thiab lub nqi siv los ua qhov chaw cua sov los yaj lub nqi rau kev ua hlau. Lwm lub cub hluav taws xob uas yaj cov khoom xws li daj phosphorus, kev lag luam silicon, thiab abrasives kuj siv graphite electrodes ua cov khoom siv hluav taws xob. Cov khoom siv lub cev thiab tshuaj lom neeg zoo heev thiab tshwj xeeb ntawm graphite electrodes kuj siv dav hauv lwm qhov kev lag luam.
Cov ntaub ntawv raw rau kev tsim cov graphite electrodes yog roj av coke, koob coke thiab thee tar pitch.
Petroleum coke yog cov khoom khov uas yooj yim hlawv tau los ntawm kev siv coking thee thiab roj av pitch. Xim yog dub thiab porous, lub ntsiab lus tseem ceeb yog carbon, thiab cov tshauv tsawg heev, feem ntau qis dua 0.5%. Petroleum coke yog cov pa roj carbon uas yooj yim graphitized. Petroleum coke muaj ntau yam kev siv hauv kev lag luam tshuaj lom neeg thiab hlau. Nws yog cov khoom siv tseem ceeb rau kev tsim cov khoom graphite dag thiab cov khoom carbon rau electrolytic aluminium.
Cov roj av coke muaj peev xwm muab faib ua ob hom: cov roj av coke nyoos thiab cov roj av calcined raws li qhov kub ntawm kev kho cua sov. Cov roj av coke yav dhau los tau los ntawm kev ncua coking muaj ntau cov volatiles, thiab lub zog kho tshuab qis. Cov roj av coke calcined tau los ntawm kev calcination ntawm cov roj av coke nyoos. Feem ntau cov chaw ua roj hauv Suav teb tsuas yog tsim cov coke xwb, thiab kev ua haujlwm calcination feem ntau yog ua tiav hauv cov nroj tsuag carbon.
Petroleum coke muaj peev xwm muab faib ua cov coke sulfur siab (muaj ntau dua 1.5% sulfur), coke sulfur nruab nrab (muaj 0.5% -1.5% sulfur), thiab coke sulfur qis (muaj tsawg dua 0.5% sulfur). Kev tsim cov graphite electrodes thiab lwm yam khoom siv graphite cuav feem ntau yog tsim los ntawm kev siv cov coke sulfur qis.
Koob coke yog ib hom coke zoo nrog cov qauv fibrous pom tseeb, cov coefficient nthuav dav thermal qis heev thiab yooj yim graphitization. Thaum lub coke tawg, nws tuaj yeem faib ua cov kab nyias nyias raws li cov qauv (qhov sib piv feem ntau yog siab dua 1.75). Ib qho qauv fibrous anisotropic tuaj yeem pom nyob rau hauv lub tshuab microscope polarizing, thiab yog li ntawd hu ua koob coke.
Qhov anisotropy ntawm cov khoom siv physico-mechanical ntawm koob coke yog qhov pom tseeb heev. Nws muaj cov hluav taws xob zoo thiab thermal conductivity sib luag rau qhov ntev ntawm cov khoom me me, thiab cov coefficient ntawm thermal expansion qis. Thaum extrusion molding, qhov ntev ntawm feem ntau cov khoom me me yog teeb tsa hauv qhov kev taw qhia extrusion. Yog li ntawd, koob coke yog cov khoom siv tseem ceeb rau kev tsim cov electrodes graphite siab lossis ultra-high-power. Cov graphite electrode tsim tawm muaj qhov tsis kam qis, cov coefficient nthuav dav thermal me me thiab kev tiv thaiv thermal zoo.
Cov tshuaj coke koob yog muab faib ua cov roj uas ua los ntawm cov roj av thiab cov tshuaj coke koob uas ua los ntawm cov thee uas ua los ntawm cov khoom siv raw ntawm cov thee.
Cov thee tar yog ib qho ntawm cov khoom tseem ceeb ntawm kev ua cov thee tar tob. Nws yog kev sib xyaw ntawm ntau yam hydrocarbons, dub ntawm qhov kub siab, semi-khoom lossis khoom ntawm qhov kub siab, tsis muaj qhov chaw yaj ruaj khov, mos tom qab cua sov, thiab tom qab ntawd yaj, nrog qhov ceev ntawm 1.25-1.35 g / cm3. Raws li nws qhov chaw mos, nws muab faib ua qhov kub qis, kub nruab nrab thiab kub siab asphalt. Qhov nruab nrab kub asphalt tso zis yog 54-56% ntawm cov thee tar. Cov khoom sib xyaw ntawm cov thee tar yog qhov nyuaj heev, uas cuam tshuam nrog cov khoom ntawm cov thee tar thiab cov ntsiab lus ntawm heteroatoms, thiab kuj cuam tshuam los ntawm cov txheej txheem coking thiab cov xwm txheej ua cov thee tar. Muaj ntau yam cim rau kev piav qhia txog cov thee tar pitch, xws li bitumen softening point, toluene insolubles (TI), quinoline insolubles (QI), coking values, thiab thee pitch rheology.
Cov thee tar yog siv ua tus binder thiab impregnant hauv kev lag luam carbon, thiab nws cov kev ua tau zoo muaj kev cuam tshuam loj heev rau cov txheej txheem tsim khoom thiab cov khoom zoo ntawm cov khoom carbon. Cov binder asphalt feem ntau siv cov asphalt hloov kho qhov kub nruab nrab lossis qhov kub nruab nrab uas muaj qhov taw tes mos nruab nrab, tus nqi coking siab, thiab β resin siab. Tus neeg sawv cev impregnating yog cov asphalt kub nruab nrab uas muaj qhov taw tes mos qis, QI qis, thiab cov khoom rheological zoo.
Daim duab hauv qab no qhia txog cov txheej txheem tsim khoom ntawm graphite electrode hauv cov lag luam carbon.
Kev Siv Hluav Taws Xob: Cov khoom siv carbonaceous raw yog kho cua sov ntawm qhov kub siab kom tso tawm cov dej noo thiab cov khoom tsis muaj zog uas muaj nyob hauv, thiab cov txheej txheem tsim khoom sib raug rau kev txhim kho ntawm kev ua noj ua haus thawj zaug hu ua calcination. Feem ntau, cov khoom siv carbonaceous raw yog calcined los ntawm kev siv roj thiab nws cov volatiles ua qhov chaw kub, thiab qhov kub siab tshaj plaws yog 1250-1350 ° C.
Calcination ua rau muaj kev hloov pauv loj heev hauv cov qauv thiab cov khoom siv physicochemical ntawm cov khoom siv carbonaceous raw, feem ntau yog kev txhim kho qhov ceev, lub zog kho tshuab thiab hluav taws xob conductivity ntawm coke, txhim kho kev ruaj khov tshuaj lom neeg thiab oxidation tsis kam ntawm coke, tso lub hauv paus rau cov txheej txheem tom ntej.
Cov khoom siv calcined feem ntau suav nrog lub tank calciner, lub qhov cub rotary thiab hluav taws xob calciner. Cov ntsuas kev tswj hwm zoo ntawm calcination yog tias qhov tseeb ceev ntawm roj av coke tsis tsawg dua 2.07g / cm3, qhov resistivity tsis ntau tshaj 550μΩ.m, qhov tseeb ceev ntawm koob coke tsis tsawg dua 2.12g / cm3, thiab qhov resistivity tsis ntau tshaj 500μΩ.m.
Cov khoom siv raw thiab cov khoom xyaw crushing
Ua ntej kev sib sau ua ke, cov roj av calcined thiab koob coke feem ntau yuav tsum tau tsoo, sib tsoo, thiab sieve.
Qhov kev sib tsoo nruab nrab feem ntau yog ua los ntawm cov khoom siv sib tsoo ntawm kwv yees li 50 hli los ntawm lub puab tsaig crusher, lub rauj crusher, lub dov crusher thiab lwm yam kom ntxiv cov khoom siv loj 0.5-20 hli uas xav tau rau kev sib sau ua ke.
Milling yog ib qho txheej txheem ntawm kev sib tsoo cov khoom siv carbonaceous rau cov hmoov me me ntawm 0.15 hli lossis tsawg dua thiab cov khoom me me ntawm 0.075 hli lossis tsawg dua los ntawm kev siv lub tshuab sib tsoo hom nplhaib (Raymond zeb), lub tshuab sib tsoo pob, lossis lwm yam zoo li.
Kev tshuaj ntsuam yog ib qho txheej txheem uas ntau yam khoom siv tom qab kev sib tsoo raug muab faib ua ntau qhov loj me me nrog ntau qhov me me los ntawm ntau lub sieves nrog cov qhov qhib sib xws. Kev tsim hluav taws xob tam sim no feem ntau xav tau 4-5 pellets thiab 1-2 qib hmoov.
Cov khoom xyaw yog cov txheej txheem tsim khoom rau kev xam, ntsuas thiab tsom cov sib xyaw ntawm cov hmoov thiab cov khoom sib xyaw raws li cov kev cai tsim khoom. Qhov kev tsim nyog ntawm kev tshawb fawb ntawm cov qauv thiab kev ruaj khov ntawm kev ua haujlwm batching yog cov yam tseem ceeb tshaj plaws uas cuam tshuam rau qhov zoo thiab kev ua tau zoo ntawm cov khoom.
Tus qauv yuav tsum txiav txim siab 5 yam:
1Xaiv hom khoom siv raw;
2 txiav txim siab qhov sib piv ntawm ntau hom khoom siv raw;
3 txiav txim siab qhov loj me ntawm cov khoom siv raw khoom;
4 txiav txim siab seb tus nqi ntawm cov binder;
5 Txheeb xyuas hom thiab qhov ntau ntawm cov khoom ntxiv.
Kev Sib Xyaws: Sib tov thiab ntsuas ntau yam khoom me me ntawm cov pa roj carbonaceous granules thiab hmoov nrog qee qhov ntau ntawm cov binder ntawm qee qhov kub, thiab sib xyaw cov plasticity paste rau hauv cov txheej txheem hu ua kev sib xyaws.
Cov txheej txheem sib tov: sib tov qhuav (20-35 feeb) sib tov ntub (40-55 feeb)
Lub luag haujlwm ntawm kev sib tsoo:
1 Thaum sib tov qhuav, ntau yam khoom siv raw sib xyaw ua ke, thiab cov khoom siv carbonaceous khov kho ntawm ntau qhov sib txawv sib xyaw ua ke thiab puv kom txhim kho qhov sib xyaw ua ke;
2 Tom qab ntxiv cov thee tar pitch, cov khoom qhuav thiab cov asphalt raug sib xyaw ua ke. Cov kua asphalt sib xyaw ua ke thiab ntub cov nplaim ntawm cov granules los ua ib txheej ntawm cov asphalt bonding txheej, thiab tag nrho cov ntaub ntawv raug sib txuas ua ke los ua ib qho yas homogeneous smear. Conducive rau molding;
3 feem ntawm cov thee tar pitch nkag mus rau hauv qhov chaw sab hauv ntawm cov khoom siv carbonaceous, ua rau qhov ceev thiab kev sib koom ua ke ntawm cov nplaum ntxiv.
Kev molding: Kev molding ntawm cov khoom siv carbon yog hais txog cov txheej txheem ntawm kev ua kom cov khoom siv carbon uas tau kneaded nyob rau hauv lub zog sab nraud siv los ntawm cov khoom siv molding kom thaum kawg tsim lub cev ntsuab (lossis cov khoom nyoos) uas muaj qee yam duab, qhov loj me, qhov ceev thiab lub zog.
Hom molding, khoom siv thiab cov khoom tsim tawm:
Txoj kev molding
Cov khoom siv niaj hnub
cov khoom tseem ceeb
Kev ua pwm
Ntsug hydraulic xovxwm
Cov pa roj carbon hluav taws xob, cov qauv graphite zoo qis
Nyem
Kab rov tav hydraulic extruder
Cov ntsia hlau extruder
Graphite electrode, square electrode
Kev co molding
Tshuab molding vibration
Cov cib carbon txhuas, cov cib carbon cua sov
Isostatic nias
Isostatic molding tshuab
Graphite isotropic, anisotropic graphite
Kev ua haujlwm nias
1 cov khoom siv txias: cov khoom siv txias disc, cov khoom siv txias lub tog raj kheej, cov khoom siv txias sib tov thiab sib tsoo, thiab lwm yam.
Tso cov khoom uas yaj tau, txo kom sov li ntawm 90-120 ° C kom ua rau cov nplaum lo rau, kom cov nplaum ntawm cov tshuaj nplaum sib xws li 20-30 feeb.
2. Kev Thauj Khoom: nias lub baffle nqa —– 2-3 zaug txiav —-4-10MPa compaction
3 ua ntej-siab: siab 20-25MPa, lub sijhawm 3-5 feeb, thaum nqus tsev
4 extrusion: nias lub baffle —5-15MPa extrusion — txiav — rau hauv lub dab dej txias
Cov kev ntsuas kev siv tshuab ntawm extrusion: qhov sib piv ntawm kev sib xyaw, qhov kub ntawm lub chamber thiab lub nozzle, qhov kub thiab txias, lub sijhawm ua ntej lub sijhawm, lub zog extrusion, qhov ceev extrusion, qhov kub ntawm dej txias
Kev tshuaj xyuas lub cev ntsuab: qhov ceev ntawm qhov ntau, kev tapping tsos, kev tshuaj xyuas
Calcination: Nws yog ib qho txheej txheem uas cov khoom siv carbon ntsuab lub cev tau sau rau hauv lub cub tawg tshwj xeeb uas tsim los ntawm kev tiv thaiv ntawm cov khoom sau kom ua tiav kev kho cua sov kub siab kom carbonize cov thee hauv lub cev ntsuab. Cov coke bitumen tsim tom qab carbonization ntawm cov thee bitumen ua rau cov carbonaceous aggregate thiab cov hmoov av ua ke khov kho, thiab cov khoom siv carbon calcined muaj lub zog siab, tsis tshua muaj hluav taws xob resistivity, zoo thermal stability thiab tshuaj stability. .
Kev calcination yog ib qho ntawm cov txheej txheem tseem ceeb hauv kev tsim cov khoom siv carbon, thiab tseem yog ib feem tseem ceeb ntawm peb txoj kev kho cua sov loj ntawm kev tsim cov electrode graphite. Lub voj voog tsim khoom calcination ntev (22-30 hnub rau kev ci, 5-20 hnub rau cov cub tawg rau 2 ci), thiab kev siv hluav taws xob ntau dua. Qhov zoo ntawm kev ci ntsuab muaj feem cuam tshuam rau qhov zoo ntawm cov khoom tiav thiab tus nqi ntawm kev tsim khoom.
Cov thee ntsuab hauv lub cev ntsuab raug coked thaum lub sijhawm ci, thiab kwv yees li 10% ntawm cov khoom tsis haum raug tso tawm, thiab qhov ntim yog tsim los ntawm 2-3% shrinkage, thiab qhov poob loj yog 8-10%. Cov khoom siv lub cev thiab tshuaj lom neeg ntawm cov pa roj carbon kuj hloov pauv ntau heev. Qhov porosity txo qis los ntawm 1.70 g / cm3 mus rau 1.60 g / cm3 thiab qhov resistivity txo qis los ntawm 10000 μΩ·m mus rau 40-50 μΩ·m vim yog qhov nce ntawm porosity. Lub zog kho tshuab ntawm cov calcined billet kuj loj. Rau kev txhim kho.
Qhov ci thib ob yog ib qho txheej txheem uas cov khoom calcined raug raus thiab tom qab ntawd calcined kom carbonize lub suab uas nyob hauv cov qhov ntawm cov khoom calcined. Cov electrodes uas xav tau qhov siab dua (txhua hom tshwj tsis yog RP) thiab cov pob qij txha yuav tsum tau bibaked, thiab cov pob qij txha kuj raug rau peb-dip plaub-ci lossis ob-dip peb-ci.
Hom cub tawg tseem ceeb ntawm roaster:
Kev ua haujlwm tas mus li - lub cub tawg nplhaib (nrog lub hau, tsis muaj lub hau), qhov cub tawg qhov av
Kev ua haujlwm tsis tu ncua - lub qhov cub rov qab, lub tshuab ci hauv pem teb, lub thawv ci
Kab nkhaus calcination thiab qhov kub siab tshaj plaws:
Ci ib zaug xwb—-320, 360, 422, 480 teev, 1250 °C
Kev ci thib ob - -125, 240, 280 teev, 700-800 ° C
Kev tshuaj xyuas cov khoom ci: qhov tsos ntawm kev tapping, hluav taws xob resistivity, bulk density, compressive strength, internal structure analysis
Kev Impregnation yog ib qho txheej txheem uas cov khoom siv carbon raug muab tso rau hauv lub thawv siab thiab cov kua impregnant pitch raug raus rau hauv cov qhov hws ntawm cov khoom electrode nyob rau hauv qee qhov kub thiab txias. Lub hom phiaj yog kom txo qhov porosity ntawm cov khoom, ua kom cov khoom loj thiab lub zog kho tshuab ntawm cov khoom, thiab txhim kho cov hluav taws xob thiab thermal conductivity ntawm cov khoom.
Cov txheej txheem impregnation thiab cov kev ntsuas kev siv tshuab yog: ci billet - ntxuav qhov chaw - preheating (260-380 °C, 6-10 teev) - loading lub tank impregnation - nqus tsev (8-9KPa, 40-50 feeb) - Txhaj tshuaj bitumen (180-200 °C) - Pressurization (1.2-1.5 MPa, 3-4 teev) - Rov qab mus rau asphalt - Txias (sab hauv lossis sab nraum lub tank)
Kev tshuaj xyuas cov khoom impregnated: impregnation qhov hnyav nce tus nqi G = (W2-W1) / W1 × 100%
Ib qho hnyav nce ib zaug ≥14%
Qhov hnyav nce ntawm cov khoom impregnated theem ob ≥ 9%
Peb yam khoom dipping hnyav nce tus nqi ≥ 5%
Graphitization yog hais txog cov txheej txheem kho cua sov siab uas cov khoom siv carbon raug cua sov rau qhov kub ntawm 2300 ° C lossis ntau dua hauv cov khoom tiv thaiv hauv lub cub tawg hluav taws xob kub siab kom hloov cov qauv amorphous carbon mus rau hauv cov qauv siv lead ua graphite peb-seem.
Lub hom phiaj thiab cov nyhuv ntawm graphitization:
1 txhim kho qhov conductivity thiab thermal conductivity ntawm cov khoom siv carbon (qhov resistivity yog txo los ntawm 4-5 zaug, thiab thermal conductivity yog nce los ntawm txog 10 zaug);
2 txhim kho qhov thermal shock tsis kam thiab tshuaj lom neeg ruaj khov ntawm cov khoom siv carbon (linear expansion coefficient txo los ntawm 50-80%);
3 ua kom cov khoom siv carbon lubricity thiab abrasion tsis kam;
4 Tshem tawm cov khoom tsis huv, txhim kho qhov huv ntawm cov khoom siv carbon (cov tshauv ntawm cov khoom raug txo los ntawm 0.5-0.8% mus txog 0.3%).
Kev ua tiav ntawm cov txheej txheem graphitization:
Kev ua kom cov khoom siv carbon graphitization yog ua tiav ntawm qhov kub siab ntawm 2300-3000 ° C, yog li nws tsuas yog tuaj yeem ua tiav los ntawm kev cua sov hluav taws xob hauv kev lag luam, uas yog, tam sim no ncaj qha hla cov khoom calcined cua sov, thiab cov khoom calcined them rau hauv lub cub tawg yog tsim los ntawm cov hluav taws xob tam sim no ntawm qhov kub siab. Tus neeg coj yog ib yam khoom uas raug cua sov rau qhov kub siab.
Cov cub tawg uas siv dav tam sim no suav nrog Acheson graphitization furnaces thiab internal heat cascade (LWG) furnaces. Qhov qub muaj cov zis loj, qhov kub sib txawv loj, thiab siv hluav taws xob ntau. Qhov tom kawg muaj lub sijhawm ua kom sov luv luv, siv hluav taws xob tsawg, hluav taws xob tsis sib xws, thiab tsis haum rau kev teeb tsa.
Kev tswj hwm ntawm cov txheej txheem graphitization yog tswj hwm los ntawm kev ntsuas qhov nkhaus fais fab uas haum rau qhov kub nce siab. Lub sijhawm muab hluav taws xob yog 50-80 teev rau lub cub tawg Acheson thiab 9-15 teev rau lub cub tawg LWG.
Lub zog siv ntawm graphitization yog loj heev, feem ntau yog 3200-4800KWh, thiab tus nqi txheej txheem suav txog li 20-35% ntawm tag nrho cov nqi tsim khoom.
Kev tshuaj xyuas cov khoom graphitized: kev tapping tsos, kev sim resistivity
Kev Siv Tshuab: Lub hom phiaj ntawm kev siv tshuab ntawm cov khoom siv carbon graphite yog kom ua tiav qhov loj me, duab, qhov tseeb, thiab lwm yam uas xav tau los ntawm kev txiav kom ua lub cev electrode thiab cov pob qij txha raws li qhov yuav tsum tau siv.
Kev ua cov graphite electrode yog muab faib ua ob txoj kev ua haujlwm ywj pheej: lub cev electrode thiab kev sib koom ua ke.
Cov txheej txheem ua lub cev muaj peb kauj ruam ntawm kev tho qhov thiab qhov tiaj tiaj, lub voj voog sab nraud thiab lub ntsej muag tiaj tiaj thiab xov milling. Cov txheej txheem ntawm kev sib koom ua ke conical tuaj yeem muab faib ua 6 txheej txheem: txiav, lub ntsej muag tiaj tiaj, lub ntsej muag lub khob hliav qab tsheb, xov milling, drilling bolt thiab slotting.
Kev sib txuas ntawm cov pob qij txha electrode: kev sib txuas conical (peb lub buckles thiab ib lub buckle), kev sib txuas cylindrical, kev sib txuas bump (kev sib txuas txiv neej thiab poj niam)
Kev tswj qhov tseeb ntawm kev ua haujlwm: kev hloov pauv ntawm cov xov taper, qhov sib txawv ntawm cov xov, qhov sib txawv ntawm qhov sib koom ua ke loj, coaxiality ntawm qhov sib koom ua ke, qhov ntsug ntawm qhov sib koom ua ke, qhov tiaj tus ntawm lub ntsej muag electrode, qhov sib txawv plaub-point. Tshawb xyuas nrog cov ntsuas nplhaib tshwj xeeb thiab cov ntsuas phaj.
Kev tshuaj xyuas cov electrodes tiav lawm: qhov tseeb, qhov hnyav, qhov ntev, txoj kab uas hla, qhov ceev ntawm cov khoom loj, kev tiv taus, kev kam rau ua ntej sib dhos, thiab lwm yam.
Lub sijhawm tshaj tawm: Lub Kaum Hli-31-2019