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Kev paub pib ntawm kev ua hlau

Steelmaking pib nrog ironmaking. Hlau los ntawm npua hlau. Npua hlau yaj los ntawm cov hlau ore muaj cov ntsiab lus carbon ntau thiab ntau yam tsis huv (xws li silicon, manganese, phosphorus, sulfur, thiab lwm yam). Yog li ntawd, npua hlau tsis muaj yas thiab tawv, thiab muaj cov khoom siv tsis zoo. Nws tsis tuaj yeem raug rau siab ua tshwj tsis yog rau melting thiab casting, uas txwv nws siv.
Txhawm rau txhawm rau kov yeej qhov tsis txaus ntawm cov npua hlau thiab ua rau nws ua lub luag haujlwm tseem ceeb hauv kev lag luam, nws kuj tseem yuav tsum tau siv oxygen los ntawm ntau qhov chaw ntawm qhov kub thiab txias kom tshem tawm cov tsis huv hauv npua hlau mus rau qee qib kom tau txais qee yam muaj pes tsawg leeg thiab qee qhov xwm txheej ntawm cov hlau-carbon hlau-hlau. Txoj hauv kev tshem tawm qhov tsis huv hauv npua hlau los ntawm oxidation ntawm qhov kub tau hu ua steelmaking.

Cov hauv paus ntsiab lus ntawm kev ua hlau
Ntau yam tsis huv hauv npua hlau muaj kev sib raug zoo nrog cov pa oxygen mus rau qib sib txawv hauv qhov chaw kub. Yog li ntawd, lawv tuaj yeem ua rau ua kua, khoom lossis cov pa roj carbon dioxide los ntawm oxidation. Cov kua thiab cov tshuaj oxide hnov ​​mob nrog lub qhov cub tawg thiab cov dej ntxiv rau hauv lub tshuab ua kom sov siab, sib xyaw ua ke kom tsim cov slag, thiab raug tshem tawm ntawm lub qhov cub thaum lub sij hawm slagging. Cov pa tseem raug coj tawm ntawm lub cub tawg los ntawm CO thaum cov hlau yaj tau kub.
Hauv cov cua sov ua cov hlau, qhov oxidation ntawm impurities feem ntau ua tiav los ntawm kev muaj FeO.
2Fe + O2 → 2FeO
1. Oxidation ntawm silicon
Si muaj kev sib raug zoo nrog oxygen, yog li oxidation ntawm silicon tau nrawm heev. Nws tau ua tiav oxidized los ua SiO2 thaum ntxov ntawm kev zom:
Si+2FeO → SiO2+2Fe
Nyob rau tib lub sij hawm SiO2 reacts nrog FeO los ua silicate:
2FeO+SiO2 → 2FeO · SiO2
Hom ntsev no yog ib feem tseem ceeb heev ntawm cov slag. Nws cuam tshuam nrog CaO los tsim cov sib xyaw ruaj khov 2CaO · SiO2 thiab FeO. Tus qub yog khov kho nyob rau hauv cov slag, thiab tom kawg dhau los ua cov khoom siv dawb hauv cov slag, uas nce cov ntsiab lus ntawm FeO hauv cov slag. Nws yog qhov zoo dua los txhawb kev oxidation ntawm impurities. Cov lus teb yog raws li hauv qab no:
2FeO · SiO2+2CaO → 2CaO · SiO2+2FeO
2. Oxidation ntawm manganese
Manganese tseem yog lub hauv paus uas yooj yim rau oxidize. MnO ua los ntawm nws muaj cov ntsiab lus melting ntau dua. MnO tsis yaj hauv cov hlau yaj, tab sis nws tsim cov khoom sib xyaw nrog SiO2 uas ntab rau saum cov hlau ua kua thiab dhau los ua ib feem ntawm cov slag.
Mn+FeO → MnO+Fe
2MnO+SiO2 → 2MnO · SiO2
Cov tshuaj tiv thaiv oxidation ntawm silicon thiab manganese tso tawm cua sov ntau, uas tuaj yeem ua rau kub hauv qhov cub sai sai (qhov no tshwj xeeb tshaj yog tshwj xeeb rau kev hloov pauv steelmaking) thiab ua kom nrawm cov txheej txheem carbon oxidation.
3. Oxidation ntawm carbon element
Kev tshem tawm cov pa roj carbon ntau yuav tsum tau nqus cov cua sov ntau, yog li nws yuav tsum tau nqa tawm ntawm qhov kub dua. Cov oxidation ntawm carbon yog cov tshuaj tiv thaiv tseem ceeb heev hauv cov txheej txheem steelmaking:
C+FeO → CO+Fe
Vim tias CO tau tsim tawm thaum cov pa roj tau oxidized, nws ua rau muaj kev ntxhov siab thaum nws khiav tawm ntawm cov kua hlau. Cov nyhuv no hu ua "rhaub". Qhov tshwm sim ntawm kev npau npau tuaj yeem txhawb kev sib koom ua ke ntawm cov muaj pes tsawg leeg thiab qhov kub ntawm lub pas dej ua ke, ua kom nrawm cov tshuaj tiv thaiv ntawm cov hlau thiab slag interface, thiab tseem pab tshem tawm cov roj thiab suav nrog hauv cov hlau.
4. Oxidation ntawm phosphorus element
Kev oxidation ntawm phosphorus tuaj yeem tshwm sim ntawm qhov kub uas tsis siab dhau. Cov txheej txheem dephosphorization muaj kev sib xyaw ua ke ntawm ntau qhov kev cuam tshuam. Cov tshuaj tiv thaiv muaj raws li hauv qab no:
2P+5FeO → P2O5+5Fe
P2O5+3FeO → 3FeO · P2O5
Thaum muaj CaO txaus hauv cov alkaline slag, cov hauv qab no yuav tshwm sim:
3FeO · P2O5+4CaO → 4CaO · P2O5+3FeO
4CaO · P2O5 tsim los ntawm yog cov khoom ruaj khov, uas tau tuav ruaj khov nyob rau hauv cov slag, yog li ua tiav lub hom phiaj ntawm dephosphorization.
Nws yuav tsum tau sau tseg tias thaum lub sijhawm txheej txheem deoxidation ntawm cov hlau yaj, deoxidizers xws li ferrosilicon thiab ferromanganese yuav tsum tau ntxiv. Yog li ntawd, tom qab deoxidation, slag feem ntau yog acidic, thiab 3FeO · P2O5 raug rhuav tshem, thiab P2O5 raug txo los ntawm nws, thiab P2O5 tsis ruaj khov. Oxide, nws tau yooj yim txo los ntawm cov pa ntawm qhov kub thiab txias, ua rau phosphorus rov qab los. Qhov no kuj qhia tau tias nws nyuaj heev kom tshem cov phosphorus hauv cov cua sov ua kua. Txhawm rau tiv thaiv qhov tshwm sim no, nws yog qhov tsim nyog kom tsim nyog nce slag qhov tseem ceeb thiab cov nyiaj slag, thiab txhim kho slag oxidation.
5. Oxidation ntawm leej faj
Sulfur muaj nyob hauv daim ntawv ntawm FeS. Thaum muaj CaO txaus hauv slag, leej faj kuj tseem tuaj yeem tshem tawm tau. Cov tshuaj tiv thaiv yog raws li hauv qab no:
FeS+CaO → CaS+FeO
Cov CaS tsim tawm tsis yog yaj hauv cov hlau yaj, tab sis cov ntawv slag ntab rau saum cov hlau yaj.
Cov tshuaj tiv thaiv saum toj no yog cov tshuaj tiv thaiv thim rov qab, thiab nws tau ua hauv cov slag uas muaj FeO. Thaum FeO cuam tshuam nrog CaS, leej faj yuav rov qab los rau cov hlau yaj, yog li cov txiaj ntsig ua kom muaj zog ntxiv tuaj ntxiv raws li FeO cov ntsiab lus hauv cov slag txo.
Thaum cov slag muaj cov pa txaus, cov tshuaj tiv thaiv sib txawv:
CaO+FeS+C → CaS+Fe+CO
Vim tias carbon deprives FeO ntawm cov pa oxygen, nws poob qhov ua tau ntawm CaS cuam tshuam nrog FeO, yog li cov tshuaj tiv thaiv tsis tuaj yeem ua mus rau qhov rov qab. Qhov no yog vim li cas desulfurization ntawm hluav taws xob rauv steelmaking ua tiav ntau dua li ob txoj hauv kev.
Hauv cov txheej txheem desulfurization, manganese tseem ua lub luag haujlwm hauv kev txhawb nqa desulfurization. Cov txheej txheem yog raws li hauv qab no:
FeS+MnO → MnS+FeO
Cov MnS tsim tawm yuav luag tsis yaj hauv cov hlau yaj thiab nkag mus rau hauv cov slag. Yog li, cov txiaj ntsig ntawm desulfurization nce nrog oxidation ntawm manganese.
6. Deoxygenation ntawm FeO
Tom qab cov txheej txheem saum toj no ntawm cov tshuaj tiv thaiv oxidation, txawm hais tias cov impurities tau oxidized kom ua tiav lub hom phiaj ntawm kev tshem tawm, tab sis kuj vim yog cov txiaj ntsig oxidation, cov hlau yaj tau muaj FeO ntau dua, uas yog hais, muaj cov pa oxygen ntau hauv cov molten hlau, uas yuav muab cov hlua hlau Qhov no yog qhov txaus ntshai heev. Ntawm qhov one tes, cov hlau muaj ntau npuas; ntawm qhov tod tes, nws kuj ua rau cov hlau ua kom sov thiab txias heev, thiab qhov kev phom sij nce nrog kev nce ntawm cov ntsiab lus carbon.
Yog li ntawd, thaum kawg ntawm cov txheej txheem steelmaking, peb yuav tsum tau sim tshem tawm cov pa ntau nyob hauv cov hlau yaj. Feem ntau siv txoj hauv kev yog ntxiv qee cov deoxidizers, xws li ferromanganese, ferrosilicon, aluminium, thiab lwm yam, rau cov hlau yaj. Lawv txhawb nqa cov pa oxygen los ntawm FeO kom ua tiav lub hom phiaj ntawm deoxidation. Cov tshuaj tiv thaiv yog raws li hauv qab no:
FeO+Mn → MnO+Fe
2FeO+Si → SiO2+2Fe
3FeO+2Al → Al2O3+3Fe
7. Lub luag haujlwm ntawm slag
Tag nrho cov txheej txheem steelmaking muaj ob txheej txheem: oxidation thiab txo qis. Cov oxidation ntawm cov pa roj carbon, silicon, manganese, thiab phosphorus feem ntau hu ua cov tshuaj tiv thaiv nyob rau lub sijhawm oxidation, thiab desulfurization thiab deoxidation yog hu ua cov tshuaj tiv thaiv hauv lub sijhawm txo. Nws tuaj yeem pom los ntawm cov qauv tshuaj tiv thaiv saum toj no uas txhawm rau tshem tawm cov tsis huv hauv cov hlau, ntau yam yuav tsum tau txiav txim siab, tab sis qhov tseem ceeb tshaj plaws yog slagging thiab slag tshem tawm.
Slag muaj cov luag haujlwm tseem ceeb hauv qab no hauv cov txheej txheem hlau:
① Cov slag yuav tsum xyuas kom meej tias cov txheej txheem steelmaking tau ua tiav hauv cov lus qhia tshwj xeeb (oxidation lossis txo qis).
② Cov slag yuav tsum ua kom tshem tawm qhov siab tshaj plaws ntawm cov teeb meem tsis zoo (phosphorus thiab sulfur) hauv cov hlau, thiab tiv thaiv cov pa hauv lub cub tawg (nitrogen thiab hydrogen) los ntawm cov hlau.
③ Cov slag yuav tsum xyuas kom muaj qhov poob qis ntawm cov hlau thiab lwm yam khoom muaj txiaj ntsig thaum ua haujlwm.

Txoj hauv kev yooj yim ntawm kev ua hlau
①Converter steelmaking
Kev hloov pauv steelmaking yog txheej txheem steelmaking uas siv cua lossis oxygen los ua kom cov hlau hauv cov hlau yaj mus rau qhov txwv tshwj xeeb los ntawm kev siv tshuab hauv qab, sab tshuab thiab tshuab sab saum toj kom tau txais cov hlau nrog cov khoom tsim nyog.

w1

② Hluav taws xob rauv steelmaking
Cov cua sov siv hluav taws xob siv hluav taws xob los hloov pauv mus ua cua sov los ua hlau. Muaj ob txoj hauv kev siv hluav taws xob cua sov: hluav taws xob rauv hluav taws xob thiab hluav taws xob hluav taws xob. Cov khoom siv hluav taws xob hluav taws xob tau siv dav tshaj plaws thiab tsim nyog rau smelting cov hlau zoo thiab hlau alloy; Cov cua sov induction yog siv rau kev sib tsoo cov qib high hlau hlau thiab cov hlau tsis muaj hlau.

w2

③ Qhib qhib hearth steelmaking
Nrog rau kev txhim kho kev lag luam, ntau cov seem hlau tau sau rau hauv kev lag luam hlau ua. Lub sijhawm ntawd, nws tsis tuaj yeem rov tshuab nws mus rau hauv cov hlau nrog cov hloov pauv, yog li cov kws tsim khoom hlau tau nrhiav txoj hauv kev ua cov hlau uas siv seem hlau ua raw khoom. Xyoo 1864, Fab Kis Fab Kis Martin tau tsim qhov qhib-hearth steelmaking txuj ci.

w3

Txoj kev loj hlob sai ntawm cov pa saum toj cua tshuab hloov pauv steelmaking txoj kev tau maj mam hloov qhov qhib-hearth steelmaking txoj kev. Nrog rau kev nce qib ntawm kev tshawb fawb thiab thev naus laus zis, qee qhov txheej txheem steelmaking tshiab txuas ntxiv mus, xws li kev kho lub tshuab nqus tsev ntawm cov hlau yaj, hluav taws xob hluav taws xob rauv smelting, thiab lub tshuab nqus tsev hluav taws xob rauv smelting, uas tau siv ntau dua.


Sijhawm Tshaj Tawm: Aug-02-2021