Nrog rau kev loj hlob ntawm magnesia carbon cib ntau lawm tshuab, daim ntawv thov Scope ntawmMagnesia carbon cibtau dav thiab dav. Magnesite carbon bricks yog siv raws li hauv ob sab phlu ntawm hluav taws xob arc furnaces, thiab cov kev pab cuam lub neej ntawm lub hauv ob sab phlu yog zoo heev. Txawm hais tias magnesia carbon hluav taws cib tau siv dav hauv cov txheej txheem metallurgical, lawv lub neej kev pabcuam tseem muaj teeb meem vim lawv cov haujlwm hnyav, tshwj xeeb tshaj yog nyob rau hauv cov kab slag ntawm lub ladle, qhov kev puas tsuaj ntawm magnesium carbon bricks yog qhov tshwj xeeb.
Nyob rau hauv lub ladle, cov tshuaj muaj pes tsawg leeg ntawm lub slag yog complex thiab hloov tau, thiab qhov kub thiab txias hloov heev thiab nquag, tshwj xeeb tshaj yog nyob rau hauv lub slag kab ntawm lub ladle. Yog li ntawd, mgo-c bricks nrog kev ua tau zoo heev feem ntau siv rau hauv kab slag. Cov txheej txheem corrosion ntawm magnesia carbon refractory cib nyob rau hauv slag hauv ladle tau kawm tob hauv tsev thiab txawv teb chaws, thiab cov ncauj lus kom ntxaws yog raws li hauv qab no.
PART.01 Slag yaig ntawm magnesia carbon cib
Nyob rau hauv lub ladle, vim lub complex lub cev thiab tshuaj ib puag ncig ntawm lub slag kab, lub hauv ob sab phlu ntawm no feem ntau yooj yim puas. Cov tshuaj erosion ntawm slag ntawm MgO-C bricks yog tsuas yog los ntawm dissolution ntawm MgO thiab oxidation ntawm carbon nyob rau hauv lub matrix ntawm MgO-C bricks. Raws li kev sib koom ua ke ntawm cov xwm txheej hauv qab no, MgO-C cib puas lawm:
1. Kev cuam tshuam ntawm qhov yooj yim: Qhov qis dua qhov pib ntawm slag, qhov zoo dua nws yog ua rau MgO-C cib. Yog tias lub hauv paus ntawm slag nce, kev ua si ntawm SiO2 hauv slag txo, uas tuaj yeem txo cov oxidation ntawm carbon. Nyob rau tib lub sijhawm, nrog kev nce qib ntawm cov hauv paus ntsiab lus, kev ua haujlwm ntawm FeO hauv slag txo qis, uas cuam tshuam rau kev yaig ntawm slag ntawm MgO-C cib;
2. Kev cuam tshuam ntawm MgO: Osbom et al. pom tias cov ntsiab lus ntawm MgO hauv txheej slag siab li 30% thaum txheeb xyuas qhov muaj pes tsawg leeg ntawm LF slag kab. Lawv ntseeg tias qhov siab dua cov ntsiab lus ntawm MgO hauv slag, qhov qeeb qeeb ntawm MgO-C cib. Qhov siab dua qhov pib, qhov qeeb qeeb ntawm MgO-C bricks los ntawm slag.
3. Cov nyhuv ntawm Al2O3: Al2O3 nyob rau hauv slag yuav txo qhov melting point thiab viscosity ntawm slag, nce lub wettability ntawm slag thiab refractory cov ntaub ntawv, ua slag yooj yim rau nkag los ntawm lub magnesia lis ciam teb, thiab ua periclase cais los ntawm cov magnesia carbon cib matrix.
4. Cov nyhuv ntawm FeO: Ua ntej, FeO hauv slag tuaj yeem ua tau yooj yim nrog graphite hauv magnesia carbon cib ntawm qhov kub thiab txias, thiab tsim cov hlaws hlau dawb ci los ua ib txheej decarburized. Thib ob, periclase nyob rau hauv magnesia carbon cib kuj yuav hnov mob nrog FeO hauv slag los tsim cov khoom lag luam qis melting point.
Thaum lub sij hawm rov ua cua sov thiab txias ntawm lub ladle, vim qhov tsis sib xws ntawm thermal expansion tus nqi ntawm cov tsim magnesia-hlau composite uas tsis tshua muaj melting point khoom thiab magnesia hlau ore, magnesium oxide nyob rau saum npoo ntawm cov khoom refractory yog tawg, uas ua rau cov khoom siv hlau nplaum. dissolution ntawm cib. Cov kws tshawb fawb txawv teb chaws kuj ntseeg tias qhov nce ntawm cov ntsiab lus hlau hauv steel slag tsis zoo rau lub neej ntawm magnesium carbon cib. Ua ntej, hlau FeO accelerates cov oxidation ntawm carbon nyob rau saum npoo ntawm magnesite carbon cib. Qhov thib ob, FeO yuav hnov mob nrog MgO ua rau cov qauv ua haujlwm ntawm magnesia carbon refractory cib xoob. Raws li kev sib koom ua ke ntawm ob lub ntsiab lus no, kev yaig ntawm magnesia carbon hluav taws cib tau nrawm dua.
PART.02 Oxidation ntawm carbon nyob rau hauv mgo carbon bricks
Thaum magnesia carbon bricks tuaj rau hauv kev sib cuag nrog slag, carbon yuav hnov mob nrog oxides xws li FeO nyob rau hauv lub slag rau decarburize, tsim ib tug decarburized txheej nyob rau hauv tej yam kev mob, uas ua rau lub nto ua hauj lwm qauv ntawm magnesium carbon bricks xoob, uas yog lub ntsiab yog vim li cas. kev puas tsuaj ntawm mgo carbon bricks. Cov pa roj carbon reacts nrog oxides xws li CO2, O2 thiab SiO2 thiab txuas ntxiv oxidized los ntawm hlau oxides hauv slag; Qhov thib ob, cov qauv xoob tsim los ntawm cov txheej txheem decarburized ua rau cov kab nrib pleb loj dua thiab qhov pores nyob rau hauv qhov kev txiav txim ntawm thermal expansion thiab scouring ntawm slag, ua rau nws yooj yim rau slag nkag mus thiab tsim ib theem qis melting point nrog MgO. Nyob rau tib lub sijhawm, cov qauv saum npoo ntawm mgo carbon bricks hloov pauv raws li kev ua haujlwm ntawm kev ua haujlwm hnyav ntawm lub pas dej molten thiab kev ua phem ntawm steel slag, thiab nws thiaj li maj mam puas los ntawm sab nraud mus rau sab hauv, ua rau muaj kev puas tsuaj loj rau magnesite carbon bricks. Tom qab qhov kub thiab txias tshaj ib qho nqi, lub cib lub cev qauv yuav puas thiab sai corroded, uas yog vim MgO thiab graphite pib rau nws tus kheej-siv ntawm kub.
PART.03 Kev cuam tshuam ntawm pores
Vim muaj cov micropores sab hauv thiab ntawm qhov chaw ntawm magnesia carbon bricks, yaig ntawm mgo c refractories cib yuav tshwm sim ntau dua. Thaum siv mgo c hluav taws cib, qhov pores ua lub luag haujlwm nrawm hauv kev tsim cov txheej txheem decarburization, uas ua rau cov slag corrode cov khoom refractory ntawm magnesia carbon bricks ntau heev. Thaum cov huab cua sab nraud nkag mus rau hauv qhov pores hauv mgo c cib kom txias, cov pa oxygen hauv huab cua reacts nrog cov pa roj carbon monoxide los tsim cov pa roj carbon monoxide thiab tawm hauv micropores. Qhov tshwm sim tsis tu ncua ntawm ob txheej txheem maj mam nce qhov porosity thiab pore loj. Qhov tseem ceeb tshaj plaws nyob rau hauv tiam ntawm pores yog xaiv cov binders nyob rau hauv magnesia carbon hluav taws cib. Phenolic resin feem ntau yog siv los ua tus khi. Yog hais tias ib qho me me ntawm phenolic resin ntxiv rau hauv magnesia carbon cib, qhov porosity yuav tsis siab dhau hauv lub xeev txias, txog 3%, tab sis cov phenolic resin yuav decompose thiab tsim dej, hydrogen, methane, carbon monoxide (carbon dioxide. ) thiab lwm yam gases tom qab cua sov, thiab tsim pores nyob rau hauv lub ntws ntawm cov gases, ua rau cov porosity. Yog li ntawd, magnesium carbon bricks yog corroded los ntawm cov slag hla lub pores, ua rau oxidation ntawm carbon thiab dissolution ntawm MgO ntau khaus, yog li ua rau cov magnesite carbon bricks. Vim yog qhov rov ua dua ntawm cov txheej txheem roj, kev puas tsuaj ntawm magnesia carbon firebricks txuas ntxiv mus.
Cov txheej txheem kev puas tsuaj ntawm magnesia carbon cib tuaj yeem ua tiav raws li: oxidation, decarburization, loosening, yaig, scouring, shedding, thiab puas. Ua ntej, cov graphite ntawm qhov chaw ua haujlwm ntawm magnesia carbon cib yog oxidized los ua ib txheej decarburized. Magnesia nyob rau hauv lub decarburized txheej yog maj eroded thiab los nyob rau hauv tej yam kev mob ntawm thermal kev nyuaj siab (cov thermal expansion tus nqi ntawm graphite thiab magnesia ntawm 1000 degree yog 1.4% thiab 0.2%, feem), tshuaj erosion, thiab mechanical scouring. Tom qab tso tawm, cov graphite raug nthuav tawm thiab txuas ntxiv mus rau oxidized los tsim cov txheej txheem decarburized, thiab tom qab ntawd cov txheej txheem magnesia dissolution tshwm sim. Raws li rov ua dua, cov magnesia carbon cib puas lawm.
