Cov nroj tsuag steel noj ntau dua magnesia refractory dua li lwm yam kev lag luam. BOF converters, EAF furnaces, steel ladles, thiab tundishes - tag nrho cov kab nrog magnesia-raws li cov khoom. Yog vim li cas: yooj yim slags generated nyob rau hauv steelmaking nres silica thiab alumina aggressively. Magnesia (MgO) yog nws tus kheej yooj yim, yog li nws tiv taus qhov yooj yim slag dissolution.
Tab sis "magnesia refractory" yog ib lo lus dav uas npog cov ntaub ntawv raw, zoo li lub cib, thiab castable formulations nrog cov khoom sib txawv. Phau ntawv qhia no qhia txog cov tsev neeg magnesia kom meej meej, sib piv cov ntaub ntawv tseem ceeb ntawm kev ua haujlwm, thiab piav qhia cov khoom twg haum rau daim ntawv thov.
Tsev Neeg Magnesia - Plaub Khoom, Plaub Lub Luag Haujlwm
| Khoom siv | Daim ntawv | Lub luag haujlwm tseem ceeb | MgO Range |
|---|---|---|---|
| Tuag Burned Magnesia (DBM) | Raw khoom / hmoov | Raw khoom rau zoo li tus cib thiab monolithics | 90–96% |
| Fused Magnesia (FM) | Raw khoom / nplej | Hwm raw khoom rau kev ua tau zoo MgO-C | 95–98% |
| Magnesia-Carbon (MgO-C) cib | Zoo li cib | BOF, EAF, ladle slag kab | 65-80% MgO + 8-20% C |
| Magnesia-Alumina Spinel Cib | Zoo li cib | Cement kiln burning tsam, ladle ua hauj lwm hauv ob sab phlu | 60–80% MgO + 10–25% Al₂O₃ |
Cov khoom plaub no ua haujlwm sib txawv hauv cov saw hlau ntau lawm. DBM thiab FM yog cov khoom siv raw uas nkag mus rau hauv kev ua cov cib. MgO-C cib thiab spinel cib yog cov khoom tiav hauv ob sab phlu uas nkag mus rau hauv koj lub qhov cub.
MgO Purity Qib: 90%, 95%, 97% - Thaum Txhua Qhov Tseem Ceeb
Tsis yog txhua daim ntawv thov xav tau 97% MgO. Nov yog cov lus qhia siv tau:
90% MgO (DBM-90):Standard qib rau cov ntaub ntawv thaub qab, ladle ua hauj lwm hauv ob sab phlu nyob rau hauv qis-demand txoj hauj lwm, thiab monolithic formulations. Fe₂O₃ cov ntsiab lus feem ntau yog 1.5–2.5%. Tsim nyog rau steelmaking kub txog 1650 degree. Tus nqi qis tshaj hauv tsev neeg magnesia.
95% MgO (DBM-95 / FM-95):Txheem rau ladle slag kab, BOF thaub qab hauv ob sab phlu, thiab EAF hauv qab. Fe₂O₃ poob rau 0.5–1.0%. Ntau qhov ceev rau FM-95: 3.35–3.50 g / cm³. Cov qib xa khoom dav tshaj plaws rau kev siv steelmaking.
97% + MgO (FM-97, FM-98):Yuav tsum muaj cov pa roj carbon ntau MgO-C cib (15-20% C) qhov twg MgO grain zoo tswj cov slag kuj. Fe₂O₃ <0.3%. FM-97 grain yog tag nrho fused - lub periclase siv lead ua yog loj thiab denser dua DBM, muab superior slag infiltration kuj. Hwm: 30–50% tshaj DBM-95.
One clarification worth stating plainly: DBM-95 and FM-95 are not interchangeable at the same price. DBM is calcined; FM is electrically fused. FM has larger periclase crystal size (>1mm vs . 0.3–0.5mm rau DBM), qis porosity, thiab ntau dua qhov ceev. Rau MgO-C cib hauv BOF slag kab txoj haujlwm, FM yog cov khoom siv raw - siv DBM los hloov FM yog qhov kev txo qis zoo uas ua rau lub neej luv luv.
Tuag hlawv Magnesia vs. Fused Magnesia: Microstructure sib txawv
Qhov sib txawv ntawm microstructure piav qhia qhov sib txawv ntawm kev ua haujlwm.
DBM ntau lawm:Magnesite ore yog calcined ntawm 1700-1800℃nyob rau hauv ib tug ncej kiln los yog teb kiln. MgO crystal (periclase) loj tom qab calcination: 0.3-0.5mm. Qee qhov seem porosity los ntawm txheej txheem calcination. Saib pebtuag hlawv magnesia nqi thiab kev ntsuam xyuasphau ntawv qhia kev siv khoom siv.
FM ntau lawm: Magnesite or DBM is melted in an electric arc furnace at 2800°C. The molten MgO solidifies into large single-crystal periclase with crystal size >1 hli thiab tsis tshua muaj porosity tsawg (qhov ntom ntom 3.45-3.55 g / cm³).
Qhov tshwm sim: FM muaj qhov kub siab dua ntawm kev sib tsoo (HMOR) thiab qis dua slag nkag mus rau hauv cov xwm txheej zoo tib yam. Rau siab-slag-hu rau txoj haujlwm - BOF ua haujlwm hauv ob sab phlu, ladle slag kab - qhov zoo dua microstructure txhais ncaj qha rau lub neej kev sib tw ntev dua.
Peb muab ob qho tib si DBM thiab FM. Rau txhua qhov kev txiav txim, peb suav nrog COA nrog crystal size distribution (D50) thiab bulk ntom. Nug rau nws - tus neeg muag khoom uas tsis tuaj yeem muab D50 cov ntaub ntawv ntawm FM lis tsis kuaj seb lawv thauj khoom li cas.
Magnesia-Carbon Brick vs Magnesia-Spinel Brick - Daim ntawv qhia daim ntawv thov
Magnesia-Carbon (MgO-C) cib
MgO-C cib ua ke nrog magnesium (65-80% MgO) nrog graphite carbon (8-20% C) thiab antioxidants (Al, Si, los yog MgAl alloy). Cov pa roj carbon theem ua ob txoj haujlwm: nws ua raws li kev sib koom ua ke tiv thaiv MgO nplej los ntawm kev tawg hauv slag, thiab nws cov thermal conductivity siab (graphite: 100-200 W / m·K) tsim cov txheej slag khov ntawm lub ntsej muag cib uas tiv thaiv tus kheej hauv ob sab phlu.
Qhov twg nws siv:BOF converter ua hauj lwm hauv ob sab phlu, EAF sab phab ntsa (slag cheeb tsam),steel ladle slag kab. Qhov feem ntau siv zoo li tus refractory hauv steelmaking.
Kev xaiv cov ntsiab lus carbon:
BOF: 15-18% C (high-carbon rau siab tshaj thermal conductivity thiab slag kuj)
EAF slag kab: 12-15% C
Ladle slag kab: 10-14% C (qis C kom tsis txhob khaws cov pa roj carbon steel)
Ib qho kev txwv ncaj ncees:MgO-C cib tsis tuaj yeem siv rau hauv oxidizing cua - cov pa roj carbon oxidizes saum 700 degree. Rau cov ntawv thov nrog oxidizing roj tiv tauj, qhia meej cov pa roj carbon tsawg lossis carbon-dawb magnesia-spinel cib hloov.
Magnesia-Alumina Spinel Cib
Magnesia-spinel cib siv MgO ua thawj theem nrog Al₂O₃ ntxiv (10–25%) uas tsim magnesium aluminate spinel (MgAl₂O₄) thaum tua. Cov theem spinel txhim kho thermal poob siab ua haujlwm zoo heev piv rau cov ntshiab magnesia cib.
Qhov twg nws siv:Cement kiln burning zone (qhov xav tau tshaj plaws hauv kev tsim cov cement), txiv qaub kiln, ladle ua haujlwm hauv ob sab phlu uas txwv tsis pub cov pa roj carbon monoxide, thiab cov khoom siv hluav taws xob uas tsis yog-ferrous.
MgO/Al₂O₃ ratio xaiv:
Cement kiln burning tsam: 70/30 (ntau dua spinel cov ntsiab lus rau siab tshaj thermal shock resistance)
Ladle ua hauj lwm hauv ob sab phlu: 80/20 (siab dua MgO kom zoo dua slag kuj thaum tuav thermal shock resistance)
BOF, EAF, Ladle - Sib piv qib rau daim ntawv thov
| Daim ntawv thov | Zone | Khoom siv pom zoo | Ntsiab Specification |
|---|---|---|---|
| BOF | Ua haujlwm hauv ob sab phlu | MgO-C cib, 15-18% C | FM-97 nplej, CCS Ntau dua lossis sib npaug li 35 MPa |
| BOF | Kev nyab xeeb hauv ob sab phlu | DBM-95 cib los yog castable | Qhov ntom ntom ntau dua lossis sib npaug li 3.00 g / cm³ |
| EAF | Sab phab ntsa (slag zone) | MgO-C cib, 12-15% C | FM-95 nplej, HMOR Ntau dua lossis sib npaug rau 8 MPa @ 1400℃- saibhluav taws xob arc rauv refractory qhia |
| EAF | Rooj | High alumina los yog corundum | Al₂O₃ Ntau dua lossis sib npaug li 90% rau thaj chaw kub |
| Ladle | Slag kab | MgO-C cib, 10-14% C | FM-97 nplej, C cov ntsiab lus sib tw rau qib steel |
| Ladle | Kev nyab xeeb / thaub qab | DBM-95 castable | Al₂O₃ + MgO tov los yog ntshiab MgO |
| Cement kiln | Hlawv cheeb tsam | Magnesia-spinel, 70/30 | PLC ± 0.5% ntawm 1650 degree |
Ib lub zeb zeb hauv Qaib Cov Txwv tau hloov lawv cov ladle slag kab txhua 80 heats. Tom qab peb muab FM-97-raws li 12% C MgO-C cib sib tw rau lawv cov qib steel (tsawg carbon steel, yog li peb capped carbon ntawm 12%), lawv mus txog 130+ heats ib phiaj los nqis tes. Kev xaiv qib - tshwj xeeb ntawm cov ntsiab lus carbon txwv - yog qhov hloov pauv tseem ceeb.
Yog xav paub ntxiv txog kev ncua lub neej kev sib tw, saib peb cov lus qhia steel ladle refractory hauv ob sab phlu.
Tuam Tshoj Sourcing: Cov ntaub ntawv zoo dab tsi yuav tsum tau
Rau tag nrho cov ntaub ntawv magnesia refractory, thov cov hauv qab no ua ntej txiav txim ntau:
Rau DBM / FM raw khoom:
Tshuaj ntsuam xyuas: MgO%, CaO%, SiO₂%, Fe₂O₃%, Al₂O₃% (tag nrho los ntawm XRF)
Qhov ntom ntom (g / cm³) - ntsuas rau ASTM C20
Grain loj faib (D50, D90) - tshwj xeeb tshaj yog tseem ceeb rau FM
Qhov chaw kuv daim ntawv pov thawj (Dashiqiao, Tuam Tshoj yog qhov tseem ceeb tshaj plaws)
Rau MgO-C thiab Spinel bricks:
COA: muaj pes tsawg leeg + lub cev muaj zog los ntawm cov khoom tsim tawm, tsis yog "tus nqi raug"
HMOR (Kub Modulus ntawm Rupture) @ 1400℃- qhov tseem ceeb ntawm qhov ntsuas kub ntawm lub zog
PLC ntawm kev pabcuam kub
Kev txheeb xyuas cov ntsiab lus carbon rau MgO-C (qee tus neeg muag khoom hauv qab tshaj tawm cov pa roj carbon kom txo nqi)
Peb khaws 3-xyoo cov ntaub ntawv ntau lawm nrog ntau-traceable COAs. Rau txhua qhov khoom xa tuaj, COA nrog rau daim ntawv xa tuaj.
Cov lus nug nquag
Dab tsi yog qhov txawv ntawm qhov tuag hlawv magnesia (DBM) thiab fused magnesia (FM)?
DBM is produced by calcining magnesite at 1700–1800°C. FM is produced by electrically fusing magnesite at 2800°C. FM has larger periclase crystal size (>1mm vs . 0.3–0.5mm rau DBM), ntau dua qhov ceev (3.45–3.55 vs. 3.15–3.35 g/cm³ rau DBM), thiab qis dua slag infiltration tus nqi. FM-97 yog tus qauv raw khoom rau kev ua haujlwm siab MgO-C cib hauv BOF thiab ladle slag kab siv.
Cov ntsiab lus carbon dab tsi kuv yuav tsum qhia meej rau MgO-C cib nyob rau hauv lub lauj kaub hlau?
Rau ladle slag kab MgO-C cib, cov ntsiab lus carbon feem ntau yog 10-14%. Cov pa roj carbon ntau dua (15-18%) yog siv hauv BOF qhov twg cov pa roj carbon khaws hauv cov hlau tsis tshua muaj qhov tseem ceeb thiab qhov siab tshaj thermal conductivity yog xav tau. Rau cov qib qis-carbon steel, qhia 10-12% C siab tshaj plaws kom txo qis cov pa roj carbon monoxide. Nco ntsoov qhia koj tus neeg muag khoom txog qib steel uas tau tsim.
Magnesia-spinel cib puas tuaj yeem hloov MgO-C cib hauv BOF?
Tsis ncaj. MgO-C cib hauv BOF tso siab rau cov pa roj carbon theem rau kev tiv thaiv tus kheej los ntawm cov txheej txheem khov slag. Magnesia-spinel cib tsis tsim cov txheej txheem tiv thaiv no. Spinel cib yog qhov zoo dua rau kev siv cov cement kiln nrog oxidizing cua. Rau BOF, nyob nrog MgO-C.
MgO purity theem 95% vs . 97% txhais li cas hauv kev xyaum?
MgO-90 rau MgO-95 yog tsim los ntawm cov khoom siv qis qis thiab muaj CaO thiab SiO₂ impurities siab dua. MgO-97 los ntawm fused magnesia muaj tsawg impurities thiab qhov loj tshaj plaws periclase siv lead ua loj. Qhov sib txawv ntawm qhov sib txawv: ntawm kab ladle slag, 95% DBM-raws li cib yuav kav 80 heats; 97% FM-raws li cib yuav kav ntev li 120-140 cua sov nyob rau hauv tib yam kev ua haujlwm.
