Magnesia Carbon Bricks Refractory

Pa magnesia-carbon cib refractory, tsim raws li qhov txias- cov txheej txheem sib xyaw nrog cov khoom siv hluavtaws, tawv thiab tau txais lub zog tsim nyog raws li cov tar puas lawm, yog li tsim cov isotropic glassy carbon. Cov pa roj carbon tsis tuaj yeem pom cov thermoplasticity, uas tuaj yeem muab kev pabcuam raws sijhawm ntawm kev ntxhov siab ntau thaum ci lossis tuav hauv ob sab phlu. Magnesia- carbon bricks uas tsim nrog asphalt binders muaj siab siab - kub plasticity vim anisotropic graphitized coke qauv tsim thaum lub sij hawm carbonization txheej txheem ntawm asphalt.

txheej txheem ntau lawm

Cov ntaub ntawv tseem ceeb ntawm MgO-C cib muaj xws li fused magnesia lossis sintered magnesia, flake graphite, organic binders thiab antioxidants.

Magnesia

Magnesia yog cov khoom siv tseem ceeb rau kev tsim cov MgO-C cib, thiab muab faib ua fused magnesia thiab sintered magnesia. Piv nrog rau sintered magnesia, fused magnesia muaj qhov zoo ntawm coarse periclase crystal grains thiab siab particle ntim ceev, thiab yog lub ntsiab raw khoom siv nyob rau hauv zus tau tej cov magnesia carbon cib refractory. Kev tsim cov khoom siv magnesia zoo tib yam yuav tsum muaj cov khoom siv magnesia kom muaj siab - kub lub zog thiab corrosion kuj. Yog li ntawd, kev saib xyuas yuav tsum tau them rau qhov purity ntawm magnesia thiab C / S piv thiab B2O3 cov ntsiab lus hauv nws cov tshuaj muaj pes tsawg leeg. Nrog rau txoj kev loj hlob ntawm kev lag luam metallurgical, smelting tej yam kev mob tau dhau los ua xav tau. Cov magnesia siv hauv MgO-C cib siv rau hauv cov khoom siv metallurgical (converters, hluav taws xob furnaces, ladles, thiab lwm yam), ntxiv rau cov tshuaj muaj pes tsawg leeg, kuj yuav tsum muaj kev ceev thiab siab ceev ntawm lub koom haum cov qauv. Crystal loj.

Txawm hais tias nyob rau hauv ib txwm MgO-C cib los yog dav siv tsawg-carbon MgO-C cib, flake graphite feem ntau yog siv los ua nws cov pa roj carbon. Graphite, raws li cov khoom siv tseem ceeb rau kev tsim MgO-C cib, feem ntau tau txais txiaj ntsig los ntawm nws lub cev zoo heev: ① Tsis yog- ntub dej ntawm slag. ② High thermal conductivity. ③ Tsawg thermal expansion. Tsis tas li ntawd, graphite thiab refractory cov ntaub ntawv tsis fuse ntawm qhov kub thiab txias thiab muaj siab refractoriness. Lub purity ntawm graphite muaj kev cuam tshuam zoo rau kev ua haujlwm ntawm MgO-C bricks. Feem ntau, graphite nrog cov ntsiab lus carbon ntau dua 95%, nyiam dua ntau dua 98%, yuav tsum tau siv.

Ntxiv nrog rau graphite, cov pa roj carbon dub kuj yog feem ntau siv hauv kev tsim cov magnesia carbon cib refractory . Cov pa roj carbon dub yog cov khoom tawg yooj yim heev ntawm cov hmoov carbonaceous uas ua los ntawm thermal decomposition lossis tsis tiav combustion ntawm hydrocarbons. Cov pa roj carbon dub yog me me (tsawg dua 1 μm), thaj chaw tshwj xeeb yog qhov loj, thiab feem ntau ntawm cov pa roj carbon monoxide yog 90 ~ 99%, siab purity, loj hmoov resistivity, siab thermal stability, tsis tshua muaj thermal conductivity, thiab yog ib qho nyuaj rau - rau - graphitize carbon. Qhov sib ntxiv ntawm cov pa roj carbon dub tuaj yeem txhim kho qhov kev tiv thaiv ntawm MgO-C cib, ua kom cov pa roj carbon ntau ntxiv, thiab ua kom cov cib ntau dua.

Feem ntau siv cov binders hauv kev tsim cov MgO-C cib suav nrog cov thee tar, thee pitch thiab petroleum pitch, nrog rau tshwj xeeb carbonaceous resins, polyols, asphalt hloov kho phenolic resins, hluavtaws resins, thiab lwm yam. Cov nram qab no hom kev khi cov neeg sawv cev yog siv:

1) Asphalt-zoo li cov khoom. Tar asphalt yog cov khoom siv thermoplastic uas muaj kev sib raug zoo rau graphite thiab magnesium oxide, siab carbon residual tus nqi tom qab carbonization, thiab tus nqi qis. Nws tau siv dav hauv yav dhau los; Txawm li cas los xij, tar asphalt muaj carcinogenic aromatic hydrocarbons, tshwj xeeb tshaj yog cov benzo- cov ntsiab lus. Siab; vim muaj kev paub txog ib puag ncig, kev siv tar asphalt yog tam sim no txo ​​qis.

2) Resin tshuaj. Synthetic resin yog tsim los ntawm cov tshuaj tiv thaiv ntawm phenol thiab formaldehyde. Nws tuaj yeem sib xyaw zoo nrog cov khoom refractory ntawm chav tsev kub. Tom qab carbonization, cov pa roj carbon residue yog siab. Nws yog tus neeg sawv cev tseem ceeb tam sim no siv los tsim MgO-C cib; Txawm li cas los xij, nws cov ntaub ntawv tom qab carbonization Lub glassy network qauv tsis zoo tagnrho rau thermal poob siab thiab oxidation tsis kam ntawm cov ntaub ntawv refractory.

3) Cov tshuaj hloov kho raws li asphalt thiab resin. Yog hais tias lub binder tuaj yeem tsim cov qauv mosaic thiab tsim cov khoom siv carbon fiber nyob rau hauv qhov chaw tom qab carbonization, ces cov ntaub ntawv no yuav txhim kho qhov siab - qhov kub thiab txias ntawm cov khoom siv refractory.

Txhawm rau txhim kho oxidation tsis kam ntawm MgO-C cib, ib qho me me ntawm cov khoom ntxiv feem ntau tau ntxiv. Cov additives feem ntau yog Si, Al, Mg, Al-Si, Al-Mg, Al-Mg-Ca, Si-Mg-Ca, SiC, thiab B4C. , BN thiab tsis ntev los no tau tshaj tawm Al-B-C thiab Al-SiC-C series additives [5–7]. Lub hauv paus ntsiab lus ua haujlwm ntawm cov khoom ntxiv tuaj yeem muab faib ua ob yam: ntawm ib sab, los ntawm qhov ntsuas kub ntawm qhov pom, uas yog, ntawm qhov kub thiab txias ua haujlwm, cov khoom siv ntxiv lossis cov khoom siv ntxiv ua rau cov pa roj carbon monoxide los ua lwm yam, thiab lawv cov kev sib raug zoo nrog cov pa oxygen ntau dua li kev sib raug zoo ntawm carbon thiab oxygen. , ua ntej carbon raug oxidized los tiv thaiv carbon; Ntawm qhov tod tes, los ntawm kev xav kinetic, cov tebchaw tsim los ntawm cov tshuaj tiv thaiv ntawm cov tshuaj ntxiv nrog O2, CO lossis carbon hloov cov microstructure ntawm cov khoom siv refractory, xws li nce qhov ntom, thaiv qhov hws, cuam tshuam cov diffusion ntawm oxygen thiab cov khoom siv tshuaj tiv thaiv, thiab lwm yam.

Cov ntaub ntawv refractory siv nyob rau hauv cov kab ladle slag thaum ntxov yog siab - zoo alkaline cib xws li ncaj qha bonded magnesia-chromium bricks thiab electrofusion bonded magnesia-chromium cib. Tom qab MgO-C cib tau zoo siv rau hauv cov converters, MgO-C cib kuj tau siv nyob rau hauv refining ladle slag kab thiab ua tau zoo.

Kev tshawb fawb qhia tau tias MgO-C cib ua los ntawm kev sib xyaw ntawm fused magnesia thiab sintered magnesia, ntxiv rau 15% phosphorus flake graphite thiab ib qho me me ntawm magnesium- aluminium alloy li antioxidants, muaj kev siv zoo thiab muaj peev xwm ntawm 100 tons. Thaum siv hauv LF ladle slag kab, piv nrog MgO-C cib nrog cov ntsiab lus C ntawm 18% yam tsis muaj tshuaj tua kab mob, qhov kev puas tsuaj raug txo los ntawm 20-30%, thiab qhov nruab nrab yaig yog 1.2-1.3mm / cub.