Kev faib tawm thiab kev ua tau zoo ntawm 4 hom fused corundum

Fused corundum yog tsim los ntawm forged alumina los yog bauxite, uas yog yaj nyob rau hauv ib qho chaw rov qab los ntawm hluav taws xob arc rauv, sib cais los ntawm hlau thiab lwm yam impurities, thiab ces condensed. Nyob ntawm cov khoom siv thiab cov txheej txheem smelting, ntau hom yog: fused dawb corundum, fused xim av corundum, nplua fused corundum (tsawg porosity corundum), bauxite-based fused corundum (feem ntau hu ua high aluminium corundum, sub-dawb corundum. ) thiab zirconium corundum.

Thaum smelting xim av corundum nrog bauxite raws li cov khoom, feem ntau tsuas yog rov qab smelting yog nqa tawm. Carbonaceous cov ntaub ntawv uas siv los ua restorants feem ntau yog coke los yog anthracite. Cov kev cai rau anthracite yog: tsau C Ntau dua lossis sib npaug rau 80%, tshauv Tsawg dua lossis sib npaug rau 10%, cov ntsiab lus tsis hloov pauv<7%, moisture <3%. The amount of coke or anthracite is considered according to the demand for recovering SiO2, Fe2O3 and TiO2 impurities. The participating material is necessary to be fully dry and roasted and dehydrated, the particle size of the charge is generally 10 to 40㎜, not too fine, the particle size of coke or anthracite is 1 to 5㎜.

Cov txheej txheem melting yog nqa tawm nyob rau hauv peb-theem hluav taws xob arc rauv, thiab muaj ob hom: void type (lub cub txias txoj kev) thiab tilting hom (dhau mus rau lwm yam ladle txias txoj kev). Cov txheej txheem tom kawg yog qhov tsim nyog thiab siv los ntawm ntau thiab ntau lub Hoobkas. Lub melting kub yog hais txog 2000 degree.

1, hluav taws xob fused dawb corundum

Tam sim no feem ntau hu ua "molten alumina" feem ntau yog hais txog "fused dawb corundum". Nws yog raws li kev lag luam alumina raws li cov khoom siv, melting ntawm qhov kub thiab txias hauv arc rauv, nws cov ntsiab lus Al2O3 tsis tsawg dua 99%, dawb, thaiv cov khoom, pom meej porosity 6% ~ 10%, lub ntsiab siv lead ua theem yog a-Al2O3. , siv lead ua yog ntev thiab pob zeb diamond, thiab feem ntau skeletal crystals. Vim tias cov khoom siv ntshiab heev, tsis muaj tshuaj lom neeg hauv kev ua haujlwm ntawm lub cub hluav taws xob, tab sis qhov kub thiab txias ceev ntawm cov kua molten muaj kev cuam tshuam zoo rau cov qauv ntawm cov khoom thaiv. Nyob rau hauv cov nqe lus ntawm homogenization, nws yog ib qho tseem ceeb kom tau raws li zoo raws li ib tug block li sai tau. Thaum Na2O ntawm qhov zoo yog condensed, nws tsim -Al2O3, uas yog ib qho yooj yim mus sib sau ua ke nyob rau hauv nruab nrab ntawm cov khoom thaiv, uas yuav adversely cuam tshuam cov hluav taws kub kuj thiab sib tsoo cov ntaub ntawv, yog li ntawd nws yog tsim nyog los saib xyuas cov ntsiab lus ntawm Na2O. ntawm qhov zoo. Tsis tas li ntawd, qhov thaiv kwv yees muaj me me ntawm nepheline, iav ca.

2, zoo fused corundum

Fine fused fused corundum yog tsim los ntawm kev lag luam alumina, uas yog fused nyob rau hauv lub cub hluav taws xob los ntawm kev ntxiv admixtures. Thaum melting yuav tsum tau ua nruj me ntsis tswj kom muaj ntau tshaj ntawm carbide. Cov tsos ntawm zoo fused fused corundum yog grey, grey dub lossis grey dawb, Al2O3 yog ntau dua 98%, qhov pom meej porosity qis dua fused dawb corundum, feem ntau tsawg dua 4%, qhov ntom ntom ntau dua 3.8g·cm3, lub ntsiab crystalline theem yog a-Al2O3, lub subcrystalline theem yog FeTiO3, CaAl12O9, Ca3Si8O9, TiN, Ti4O7, thiab lwm yam. Muaj kuj yog ib tug me me iav theem. Cov ntsiab lus C hauv corundum zoo yuav tsum tsawg dua 0.14%, thiab qhov tsim ntawm -Al2O3 yuav tsum raug txo kom ntau li ntau tau los txhim kho lub zog thiab corrosion kuj ntawm corundum hais. Thaum fused corundum muaj carbides (Al4C3, Al4O4C), carbides tuaj yeem hnov ​​​​mob nrog dej ntawm chav tsev kub:

(Al4C3+12H2O → 4Al(OH)3+3CH4↑

Ua rau cov hmoov ntawm fused corundum hais. Thaum cov khoom siv amorphous refractory yog tsim, lub cev kev tsim kho tuaj yeem loosened, bulging, thiab txawm tawg loj heev. Fine fused corundum yog sib sau ua ke hauv cov khoom siv refractory, thiab kev siv cov amorphous refractory yog nthuav.

3, fused xim av corundum

Brown corundum yog ua los ntawm ntuj bauxite, carbon (feem ntau coke) ua ib tug restorative tus neeg saib xyuas, thiab hlau filings raws li ib tug settler (paub tus neeg sawv cev) los tsim ferrosilicon sinking nyob rau hauv qab ntawm lub cub hluav taws xob.

Xim av corundum yog xim av, feem ntau Al2O3 Ntau dua lossis sib npaug li 94.5%, SiO2 Tsawg dua lossis sib npaug li 3.5%, TiO2 Tsawg dua lossis sib npaug li 3.5%, Fe2O3 Tsawg dua lossis sib npaug li 1%. Cov ntxhia muaj pes tsawg leeg feem ntau yog a-Al2O3, thiab lub hauv paus ntawm cov khoom siv lead ua yog pob zeb diamond-puab, tuab phaj zoo thiab cov khoom tawg, thiab muaj ntau silicon oxide thiab calcium oxide yaj crystals nyob ib ncig ntawm nws, uas yog cov phaj ntev, thiab qhov ntxhib tshaj plaws yog skeletal lamellae. Vim tias cov impurities tsis tau raug tshem tawm tag nrho, xim av corundum kuj tseem muaj cov theem nrab siv lead ua xws li rutile thiab iav theem, ferroalloys thiab cov kev daws teeb meem. Cov xim ntawm xim av corundum feem ntau yog nyob ntawm titanium oxide uas tseem nyob hauv cov khoom.

Brown corundum feem ntau yog siv los ua abrasive. Nyob rau hauv xyoo tsis ntev los no, nws tau siv nyob rau hauv loj thiab nruab nrab moj tej tawg rauv castable thiab hlau anhydrous moj tej tawg av nkos aggregate thiab cov khoom siv los tsim cov corundum bricks (xws li siab alumina silicon carbide cib).

4, bauxite-based fused corundum

Kuj hu ua subwhite corundum los yog siab aluminium corundum, nws yog qhov ua tau zoo fused corundum raws li bauxite. Nws yog tsim los ntawm melting super qib lossis qib thawj bauxite nyob rau hauv cov xwm txheej ntawm kev rov qab los thiab kev tswj hwm, thiab tus neeg sawv cev melting yog suav nrog tus neeg sawv cev rov qab (carbon), tus neeg sawv cev (hlau chips) thiab tus neeg sawv cev decarburizing (hlau nplai). TiO2 rov qab los nrog ntau tus neeg sawv cev rov qab los ntawm kev tawm dag zog thaum ntxov, thiab tom qab ntawd koom nrog tus neeg sawv cev decarburizing lossis oxygen tshuab kom tshem tawm cov pa roj carbon ntau dhau ntawm kev tawm dag zog, thiab tom qab ntawd tau txais subwhite corundum. Nws lub hom phiaj ntawm lub cev thiab tshuaj lom neeg yog ze rau qhov zoo fused corundum, cov xim kuj tseem nyob ze, cov ntsiab lus ntawm Al2O3 yog ntau dua 97%, qhov pom tseeb porosity tsawg dua 4%; Corundum siv lead ua feem ntau yog granular, nplai 1 ~ 15㎜; Lub ntsiab impurity deposits yog calcium hexaluminate (CA6), rutile, aluminium titanate thiab nws cov khoom tov. Txawm li cas los xij, cov ntxhia muaj pes tsawg leeg muaj ntau dua titanium tebchaw, thiab cov coefficient ntawm thermal expansion yog siab tshaj qhov zoo fused corundum. Siv rau hauv cov khoom siv amorphous refractory, kub moj tej tawg rauv cib thiab Al2O3-SiC-C cib.