Qhov sintering ntawmsilica cibQhov tseeb yog homogeneous polycrystalline transformation txheej txheem ntawm SiO2. Nyob rau hauv qhov kev txiav txim ntawm mineralizers, silica raw cov ntaub ntawv yog maj mam sintered thiab pib hloov mus rau hauv tridymite thiab cristobalite, tsuas yog ib tug me me ntawm cov residual quartz. Thaum silica refractory bricks yog rhuab mus rau 1450 degree thaum siv, muaj tag nrho ntim expansion ntawm 1.5% ~ 2.2%. Qhov kev nthuav dav seem no yuav ua rau cov pob qij txha masonry kaw, uas yog qhov tsim nyog los xyuas kom meej tias silicon cib masonry nthuav tawm zoo nruj thiab lub zog ntawm cov qauv. Ntxiv mus, qhov no homogeneous polycrystalline transformation ntawm SiO2 txiav txim siab hais tias lub hom phiaj ntawm refractory khoom saib xyuas nyob rau hauv thaum ntxov theem ntawm kiln ci yog silica hluav taws cib, thiab cov cua sov tus nqi yog yus muaj los ntawm qeeb thiab uniform cua sov. Nyob rau hauv qhov kub ntawm 150 ~ 300 degree, nws yuav tsum tau them tshwj xeeb mloog mus rau qeeb cua sov nyob rau hauv no kub ntau yam thaum ci kilns vim lub crystal transformation ntawm B thiab tsuas cristobalite yog nrog los ntawm ib tug loj ntim nyhuv.
Kev hloov pauv ceev thiab qib ntawm quartz rau tridymite tsis yog tsuas yog cuam tshuam nrog qhov kub thiab txias thiab muaj cov ntxhia pob zeb, tab sis kuj tseem cuam tshuam rau cov yam ntxwv xws li lub sijhawm kub, qhov loj me ntawm cov khoom siv raw, thiab cov khoom siv lead ua loj ntawm lub sijhawm hloov pauv. Kev hloov pauv sai yog qhov kub thiab txias, lub sijhawm ua haujlwm kub siab ntev, cov khoom me me, cov muaju me me, thiab cov ntxhia pob zeb muaj zog, thiab vice versa. Lub ntsiab siv lead ua theem ntawm silica cib yog tridymite thiab cristobalite. Lub melting point ntawm tridymite yog 1670 degree, thiab nws muaj siab ntim stability. Yog hais tias lub tridymite nyob rau hauv silica firebrick yog nyob rau hauv daim ntawv ntawm spearhead ntxaib crystals thiab interlaced nyob rau hauv ib tug network faib, lub cib yuav muaj ib tug ntau dua load softening point thiab txhua yam muaj zog. Thaum muaj ntau qhov seem quartz nyob rau hauv silica refractory cib, nws yuav txuas ntxiv mus rau kev hloov pauv siv lead ua thaum siv, thiab qhov ntim nthuav dav yuav loj, uas yuav ua rau cov qauv cib xoob thiab tawg. Cov kev hloov pauv ntawm lub cev thiab tshuaj lom neeg uas tshwm sim hauv silica hluav taws cib thaum lub sijhawm tua hluav taws tuaj yeem ua tiav raws li hauv qab no:
①<150℃ remove the residual moisture of the brick blank.
②Thaum 450 ~ 550 degree, Ca(OH)2 pib decompose, thiab 550% ntawm decomposition tiav. Lub sijhawm no, kev sib txuas ntawm silica bricks raug rhuav tshem vim qhov kev ua ntawm CaO, thiab lwm yam, lub zog txo qis, thiab qhov khoob yuav nkig.
③ Ntawm 550 ~ 650 degree, -quartz cib hloov mus rau hauv quartz thiab lub ntim nthuav dav.
④ Ntawm 600 ~ 700 degree, cov tshuaj tiv thaiv theem tshwm sim ntawm CaO thiab SiO2, thiab lub zog ntawm lub cev tau txhim kho.
⑤ Ntawm 800 ~ 1100 degree, kua theem cov tshuaj tiv thaiv tshwm sim hauv lub cev cib, thiab lub zog ntawm lub cev nce sai. Pib los ntawm 1100 degree, qhov kev hloov pauv ntawm quartz nce siab heev, thiab qhov tsis tshua muaj lub ntiajteb txawj nqus quartz variants nyob rau lub sijhawm no tsim cov ntim loj.
⑥Thaum 1300 ~ 1350 degree, vim qhov nce ntawm cov tridymite thiab cristobalite, qhov tseeb tshwj xeeb lub ntiajteb txawj nqus ntawm lub cev txo, thiab lub ntim expansion yuav ua rau tawg.
⑦ Ntawm 1350 ~ 1470 degree, lub degree ntawm quartz transformation thiab qhov tshwm sim nthuav dav heev. Tsuas yog monoquartz, metastable cristobalite, mineralizers thiab impurities cuam tshuam los tsim cov theem ua kua, thiab cuam tshuam cov quartz hais los ua cov kab nrib pleb thaum metastable cristobalite tsim, uas txhawb nqa qhov kev sib cais tas li ntawm monoquartz thiab metastable cristobalite nyob rau hauv lub tsim kua theem, ua rau nws ib tug supersaturated. yaj ntawm silicon thiab oxygen, thiab tom qab ntawd tsis tu ncua crystallizes los ntawm yaj hauv daim ntawv ntawm ruaj khov tridymite. Nyob rau lub sijhawm no, qhov ntau dua cov kua viscosity, qhov ceev ntawm silica refractory cib transformation ceev, thiab qhov muaj peev xwm ntawm cov kab nrib pleb ntau dua.
Yog li ntawd, txhawm rau tiv thaiv cov silica cib los ntawm kev hloov nws daim ntawv siv lead ua thaum lub sijhawm tua, nrog rau kev hloov pauv loj uas ua rau muaj kev tawg, cov txheej txheem hauv qab no yuav tsum tau ua:
(1) Cov cua kub ntawm qhov sib txawv ntawm qhov hluav taws kub kub yuav tsum tau tswj. Thaum qhov kub qis dua 600 degree, qhov cua sov yuav tsum tau qeeb. Cov cua sov tuaj yeem ua kom nrawm ntawm 600 ~ 1000 degree, thiab cov cua sov yuav tsum qeeb ntawm 1100 ~ 1300 degree. Thaum qhov kub ntawm qhov hluav taws kub yog 1300 degree (1430 degree txog 1450 degree), qhov cua kub yuav tsum qeeb tshaj thaum lub sij hawm tua. Thaum cov hluav taws kub silica cib txias hauv qab 600 degree, tshwj xeeb tshaj yog ntawm 300 degree, nws yuav tsum tau qeeb. Qhov no tuaj yeem cuam tshuam qhov ntim hloov pauv ntawm cov khoom siv lead ua, ua rau nws cov ntsiab lus tridymite thiab cristobalite siab dua, thiab zam kev tsim cov kab nrib pleb.
(2) Kev txo qhov cua yuav tsum tau siv nyob rau hauv qhov kub-kub tua hluav taws theem, uas yog haum rau cov mineralization ntawm tsawg-valent hlau oxide thiab txhawb lub loj-scale tiam ntawm tridymite. Txwv tsis pub, nyob rau hauv ib qho chaw oxidizing, tshwj xeeb tshaj yog thaum cov mineralizer tsis txaus, feem ntau ntawm -quartz hloov dua siab tshiab rau hauv -quartz. Qhov kev hloov pauv no hu ua "kev hloov pauv qhuav". Thaum lub sij hawm qhuav hloov dua siab tshiab, vim qhov loj tsis sib npaug ntim expansion ntawm lub cib lub cev thiab tsis muaj cov kua theem tsis muaj kev ntxhov siab, cov khoom qauv yuav xoob thiab tawg. Nyob rau tib lub sijhawm, kev rwb thaiv tsev tsim nyog yuav tsum tau nqa tawm ntawm qhov sib txawv ntawm qhov kub thiab txias ntawm silica hluav taws cib firing kom cov silica cib muaj cov theem tsim nyog thiab ua tau raws li kev siv.
(3) Txhim kho cov khoom thauj khoom ib nrab kom txo tau qhov tshwm sim ntawm cov kab nrib pleb. Cov kab nrib pleb ntawm silica refractory cib, uas yog, cov kab nrib pleb sib npaug rau cov kev taw qhia siab ntawm cov khoom, feem ntau tshwm sim los ntawm cov cua kub tsis sib xws ntawm ntau qhov chaw ntawm cov khoom thaum tua. Lawv feem ntau tshwm sim ntawm qhov hluav taws-tau txais qhov chaw sab nraum lub cib pawg, tshwj xeeb tshaj yog qhov chaw ntawm cov khoom saum toj kawg nkaus. Lub mesh tawg rau ntawm qhov chaw ntawm silica refractory cib feem ntau yog tshwm sim los ntawm kub kub ntau dhau thiab kev hloov pauv loj ntawm cov khoom, ntxiv rau qhov microscopic unevenness ntawm qhov dawb paug nws tus kheej vim tsis sib xws kneading los yog hloov cov ntaub ntawv raw. Thaum thauj khoom, tshwj xeeb silica firebricks yuav tsum tau muab tso rau hauv lub tsheb kiln, thiab cov qauv zoo tib yam cib raug ntsia sab nraum lub tsheb kiln; lub protruding qhov chaw ntawm qhov tshwj xeeb-zoo li tus cib los yog qhov chaw uas muaj cov kab nrib pleb yuav tsum muab tso rau hauv; sab saum toj ntawm lub tsheb kiln yuav tsum tau them nrog qee cov cib nyias kom tsis txhob cuam tshuam ncaj qha ntawm cov nplaim taws, thiab lwm yam, txwv tsis pub nws yuav ua rau tawg ntau dua.
