Tsawg Cement Refractory Castable Khoom Taw Qhia

Tsawg cement refractory castables piv rau cov tsoos aluminate cement refractory castables. Cov cement ntxiv tus nqi ntawm cov tsoos aluminate cement refractory castables feem ntau yog 12-20%, thiab cov dej ntxiv yog feem ntau 9-13%. Vim muaj dej ntau ntxiv, lub cev cam khwb cia muaj ntau qhov pores, tsis ntom, thiab tsis muaj zog; vim muaj cov cement ntau ntxiv, txawm tias muaj zog dua li qub thiab tsis tshua muaj zog tuaj yeem tau txais, lub zog txo vim yog crystalline transformation ntawm calcium aluminate ntawm nruab nrab kub. Obviously, CaO qhia tau ua nrog SiO2 thiab Al2O3 nyob rau hauv castable los tsim ib co tsawg-melting point tshuaj, uas ua rau deterioration ntawm cov khoom ntawm high-temperature zog.

Thaum ultrafine hmoov technology, high-efficiency admixtures thiab scientific particle gradation yog siv, cov cement cov ntsiab lus ntawm cov castable yog txo kom tsawg tshaj li 8% thiab cov dej ntsiab lus yog txo mus rau ≤7%, thiab ib tug tsawg-cement series refractory castable yuav ua tau. npaj thiab coj mus rau hauv Cov ntsiab lus CaO yog ≤2.5%, thiab nws cov ntsuas kev ua tau zoo feem ntau tshaj cov aluminate cement refractory castables. Hom refractory castable no muaj thixotropy zoo, uas yog, cov khoom sib xyaw muaj cov duab thiab pib ntws nrog me ntsis sab nraud quab yuam. Thaum lub zog sab nraud raug tshem tawm, nws tuav cov duab tau. Yog li ntawd, nws tseem hu ua thixotropic refractory castable. Self-flowing refractory castable tseem hu ua thixotropic refractory castable. belongs rau qeb no. Lub ntsiab lus meej ntawm qis cement series refractory castables tsis tau txhais kom deb li deb. American Society for Testing and Materials (ASTM) txhais thiab faib cov castable refractory raws li lawv cov ntsiab lus CaO.

Ntuab thiab lub zog siab yog qhov tseem ceeb tshaj plaws ntawm cov tsis muaj kev hloov kho al series qis dua cas los. Qhov no yog qhov zoo rau kev txhim kho lub neej kev pab cuam thiab kev ua tau zoo ntawm cov khoom, tab sis nws kuj coj teeb meem rau ci ua ntej siv, uas yog, nchuav tuaj yeem tshwm sim tau yooj yim yog tias koj tsis ceev faj thaum ci. Qhov tshwm sim ntawm lub cev tawg tuaj yeem xav tau rov ua dua qhov tsawg kawg nkaus, lossis tuaj yeem ua rau muaj kev nyab xeeb ntawm tus kheej ntawm cov neeg ua haujlwm nyob ib puag ncig thaum mob hnyav. Yog li ntawd, ntau lub teb chaws kuj tau ua ntau yam kev tshawb fawb txog kev ci ntawm cov cement series refractory castables tsawg. Cov kev ntsuas tseem ceeb yog: los ntawm kev tsim cov qhov cub tsim nyog thiab qhia cov tshuaj tiv thaiv kev tawg zoo heev, thiab lwm yam, qhov no tuaj yeem ua rau cov castable refractory dej yog tshem tawm smoothly tsis ua rau lwm yam kev mob tshwm sim.

Ultrafine hmoov tshuab yog cov thev naus laus zis tseem ceeb rau qis-cement series refractory castables (tam sim no feem ntau ntawm cov hmoov ultrafine siv hauv ceramics thiab cov ntaub ntawv refractory yog nyob nruab nrab ntawm 0.1 thiab 10m, thiab lawv tsuas yog ua haujlwm raws li dispersion accelerators thiab structural densifiers. . cement hais tias dispersed heev tsis muaj flocculation, thaum lub tom kawg ua rau cov micropores nyob rau hauv lub pouring lub cev puv puv thiab txhim kho lub zog.

Tam sim no feem ntau siv hom ultrafine hmoov muaj xws li SiO2, α-Al2O3, Cr2O3, thiab lwm yam. Qhov chaw tshwj xeeb ntawm SiO2 micropowder yog li 20m2 / g, thiab nws qhov loj me yog li 1/100 ntawm cov cement particle loj, yog li nws muaj qhov zoo. filling khoom. Tsis tas li ntawd, SiO2, Al2O3, Cr2O3 micropowder, thiab lwm yam kuj tuaj yeem tsim cov colloidal hais hauv dej. Thaum muaj cov dispersant tam sim no, ib qho hluav taws xob sib tshooj ob txheej yog tsim nyob rau saum npoo ntawm cov khoom los tsim electrostatic repulsion, uas overcomes lub van der Waals quab yuam ntawm cov khoom thiab txo lub zog interface. Nws tiv thaiv adsorption thiab flocculation ntawm cov khoom; Nyob rau tib lub sij hawm, cov dispersant yog adsorbed nyob ib ncig ntawm cov hais los ua ib tug hnyav txheej, uas kuj ua rau kom lub fluidity ntawm castable. Qhov no kuj yog ib qho ntawm cov txheej txheem ntawm cov hmoov ultrafine, uas yog, ntxiv cov hmoov ultrafine thiab cov dispersants uas tsim nyog tuaj yeem txo cov dej haus ntawm cov castables thiab txhim kho fluidity.

Kev teeb tsa thiab hardening ntawm qis-cement refractory castables yog qhov tshwm sim ntawm kev sib xyaw ua ke ntawm kev sib txuas ntawm cov dej sib txuas thiab cohesion bonding. Lub hydration thiab hardening ntawm calcium aluminate cement feem ntau yog hydration ntawm hydraulic theem CA thiab CA2 thiab cov txheej txheem siv lead ua loj hlob ntawm lawv cov hydrates, uas yog, lawv hnov ​​​​mob nrog dej los tsim hexagonal flake lossis koob-zoo li CAH10, C2AH8 thiab Hydration khoom xws li raws li cubic C3AH6 crystals thiab Al2O3аq gels ces tsim ib qho kev sib txuas condensation-crystallization network qauv thaum lub sij hawm kho thiab cua sov txheej txheem. Lub agglomeration thiab bonding yog vim lub active SiO2 ultrafine hmoov tsim colloidal hais thaum nws ntsib dej, thiab ua tau raws li cov ions maj mam dissociated los ntawm cov additives (ie electrolyte tshuaj). Vim tias cov nqi saum npoo ntawm ob yog qhov sib txawv, uas yog, qhov chaw colloid muaj adsorbed counter ions, ua rau £ 2 Lub peev xwm txo qis thiab condensation tshwm sim thaum adsorption ncav cuag "isoelectric point". Nyob rau hauv lwm yam lus, thaum lub electrostatic repulsion nyob rau saum npoo ntawm cov colloidal hais yog tsawg tshaj li nws attraction, cohesive bonding tshwm sim nrog kev pab los ntawm van der Waals quab yuam. Tom qab lub refractory castable tov nrog silica hmoov yog condensed, cov Si-OH pawg tsim nyob rau saum npoo ntawm SiO2 yog qhuav thiab dehydrated rau choj, tsim ib tug siloxane (Si-O-Si) network qauv, yog li hardening. Nyob rau hauv lub siloxane network qauv, cov bonds ntawm silicon thiab oxygen tsis txo qis raws li qhov kub thiab txias, yog li ntawd lub zog kuj tseem nce ntxiv. Nyob rau tib lub sijhawm, ntawm qhov kub thiab txias, SiO2 network qauv yuav hnov ​​​​mob nrog Al2O3 qhwv hauv nws los ua mullite, uas tuaj yeem txhim kho lub zog ntawm qhov nruab nrab thiab kub.