Txhim kho qhov refire kab variability ntawmtsawg cement refractory castables(feem ntau yog txwv tsis pub shrinkage / nthuav dav ntawm qhov kub thiab txias thiab ua kom lub ntim ruaj khov) yuav tsum tau hais txog peb qhov tseem ceeb: kev ua kom zoo ntawm cov khoom siv raw, kev tswj cov khoom ntxiv, thiab kev tswj cov txheej txheem. Cov txheej txheem tshwj xeeb yog raws li hauv qab no:
1. Optimizing raw khoom xaiv
Qhov siab - qhov kub thiab txias ntawm cov ntaub ntawv raw ncaj qha txiav txim siab qhov sib txawv ntawm refire kab sib txawv. Ua ntej tshaj ob yam hauv qab no:
1. Aggregates thiab Powders: Siv tsawg-shrinkage/pre- cov ntaub ntawv nyoos. Aggregates yuav tsum zoo dua yog ua ntej- hlawv corundum, mullite, siab- alumina bauxite (Ntau dua lossis sib npaug li 90% Al₂O₃), thiab lwm yam khoom siv siab- kub. Ua ntej- kub hnyiab tuaj yeem tshem tawm cov khoom siv raw ntawm cov khoom siv hluav taws xob hauv qhov hluav taws xob, tiv thaiv cov kab ntau dhau castable variability vim yog qhov sib npaug sib npaug ntawm qhov kub thiab txias. Rau cov hmoov, tsis txhob siv uncalcined aluminium hydroxide lossis qis-qib av nplaum kom txo qis decomposition/sintering shrinkage ntawm qhov kub thiab txias.
2. Tswj cov nyiaj Binder. Lub binder (aluminate cement) nyob rau hauv qis cement refractory castables muaj CaO, uas reacts nrog Al₂O₃ ntawm qhov kub thiab txias los tsim calcium aluminates (xws li CA₆), nrog rau qee qhov ntim hloov. Cov ntsiab lus ntawm cov cement yuav tsum tau tswj rau 3% -6% (los ntawm tag nrho qhov hnyav). Ua ke nrog silica fume thiab ultrafine alumina hmoov, qhov no txo cov cement reliance thiab minimizes calcium aluminate tsim.
2. Ntxiv Lub Hom Phiaj Ua Haujlwm Ntxiv Ntxiv
Cov additives tshwj xeeb tuaj yeem qhia tau ncaj qha offset shrinkage lossis stabilize siab -cov qauv kub:
1. Anti-cov tshuaj tiv thaiv shrinkage (expansive agents) xws li kyanite, sillimanite, thiab andalusite (3%-8%) tuaj yeem ntxiv. Cov zaub mov no maj mam decompose ntawm qhov kub thiab txias los ua mullite, uas nthuav tawm li ntawm 1.5% -3%. Qhov no precisely offsets lub castable sintering shrinkage, ua kom cov resintering kab hloov tus nqi nyob rau hauv ± 0.5% (1500℃x 3h).
2. High-kub stabilizers, xws li chromium oxide thiab zirconium oxide (1%-}3%), tuaj yeem cuam tshuam kev tsim thiab kev tsiv teb tsaws ntawm qis- cov theem melting point (xws li anorthite thiab iav) nyob rau hauv qis cement refractory castables, txo cov txheej txheem tsis sib haum xeeb los yog kev sib cog lus ntawm qhov kub thiab txias.
3. nruj me ntsis tswj kev tsim kho thiab kev kho cua sov
Cov txheej txheem tsis xws luag tuaj yeem ua kom muaj kev hloov pauv hauv kab rov ua dua thiab xav tau cov kev ntsuas tseem ceeb:
1. Xyuas kom muaj kev tsim kho kom zoo. Tswj cov dej ntxiv thaum sib tov (feem ntau 5% -7%) kom tsis txhob muaj cov dej noo ntau dhau, uas tuaj yeem ua rau cov porosity nce (qhov pore shrinkage ntawm qhov kub thiab txias tuaj yeem ua rau cov kab sib txawv tag nrho). Siv cov tshuab kev co (kev vibration zaus 2000-3000 zaug / feeb) kom ntseeg tau tias cov cement refractory castables tsawg dua los yog sib npaug ntawm 2.6g / cm³ thiab txo cov porosity sab hauv.
2. Kev kho kom zoo thiab kho cua sov
a. Kev kho lub sijhawm: Kev kho ntawm 20-25℃thiab cov av noo txheeb ze Ntau dua lossis sib npaug li 80% rau 24-48 teev ua kom muaj dej txaus ntawm cov cement thiab tsim cov khoom siv dej ruaj khov (xws li CAH₁₀ thiab C₂AH₈). Qhov no tiv thaiv lub cev qhuav dej ntawm qhov kub siab tom qab, uas tuaj yeem ua rau cov txheej txheem loosening.
b. Thaum tshav kub kub: Txhim kho qhov "tsawg- kub, qeeb- nce, siab- kub, tuav" nkhaus. Hauv qhov qis - qhov kub thiab txias (tsawg dua lossis sib npaug li 300 degree), qhov cua sov yuav tsum tsawg dua lossis sib npaug li 5℃/ h (kom tshem tawm cov dej dawb thiab dej crystallization); nyob rau hauv qhov nruab nrab- qhov kub thiab txias (300{11}}800 degree), qhov cua sov yuav tsum tsawg dua lossis sib npaug li 10℃/ h (kom tsis txhob tawg sai ntawm cov khoom hydration thiab tawg); thiab nyob rau hauv qhov kub thiab txias ntau (1000-1500 degree), qhov cua sov yuav tsum yog 2-4 teev los txhawb kev sib xyaw sintering thiab txo qhov ntim qhov hloov pauv.
