A magnesia alumina spinel brick is a high-grade basic shaped refractory manufactured from high-purity dead-burned or electro-fused magnesia co-sintered with pre-reacted or in-situ magnesium aluminate spinel (MgAl2O4, containing Al2O3 5% to 15% and MgO >= 80% mus rau 88%), engineered xa refractoriness nyob rau hauv load (RUL T0.6) saum toj no 1650℃thiab dej-quench thermal shock tsis kam tshaj 15 mus rau 25 cycles. Tsim tshwj xeeb los hloov cov phom sij hexavalent-chromium-generating magnesia-chrome cib hauv cov cement rotary kilns, spinel-toughened yooj yim refractories muab cov ntaub ntawv tseem ceeb rau sab sauv thiab sab hauv qhov chaw hloov pauv uas hloov pauv thermal stresses, tsis ruaj tsis khov clinker txheej, thiab gaseous alkali-sulfur ntsev tawm tsam yooj yim cib.
Thaum ncaj magnesia bricks nthuav tawm tshwj xeeb tshuaj refractoriness tiv thaiv cov oxides yooj yim, lawv cov kab hluav taws xob thermal expansion coefficient (14 x 10^-6 / degree) ua rau lawv muaj kev puas tsuaj loj heev thaum lub sij hawm kub kub swings. Los ntawm kev qhia cov txheej txheem hluavtaws spinel nrog qis thermal expansion (8.0 x 10^-6 / degree), engineers qhia microscopic thermal expansion mismatch tawg uas ntes tawg propagation thiab dissipate kev nyuaj siab. Cov kev qhia no qhia txog theem toughening mechanics, tshuaj qib specifications, cement kiln hauv ob sab phlu tsim, thiab ncaj qha kev cai los ntawm peb lub Hoobkas hauv Suav teb.
Spinel Toughening Mechanism: Vim Li Cas Ntshiab Magnesia Fail
Pure periclase (MgO) refractories raug kev txom nyem los ntawm cov txheej txheem brittleness:
Thermal Stress & Brittle Failure:Thaum lub qhov cub hluav taws xob muaj kev cuam tshuam thaum muaj xwm txheej ceev, kev cuam tshuam kev noj mov nyoos, lossis kev hloov pauv ntawm qhov cub, qhov kub thiab txias ua rau muaj kev ntxhov siab heev hauv cov txheej cib ua haujlwm. Nyob rau hauv cov ntshiab magnesia cib, tensile stresses propagate sai heev los ntawm cov tuab periclase siv lead ua matrix, ua loj macroscopic tawg dav hlau uas ua rau 20 mus rau 50 hli tuab slabs rau spill tawm ntxov ntxov.
Microcrack Energy Dissipation Txoj Cai:Thaum kub kub kub ntawm 1650℃mus rau 1750℃nyob rau hauv industrial tunnel kilns, periclase thiab magnesium aluminate spinel sinter nruj ua ke. Thaum txias, vim tias spinel cog lus tsawg dua li cov periclase matrix ib puag ncig, tswj microcracks tsim raws li ob-theem lis ciam teb.
Kev ntes Crack Propagation:Thaum mechanical los yog thermal stresses ntaus lub cib nyob rau hauv kev ua hauj lwm kev pab cuam, ua ntej cov kab nrib pleb ntsib cov uas twb muaj lawm ciam teb microcracks. Lub zog ntawm qhov tawg yog absorbed, deflected, thiab dispersed los ntawm microscopic grain branching es tsis koom ua ke rau hauv ib tug loj heev structural shear dav hlau. Yog li ntawd, Hoobkas-engineeredMagnesia alumina spinel cibTxhua zaus muaj sia nyob tshaj 20 lub voj voog dej-quench (1100℃rau dej txias) yam tsis muaj kev tawg.
Technical Specifications: Pre-Synthesized vs. In-Situ Spinel Qib
Cov neeg tsim khoom tsim cov txheej txheem spinel refractories siv ob txoj hauv kev metallurgical: kev sib xyaw ua ntej-synthesized fused / sintered spinel grain, los yog tsim cov spinel hauv qhov chaw tua hluav taws:
1. Tus Qauv Qib rau Upper Transition Zone (8% rau 10% Al2O3)
MgO Cov ntsiab lus: >= 84.0%
Al2O3 Cov ntsiab lus:8.5% mus rau 10.5% (Pre-reacted spinel aggregates)
Fe2O3 Cov ntsiab lus: <= 1.0%
CaO Content: <= 1.5% (Strict low-lime limit to prevent liquid phases)
Bulk Density:2.88-2.95g / cm3 (ASTM C134)
Pom tseeb Porosity: <= 16.5% (ASTM C20)
Cold Crushing Strength (CCS): >= 60.0 rau 75.0 MPa (ASTM C133)
Refractoriness nyob rau hauv Load (RUL T0.6): >= 1680℃(ASTM C16)
Thermal Shock Resistance (1100℃Dej Quench): >= 20 cycles
2. Qib High-Density rau Lower Transition Zone (5% mus rau 7% Al2O3)
MgO Cov ntsiab lus: >= 87.0%
Al2O3 Cov ntsiab lus:5.0% txog 7.0%
Fe2O3 Cov ntsiab lus: <= 0.8%
Bulk Density:2.95-3.02 g / cm3
Pom tseeb Porosity: <= 15.5%
Cold Crushing Strength (CCS): >= 65.0 rau 80.0 MPa
Refractoriness nyob rau hauv Load (RUL T0.6): >= 1700 degree
Thermal Shock Resistance (1100℃Dej Quench): >= 15 cycles
Rau cov neeg kho tshuab torque hnyav thiab hnyav clinker abrasion, cov nroj tsuag siv pre-reacted fusedmagnesium aluminium spinel raw khoomlos xyuas kom meej xoom unreacted dawb alumina tseem nyob rau hauv lub cib qauv.
Cement Rotary Kiln Transition Zones: Kev Ua Haujlwm Sib Tw
Niaj hnub nimno precalciner cement kilns uas muaj peev xwm ntau lawm ntawm 3,000 txog 10,000 metric tons hauv ib hnub nthuav tawm cov ntaub ntawv refractory rau peb txoj kev puas tsuaj rau kev puas tsuaj:
1. Tsis ruaj tsis khov Clinker Txheej Cycling
Tsis zoo li qhov chaw kub kub hauv nruab nrab qhov chaw ruaj khov molten clinker adheres khov kho rau cib ntsej muag, cov kev hloov pauv sab saud thiab sab qis ua haujlwm ntawm 1200℃txog 1450 degree. Nyob rau hauv no ntau yam, lub clinker txheej rov qab sticks thiab peels tam sim ntawd. Thaum txheej slabs tev tawm, lawv rub cov khoom siv cib ntsej muag nrog lawv. Spinel bricks muaj siab kub modulus ntawm rupture (HMOR> 4.5 MPa ntawm 1400 degree), tiv thaiv txheej shear tev.
2. Volatile Alkali & Sulfur ntsev Infiltration
Lwm lwm cov roj hluav taws xob (RDF, log tsheb, biomass) qhia cov ntsiab lus siab ntawm cov poov tshuaj tsis haum (K2O), sodium (Na2O), chlorine (Cl), thiab sulfur (SO3) rau hauv cov pa roj carbon dioxide. Cov roj ntsev no nkag mus rau hauv qhov dej qhib rau hauv 800℃mus rau 1000℃cib sab hauv, condensing rau hauv poov tshuaj sulfate (K2SO4) thiab spurrite. Qhov no alkali ntsev infiltration ua rau volumetric densification thiab sib sib zog nqus spalling. Magnesia-spinel cib tiv thaiv alkali-ntsev nthuav dav zoo dua li ib txwmMagnesia refractory khoom.
3. Sib piv: Magnesia-Alumina Spinel vs. Magnesia-Hercynite Cib
Nyob rau hauv high-stress burning zone interfaces uas ceev txheej txheej yog qhov tseem ceeb, cov neeg ua haujlwm cement feem ntau ntsuasmagnesia hercynite cib(Iron-alumina spinel FeAl2O4). Hercynite accelerates kua-theem txheej adherence, whereas magnesia-alumina spinel muab ntau dua refractoriness nyob rau hauv load thiab qis thermal conductivity, ua rau nws cov nqi-zoo tshaj nyob rau hauv cov kev hloov chaw.
Kiln Masonry, Expansion Paper & Mechanical Ring Wedging
Kev txhim kho kom zoo ntawm cov refractories yooj yim nyob rau hauv teb kilns tiv thaiv kev sib koom ua ke ntxov ntxov:
Radial Expansion Allowances:Cov cib yooj yim nthuav dav ntau dua li lub plhaub plhaub hlau. Txhua 1.0 mus rau 1.5 linear meters ntawm lub nplhaib hauv ob sab phlu yuav tsum tau qhuav-puab cardboard expansion spacers (1.5 mus rau 2.0 mm tuab) los yog ceramic fiber ntawv strips uas hlawv tawm huv si thaum lub cub commissioning, tiv thaiv compressive crushing ntawm cib npoo.
Steel Shim Ring Wedging:Txhua lub nplhaib cib raug ntsia kom qhuav thiab kaw nruj siv cov cib tseem ceeb tshwj xeeb. Hlau shims (1.5 mus rau 2.0 hli txias-kuav los tiag steel phaj) yog tsav mus rau hauv lub kaw pob qij txha siv pneumatic tsav hammers. Thaum ua haujlwm kub, cov hlau hlau no oxidize thiab tshuaj fuse nrog cov cib uas nyob ib sab, tsim kom muaj lub nplhaib monolithic masonry uas tshem tawm cov cib poob thaum lub sij hawm sib hloov.
Factory Direct Quality Assurance & Sourcing Terms
Procuring magnesia alumina spinel cib ncaj qha los ntawm cov chaw tsim khoom hauv Suav teb tau lees paub siab periclase purity thiab qhov tseeb qhov tseeb:
Ultra-High Tonnage Pressing:Cov cib yog molded ntawm 1600 txog 2500 metric tuj siab automated hydraulic presses, kom ntseeg tau tias cov khoom siv sab hauv qhov ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom hauv +/- 1.0 hli rau VDZ (B-series, A-series) thiab ISO standard rotary kiln wedge shapes.
Kev tiv thaiv dej: Basic refractories are sensitive to moisture hydration (MgO + H2O ->Mg (OH) 2). Txhua lub pallet tau ntim nrog cov khoom siv desiccant, muab ob npaug rau hauv cov dej tsis muaj dej polyethylene shrink qhwv, khi nrog high-tensile PET strapping, thiab mounted ntawm fumigated ISPM 15 ntoo export pallets.
Cov ntsiab lus lag luam & Lub Sijhawm Lead:Yam tsawg kawg nkaus txiav txim kom muaj nuj nqis (MOQ) yog 10 metric tons rau cov qauv duab thiab 20 metric tons rau ua tiav kiln nplhaib profiles. Standard ntau lawm lub sij hawm yog 12 mus rau 18 hnub ua hauj lwm FOB Qingdao Chaw nres nkoj.
Txhawm rau xa cov kab hluav taws xob hluav taws xob, thov daim ntawv pov thawj xeem (MTC), lossis tau txais tus nqi xa tawm ncaj qha, hu rau peb pab pawg engineering ntawminquiry@topower.tech.
