Aluminosilicate refractory cov ntaub ntawv nrog cov ntsiab lus Al2O3 ntau dua 48% yog suav nrog cov khoom siv high-aluminium refractory. Nws cov khoom kawg yog lub siab alumina cib feem ntau siv hauv thermal kilns. Raws li cov ntsiab lus Al2O3,siab alumina cibtuaj yeem muab faib ua peb qib:
Class I: Al2O3>75%;
Chav Kawm II: Al2O360% ~ 75%;
Qib III: Al2O348% ~ 60%.
Muab faib raws li ntxhia muaj pes tsawg leeg: tsawg mullite thiab mullite (Al2O348% ~ 71.8%); mullite-corundum thiab corundum-mullite (Al2O371.8% ~ 95%); corundum (Al2O395% ~ 100%). Nyob rau hauv qhov ntau ntawm Al2O3 tsawg dua 71.8%, raws li Al2O3 cov ntsiab lus nce, lub ntsiab siv lead ua theem mullite hauv high-aluminium khoom nce; nyob rau hauv thaj tsam ntawm Al2O3 ntau dua 71.8%, raws li Al2O3 cov ntsiab lus nce, tus nqi ntawm mullite txo qis thiab tus nqi ntawm corundum txo. Tus naj npawb nce. Qhov hluav taws kub tsis kam ntawm cov khoom nce nrog qhov nce hauv Al2O3 cov ntsiab lus.
High alumina cib xa mus rau aluminosilicate lossis ntshiab alumina sintered cov khoom uas muaj ntau tshaj 48% Al2O3. Feem ntau, siab alumina refractory cib muaj tsawg dua 80% Al2O3, thiab cov uas muaj ntau tshaj 80% Al2O3 hu ua corundum bricks.
Piv nrog av nplaum cib, qhov zoo tshaj plaws ntawm alumina hluav taws kub cib yog siab refractoriness thiab load softening kub.
1. Refractory tsis kam
Lub refractoriness ntawm siab aluminium bricks fluctuates dav, feem ntau ntawm 1770 thiab 2000 degree. Nws yog feem ntau cuam tshuam los ntawm Al2O3 cov ntsiab lus thiab nce nrog qhov nce ntawm Al2O3 cov ntsiab lus hauv cov khoom. Nyob rau tib lub sijhawm, lub refractoriness kuj cuam tshuam los ntawm cov ntsiab lus thiab hom impurities, thiab muaj feem xyuam rau cov ntxhia qauv ntawm cov khoom.
2. Load softening kub
Lub softening deformation kub ntawm siab alumina bricks nyob rau hauv load yog ntau tshaj 1400 degree, thiab nce nrog rau qhov nce ntawm Al2O3 cov ntsiab lus. Rau cov khoom lag luam nrog cov ntsiab lus Al2O3 tsawg dua 71.8%, qhov ntsuas kub ntawm qhov muag yog nyob ntawm qhov sib piv ntawm mullite thiab iav theem, thiab nce nrog qhov nce ntawm qhov ntau ntawm mullite. Tus nqi thiab qhov xwm txheej ntawm cov iav theem muaj qhov cuam tshuam loj rau qhov chaw thau khoom muag. Thaum cov ntsiab lus Al2O3 yog 71.8% mus rau 90%, nws yog cov khoom siv mullite lossis corundum. Raws li Al2O3 cov ntsiab lus nce, lub khob theem ntim yeej tseem tsis hloov pauv. Txawm hais tias corundum nce, lub mullite txo; Yog li ntawd, qhov softening kub nyob rau hauv load tsis nce. Qhov tseem ceeb. Tom qab Al2O3 cov ntsiab lus ntau dua 90%, raws li Al2O3 cov ntsiab lus nce, cov iav theem txo qis thiab cov load softening kub nce ntau, los ntawm 1630 degree thaum Al2O3 yog 90% mus rau 1900 degree thaum Alz03 yog 100%. Lub load softening kub nce nrog qhov nce hauv Al2O3 cov ntsiab lus. txhim kho.
3. Thermal conductivity
High-aluminium refractory khoom muaj thermal conductivity ntau dua li cov khoom siv av nplaum. Yog vim li cas yog tias muaj tsawg iav nrog tsawg thermal conductivity nyob rau hauv high-aluminium cov khoom, thaum lub sij hawm tus nqi ntawm mullite thiab corundum crystals nrog zoo thermal conductivity tsub kom, uas txhim kho cov thermal conductivity ntawm cov khoom. Thermal conductivity txo thaum kub nce.
Lub thermal conductivity ntawm siab alumina cib txawv ntawm av nplaum cib thiab silica cib. Lub thermal conductivity ntawm high aluminium refractory cib txo qis thaum kub nce. Thaum cov ntsiab lus Al2O3 nyob rau hauv high alumina firebricks yog siab dua, ntau mullite thiab corundum crystals muaj, qhov pom tseeb dua qhov nyiam ntawm thermal conductivity kom txo thaum kub nce. Tab sis siab dua 1000 degree, tus nqi txo qis. Lub thermal conductivity ntawm av nplaum cib thiab silica cib nce nrog qhov kub thiab txias, qhia txog kev sib raug zoo, thiab tsis hloov ze li ntawm 1000 degree. Nyob rau hauv ib txwm kub, thermal conductivity ntawm high aluminium refractory bricks yog 2 mus rau 3 lub sij hawm ntau dua li cov av nplaum cib, tab sis lawv cov thermal conductivity yeej zoo ib yam li saum toj no 1000 degree.
Ntau yam uas tsis tshua muaj Al2O3 cov ntsiab lus nyob rau hauv siab alumina cib zoo ib yam li av nplaum cib nyob rau hauv load softening point thiab thermal shock kuj. Txawm li cas los xij, raws li Al2O3 cov ntsiab lus nce, cov khoom muag muag thiab thermal shock kuj maj mam nce. Cov yam ntxwv ntawm siab alumina refractory cib ua rau lawv kub-kub hom av nplaum cib, yog li lawv tuaj yeem siv rau hauv qhov kub kub ntawm cov iav melting furnaces. Ntau yam uas tsis tshua muaj porosity tuaj yeem siv rau hauv qhov kub thiab txias ntawm lub tshuab regenerator, xws li lub ru tsev thiab phab ntsa ntawm lub regenerator.
