Isitena se-Magnesia alumina

Izitena ze-Magnesia ze-alumina zenziwe nge-sintered magnesia ekumgangatho ophezulu kwaye malunga ne-8% ye-Al2O3 umgubo ocolekileyo okanye i-bauxite ekumgangatho ophezulu (Al2O3> 78%, SiO2 <20%, isixa esincinci se-Fe2O3 kunye nokunye ukungcola), kusetyenziswa isulfite ulwelo lwenkunkuma olungumgubo njengesibopheleli, iimveliso zeAlkaline ezibonakalisayo ezenziwa ngokudibanisa, ukuxuba, ukubilisa, ukomisa, ukudubula kunye nezinye iinkqubo.

Umxholo we-magnesium oxide kwisitena se-magnesia alumina umalunga ne-85%. Umxholo we-alumina yi-5% ukuya kwi-10%, izinto ezisisiseko zokuphamba kunye ne-periclase njengesigaba esiphambili sekristal kunye ne-magnesia-aluminium spinel njengesigaba sekristale sesibini (njengesigaba esiphambili sokubopha). I-porosity ebonakalayo ngokubanzi iyi-15-18%. Umlingani wolwandiso lwe-thermal ngu-10.6 × 10-6 / ° C. Ukuxhathisa ukothuka kwe-thermal kungcono kune-magnesia yezitena ezihambelanayo. Ngenxa yokuba i-magnesium aluminium spinel enendawo yokunyibilika ephezulu isasazwa kwi-matrix, amandla ayo aphezulu obushushu aphezulu, kwaye ubushushu obuqala ukuthambisa umthwalo bungaphezulu kwe-1580 ° C. Ukuxhathisa kwe-slag kungcono. Ngokubanzi, umgangatho ophezulu we-sintered magnesia usetyenziswa njengezinto ezinamatye amakhulu, kunye nomgubo ocolekileyo owenziwe ngemagnesia kunye ne-bauxite okanye i-bauxite clinker okanye i-alumina yemizi-mveliso iyongezwa kwinxalenye ethile, kwaye ifunyenwe ngokudibanisa, ukwenza kunye nokudubula.

1. Magnesia alumina izitena zingenziwa ngokudibanisa 5-10% Al2O3 kwi magnesia sintered. I-A12O3 yongezwa ngomgubo ocolekileyo ngohlobo lwe-alumina yoshishino okanye i-alumina high bauxite clinker.

2. Ukuba i-Al2O3 yaziswa ngomhlaba one-alumina ephezulu, inyanzelekile ukuba yazise ukungcola okunje nge-SiO2 ngaxeshanye, ngaloo ndlela kuncitshiswe ukubuyisela amandla kunye namandla aphezulu obushushu kwimveliso. Ke ngoko, isixa se-alumina esongeziweyo akufuneki sibe sikhulu kakhulu.

3. Inkqubo yeeparameter zokwenza izitena ze-magnesia alumina ziphantse zafana nezitena zemagnesia. Kuphela nje kukuba iqondo lokushisa lokudubula liphezulu ngokubanzi kunobushushu be-magnesia ngezitena nge-30-50 ° C, efikelela kwi-1750-1800 ° C.

Izitena zeMagnesia alumina zineempawu ezilandelayo:

1. Izitena zeMagnesia alumina zinokuqina okuzinzileyo kwaye ziyakwazi ukumelana nokupholisa amanzi amaxesha angama-20-25 okanye nangaphezulu. Esi sesona sibonelelo saso sibalaseleyo. Izitena zeMagnesia alumina zinokuqina okuzinzileyo kobushushu. Zombini i-magnesia alumina spinel kunye ne-periclase ze-cubic crystal system. Ukwandiswa kobushushu kwicala ngalinye lekristal axis kuyafana, ke ulwandiso kunye nokuncipha kubini xa ubushushu buguquka. Iyafana ngakumbi kwaye ivelisa uxinzelelo lwe-thermal oluncinci.

2. Ezona mpawu ziphambili zemagnesia alumina izitena nazo zomelele kancinci kunezo zezitena zemagnesia. Ngenxa yokunyibilika okuphezulu kwe-magnesia-aluminium spinel uqobo lwayo, ubushushu obuthambisa isitena se-magnesia-aluminium bulunge ngakumbi kunesitena se-magnesia, esifikelela kwi-1620 ukuya kwi-1690 ℃.

3. Ukwenziwa kwemichiza yezitena ze-magnesia-aluminium kwahluka ngezinto ezahlukeneyo, ngokubanzi iMGO> 81%, Al2O3 8.7%, SiO2 <6.0%, CaO <1.5%, Fe2O3 <1.0%.

4. Ukwakhiwa kwezimbiwa kwe-magnesia alumina izitena. Kwimbumba yayo yezimbiwa, i-crystal ephambili yi-periclase, kwaye i-matrix yenziwe nge-magnesium ferrite, i-forsterite, i-forsterite kunye ne-magnesia spinel.

5. Refractoriness kunye nomthwalo ukuthambisa lobushushu isitena magnesia alumina. Kwisitena se-magnesia alumina, iikristali ze-periclase kunye ne-magnesia alumina spinel zenza isikhokelo senethiwekhi. Nangona inani elincinci lokunyibilika okungafunekiyo ligcwaliswe kukungabikho kwesakhelo senethiwekhi, isakhelo senethiwekhi sisenakho ukubanakho ukumelana nobushushu obuphezulu kunye nomthwalo, ngoko ke ukuphinda ukwenze kunye nomthwalo wokunciphisa ubushushu bezitena ze-magnesia alumina ziphakame kakhulu, Ukutsala kwakhona kunokufikelela kuma-2100 ℃, kwaye ubushushu obuthomalisayo ngumthwalo yi-1570 ℃.

6. Ukwanda kwe-thermal kunye nokuzinza kwe-thermal kwezitena ze-magnesia-aluminium. Ngenxa yokuba ulungelelwaniso lomgama we-magnesia-aluminium spinel incinci, umlinganiso wolwandiso lomlinganiso wesitena se-magnesia-aluminium mncinci kakhulu. Kuluhlu lwama-20 ~ 1000 ℃, ulungelelwaniso lomgama olwandisiweyo lwezitena ze-magnesia alumina ngu-10.6 × 10-6 ℃ -1 kuphela. Ngenxa yokuba i-magnesia alumina spinel idlala indima ekuphuculeni ukuxhathisa kukothuka kwezitena, isitena se-magnesia alumina sinokumelana okungcono kwe-thermal, kwaye inani lokupholisa amanzi lingaphezulu kwamaxesha angama-20.

7. Ukuxhathisa kwe-slag ye-magnesia-aluminium yezitena. Ngenxa yokuba izitena ze-magnesia-aluminium zinobuninzi obuphezulu kunye ne-porosity ephantsi, i-periclase ijikelezwe yi-magnesia-aluminium spinel, kwaye i-AI2O3 yi-oxide engathathi hlangothi, ngoko-ke i-magnesia-aluminium izitena Ukukwazi ukumelana ne-acid kunye ne-alkaline slag errosion yomelele.

Amandla e-magnesia alumina izitena ukukhusela i-periclase particles kwi-slag errosion yomelele kune-forsterite, ke amandla e-magnesia alumina ngezitena okumelana ne-alkaline slag kunye ne-iron oxide slag iyomelezwa.

Izitena zaseMagnesia-alumina zinezixhobo zibalaseleyo zikhankanywe apha ngasentla, ke ziye zasetyenziswa ngokubanzi njengezinto zokwakha uphahla lwezinto zokunyibilikisa ezinobushushu obuphezulu ezinje ngentsimbi eyenza amaziko avulekileyo eziko kunye neziko lokunyibilikisa ubhedu, kwaye bayifezekisile Iziphumo zokwandisa ubomi beziko. Iziko elikhulu elivulekileyo linokufikelela kumaziko angama-300, kwaye iziko eliphakathi nelincinci elivulekileyo lineziko elingaphezulu kwe-1000.