Qhov txawv ntawm Alumina Powder thiab Calcined Alumina Powder yog dab tsi?

Txawm hais tias alumina, corundum, ruby ​​thiab sapphire muaj cov npe sib txawv, lawv cov duab, hardness, zog, thiab kev siv kuj txawv, thiab lawv cov nqi sib txawv, tab sis lawv cov tshuaj muaj pes tsawg leeg yog tib yam, thiab lawv txhua tus yog alumina.

Nyob rau hauv lub lattice ntawm -type alumina, cov pa oxygen ions yog hexagonally packed, thiab Al₃ntxiv rau yog symmetrically faib nyob rau hauv lub octahedral coordination chaw ncig los ntawm cov pa ions. Lub lattice zog yog loj heev, yog li lub melting point thiab boiling point yog siab heev. Alpha alumina yog insoluble nyob rau hauv dej thiab kua qaub, tseem hu ua txhuas oxide nyob rau hauv kev lag luam, thiab yog cov yooj yim raw khoom rau ua hlau txhuas; nws kuj yog siv los ua ntau yam refractory bricks, refractory crucibles, refractory hlab, thiab kub siab sim ntsuas; nws kuj tseem siv tau los ua ib qho abrasive, nplaim hluav taws, muab tub lim, thiab lwm yam.; high-purity alpha alumina kuj yog cov khoom siv raw rau kev tsim cov khoom siv dag zog corundum, dag ruby ​​thiab sapphire; nws kuj yog siv nyob rau hauv zus tau tej cov niaj hnub loj-scale integrated circuit substrates.

-type alumina yog tau los ntawm lub cev qhuav dej ntawm aluminium hydroxide ntawm qhov kub thiab txias ntawm 140-150 degree C. Nws tseem hu ua activated alumina thiab aluminium kua nplaum hauv kev lag luam. Nyob rau hauv nws cov qauv, cov pa oxygen ions nyob ze-packed ze rau lub cubic center, thiab Al₃ntxiv rau yog irregularly faib nyob rau hauv lub octahedral thiab tetrahedral voids surrounded los ntawm cov pa ions. -type alumina yog insoluble nyob rau hauv dej, tab sis yuav yaj nyob rau hauv muaj zog acid los yog muaj zog alkali tov, thiab nws yog kiag li hloov mus rau hauv -type alumina thaum nws yog rhuab mus rau 1200 degree. -type alumina yog cov khoom ntxeem tau, nrog thaj tsam sab hauv ntawm ntau pua square metres ib gram, kev ua haujlwm siab thiab muaj peev xwm adsorption muaj zog. Cov khoom lag luam feem ntau yog xim tsis muaj xim lossis me ntsis liab cylindrical hais nrog zoo siab tsis kam. nws yog ib tug deacidifying tus neeg sawv cev rau transformer roj thiab turbine roj nyob rau hauv kev lag luam, thiab kuj yog siv rau chromatographic tsom xam; nws yog qhov nruab nrab muaj zog desiccant hauv chav kuaj, nws lub peev xwm ziab tsis muaj tsawg dua li ntawm phosphorus pentoxide, thiab nws tuaj yeem rov tsim dua thiab rov siv dua tom qab cua sov rau 6-8h hauv qab 175 degree .

Tam sim no, alumina tsim los ntawm Bayer txoj hauv kev hauv ntiaj teb suav rau ntau dua 90 feem pua ​​​​ntawm tag nrho cov zis. Feem ntau ntawm cov alumina yog siv los ua hlau txhuas, thiab tsawg dua 10 feem pua ​​yog siv rau lwm lub hom phiaj.

Lub ntuj tshwm sim -type alumina siv lead ua hu ua corundum, uas feem ntau nthuav tawm cov xim sib txawv vim txawv impurities. Corundum feem ntau yog xiav lossis daj grey, nrog iav lossis pob zeb diamond luster, ntom ntawm 3.9-4.1g/cm³, hardness ntawm 8.8, thib ob tsuas yog pob zeb diamond thiab silicon carbide, thiab tuaj yeem tiv taus qhov kub thiab txias.Corundum xuab zeb uas muaj hlau oxides hu ua emery, tsaus grey thiab tsaus dub, feem ntau siv los ua cov ntaub ntawv abrasive, siv los ua ntau yam ntaub ntawv abrasive, sib tsoo lub log, sib tsoo pob zeb, thiab kuj siv los ua cov cuab yeej kho qhov muag thiab qee yam khoom siv hlau

Vim tias cov khoom tsim tawm ntawm ntuj corundum tsis txaus, kev lag luam feem ntau sinters ntshiab-hom alumina hmoov nyob rau hauv qhov kub-kub hluav taws xob rauv los ua cov khoom siv dag zog corundum, tseem hu ua fused corundum.It tuaj yeem tiv taus qhov kub siab tshaj 1800 degree, thiab yog qhov raw khoom rau kev tsim cov khoom tshwj xeeb refractory siab heev. Nws muaj cov yam ntxwv ntawm lub zog txhua yam ntawm qhov kub thiab txias, zoo thermal poob siab tsis kam, muaj zog yaig tsis kam, thiab thermal expansion coefficient me me. , Nozzle, radar kav hlau txais xov tiv thaiv npog, atomic zog reactor cov ntaub ntawv, advanced high-frequency insulating ceramics, crucibles rau smelting ntshiab hlau thiab alloys, high-temperature cua sov ntsiab, thermocouple tiv thaiv tubes, linings ntawm ntau yam kub kub furnaces, thiab lwm yam. Artificial corundum kuj yog siv los ua precision ntsuas bearings thiab hlau kos duab tuag.

High-zoo corundum tov nrog ib tug me me ntawm txawv oxide impurities yog lub npe nrov ruby ​​thiab sapphire.

Ruby yog ib qho tsim tawm pob tshab liab corundum, nrog cov xim xws li daj ntseg liab mus rau tob carmine, qee qhov muaj xim daj, thiab qee qhov nrog lub hnub qub, nrog pigeon ntshav liab yog qhov khoom lag luam zoo tshaj plaws. Cov xim liab yog vim cov siv lead ua muaj me me ntawm chromium oxide. Ruby yog cov khoom muaj nqis ntawm lub pov haum, lub hnub yug rau lub Xya Hli. Ruby yog Ruby hauv lus Askiv, muab los ntawm Latin ruber lub ntsiab lus liab, nrog lub hardness ntawm 9, qhov ceev ntawm 4g / cm3, thiab lub pob zeb diamond luster.Tsis muaj ntau lub ntuj rubies hnyav 1 carat, thiab ntau tshaj 5 carats yog tsawg. Ntawm cov rubies mined txhua xyoo hauv ntiaj teb, qhov zoo tshaj plaws tsuas yog suav rau ib txhiab. Lub ntiaj teb loj tshaj plaws ntuj ruby ​​txog tam sim no nrhiav tau hnyav 3450 carats los ntawm Myanmar, lub ntiaj teb nto moo loj lub hnub qub ruby ​​hnyav 138.7 carats, thiab nto moo pigeon ntshav ruby ​​hnyav 55 carats.Lub keeb kwm nto moo tshaj plaws ntawm rubies hauv ntiaj teb yog nyob rau sab qaum teb ntawm Mandela. , Myanmar, nrog rau Thaib teb, Sri Lanka thiab Cambodia. Cov nyiaj ruby ​​loj loj tau pom nyob rau hauv Nganga, Kenya, Africa hauv 1973, Alispoli hauv nruab nrab Australia xyoo 1978, thiab Hunza, Pakistan thaum xyoo 1970s.