Yintoni icorundum?

I-Corundum (Al2O3) inobuncwane obuninzi bezinto ezibonakalayo, ezibalelwa malunga ne-25% yobunzima bomhlaba. Ayibizi kakhulu kwaye ineempawu ezininzi ezibalaseleyo. Kukho iikristale ezininzi ezahlukeneyo ze-Al2O3, kwaye kukho iintlobo ezingaphezu kweshumi zeentlobo ezixeliweyo, kodwa kukho ezintathu eziphambili, ezizezi, α-Al2O3, β-Al2O3, kunye ne-γ-Al2O3.

I-tabular corundum

I-γ-Al2O3 yisakhiwo se-spinel, esingazinzile kumaqondo aphezulu kwaye ayifane isetyenziswe njengento enye. I-β-Al2O3 ngokuyimfuneko yialuminithi equlethe iintsimbi zealkali okanye iintsimbi zomhlaba zealkaline. Ukwakhiwa kweekhemikhali zayo kunokuqikelelwa yi-RO · 6Al2O3 kunye ne-R2O · 11Al2O3, i-hexagonal lattice, i-density 3.30 ~ 3.63g / cm3, 1400 ~ 1500 Iqala ukubola kwi-℃ kwaye iguqule ibe yi-α-Al2O3 kwi-1600℃. I-α-Al2O3 ifom ephezulu yokushisa, eneqondo lokushisa elizinzile eliphakamileyo njenge-melting point, kunye nobuninzi be-3.96 ~ 4.01g / cm3, ehambelana nomxholo wokungcola. Iseli yeyunithi yiprism ebukhali, ekhoyo ngohlobo lwendalo ye-corundum, irubhi kunye nesafire kwindalo. I-α-Al2O3 inesakhiwo esincinci, umsebenzi ophantsi, iimpawu zombane ezilungileyo, kunye neempawu ezibalaseleyo zomatshini. Ubunzima be-Mohs yi-9. I-α-Al2O3 yeye-hexagonal crystal system, isakhiwo se-corundum, a = 4.76, c = 12.99.

I-Al2O3 inamandla omatshini aphezulu. Ukucoceka kokwakheka kwe-Al2O3, kokukhona amandla aphezulu. Amandla oomatshini angasetyenziselwa ukwenza i-porcelain yesixhobo kunye namanye amacandelo oomatshini. I-resistantivity ye-Al2O3 iphezulu, ukusebenza kombane wokufakelwa kombane kukuhle, ukuxhathisa kwiqondo lokushisa kwegumbi ngu-1015Ω · cm, kwaye amandla e-dielectric yi-15kV / mm. Ukusebenzisa i-insulation yayo kunye namandla, inokwenziwa kwi-substrates, iziseko, iiplagi ze-spark, iigobolondo zesekethe, njl. njl. abrasives, umzobo uyafa, iibheringi, ukuthwala amatyholo kunye namatye anqabileyo okwenziwa. I-Al2O3 inendawo ephezulu yokunyibilika kunye nokumelana nokugqwala. Inendawo yokunyibilika ye-9°C. Inokumelana kakuhle nokukhukuliseka kweentsimbi ezityhidiweyo ezifana neBe, Sr, Ni, Al, V, Ti, Mn, Fe, CO kunye ne-sodium hydroxide, iglasi, kunye ne-slag. Kananjalo inokumelana okuphezulu; ayidibanisi ne-Si, P, Sb, Bi kwi-atmosphere ye-inert, ngoko ingasetyenziselwa njengezinto eziphikisayo, iibhubhu zesithando somlilo, i-glass drawing crucibles, iibhola ezingenanto, iifibers kunye nezikhuselo zokukhusela i-thermocouple, njl.

I-Al2O3 inozinzo oluhle kakhulu lweekhemikhali. Iisulfides ezininzi eziyinkimbinkimbi, i-phosphides, i-arsenides, i-chlorides, i-nitrides, i-bromides, i-iodides, i-fluorides eyomileyo, i-sulfuric acid, i-hydrochloric acid, i-nitric acid, kunye ne-hydrofluoric acid ayidibanisi ne-Al2O3. Ngoko ke, inokwenziwa ibe yintsimbi ecocekileyo kunye ne-crystal eyodwa yokukhula kwe-crucibles, amalungu omntu, amathambo okufakelwa, njl njl. amacandelo oscillation. I-ionic conductivity ye-Al2O3 isetyenziswe njengezinto eziphathekayo kwiiseli zelanga kunye neebhetri zokugcina. I-Al2O3 isetyenziswa ngokuqhelekileyo kwi-ceramic surface metallization technology.

Isigaba esiphambili se-crystalline ye-alumina-based fused corundum yisigaba se-corundum kunye nobukhulu be-1.0-1.5mm kunye neekristale ezidibeneyo. Ezinye zilandelelanisa amanani e-rutile, i-alumina kunye ne-aluminium titanate, kwaye ibekwe ngaphakathi kwesigaba se-corundum okanye phakathi kwezigaba zekristale. Inani elincinci lesigaba seglasi. E-China, emva kweminyaka engaphezu kweshumi yemizamo engapheliyo, inkqubo yokunyibilika kwe-bauxite-based fused corundum yenze inkqubela phambili enkulu, kunye nomthamo wemveliso yonyaka ngaphezu kweetoni ze-110,000. I-Bauxite-based fused corundum isetyenziswe ngempumelelo njengemathiriyeli ekrwada kwizitena ezahlukeneyo ezitshisiweyo kunye nezixhobo ezichasayo ezingamiliselwanga. Ngokomzekelo, inokuthi ithathe indawo ye-corundum eshinyeneyo kwi-blast furnace castables, kwaye isetyenziswe njengento ye-matrix kunye ne-granular material ukuvelisa i-creep ephantsi. Izitena eziphezulu ze-alumina zisetyenziselwa ukutshintsha i-corundum emhlophe kwezinye ii-refractories ze-Al2O3-SiO2 ukulungiselela iimveliso eziphezulu zokusebenza.

I-Brown corundum smelting isekelwe kumgaqo-siseko osisiseko wokuba i-aluminium inobudlelwane obukhulu be-oksijini kunentsimbi, i-silicon, i-titanium, njl. Ngokulawula inani le-agent yokunciphisa, ukungcola okuphambili kwi-bauxite kuyancitshiswa ngokunciphisa ukunyibilika, kunye nefom yokungcola encitshisiweyo. iialloyi zeferrosilicon. Ihlukaniswe kwi-corundum melt ukufumana i-brown corundum kunye nomgangatho we-crystal ohlangabezana neemfuno kunye nomxholo we-Al2O3 omkhulu kune-94.5%. I-Fe2O3 iyancitshiswa ukuvelisa i-ferrosilicon alloy kwaye isuswe ngexesha le-smelting process, kodwa inani elincinci le-iron oxide kunye ne-alumina eveliswa yi-spinel lisasele kwimveliso. I-TiO2 iyancipha ngokuyinxenye kwi-alloy ye-ferrosilicon ngexesha lenkqubo yokunyibilikisa, kwaye inxalenye enkulu yayo ihlala kwi-brown corundum, eyona nto iphambili kumbala we-brown corundum. I-CaO kunye ne-MgO kunzima ukunciphisa ngexesha lenkqubo yokunyibilikisa, kwaye uninzi lwe-CaO kunye ne-MgO kwizinto eziluhlaza zisekho kwimveliso. Nangona i-Na2O kunye ne-K2O inokuguquguquka kwiqondo lokushisa eliphezulu ngexesha lenkqubo yokunyibilikisa, ayinakuncitshiswa kwaye ihlale kwi-corundum emdaka, enempembelelo enkulu kumgangatho.

Brown corundum

Izinto eziluhlaza ze-brown corundum zenziwe nge-alpha-alumina crystal grains kunye nenqanaba elincinci leglasi, i-α-alumina crystals yenziwe nge-Al2O3 isisombululo esiqinileyo esiqulethe i-Ti2O3, kwaye isigaba seglasi sininzi siqulunqwe yi-titanium dioxide kunye ne-silicon dioxide kunye nezinye. Landela i-oxidation ekhoyo kwi-arc yombane.物组合。 Ukwakheka kwezinto. Ezi oksidi zenza isigaba seglasi, kwaye zine-solubility ephantsi kuphela kwisakhiwo sekristale yeenkozo ze-alumina. I-Ti2O3 kuphela kwe-oxide ethi i-Ti inokunyibilika kwiinkozo ze-alumina. I-TiO2 yioksidi ezinzileyo ye-thermodynamically ye-Ti. Ngexesha lokunyibilika kunye nokunciphisa i-corundum emdaka, inxalenye ye-TiO2 iyancitshiswa ibe yi-sub-oxidation ye-titanium. (Ti2O3), ngaphezu kwe-1000℃, i-oksijini inokusasazeka kwiinkozo ze-Ga-alumina, i-oxidize i-Ti2O3 ibe yi-TiO2 ezinzileyo kwaye emva koko iyisongele kwiinkozo ze-α-alumina, ngoko uninzi lwe-titanium dioxide yi-α-alumina Isisombululo esiqinileyo sekristale. iinkozo zikhona.

I-TiO2 egqithisileyo kwi-brown corundum ayikwazi ukuhlala kwisigaba seglasi, kodwa isabela nge-alumina ukuze yenze i-aluminium titanate (TiO2 · Al2O3). I-Aluminiyam i-titanate yinqanaba lesithathu kwi-interface phakathi kweenkozo ze-α-alumina kunye nesigaba seglasi; Ukuqina kwe-brown corundum kwanda ngokukhula kwe-crystal nuclei ye-TiO2. Isigaba se-TiO2 esisasazwe ngokufanayo kwiinkozo zekristale ze-α-alumina ziqinisa amasuntswana e-α-alumina. Isisombululo esiqinileyo se-corundum i-Ti2O3 ibangela ukuba i-brown corundum ibonakale eluhlaza okwesibhakabhaka.

I-Ti2O3 kuphela kwe-oxide ethi i-Ti inokunyibilika kwiinkozo ze-alumina. I-TiO2 yioksidi ezinzileyo ye-thermodynamically ye-Ti. Ngexesha lokunyibilika kunye nokunciphisa i-corundum emdaka, inxalenye ye-TiO2 iyancitshiswa ibe yi-sub-oxidation ye-titanium. (Ti2O3), ngaphezu kwe-1000℃, i-oksijini inokusasazeka kwiinkozo ze-Ga-alumina, i-oxidize i-Ti2O3 ibe yi-TiO2 ezinzileyo kwaye emva koko iyisongele kwiinkozo ze-α-alumina, ngoko uninzi lwe-titanium dioxide yi-α-alumina Isisombululo esiqinileyo sekristale. iinkozo zikhona. I-TiO2 egqithisileyo kwi-brown corundum ayikwazi ukuhlala kwisigaba seglasi, kodwa isabela nge-alumina ukuze yenze i-aluminium titanate (TiO2 · Al2O3). I-aluminiyam i-titanate yinqanaba lesithathu kwi-interface phakathi kweenkozo ze-α-alumina kunye nesigaba seglasi; Ukuqina kwe-brown corundum kwanda ngokukhula kwe-crystal nuclei ye-TiO2. Isigaba se-TiO2 esisasazwe ngokufanayo kwiinkozo zekristale ze-α-alumina ziqinisa amasuntswana e-α-alumina. Isisombululo esiqinileyo se-corundum i-Ti2O3 ibangela ukuba i-brown corundum ibonakale eluhlaza okwesibhakabhaka.