Phapano ke efe lipakeng tsa alumina, corundum le safire?

Ho na le li-incarnations tse ngata tsa alumina. Ha metsoalle e mengata e utloa mabitso a kang “alumina”, “corundum”, “ruby” le “sapphire”, ha ba khone ho khetholla phapang pakeng tsa tsena ‘me hangata ba ikutloa ba ferekane. Ehlile, boemo bona bo boetse bo amana le khaello ea hajoale ea litekanyetso tse ts’oanang tsa mefuta e mengata ea alumina. E le ho li khetholla, mongoli o tla kopanya lintlha tse ling ho u thusa ho tseba mantsoe ana.

1. Alumina

Alumina, eo hangata e tsejoang e le bauxite, e na le boima ba 3.9-4.0g/cm3, sebaka se qhibilihang sa 2050 ° C, ntlha e belang ea 2980 ° C, ‘me ha e qhibilihe metsing. Alumina e ka ntšoa ho bauxite indastering. . Har’a mefuta ena ea Al2O3, ke α-Al2O3 feela e tsitsitseng, le mefuta e meng ea kristale e sa tsitsang. Ha mocheso o ntse o phahama, mefuta ena ea kristale ea nakoana e tla qetella e fetoha α-Al2O3.

Ka har’a kristale lattice ea α-alumina, li-ion tsa oksijene li tletse haufi-ufi ka li-hexagon, ‘me Al3+ e arolelitsoe ka mokhoa o lekanang bohareng ba octahedral ligand e pota-potiloeng ke li-ion tsa oksijene. Matla a lattice a maholo haholo, kahoo ntlha ea ho qhibiliha le ntlha e belang e phahame haholo. Alpha-alumina ha e qhibilihe ka metsing le ka asiti. E boetse e tsejoa e le aluminium oxide indastering mme ke thepa ea mantlha ea ho lokisoa ha aluminium ea tšepe. Ntle le moo, e ka sebelisoa ho lokisa lisebelisoa tse fapaneng tsa refractory, lisebelisoa tsa abrasive, le li-substrates bakeng sa lipotoloho tse kopaneng. Ho phaella moo, bohloeki bo phahameng ba α-alumina e boetse e le thepa e tala bakeng sa tlhahiso ea corundum ea maiketsetso, lirubi tsa maiketsetso le safire.

Alumina ea mofuta oa γ e hlahisoa ka ho felloa ke metsi a aluminium hydroxide ka mocheso oa 500-600 ° C, ‘me e boetse e bitsoa activated alumina indastering. Ka sebopeho sa eona, li-ion tsa oksijene li batla li tletse ka lifofane tse emeng, ‘me Al3+ e arolelitsoe ka mokhoa o sa tloaelehang sebakeng sa octahedral le tetrahedral voids e pota-potiloeng ke li-ion tsa oksijene. E ka sebelisoa e le li-catalysts, catalyst carriers, adsorbents, desiccants, joalo-joalo indastering. Ba thahasellang sampole ena ba ka sheba poso ea “Tokisetso le Ts’ebeliso ea Alumina e kentsoeng”.

Ka bokhutšoanyane: Alumina e ka nkoa e le ntho e entsoeng ka Al2O3 (e na le litšila tse itseng, hangata e sa hloeka). Mofuta ona oa ntho o na le meaho e fapaneng ea kristale, bohloeki bo fapaneng ba sehlahisoa, le mefuta e fapaneng, e emelang lihlahisoa tse fapaneng. , E sebelisoa libakeng tse fapaneng.

Alumina bolo e phahameng-karolo e kholo ke alumina

2. Corundum le corundum ea maiketsetso

Likristale tsa mofuta oa α-alumina tse hlahang ka tlhaho li bitsoa corundum, ‘me hangata li bontša mebala e fapaneng ka lebaka la litšila tse fapaneng. Corundum ka kakaretso e boputsoa kapa e boputsoa bo bosehla, e na le khalase kapa daemane e benyang, boima ba 3.9-4.1g/cm3, boima ba 8.8, ea bobeli ho daemane le silicon carbide, ‘me e khona ho mamella mocheso o phahameng.

Natural yellow corundum

Ho na le mefuta e meraro haholo ea tlhaho ea tlhaho ea corundum: a. Corundum ea boleng bo holimo, e tsejoang ka hore ke lehakoe: safire e na le titanium, ruby e na le chromium, joalo-joalo; b corundum e tloaelehileng: e ntšo kapa e sootho e khubelu; c emery: e ka aroloa ka emery emery le limonite emery , Ke mofuta oa kristale e kopantsoeng e nang le boima bo tlaase. Har’a mefuta e meraro e ka holimo ea corundum ea tlhaho, ea pele e sebelisoa haholo-holo bakeng sa mabenyane, ‘me e’ meli ea ho qetela e ka sebelisoa e le li-abrasives ho etsa mabili a sila, majoe a oli, sandpaper, lesela la emery kapa phofo, li-abrasive pastes, joalo-joalo.

Hobane tlhahiso ea corundum ea tlhaho e haella, corundum e sebelisoang indastering ke boholo ba maiketsetso a corundum ho e-na le lihlahisoa tsa tlhaho tsa corundum.

Alumina ea indasteri ke phofo e hlephileng ea kristale e nang le sebopeho sa porous le se hlephileng, se sa lumellaneng le ho kopana ha likristale tsa Al2O3 hammoho le tse ling ‘me kahoo ha li khone ho sintering. Hangata ka mor’a calcination kapa fusion recrystallization, γ-Al2O3 e fetoha α-Al2O3 (corundum) bakeng sa sintering le densification. Ho ea ka mokhoa oa tlhahiso, corundum e arotsoe ka leseli le chesitsoeng (1350 ~ 1550 ℃) corundum (e tsejoang hape e le leseli le chesitsoeng α-Al2O3), sintered (1750 ~ 1950 ℃) corundum, le fused corundum.

Lehlabathe la maiketsetso la corundum-white corundum

Ka bokhutšoanyane: ke tloaelo ho bitsa α-crystal alumina e le corundum. Ebang ke corundum ea tlhaho kapa corundum ea maiketsetso, thepa e ka sehloohong ea corundum ke alumina, ‘me karolo ea eona e ka sehloohong ea kristale ke α-alumina.

3. Gem grade corundum le ruby ea maiketsetso, safire

Corundum ea boleng bo phahameng e kopantsoeng le litšila tse nyenyane tse fapaneng tsa oxide ke ruby e tummeng le safire, e leng thepa ea ho etsa mabenyane a bohlokoa, ‘me likaroloana tsa eona li ka sebelisoa ho etsa li-bearings tsa lisebelisoa tse nepahetseng le litebelo.

safire

Hona joale, motsoako oa safire e khubelu o kenyelletsa mokhoa oa ho qhibiliha ha lelakabe (mokhoa oa ho qhibiliha mollo), mokhoa oa ho phalla, mokhoa oa hydrothermal joalo-joalo. Har’a bona, mokhoa oa hydrothermal o na le maemo a phahameng a tekheniki le maemo a thata a tekheniki. Leha ho le joalo, kholo ea likristale tsa mahakoe e tšoana haholo le likristale tsa tlhaho. E ka ba ea bohata ka ho fetisisa, ‘me ea’ nete le ea bohata ha e khethollehe. Likristale tsa majoe tse hōlileng ka mokhoa ona li kenyelletsa emerald, likristale, lirubi, joalo-joalo.

Bofubelu ba maiketsetso le safire ha li tšoane feela le lihlahisoa tsa tlhaho ka ponahalo, empa hape le ka thepa ea ‘mele le ea lik’hemik’hale le ea optical, empa theko ke 1/3 feela ho 1/20 ea lihlahisoa tsa tlhaho. Ke feela ka tlas’a microscope moo moea o monyenyane o ka har’a mahakoe a maiketsetso o ka fumanoang Li-bubble li pota-potile, ‘me li-bubble tsa moea lihlahisoa tsa tlhaho li bataletse.

Ka bokhutšoanyane: le hoja alumina, corundum, ruby le safire li na le mabitso a sa tšoaneng, libopeho tsa tsona, boima, thepa, le tšebeliso ea tsona li fapane, empa lik’hemik’hale tsa tsona tse ka sehloohong ke alumina. Mofuta o ka sehloohong oa kristale oa corundum ke α-mofuta oa alumina. Corundum ke thepa ea polycrystalline α-alumina, ‘me corundum ea boleng bo phahameng (corundum-grade corundum) ke sehlahisoa se le seng sa kristale sa alumina.

Ka lebaka la bofokoli ba tsebo ea mongoli, sengoloa se qaqisa lipolelo tse sa nepahalang. Ke kopa le boeletsi ba indasteri, kea leboha.