Yintoni umahluko phakathi kwe-alumina, i-corundum kunye nesafire?

Zininzi incarnations alumina. Xa abahlobo abaninzi besiva izibizo ezifana ne “alumina”, “corundum”, “ruby” kunye ne “sapphire”, abakwazi ukwahlula umahluko phakathi kwezi kwaye bahlala bedidekile. Ewe kunjalo, le meko ikwanxulumene nokungabikho kwangoku kwemigangatho efanayo kwiindidi ezininzi ze-alumina. Ukuze ubahlule, umbhali uya kudibanisa ulwazi lwakho ukuze akuncede uchonge le migaqo.

1. IAlumina

I-alumina, eyaziwa ngokuba yi-bauxite, inobuninzi be-3.9-4.0g/cm3, indawo yokunyibilika ye-2050 ° C, indawo yokubilisa ye-2980 ° C, kwaye ayinyibiliki emanzini. I-alumina inokukhutshwa kwi-bauxite kwishishini. . Phakathi kwezi zintlukwano ze-Al2O3, kuphela i-α-Al2O3 ezinzileyo, kunye nezinye iifom ze-crystal azinzanga. Njengoko iqondo lokushisa liphakama, ezi fom ze-crystal eziguqukayo ekugqibeleni ziya kuguqulwa zibe yi-α-Al2O3.

Kwi-crystal lattice ye-α-alumina, ii-ion ze-oxygen zipakishwe ngokusondeleyo kwii-hexagons, kwaye i-Al3 + isasazwa ngokulinganayo kumbindi we-octahedral ligand ejikelezwe yi-oxygen ion. I-lattice energy inkulu kakhulu, ngoko ke indawo yokunyibilika kunye neqondo lokubilisa liphezulu kakhulu. I-alpha-alumina ayinyibiliki emanzini nakwi-asidi. Ikwabizwa ngokuba yi-aluminiyam oxide kwishishini kwaye iyimathiriyeli ekrwada esisiseko yokulungiselela i-aluminiyam yesinyithi. Ukongeza, inokusetyenziselwa ukulungisa izinto ezahlukeneyo zokuchasa, izixhobo zokuqhafaza, kunye ne-substrates yeesekethe ezidibeneyo. Ukongezelela, ukucoceka okuphezulu kwe-α-alumina kukwayinto eluhlaza yokuveliswa kwe-corundum yokwenziwa, iirubhi ezenziweyo kunye nesafire.

I-γ-uhlobo lwe-alumina iveliswa ngokuchithwa kwe-aluminium hydroxide kwiqondo lokushisa kwe-500-600 ° C, kwaye ikwabizwa ngokuba yi-alumina esebenzayo kwishishini. Kwisakhiwo sayo, iiyoni ze-oxygen ziphantse zipakishwe kwiinqwelomoya ezithe nkqo, kwaye i-Al3 + ihanjiswa ngokungaqhelekanga kwi-octahedral kunye ne-tetrahedral voids ejikelezwe yi-oxygen ion. Ingasetyenziswa njenge-catalysts, catalyst carriers, adsorbents, desiccants, njl. kwishishini. Abo banomdla kule sampuli banokuphequlula isithuba esithi “Ukulungiselela kunye nesicelo seAlumina esebenzayo”.

Ngamafutshane: I-Alumina inokuqwalaselwa njengento ehlanganiswe ne-Al2O3 (iqulethe ukungcola okuthile, ngokuqhelekileyo ayihlambulukanga). Olu hlobo lwento lunezakhiwo ezahlukeneyo zekristale, ukucoceka kwemveliso eyahlukeneyo, kunye neefom ezahlukeneyo, ezimele iimveliso ezahlukeneyo. , Isetyenziswa kwiindawo ezahlukeneyo.

Ibhola ye-alumina ephezulu-icandelo eliphambili yi-alumina

2. I-Corundum kunye ne-artificial corundum

Iikristale ze-alumina ezenzeke ngokwemvelo zibizwa ngokuba yi-corundum, kwaye zihlala zibonisa imibala eyahlukeneyo ngenxa yokungcola okwahlukeneyo. ICorundum ngokuqhelekileyo inombala oluhlaza okwesibhakabhaka okanye omthubi grey, kunye neglasi okanye idayimane ikhazimula, ingxinano 3.9-4.1g/cm3, ukuqina 8.8, okwesibini kuphela kwidayimane kunye nesilicon carbide, kwaye inokumelana namaqondo obushushu aphezulu.

I-corundum etyheli yendalo

Kukho ubukhulu becala ezintathu iintlobo ze-corundum yendalo kwindalo: a. I-corundum esemgangathweni, eyaziwa ngokuba yi-gemstone: isafire iqukethe i-titanium, i-ruby iqukethe i-chromium, njl.; b i-corundum eqhelekileyo: emnyama okanye ebomvu ebomvu; c emery: inokwahlulwa ibe yi-emerald emery kunye ne-limonite emery, luhlobo lwekristale edibeneyo enobunzima obuphantsi. Phakathi kwezi ntlobo zintathu zingentla ze-corundum yendalo, eyokuqala isetyenziselwa ubucwebe, kwaye ezi zimbini zokugqibela zingasetyenziswa njenge-abrasives ukwenza amavili okugaya, i-oilstones, i-sandpaper, ilaphu le-emery okanye i-powder, i-abrasive pastes, njl.

Ngenxa yokuba ukuveliswa kwe-corundum yendalo kunqongophala, i-corundum esetyenziswa kwishishini ininzi i-corundum yokwenziwa endaweni yeemveliso ze-corundum yendalo.

I-Alumina ye-Industrial i-crystalline powder evulekileyo ene-porous and loose structure, engahambelaniyo noqhagamshelwano lwe-Al2O3 crystals kunye nomnye kwaye ngoko ayihambisani ne-sintering. Ngokuqhelekileyo emva kokubala okanye i-fusion recrystallization, i-γ-Al2O3 iba yi-α-Al2O3 (i-corundum) ye-sintering kunye noxinaniso. Ngokwendlela yokuvelisa, i-corundum ihlukaniswe ibe yi-corundum evuthayo (1350 ~ 1550 ℃) i-corundum (eyaziwa ngokuba yi-light burned α-Al2O3), i-sintered (1750 ~ 1950℃) i-corundum, kunye ne-corundum edibeneyo.

Isanti eyenziwe nge-corundum-emhlophe ye-corundum

Ngamafutshane: kuyinto yesiko ukubiza i-α-crystal alumina njenge-corundum. Ingaba i-corundum yendalo okanye i-artificial corundum, eyona nto iphambili ye-corundum yi-alumina, kwaye isigaba sayo esiphambili se-crystal yi-α-alumina.

3. I-Gem grade corundum kunye nerubhi eyenziweyo, isafire

I-corundum ephezulu exutywe kunye nenani elincinci lezinto ezingcolileyo ze-oxide yi-ruby eyaziwayo kunye nesafire, eyona nto iyinto yokwenza ubucwebe obuxabisekileyo, kunye neengqungquthela zayo zingasetyenziselwa ukwenza iibheringi zezixhobo ezichanekileyo kunye namawashi.

isafire

Okwangoku, i-synthesis yesafire ebomvu ibandakanya indlela yokuncibilika komlilo (indlela yokuncibilika komlilo), indlela ye-flux, indlela ye-hydrothermal kunye nokunye. Phakathi kwabo, indlela ye-hydrothermal ineemeko eziphezulu zobuchwepheshe kunye neemeko ezinzima zobugcisa. Nangona kunjalo, ukukhula kweekristale zegem kufana kakhulu neekristale zendalo. Isenokuba yeyona nkohliso, kwaye eyinyani kunye neyobuxoki ayibonakali. Iikristale zegem ezikhulile ngale ndlela ziquka ii-emeralds, iikristale, iirubhi, njl.

I-Artificial ebomvu kunye nesafire ayifani nje kuphela neemveliso zendalo ngokubonakala, kodwa nakwizakhiwo zomzimba kunye neekhemikhali kunye ne-optical, kodwa ixabiso li-1/3 kuphela kwi-1/20 yeemveliso zendalo. Kuphela phantsi kwe-microscope apho umoya omncinci kwiigugu ezenziweyo unokufumaneka Amaqamza ajikelezileyo, kwaye amaqamza omoya kwiimveliso zendalo acaba.

Ngamafutshane: nangona i-alumina, i-corundum, i-ruby kunye nesafire inamagama ahlukeneyo, iimilo zabo, ubunzima, iipropati, kunye nokusetyenziswa nazo zihluke, kodwa i-chemical chemistry i-alumina. Ifom ye-crystal ephambili ye-corundum yi-α-uhlobo lwe-alumina. I-Corundum yi-polycrystalline α-alumina material, kunye nekhwalithi ephezulu ye-corundum (i-jewel-grade corundum) yimveliso ye-crystal eyodwa ye-alumina.

Ngenxa yokusikelwa umda kolwazi lombhali, eli nqaku lichaza kabanzi ngamabinzana angafanelekanga. Ndicela iingcebiso kwiingcali zoshishino, enkosi.