I-Boehmite 101: Isakhiwo seCrystal, iiPropati, kunye neMineraloji

1. Intshayelelo

I-Boehmite, ngokwekhemikhali ephawulwe njenge-aluminiyam oxide hydroxide (AlO(OH)), ime njengesiseko, inika umdla kakhulu, kunye nesigaba seminerali esisebenza ngeendlela ezahlukeneyo phakathi kosapho olubanzi lwe-aluminiyam oxyhydroxide. Ngelixa ibinokuthi iqatshelwe ziingcali zejolojisti kunye neenjineli zemigodi njengendawo eqhelekileyo ye-bauxite ore eyenzelwe ukutsalwa kwesinyithi se-aluminiyam ngokwenkqubo ye-Bayer, i-boehmite iye yavela kwisithuba seminyaka emininzi edlulileyo ukuya kwixabiso eliphezulu{1}}ikhemikhali ekhethekileyo, i-catalyst ephucukileyo kwi-precursor yayo esebenzayo, kunye ne-right advanced performance. Iimpawu zayo ezikhethekileyo zesakhiwo, uzinzo olumangalisayo lwe-thermal, i-chemistry esebenza kakhulu, kunye neprofayile yendalo engqongileyo iye yayibeka phambili ngokupheleleyo kwizicelo zemizi-mveliso zanamhlanje, ukusuka ekucoceni kwepetrochemical kunye nokulungiswa kwendalo ukuya ekusikeni{3}}i-edge ye-lithium{4}}izixhobo zokhuseleko lwebhetri yeion kunye{5}}nokusebenza okuphezulu kwe-nanomer.

Ukuqonda i-boehmite kufuna i-multidisciplinary, uphando olunzulu lwezenzululwazi ngemvelaphi yayo ye-mineralogical, i-atomic-ubumbeko lwekristale yenqanaba, ukuziphatha kwe-thermodynamic, kunye neempawu ezahlukileyo ze-physicochemical. Njengoko imizi-mveliso yanamhlanje isiya ifuna imathiriyeli ekhethekileyo enokumelana nemeko-bume yokusebenza engqongqo, ithobela imigaqo engqongqo yokhuseleko lwamazwe ngamazwe, kwaye ibonelele ngobuchule obuphezulu bokusebenza, i-boehmite ithathe ingqalelo emandla yabaphandi bezemfundo, izazinzulu zemathiriyeli, kunye nabavelisi bemizi-mveliso ngokufanayo. Eli nqaku libanzi libonelela nge{3}}ubunzulu, ujongo olucokisekileyo lwe-boehmite, iphonononga ngobuchule ukwenzeka kwayo kwendalo, ubume bayo bekristale ye-orthorhombic, isimilo esibalulekileyo somzimba kunye neekhemikhali, kunye nosetyenziso lwayo lwemizi-mveliso olwahlukeneyo lwale mihla oluqinisa ixabiso layo lezoqoqosho nobuchwepheshe kuqoqosho lwemathiriyeli yehlabathi.

2. IMineraloji kunye neZenzeko zeNdalo zeBoehmite

Umxholo weGeological and Formation

I-Boehmite sisimbiwa sesibini esixhaphakileyo esenzeka ikakhulu kwiidiphozithi ze-bauxite, ezisebenza njengomthombo wentengiso we-aluminiyam wesinyithi kunye neemveliso ezahlukeneyo ze-aluminiyam{0}ezisekelwe kwimichiza. Yenzeka ikakhulu ngenxa yemozulu eshushu, ixesha elide lemichiza ye-aluminiyam{2}}ethwele amatye e-silicate, i-feldspars, kunye namatye omzali atshisayo okanye i-metamorphic phantsi kweemeko zemozulu ezishushu kunye ne-subtropical, okanye ngenye indlela ngokuguqulwa kweeminerali eziphambili ze-aluminosilicate phantsi kwe-hydrothermal ethile okanye i-diagenetic geological regimes. Kwiindlela ezininzi eziphambili ze-bauxite emhlabeni jikelele, i-boehmite ihlangana ngokusondeleyo kunye nezinye i-aluminiyam hydroxides kunye nee-oxides, ngakumbi i-gibbsite (Al(OH)3) kunye ne-diaspore (AlO (OH)). Ubuninzi obunxulumeneyo, i-crystallinity, kunye nokusabalalisa kwendawo ye-boehmite ngaphakathi kwediphozithi ye-bauxite isebenza njengezibonakaliso ezibalulekileyo zezoqoqosho kunye nezobuchwephesha kwimisebenzi yezemigodi yorhwebo, njengoko i-boehmite ifuna ubushushu obugqithisileyo, uxinzelelo, kunye neemeko ze-caustic zokugaya ngexesha lenkqubo ye-industrial Bayer xa kuthelekiswa ne-gibbsite, echaphazela ngokuthe ngqo uyilo lobunjineli bezityalo, ukusetyenziswa kwamandla, kunye noqoqosho olusebenzayo jikelele.

Ukuchongwa kunye neCrystallography

Ngokwemineralogical, i-boehmite yaqala ukuchongwa yaza yachazwa ngokwenzululwazi ekuqaleni kwenkulungwane yamashumi amabini, ekugqibeleni yathiywa ngegama lekhemisti edumileyo yaseJamani uJohannes Böhm, owaqhuba izifundo zobuvulindlela bolwakhiwo kwiihydroxides ezahlukeneyo zealuminiyam esebenzisa ii-X{0}}iindlela zokwahlukana kwereyi zakuqala. Ngokwendalo, i-boehmite ayifane yenzeke njengenkulu,{2}}eyenziwe kakuhle iikristale zemacroscopic ezinokuqokelelwa ngokulula ngesandla okanye zodwa ngoomatshini; endaweni yoko, ibonisa ngokwesiqhelo njengeaggregates microcrystalline, ubunzima bomhlaba, udongwe{3}}olufana nezixhobo zematrix, okanye{4}}izaleko ezicolekileyo zokhuselo ngaphakathi kwe-bauxite ores kunye neeprofayile ze-lateral. Ubuchule bokuhlalutya obukwinqanaba eliphezulu, obufana nomgubo X-i-ray diffraction (XRD),{7}}isisombululo esiphezulu sothumelo lwe-electron microscopy (TEM), i-electron microscopy (SEM), kunye neFourier{8}}iguqule i-infrared spectroscopy (FTIR), zibaluleke kakhulu ekuchongeni kwayo ngokuchanekileyo kunye nenkangeleko ye-electronic millication ngokulula kunye ne-quantification ye-quantification yeminerali Ukuqonda usasazo lwayo lwendalo kunceda iingcali zejoloji zenze imephu ye-bauxite genesis ngokuchanekileyo kwaye incede iinjineli zemigodi ekuphuculeni intsimbi ekrwada{10}}ekusetyenzweni kwamaqhinga kuzo zonke iindawo zokuvelisa i-aluminiyam yehlabathi.

3. Ubume beCrystal beBoehmite

I-Orthorhombic Crystalline Framework

Kwinqanaba le-athomu, i-crystal structure ye-boehmite ichazwa yinkqubo ye-orthorhombic lattice, ngokuqhelekileyo yeqela lesithuba se-Cmcm. Uyilo lwangaphakathi lwe-boehmite luqulunqwe ngokusisiseko ngamacwecwe aphindwe kabini okanye iileya ze-octahedra, apho i-ion nganye ye-aluminiyam esembindini ilungelelaniswa ngokulinganayo yioksijini emithandathu ejikelezileyo kunye ne-hydroxyl ion. Ngaphakathi kwala maphepha andisiweyo, iiathom zeoksijini kunye namaqela e-hydroxyl acwangciswe ngokuxineneyo, avale{2}}uqwalaselo olupakishiweyo, ngelixa ii-ion zealuminiyam zithatha iisayithi ze-octahedral interstitial phakathi kwazo. Isici esichazayo soyilo kunye ne-thermodynamic ye-boehmite's crystal lattice luthungelwano olubanzi, olu-odolwe kakhulu lweebhondi ze-hydrogen ezomeleleyo ezisebenza ngokuthe ngqo phakathi kwamashiti e-octahedral akufutshane. Le bhondi ye-hydrogen ye-interlayer eyomeleleyo ibamba isakhelo solwakhiwo kunye ngokuqinileyo, inika ubulukhuni obukhulu bomatshini, ukumelana neekhemikhali, kunye nozinzo lobushushu xa kuthelekiswa ne-aluminiyam hydroxides njenge-gibbsite, ebonisa amandla abuthathaka kakhulu kwi-interlayer bonding.

Ukuthelekiswa koLwakhiwo kunye neePolymorphs

I-Boehmite yabelana ngeyona khemikhali i-stoichiometry efana ne-diaspore, zombini zihlelwa njenge-aluminiyam oxide hydroxides kunye ne-empirical formula AlO(OH), ukanti zikhazimla kwiinkqubo zekristale ezahluke ngokupheleleyo-i-boehmite inokwakheka kwe-orthorhombic, ngelixa i-diaspore iqaqambisa kwinkqubo ye-monoclinic. Olu lwakhiwo lwepolymorphism lubangela ukuxinana komzimba okwahlukileyo kakhulu, iiplani zokuqhekeka, amaxabiso obunzima, kunye nokuziphatha kwe-thermodynamic. Ngaphezu koko, xa kuthelekiswa ngokuthe ngqo kwi-trihydroxide mineral gibbsite (Al (OH) 3), i-boehmite iqulethe amanzi angaphantsi kakhulu kwi-athomu ye-aluminiyam. Lo mahluko usisiseko wecrystallographic uyalela ukuba iminerali nganye iphendule njani kunyango lobushushu, iphembelela uthotho oluthile, olulandelelanayo lwenguquko yesigaba eyenzeka xa ezi mathiriyeli ziphantsi kobushushu obuphezulu kwi-industrial calciners, iikhilni ze-ceramic, okanye izixhobo zokuhlalutya thermal elebhu.

4. IiPropati zePhysicochemical of Boehmite

Ukuziphatha kweThermal kunye neThermodynamic

Enye yezona mpawu zibalulekileyo nezixhatshaziweyo kurhwebo lwe-boehmite kukuqikelelwa kwayo,{0}}kubhalwe kakuhle ukuziphatha kobushushu. Xa i-boehmite iphantsi kobushushu obuqhubekayo, ifumana uthotho lwenguqu enzima, ene-endothermic kakhulu. Njengoko iqondo lobushushu linyuka lidlule malunga nama-300 degrees celsius ukuya kutsho malunga nama-500 degrees celcius, i-crystal lattice ikhupha amaqela ayo e-hydroxyl ebotshelelwe ngokwesakhiwo njengomphunga wamanzi acocekileyo, aguquka ngokucwangcisiweyo abe ziialumina ezahlukeneyo eziguqukayo, ezifana ne-gamma{5}}i-alumina, idelta{6}}i-alumina eguqulwayo ibe yi-alumina, ne-alumina egqibeleleyo ialpha-i-alumina kumaqondo obushushu aphezulu agqitha kwi-1100 degrees celcius. Le nkqubo ye-endothermic dehydration, kunye nokukwazi kwayo ukukhulula umphunga wamanzi acocekileyo ngokukhuselekileyo phantsi koxinzelelo lwe-thermal, yenza i-boehmite ibe ngumqobo okhethekileyo we-thermal kunye{11}netyhefu, i-eco{12}}idangatye elinobuhlobo{13}}elingakhathaliyo kwi-polymer ekhethekileyo kunye nokusetyenziswa kombane.

I-Surface Chemistry kunye ne-Reactivity

I-Boehmite ibonisa ubuchwephesha bomphezulu obumangalisayo, obuphawulwa ngendawo ethile ephezulu kakhulu, ngakumbi xa idityaniswe ngeendlela ezikhethekileyo ze-hydrothermal zemvula ukuvelisa i-nano{0}}amasuntswana obungakanani, iikristale zefibrous, okanye ii-colloidal boehmite sols. Umphezulu wamasuntswana okwenziwa kwe-boehmite uxinene ngamaqela e-hydroxyl esebenzayo, enikezela ngendalo eyahlukileyo ye-amphoteric eyivumela ukuba isebenze ngokufanelekileyo kunye neentlobo ze-acidic kunye nesiseko sekhemikhali kwisisombululo. Kukumiswa kwamanzi, i-boehmite inokwenza i-sols ezinzileyo, i-translucent colloidal, ipropathi exhatshazwa kakhulu kwisol ephucukileyo{3}}iindlela zokusetyenzwa kwejeli kwiiseramikhi zobugcisa, iingubo ezikhuselayo, kunye nokuveliswa kwenwebu. Ezi ziphatho zikhethekileyo ze-colloidal, zidityaniswe ne-morphologies yamasuntswana anokutyhutyha ukusuka kwipleyiti{5}}njengeekristale ukuya phezulu{6}}umbono{7}}umlinganiselo weenaliti ze-fibrous, zivumela izazinzulu ezibonakalayo ukuba zilungise i-boehmite yolawulo olujoliswe kuyo, ulwando oluphuculweyo lwe-adsorption, kunye ne-heterogeneous heterogeneous application.

5. Ukubaluleka koShishino kunye nezicelo zangoku

I-Precursor ye-Specialty Aluminas kunye neCatalysts

I-Boehmite isebenza njengesandulela kwimizi-mveliso eyimfuneko enkulu-enkulu yokwenziwa koguqulo oluphezulu{1}}i-aluminas ezisulungekileyo, ngakumbi i-gamma{2}}ye-alumina. Ezi alumina zotshintsho zine-porosity engaqhelekanga, imfezeko yolwakhiwo, kunye neendawo ezinkulu ezithe ngqo, zizenza zibe yinkulumbuso inkxaso esetyenziswa kakhulu kwi-petroleum yokucoca i-hydroprocessing, ii-automobile catalytic converters, kunye ne-complex chemical synthesis reaction. Ngokulawula ngononophelo iiparamitha zemvula, iimeko zokuguga, kunye nokusetyenzwa kwe-hydrothermal ye-boehmite precursors, abavelisi beekhemikhali banokulungelelanisa ngokuchanekileyo umthamo wepore, ukuhanjiswa kobungakanani bepore, amandla okutyumza oomatshini, kunye neendawo ezineasidi yomphezulu ukuhlangabezana neemfuno eziqatha ze-catalysis yanamhlanje.

Izicelo eziPhezulu kuGcino lwaMandla

Kwiminyaka yakutsha nje, i-boehmite ifumene usetyenziso olukhula ngokukhawuleza, oluphezulu{0}}lobuchwepheshe kwicandelo logcino lwamandla ehlabathi, ngakumbi njengemathiriyeli yokwambathisa ephucukileyo yezahluli kwi-lithium{1}}iion kunye ne-sodium{2}}ibhetri ye-ion. Ngenxa yozinzo oluphezulu lwe-thermal, iipropati ezibalaseleyo zokugquma umbane, ilangatye{4}}indalo erhabaxa, kunye nokungangeni kwekhemikhali, i-ultra{5}}yomgubo wokwenziwa we-boehmite ocolekileyo uqatywe njengomaleko obhityileyo weceramic kwizahluli zebhetri yepolymer. Olu gqumo lukhuselayo lwe-inorganic kuthintela ukushwabana kwesahlukanisi, imijikelezo emfutshane yangaphakathi, kunye nokubaleka kwe-thermal phantsi koxinzelelo oluphezulu{7}}lobushushu bokusebenza, ukutshaja, okanye i-nail{8}}yemeko yokungena, ngaloo ndlela iphucula kakhulu ukhuseleko, ukuthembeka, kunye nobomi beebhetri zemoto yombane, igridi yegridi{9} kunye nezixhobo zokugcina amandla ombane.

I-Flame Retardancy kunye ne-Nanomaterial Synthesis

Ngaphaya kogcino lwamandla kunye ne-catalysis, i-boehmite iya isetyenziswa njenge-eco-enobubele, i-halogen{1}}i-retardant yasimahla yedangatye{2}}kukusebenza kweeplastiki zobunjineli eziphakamileyo, iilayithi zebhodi yesekethe eprintiweyo, kunye nemathiriyeli yokwakha ekumgangatho ophezulu. Xa idityaniswe kwiipolymers kwi-filler high loading, ukuchithwa kwayo kwe-endothermic kubamba ubushushu be-ambient kwaye kunciphise iigesi ezivuthayo ze-pyrolysis ngexesha lesiganeko somlilo. Ukongeza, iinanoparticles zokwenziwa ze-boehmite zisasazwa ngokubanzi njengezomeleza izihluzi kwi-polymer nanocomposites, umkrwelo{5}}izinto zokuhombisa ezinganyangekiyo, kunye neembrane ze-ceramic zokuhluza, ebonisa ukuzivelela kwekhompawundi okumangalisayo ukusuka kwimveliso yezemigodi ukuya kubuchwephesha obuphezulu obuqhubela phambili{6}

6. Isiphelo

I-Boehmite (i-AlO (OH)) idlule ngempumelelo inkcazo yayo yendabuko njengokungcola okungafunekiyo kwe-bauxite okanye iproduct yesiqhelo yokumbiwa kwemigodi ukuze ibe yimathiriyeli yekona kubunjineli bemichiza obuphambili, isayensi yezinto, kunye nobuchwepheshe bale mihla. Isakhiwo sayo esikhethekileyo sekristale ye-orthorhombic, ebonakaliswa yi-robust interlayer hydrogen bonding, ibonelela ngozinzo olukhethekileyo lwe-thermal kunye neendlela zokuguqulwa kwesigaba esiqikelelweyo. Idityaniswe nommandla wayo ophakamileyo ophezulu, ikhemistri yomphezulu we-amphoteric, kunye neepropathi eziguquguqukayo ze-colloidal, i-boehmite yenza ukuba uphuculo olubalulekileyo lwetekhnoloji kumacandelo ahlukeneyo amashishini. Ukusuka ekukhonzeni njengesandulela esiphambili-soncedo olusebenzayo oluxhasa ukusebenza njengokhuseleko olubalulekileyo kwiibhetri ze-lithium-ze-ion kunye ne-eco{5}}i-eco-friendly retardant kwi-polymers ezenziweyo, i-boehmite ingumzekelo wendlela isiseko se-mineralogy esiqhubeka ngayo nokukhuthaza nokuqhubela phambili ukuveliswa kwemveliso kwihlabathi langoku.