I-alumina ifunyaniswe ikhona ubuncinci iifom ezisi-8, ziyi-α- Al2O3, θ-Al2O3, γ- Al2O3, δ- Al2O3, η- Al2O3, χ- Al2O3, κ- Al2O3 kunye ne-ρ- Al2O3, iimpawu zabo zesakhiwo semacroscopic ngokwahlukeneyo. nazo zahlukile. I-alumina esebenzayo yeGamma yikhyubhiki evaliweyo epakishwe ngekristale, enganyibilikiyo emanzini, kodwa inyibilika kwiasidi kunye nealkali. I-alumina esebenzayo ye-gamma ibuthathaka kwinkxaso ye-asidi, inendawo ephezulu yokunyibilika eyi-2050 ℃, ijeli ye-alumina ekwimo ye-hydrate inokwenziwa kwi-oxide ene-porosity ephezulu kunye nomphezulu othile ophakamileyo, inezigaba zotshintsho kuluhlu olubanzi lobushushu. Kwiqondo lokushisa eliphezulu, ngenxa yokuphelelwa ngamanzi emzimbeni kunye ne-dehydroxylation, i-Al2O3surface ibonakala ilungelelanisa i-oksijini engaxutywanga (iziko le-alkali) kunye ne-aluminium (iziko le-asidi), kunye nomsebenzi we-catalytic. Ke ngoko, i-alumina ingasetyenziselwa njengomphathi, i-catalyst kunye ne-cocatalyst.
I-alumina esebenzayo yeGamma inokuba ngumgubo, iigranules, imicu okanye ezinye. Singenza ngokwemfuno yakho.γ-Al2O3, yayibizwa ngokuba yi "alumina esebenzayo", luhlobo lwezixhobo eziqinileyo ezisasazekileyo, ngenxa yesakhiwo sayo sepore esihlengahlengiswayo, indawo enkulu yomphezulu othile, ukusebenza kakuhle kwe-adsorption, umphezulu kunye neenzuzo ze-asidi. kunye nokuzinza okuhle kwe-thermal, umphezulu we-microporous kunye neempawu ezifunekayo zesenzo se-catalytic, ngoko ke ibe yeyona nto isetyenziswa kakhulu, i-catalyst carrier kunye ne-chromatography carrier kumashishini ekhemikhali kunye ne-oyile, kwaye idlala indima ebalulekileyo kwi-oyile hydrocracking, ukulungiswa kwe-hydrogenation, ukuguqulwa kwe-hydrogenation, i-dehydrogenation reaction kunye nenkqubo yokucoca i-automobile exhaust.I-Gamma-Al2O3 isetyenziswa ngokubanzi njenge-catalyst carrier ngenxa yokulungelelaniswa kwesakhiwo sayo se-pore kunye ne-acidity yomhlaba. Xa i-γ- i-Al2O3 isetyenziswa njengomthwali, ngaphandle kwayo ingaba nemiphumo yokusabalalisa kunye nokuzinzisa amacandelo asebenzayo, inokubonelela ngeziko le-asidi yealkali esebenzayo, i-synergistic reaction kunye ne-catalytic active components. Ubume bepore kunye neepropathi zomphezulu we-catalyst zixhomekeke kwi-γ-Al2O3 carrier, ngoko ke umthwali wokusebenza okuphezulu unokufunyanwa kwimpendulo ethile ye-catalytic ngokulawula iipropathi ze-gamma alumina carrier.
I-alumina esebenzayo ye-Gamma yenziwe ngokubanzi nge-precursor yayo ye-pseudo-boehmite nge-400 ~ 600℃ yokuphelelwa ngubushushu obuphezulu, ngoko ke iipropathi zomphezulu ze-physicochemical zimiselwa ikakhulu yi-precursor pseudo-boehmite, kodwa zininzi iindlela zokwenza i-pseudo-boehmite, kunye nemithombo eyahlukeneyo. ye-pseudo-boehmite ikhokelela ekuhlukeni kwe-gamma - i-Al2O3. Noko ke, kwezo catalysts kunye neemfuno ezikhethekileyo ukuba alumina carrier, bathembele kuphela kulawulo precursor pseudo-boehmite kunzima ukufikelela, kufuneka kuthatyathwe prophase ukulungiselela kunye post processing ukudibanisa iindlela ukulungisa iipropati alumina ukuhlangabezana neemfuno ezahlukeneyo. Xa iqondo lobushushu lingaphezulu kwe-1000 ℃ lisetyenziswayo, i-alumina yenzeka inguquko yesigaba esilandelayo: γ→δ→θ→α-Al2O3, phakathi kwabo γ, δ, θ zii-cubic ezisondeleleneyo zokupakisha, umahluko ulele kuphela kunikezelo lwe-ion aluminiyam kwi. i-tetrahedral kunye ne-octahedral, ngoko ke olu tshintsho lwesigaba alubangeli ukuhluka okukhulu kwezakhiwo. Ii-ion zeoksijini kwisigaba se-alpha zi-hexagonal ukupakisha ngokusondeleyo, amasuntswana e-aluminiyam oxide kukuhlangana kwakhona, indawo ethile yomphezulu inqabile kakhulu.
lKuphephe ukufuma, kunqande ukuskrola, ukujula kunye nokothuka okubukhali ngexesha lokuhamba, izibonelelo zemvula kufuneka zilungiswe.
l Kufuneka igcinwe kwindawo eyomileyo nengena umoya ukunqanda ukosuleleka okanye ukufuma.
