Alumina an gano ya wanzu aƙalla nau'i 8, sune α- Al2O3, θ-Al2O3, γ- Al2O3, δ- Al2O3, η- Al2O3, χ- Al2O3, κ- Al2O3 da ρ- Al2O3, macroscopic tsarin kaddarorin su. ma daban-daban. Gamma kunna alumina wani nau'in lu'u-lu'u ne mai cike da lu'ulu'u, wanda ba zai iya narkewa a cikin ruwa, amma mai narkewa cikin acid da alkali. Gamma kunna alumina ne rauni acidic goyon baya, yana da wani babban narkewa batu 2050 ℃, alumina gel a hydrate nau'i za a iya sanya a cikin oxide tare da high porosity da kuma high takamaiman surface, yana da miƙa mulki bulan a cikin wani m zazzabi kewayon. A mafi yawan zafin jiki, saboda rashin ruwa da dehydroxylation, Al2O3surface yana bayyana daidaituwar oxygen unsaturated (cibiyar alkali) da aluminum (cibiyar acid), tare da aikin catalytic. Don haka, ana iya amfani da alumina azaman mai ɗaukar hoto, mai kara kuzari da cocatalyst.
Gamma kunna alumina zai iya zama foda, granules, tube ko wasu. Za mu iya yi kamar yadda ka bukata.γ-Al2O3, aka kira "kunna alumina", shi ne wani irin porous high watsawa m kayan, saboda ta daidaitacce pore tsarin, babban takamaiman surface area, mai kyau adsorption yi, surface tare da abũbuwan amfãni daga acidity. kuma mai kyau thermal kwanciyar hankali, microporous surface da ake bukata Properties na catalytic mataki, saboda haka zama mafi yadu amfani kara kuzari, mai kara kuzari da kuma chromatography m a cikin sinadaran da kuma man masana'antu, da kuma taka muhimmiyar rawa a cikin man hydrocracking, hydrogenation refining, hydrogenation sake fasalin. Dehydrogenation dauki da mota shaye tsarkakewa tsari.Gamma-Al2O3 ne yadu amfani a matsayin kara kuzari m saboda adjustability na pore tsarin da surface acidity. Lokacin da γ- Al2O3 aka yi amfani da matsayin m, kuma iya samun effects zuwa tarwatsa da kuma tabbatar da aiki aka gyara, kuma iya samar da acid alkali aiki cibiyar, synergistic dauki tare da catalytic aiki aka gyara. Tsarin pore da kaddarorin saman mai kara kuzari sun dogara da mai ɗaukar hoto na γ-Al2O3, don haka za a sami babban mai ɗaukar hoto don takamaiman halayen motsa jiki ta hanyar sarrafa kaddarorin jigilar gamma alumina.
Gamma activated alumina gabaɗaya ana yin sa ne daga precursor pseudo-boehmite ta hanyar 400 ~ 600 ℃ high zafin jiki dehydration, don haka saman physicochemical Properties an fi mayar ƙaddara ta precursor pseudo-boehmite, amma akwai da yawa hanyoyin da za a yi pseudo-boehmite, da daban-daban kafofin. na pseudo-boehmite yana haifar da bambancin gamma - Al2O3. Koyaya, ga waɗancan masu haɓakawa tare da buƙatu na musamman ga mai ɗaukar alumina, dogaro kawai akan sarrafa precursor pseudo-boehmite yana da wahala a cimma, dole ne a ɗauka don prophase shirye-shirye da post aiki hada hanyoyin don daidaita kaddarorin alumina don saduwa da buƙatu daban-daban. Lokacin da yawan zafin jiki ya fi 1000 ℃ da ake amfani da shi, alumina yana faruwa bayan canjin lokaci: γ→δ→θ→α-Al2O3, daga cikinsu akwai γ,δ, θ cubic kusa shiryawa, bambanci kawai ya ta'allaka ne a cikin rarraba ions na aluminum a ciki. tetrahedral da octahedral, don haka waɗannan canje-canjen lokaci baya haifar da bambance-bambancen tsarin. Oxygen ions a cikin alpha zamani kunshin hexagonal kusa shiryawa, aluminum oxide barbashi suna da kabari haduwa, takamaiman surface yankin ya ki sosai.
Ka guji danshi, guje wa gungurawa, jefawa da firgita yayin sufuri, yakamata a shirya wuraren hana ruwan sama.
Yakamata a adana shi a cikin busasshen ma'ajin da ke da iska don hana gurɓatawa ko danshi.
