A chọpụtala na alumina dị ma ọ dịkarịa ala ụdị 8, ha bụ α- Al2O3, θ-Al2O3, γ- Al2O3, δ- Al2O3, η- Al2O3, χ- Al2O3, κ- Al2O3 na ρ- Al2O3, njirimara nhazi macroscopic ha dịkwa iche. Alumina nke a na-akpọ Gamma activated bụ kristal dị kubik, nke a na-anaghị agbaze na mmiri, mana ọ na-agbaze na acid na alkali. Alumina nke a na-akpọ Gamma activated anaghị akwado acidic, nwere ebe ịgbaze dị elu 2050 ℃, enwere ike ime gel alumina n'ụdị hydrate ka ọ bụrụ oxide nwere nnukwu porosity na elu pụrụ iche, ọ nwere usoro mgbanwe n'ọtụtụ okpomọkụ. Na okpomọkụ dị elu, n'ihi mmiri ịkpọ nkụ na dehydroxylation, Al2O3surface na-apụta nhazi oxygen unsaturated (center alkali) na aluminum (center acid), yana ọrụ catalytic. Ya mere, enwere ike iji alumina dị ka ihe na-ebu ibu, ihe na-akpali akpali na cocatalyst.
Alumina Gamma nke a na-arụ ọrụ nwere ike ịbụ ntụ ntụ, granules, strips ma ọ bụ ndị ọzọ. Anyị nwere ike ime dịka ihe ị chọrọ. γ-Al2O3, nke a na-akpọ "alumina activated", bụ ụdị ihe siri ike nke nwere oghere dị elu, n'ihi nhazi oghere ya a na-agbanwe agbanwe, nnukwu mpaghara elu kpọmkwem, arụmọrụ adsorption dị mma, elu nwere uru nke acidity na ezigbo nkwụsi ike okpomọkụ, elu microporous nwere ihe ndị dị mkpa nke ihe omume catalytic, ya mere ọ na-aghọ ihe na-akpali akpali, ihe na-ebu catalytic na ihe na-ebu chromatography kachasị eji na ụlọ ọrụ kemịkalụ na mmanụ, ma na-arụ ọrụ dị mkpa na hydrocracking mmanụ, nhazi hydrogenation, mgbanwe hydrogenation, mmeghachi omume dehydrogenation na usoro nhicha ikuku ụgbọala. A na-eji Gamma-Al2O3 eme ihe dị ka ihe na-ebu catalytic n'ihi nhazi oghere ya na acidity elu. Mgbe ejiri γ-Al2O3 mee ihe dị ka ihe na-ebu ibu, ọ nwekwara ike inwe mmetụta iji gbasaa ma mee ka ihe ndị na-arụ ọrụ sie ike, ọ nwekwara ike inye etiti alkali acid, mmeghachi omume synergistic na ihe ndị na-arụ ọrụ catalytic. Ọdịdị oghere na ihe ndị dị n'elu nke ihe na-akpali akpali na-adabere na ihe na-ebu γ-Al2O3, yabụ a ga-ahụ ihe na-ebu arụmọrụ dị elu maka mmeghachi omume catalytic kpọmkwem site na ijikwa ihe onwunwe nke ihe na-ebu gamma alumina.
A na-ejikarị alumina a na-emepụta Gamma activated alumina site na pseudo-boehmite ya ruo okpomọkụ dị elu nke 400 ~ 600℃, yabụ ihe ndị dị n'elu na-ekpebikarị site na pseudo-boehmite nke bu ụzọ ya, mana enwere ọtụtụ ụzọ isi mee pseudo-boehmite, ebe dị iche iche nke pseudo-boehmite na-eduga na ụdị gamma - Al2O3. Agbanyeghị, nye ihe mkpali ndị ahụ nwere ihe pụrụ iche maka onye na-ebu alumina, naanị dabere na njikwa nke pseudo-boehmite bu ụzọ siri ike inweta, a ga-eburu ya na nkwadebe prophase na ụzọ njikọta mgbe nhazi gasịrị iji gbanwee ihe onwunwe nke alumina iji mezuo ihe dị iche iche achọrọ. Mgbe okpomọkụ dị elu karịa 1000 ℃ na-eji, alumina na-eme mgbe mgbanwe nkebi gasịrị: γ→δ→θ→α-Al2O3, n'ime ha γ、δ、θ bụ ngwugwu cubic close, ọdịiche dị naanị na nkesa nke aluminom ion na tetrahedral na octahedral, yabụ mgbanwe nkebi ndị a anaghị akpata nnukwu mgbanwe nke ihe owuwu ahụ. Ion oxygen dị na usoro alfa bụ ihe mkpuchi dị n'akụkụ hexagonal, ihe ndị dị na aluminum oxide bụ ihe jikọrọ ọnụ nke ukwuu, mpaghara elu kpọmkwem dara nke ukwuu.
Zere mmiri mmiri, zere ịpịgharị, ịtụfu ihe na ịma jijiji dị nkọ n'oge njem. E kwesịrị ịkwadebe ebe mmiri na-anaghị ezo.
A ga-echekwa ya n'ụlọ nkwakọba ihe kpọrọ nkụ ma nwee ikuku iji gbochie mmetọ ma ọ bụ mmiri mmiri.
