Alumina yasanze ibaho byibuze form 8, ni α- Al2O3, θ-Al2O3, γ- Al2O3, δ- Al2O3, η- Al2O3, χ- Al2O3, κ- Al2O3 na ρ- Al2O3, imitungo yabo ya macroscopique nayo iratandukanye. Gamma ikora alumina ni cubic yegeranye yuzuye kristu, idashonga mumazi, ariko igashonga muri aside na alkali. Gamma ikora alumina nintege nke ya acide, ifite aho ishonga cyane 2050 ℃, gelina ya alumina muburyo bwa hydrate irashobora gukorwa muri oxyde ifite ububobere buke nubuso bwihariye, ifite ibyiciro byinzibacyuho mubushyuhe bwinshi. Ku bushyuhe bwinshi, kubera umwuma no kubura dehydroxylation, Al2O3surface igaragara ihuza guhuza ogisijeni idahagije (centre ya alkali) na aluminium (centre acide), hamwe nibikorwa bya catalitiki. Kubwibyo, alumina irashobora gukoreshwa nkabatwara, catalizator na cocatalyst.
Gamma ikora alumina irashobora kuba ifu, granules, imirongo cyangwa izindi. Turashobora gukora nkuko ubisabwa. gutunganya hydrogène, kuvugurura hydrogène, reaction ya dehydrogenation hamwe nuburyo bwo kweza ibinyabiziga biva mu modoka.Gamma-Al2O3 ikoreshwa cyane nk'itwara rya catalizator kubera guhuza imiterere ya pore na acide yo hejuru. Iyo γ- Al2O3 ikoreshwa nkuwitwaye, usibye irashobora kugira ingaruka zo gutatanya no guhagarika ibice bikora, irashobora kandi gutanga aside alkali ikigo gikora, guhuza imbaraga hamwe nibikorwa bya catalitiki ikora. Imiterere ya pore hamwe nubuso bwibintu bya catalizator biterwa na γ-Al2O3 itwara, bityo rero imikorere yo hejuru yaboneka kubisubizo byihariye bya catalitiki mugucunga imitungo ya gamma alumina.
Gamma ikora alumina muri rusange ikozwe mubibanjirije pseudo-boehmite ikoresheje 400 ~ 600 ℃ yubushyuhe bwo hejuru, bityo rero imiterere ya fiziki ya chimique igenwa ahanini na pseudo-boehmite, ariko hariho inzira nyinshi zo gukora pseudo-boehmite, kandi amasoko atandukanye ya pseudo-boehmite. Ariko, kuri izo catalizator zifite ibisabwa byihariye kubatwara alumina, gusa wishingikiriza kugenzura prursor pseudo-boehmite biragoye kubigeraho, bigomba gufatwa kugirango hategurwe imyiteguro hamwe nogutunganya inyandiko ihuza uburyo bwo guhindura imitungo ya alumina kugirango yuzuze ibisabwa bitandukanye. Iyo ubushyuhe buri hejuru ya 1000 ℃ mukoresha, alumina ibaho nyuma yo guhinduka kwicyiciro: γ → δ → θ → α-Al2O3, muribo γ 、 δ 、 θ ni kubipakira hafi, itandukaniro riri gusa mugukwirakwiza ion ya aluminium muri tetrahedral na octahedral, bityo rero guhinduka kwicyiciro ntigutera guhinduka kwinshi mubyubatswe. Oxygene ion mugice cya alfa ni impande esheshatu zipakira, uduce twa aluminium oxyde duhura cyane, ubuso bwihariye bwagabanutse cyane.
Irinde ubushuhe, irinde kuzunguruka, guta no gutungurwa bikabije mugihe cyo gutwara, ibikoresho bitarinda imvura bigomba gusomwa ..
Igomba kubikwa mububiko bwumye kandi buhumeka birinda kwanduza cyangwa ubuhehere.
