Magnesia alumina spinel isitini

Izitini zeMagnesia alumina spinel zisebenzisa i-main magnesia yezitini kanye nesihlabathi sintered magnesia alumina spinel ngesilinganiso se-C / S esingu-0.4 njengezinto zokusetshenziswa, ngosayizi wezinhlayiyana obucayi ka-3mm. Usayizi wezinhlayiyana ze-magnesia usebenzisa izinhlayiya ezinkulu ezi-3 ~ 1mm, <1mm izinhlayiya eziphakathi kanye ne- <0.088mm powder omuhle njengezithako ezinamazinga amathathu. Sebenzisa i-sulfite pulp udoti oketshezi njenge-ejenti ebophayo, hlanganisa nesigayo esimanzi, bese ulolongelwa umshini wokucindezela isitini ongu-300t. Ngemuva kokuthi umzimba oluhlaza usumisiwe, ukhishwa ngo-1560 ~ 1590 ° C. Isimo esibuthakathaka se-oxidizing kufanele silawulwe ngesikhathi senqubo yokudubula.

Izakhiwo ezinamazinga okushisa aphezulu kanye nokuqina kokushaqeka okushisayo kwezitini ze-periclase-spinel zingcono kunezitini ezijwayelekile ze-magnesia alumina. Amandla wokucindezela ekamelweni lokushisa yi-70-100MPa, futhi ukuzinza kokushaqeka okushisayo (1000 ℃, ukupholisa amanzi) izikhathi eziyi-14-19. Izitini ze-periclase-spinel zingasetshenziswa endaweni enezinga lokushisa eliphakeme lama-kilns asebenzayo e-lime rotary kanye nama-kilnary rotary kilns.

i-magnesium-aluminium spinel yezwe lami isebenzisa izinqubo ezimbili zokukhiqiza: ukubumbana nokuxubana. Izinto zokusetshenziswa ikakhulukazi i-magnesite ne-industrial alumina powder noma i-bauxite. Ngokwezinkomba ezihlukile ze-magnesia ne-alumina, i-magnesia-rich spinel ne-aluminium-rich spinel ihlukaniswa futhi isetshenziswe emikhakheni ehlukene.

1. Ngokwenqubo noma indlela yokukhiqiza: i-sintered magnesium aluminium spinel (sintered spinel) ne-fused aluminium magnesium spinel (fused spinel).

2. Ngokuya ngezinto zokusetshenziswa zokukhiqiza, ingahlukaniswa: i-bauxite-based magnesia-aluminium spinel ne-alumina-based magnesia-aluminium spinel. (Sintering noma electrofusion)

3. Ngokuya ngokuqukethwe nokusebenza, ihlukaniswe yaba: i-spinel ene-magnesium, i-spinel ene-aluminium ne-spinel esebenzayo.

Isitini seMagnesia alumina spinel sibizwa nangokuthi isitini se-periclase-spinel, esenziwe nge-high-purity fused magnesia noma i-high-purity-two-step calcined magnesia kanye ne-high-purity pre-synthesized magnesia-aluminium spinel njengezinto zokusetshenziswa eziyinhloko, kusetshenziswa izithako eziqondile Process Inqubo yokukhiqizwa kokudubula okuphezulu nokucindezela okuphezulu. Uma kuqhathaniswa nezitini ze-magnesia-chromium, lesi sitini esiyinhlanganisela ye-magnesia-aluminium asiqedi nje kuphela ukulimala kwe-chromium enezinhlanga, kepha futhi sinokumelana okuhle nokugqwala, ukumelana nokwehla kwe-oxidation, ukumelana nokushisa nokuqina kwevolumu yokushisa okuphezulu. Kuyinto usimende omkhulu naphakathi nendawo Izinto ezifanele kakhulu zokuphikisa ezingenayo i-chromium yendawo eguqukayo yomlilo ojikelezayo. Iphinde yasetshenziswa ezintweni ezinokushisa okuphezulu njengama-lime kilns, ama-kilns kilns, kanye nemishini yokucwenga ngaphandle kwesithando, futhi ithole nemiphumela emihle.

Izinkomba zomzimba nezamakhemikhali zezitini ezikhiqizwayo ze-magnesium-aluminium yilezi: I-MgO 82.90%, i-Al2O3 13.76%, i-SiO2 1.60%, i-Fe2O3 0.80%, i-porosity ebonakalayo i-16.68%, ubukhulu be-2.97g / cm3, amandla okushisa ajwayelekile acindezela u-54.4MPa, 1400 ℃ amandla eguquguqukayo 6.0MPa.

Izitini zeMagnesium-aluminium spinel zisetshenziswe ngempumelelo endaweni yezinguquko yamakhemikhali ajikelezayo kasimende, kepha zithambekele ekubumbaneni nokwakhiwa kwesakhiwo lapho zisetshenziswa endaweni yokudubula, kunzima ukulengiswa esikhunjeni somlilo, nokumelana nentuthu ye-alkali kanye nokuqina kwesigaba samanzi esamente esiminyene. Futhi ikhono elimpofu lokumelana nengcindezi yomshini ebangelwa ukuguqulwa komzimba womlilo kukhawulela uhlelo lokusebenza endaweni yokudubula. Ngalesi sizathu, abacwaningi bakhiqize izitini ze-magnesia-aluminium spinel eziguquliwe ezifanele indawo yokudubula yamakhemikhali ajikelezayo kasimende. Ngesikhathi sokudubula nokusetshenziswa, ingxenye ye-Fe2 + esakhiweni se-periclase-spinel refractory ixhunywe ku-Fe3 +. Ngemuva kwalokho, ingxenye ye-Fe2 + ne-Fe3 + ku-iron-aluminium spinel iyahlukahluka kwi-matrix ye-periclase ukwakha i-MgOss. Ngasikhathi sinye, ezinye i-Mg2 + ku-matrix nazo ziyahlukahluka zibe yizinhlayiya ze-iron-aluminium spinel, bese iphendula nge-Al2O3 esele kusukela ekubola kwe-iron-aluminium spinel ukwakha i-magnesium-aluminium spinel. Lolu chungechunge lokuphendula luhambisana nokukhuliswa kwevolumu, okuholela ekwakhiweni kwama-microcracks. Ku

Izitini ze-iron-aluminium spinel zinezinto ezinhle zokulengiswa eziko kanye nokumelana nokushaqeka okushisayo. Phakathi kwabo, isizathu sokuthi i-iron aluminium spinel ilenga kahle esikhunjeni somlilo iyafana naleyo yesitina se-mafic-iron spinel. Futhi kungenxa yesenzo se-CaO ku-clinker yesamente kanye ne-Fe2O3 e-solid-dissolated ku-periclase ukwakha amakristalu angamanzisa i-periclase. , I-calcium ferrite ebopha i-clinker ne-firebrick ndawonye. Isizathu sokumelana okuhle kokushisa okushisayo ukwakhiwa kwama-microcracks.

Kuhlelo lwe-MgO-Al2O3, inani lesisombululo eliqinile le-Al2O3 ku-periclase ngo-1600 ° C cishe lingu-0; inani lesisombululo eliqinile ku-1800 ° C liyi-5% kuphela, elincane kakhulu kune-Cr2O3. Kuhlelo lwe-MgO-Al2O3, okuwukuphela kwengxube kanambambili yi-magnesium aluminium spinel. Iphuzu lokuncibilika le-magnesium aluminium spinel liphakeme njenge-2135 ℃, futhi izinga lokushisa eliphansi kakhulu le-MgO-MA nalo liyi-2050 ℃. I-Magnesium-aluminium spinel iyiminerali engokwemvelo, etholakala kakhulu ekufakeni isihlabathi esimhlophe, ngakho-ke inokuzinza okuhle kwamakhemikhali ezintweni zemvelo.

I-modulus ye-elasticity incane, isitini se-magnesia alumina (0.12 ～ 0.228) × 105 MPa, kanti isitini semagnesia siyi (0.6 ～ 5) × 105MPa; UMA angadlulisa i-MF kusuka ku-periclase, futhi angashanela i-FeO. Impendulo imi kanjena: FeO + MgO • AI2O3 → MgO + FeAl2O4, FeO + MgO → (Mg • Fe) O, MA ithatha i-Fe2O3 futhi inwebeke kancane futhi inendawo encibilika kakhulu. I-Spinel inendawo encibilikayo engu-2135 ° C, kanti ukushisa kwayo kokuqala okuncibilikayo nge-periclase kuphakeme kuno-1995 ° C. Ukuhlanganiswa kwalaba bobabili kuzothuthukisa ukusebenza kokubopha izitini zemagnesia. Ukushisa okuthambisa umthwalo kuphezulu, kepha ukwakheka kwe-spinel kuhambisana nokukhuliswa kwevolumu, futhi amandla okuhlanganisa nawokuphinda asebenze kabusha abuthakathaka, ngakho-ke kudingeka izinga lokushisa eliphakeme lokudubula. Ukumelana nokushaqeka okuhle kakhulu. amandla aphezulu. Ukumelana nokuguguleka okuqinile.