Izitini eziphakeme ze-alumina

A. High alumina brick application

Mainly used for lining of blast furnaces, hot blast furnaces, electric furnace tops, blast furnaces, reverberatory furnaces, and rotary kilns. In addition, isitini esiphakeme se-aluminas are also widely used as open hearth regenerative checker bricks, plugs for pouring systems, nozzle bricks, etc. However, the price of high alumina bricks is higher than that of clay bricks, so it is not necessary to use high alumina bricks where clay bricks can meet the requirements. To

B. Performance of high alumina bricks:

(1) Refractoriness

Ukuphinda kukhanye kwezitini eziphakeme ze-alumina kuphakeme kunezitini zobumba nezitini ezinesi-silica, kufinyelela ku-1750 ~ 1790 ℃, okungeyokusebenza okuphambili okukhanyelayo. I-refractoriness ithinteka kakhulu ngokuqukethwe, uhlobo nobuningi be-Al2O3, futhi ukuphindeka emuva kukhuphuka njengoba okuqukethwe i-Al2O3 kwanda.

(2) Load softening temperature:

Ngenxa yokuthi izitini eziphakeme ze-alumina zine-Al2O3 ephezulu, ukungcola okuncane, kanye nemizimba yeglasi engatholakali kalula, izinga lokushisa lokuthambisa umthwalo liphakeme kunalelo lezitini zobumba. Kodwa-ke, ngenxa yokuthi amakristalu e-mullite awenzi isakhiwo senethiwekhi, izinga lokushisa lokuthambisa umthwalo alikaphakeme njengalelo lezitini ze-silica.

(3) Thermal conductivity:

Izitini eziphakeme ze-alumina zinokuqhuba okungcono kokushisa kunezitini zobumba. Isizathu ukuthi kunezigaba ezimbalwa zengilazi ezinokuqhutshwa okuphansi kokushisa emikhiqizweni ephezulu ye-alumina, kuyilapho inani lamakristalu e-mullite ne-corundum anokuhamba okungcono okushisayo kukhuphuka, okuthuthukisa ukuqhutshwa kokushisa komkhiqizo.

(4) Thermal shock resistance:

Ukumelana nokushisa okushisayo kwezitini eziphakeme ze-alumina kuphakathi kwemikhiqizo yobumba nemikhiqizo enosilikhi. Umjikelezo wokupholisa amanzi ngo-850 ° C izikhathi ezi-3 kuye kwezi-5 kuphela. Lokhu ikakhulukazi kungenxa yokuthi i-corundum inokwanda okushisayo okuphezulu kune-mullite ngaphandle koguquko lwe-crystal. Njengamanje, kungenzeka ukuthuthukisa ukwakheka kwezinhlayiyana zomkhiqizo, ukunciphisa okuqukethwe kwempuphu ecolekileyo, futhi ukwandise usayizi wezinhlayiya obucayi kanye nokufakwa kwezinhlayiyana kwe-clinker ukuthuthukisa ukumelana nokushaqeka komkhiqizo.

(5) Slag resistance:

Izitini eziphakeme ze-alumina zine-Al2O3 eningi, esondelene nezinto zokwakha ezingathathi hlangothi, futhi ingamelana nokuguguleka kwe-slag ene-acid ne-alkaline slag. Ngenxa yokufakwa kwe-SiO2, ikhono lokumelana ne-alkaline slag libuthakathaka kunaleyo ye-acidic slag. Ngaphezu kwalokho, ukumelana kwe-slag kwezitini eziphakeme ze-alumina nakho kuhlobene nokuqina komkhiqizo ku-slag. Ngokuvamile, ngemuva kokubumba okuphezulu kwengcindezi nokudubula okushisa okuphezulu, imikhiqizo ene-porosity ephansi inokumelana okuphezulu kwe-slag.

The parameter index of high alumina bricks varies widely, and its physical properties should be determined according to the grade of the product and the place of use when it is used. At present, the general high alumina brick standard GB2988-88 is generally adopted. If you need to use super high alumina bricks, please refer to GB/T 2988-2012 standard physical and chemical indicators. The index of high alumina brick is the basic performance requirement. According to the conditions of use, creep resistance and thermal shock resistance should also be considered. The chemical resistance directly depends on the A12O3 content and porosity.

(6) Physical and chemical indicators: