Yuqori alumina g’isht

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, yuqori alumina g’ishts 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

Yuqori alyuminiyli g’ishtlarning refrakterligi gil g’isht va yarim kremniyli g’ishtlarga qaraganda yuqori bo’lib, ilg’or o’tga chidamli materiallarga tegishli 1750 ~ 1790 ℃ ga etadi. Refrakterlikka asosan Al2O3 ning tarkibi, turi va miqdori ta’sir qiladi va al2O3 tarkibi ortishi bilan refrakterlik kuchayadi.

(2) Load softening temperature:

Yuqori alyuminiyli g’ishtlarda yuqori Al2O3, aralashmalar kamroq va eriydigan shisha korpuslari kam bo’lganligi sababli, yukni yumshatish harorati loy g’ishtlarga qaraganda yuqori. Biroq, mullit kristallari tarmoq tuzilishini hosil qilmagani uchun yukni yumshatish harorati hali ham silika g’ishtlarnikidan yuqori emas.

(3) Thermal conductivity:

Yuqori alumina g’ishtlari gil g’ishtlarga qaraganda yaxshi issiqlik o’tkazuvchanligiga ega. Sababi shundaki, yuqori alumina alyuminiyli mahsulotlarda issiqlik o’tkazuvchanligi past bo’lgan shisha fazalar kam, issiqlik o’tkazuvchanligi yaxshi bo’lgan mullit va korund kristallari soni ko’payadi, bu esa mahsulotning issiqlik o’tkazuvchanligini yaxshilaydi.

(4) Thermal shock resistance:

Yuqori alyuminiyli g’ishtlarning issiqlik zarbasiga chidamliligi loy mahsulotlari va kremniyli mahsulotlar orasida bo’ladi. 850 ° C haroratda suvni sovutish aylanishi atigi 3-5 marta. Bu, asosan, korundning kristalli transformatsiyasiz mullitga qaraganda yuqori issiqlik kengayishiga ega bo’lishi bilan bog’liq. Hozirgi vaqtda mahsulotning zarracha tuzilishini yaxshilash, mayda kukun tarkibini kamaytirish va klinkerning zarracha kattaligi va zarracha gradatsiyasini oshirish, mahsulotning issiqlik zarbasiga chidamliligini oshirish mumkin.

(5) Slag resistance:

Yuqori alyuminiyli g’ishtlarda neytral refrakter materiallarga yaqin bo’lgan Al2O3 ko’proq bo’ladi va kislotali cüruf va gidroksidi cüruf eroziyasiga qarshi tura oladi. SiO2 tarkibiga kirganligi uchun ishqoriy cürufga qarshilik ko’rsatish qobiliyati kislotali cürufga qaraganda kuchsizroqdir. Bundan tashqari, yuqori alyuminiyli g’ishtlarning cürufga chidamliligi ham shlak tarkibidagi mahsulotning barqarorligi bilan bog’liq. Umuman olganda, yuqori bosimli qoliplash va yuqori haroratli olovdan so’ng, g’ovakligi past bo’lgan mahsulotlar shlaklarga nisbatan yuqori qarshilikka ega.

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: