Mullit sintezi

Mullitning sintez usullarini sinterlash usuli va elektr eritish usuliga bo'lish mumkin. Sinterlash usuli xom ashyoni tayyorlash usuliga ko'ra quruq usul va nam usulga bo'linishi mumkin. Quruq usul - ingredientlarni birga maydalash va keyin ularni to'p yoki ixcham bosgandan so'ng aylanuvchi pech yoki tunnel pechida yoqishdir. Nam jarayon aralash materialni suv bilan atala ichiga maydalash, so'ngra bosish va filtrlash uchun loy kekiga suvsizlantirish va loyni loy qismiga yoki loy bo'shligiga vakuum bilan siqish va keyin yoqishdir.
Elektr eritish usuli - aralash materialni yoy pechiga qo'shish, yoy natijasida hosil bo'lgan yuqori haroratda eritish, sovutish kristallanishi, tabiiy xom ashyolardan (masalan, boksit va boshqalar) foydalanish, to'g'ridan-to'g'ri ezilgan bo'lishi mumkin.<1.5mm particles without grinding, and then mixed with other powdered raw materials in the mixer evenly.
Mullitni sinterlash orqali sintez qilish odatda 1650 ~ 1700 daraja haroratda amalga oshiriladi. Mullitning sinterlash orqali sinteziga ta'sir qiluvchi asosiy omillar xom ashyoning tozaligi, xom ashyoning nozikligi va kalsinlanish haroratidir. Sinterlash usuli bilan lenitning sintezi asosan Al2O3 va SiO2 o'rtasidagi qattiq faza reaktsiyasiga bog'liq, shuning uchun xom ashyoning tarqalishini yaxshilash bir xil fazali reaktsiya jarayonini tezlashtiradi. Xususan, zarralar<8μm have a great effect on the formation and sintering of synthetic mullite. It can be seen that the full mixing and fine grinding of raw materials is an important process condition to promote the solid phase of the synthesis of mullite. Mullite generally begins to form at 1200 ° C and ends at 1650 ° C. At this time, it is micro-grained, and the crystallization develops well when the temperature exceeds 1700℃. It can be seen that the combustion temperature directly affects the formation and crystal development of mullite. Therefore, heating to a certain firing temperature and extending a certain holding time are necessary conditions for the synthesis of mullite. The purity of the raw materials used to synthesize mullite is very strict, and a small amount of impurities will reduce the content of mullite.
Sanoat ishlab chiqarishida Fe2O3, TiO2, CaO, MgO, Na2O, K2O kabi turli xil aralashmalarni olib kelish muqarrar, ular orasida eng zararli Na2O va K2O mullit hosil bo'lishiga to'sqinlik qiladi va ishlab chiqarishga olib keladi. ko'p miqdordagi silikaga boy shisha fazalar, mullit tarkibini kamaytiradi. Fe2O3 mullitning toshga aylanishi jarayonini sekinlashtiradi va shisha fazalar sonini oshiradi. TiO2 ning oz miqdori mavjud bo'lganda, Ti ionlarining bir qismi qattiq eritma hosil qilish uchun mullit xarakteriga kiradi, mullit va kristalning rivojlanishi va o'sishiga yordam beradi, TiO2 miqdori juda yuqori bo'lsa, u hali ham oqim rolini o'ynaydi. Elektroerituvchi mullit aralashmani yoy pechida eritib, eritmadan mullitni sovutish orqali tayyorlanadi. Kristallanish jarayoni Al2O3-SiO2 tizimining faza diagrammasiga o'xshaydi.
When the Al2O3 of the compound is higher than 71.8% of the theoretical group in mullite, a mullite solid solution with excess Al2O3 is formed, that is, β-mullite, and only when the Al2O3>80% korund fazasi paydo bo'ladi. Eritilgan mullitning mineral fazali tarkibi odatda mullit kristalli va shisha fazadir. Sinterlangan mullit bilan solishtirganda, eritilgan mullit kristallari yaxshi rivojlangan, katta donalar va kamroq nuqsonlar bilan va kristall o'lchami sinterlangan mullitdan yuzlab marta kattaroqdir, shuning uchun yuqori haroratli mexanik xususiyatlar va eroziyaga chidamlilik nisbatan yaxshi.

Issiq teglar: mullitning sintezi, Xitoyning mullit ishlab chiqaruvchilari, etkazib beruvchilari sintezi