Sentèz mullite

Metòd sentèz mullit la ka divize an metòd SINTERING ak metòd k ap fonn elektrik. Metòd SINTERING ka divize an metòd sèk ak metòd mouye selon fason preparasyon materyèl bwit yo. Pwosesis sèk la se moulen engredyan yo ansanm ak Lè sa a, boule li nan au rotary oswa tinèl apre peze boul oswa kontra enfòmèl ant. Pwosesis mouye a se moulen materyèl konpoze an nan sispansyon ak dlo, Lè sa a, peze ak filtre dezidrate nan gato labou, ak vakyòm peze labou nan seksyon labou oswa labou vid ak Lè sa a, boule.
Metòd elektrik la k ap fonn se ajoute materyèl la konpoze nan founo a arc, fonn nan tanperati ki wo ki te fòme pa arc la, fre kristalizasyon, itilize nan engredyan natirèl matyè premyè (tankou boksit, elatriye) ka kraze dirèkteman nan<1.5mm particles without grinding, and then mixed with other powdered raw materials in the mixer.
Se sentèz mullite pa SINTERING jeneralman te pote soti nan 1650 ~ 1700 degre. Faktè prensipal yo ki afekte sentèz mullite pa SINTERING se pite nan matyè premyè, rafineman nan matyè premyè ak tanperati kalsinasyon. Sentèz mullite pa metòd SINTERING sitou depann sou Al? O? Reyaksyon faz solid ant SiO2 ak sio2 fini, kidonk amelyore dispèsyon matyè premyè yo pral akselere pwosesis reyaksyon faz solid. An patikilye, patikil yo<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 microcrystalline, 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. In industrial production, it is inevitable to bring a variety of impurities, mainly Fe? O? TiO? , CaO, MgO, Na? O·K? O, the most harmful of which is Na? O, K? O, they inhibit the formation of mullite and lead to the production of a large number of silicon-rich glass phases, reducing mullite content. Fe? O? It will slow down the mullite process and increase the amount of glass phase. Be TiO? When a small amount of Ti ions exist, part of Ti ions enter the mullite lattice to form a solid solution, promoting the formation of mullite and crystal development and growth, when the TiO2 content is too high, it still acts as a flux.
Se mullite electromelting prepare pa fonn konpoze an nan yon gwo founo dife elektrik, epi mullite a refwadi soti nan fonn lan. Pwosesis la kristalizasyon se menm jan ak sa yo ki nan Al? O? -SiO? Pwosesis kristalizasyon dyagram faz sistèm lan sanble. Lè Al la? O? Lè konpozisyon teyorik mullite a pi wo pase 71.8%, fonn depase Al fòme. O? Solisyon solid mullite, beta-mullite, se sèlman Al? O? Faz korundum la parèt sèlman nan 80%. Konpozisyon faz mineral nan mullite fusion se jeneralman mullite kristal ak faz vè. Lachin nan elektrik fonn mullite endistri estanda YB/T 104-2004 "Elèktrik fonn mullite" pwodwi a elektrik fonn mullite dapre Al? O? Kontni an divize an klas DM-1 ak DM-2, epi kondisyon teknik ki enpòtan yo ka wè nan estanda nasyonal korespondan yo. Konpare ak mullite sintered, kristal mullite fusion yo byen devlope ak grenn gwo ak mwens domaj, ak gwosè kristal la se dè santèn de fwa sa yo ki nan mullite sintered, kidonk pwopriyete yo tanperati ki wo mekanik ak rezistans ewozyon yo relativman bon.