Okwu mmalite
Cristobalite bụ obere njupụta SiO2 homomorphous variant, yana nkwụsi ike nke thermodynamic ya bụ 1470 ℃ ~ 1728 ℃ (n'okpuru nrụgide nkịtị). β Cristobalite bụ oge okpomọkụ ya dị elu, mana enwere ike ịchekwa ya n'ụdị metastable ka ọ dị obere ruo mgbe mgbanwe mgbanwe ụdị mgbanwe na-eme na ihe dịka 250 ℃ α Cristobalite. Ọ bụ ezie na cristobalite nwere ike kristal site na SiO2 gbazee na mpaghara nkwụsi ike nke thermodynamic ya, ọtụtụ cristobalite na okike na-etolite n'okpuru ọnọdụ metastable. Dịka ọmụmaatụ, diatomite na-agbanwe n'ime cristobalite chert ma ọ bụ microcrystalline opal (opal CT, opal C) n'oge digenesis, na akụkụ ndị bụ isi nke ịnweta ha bụ α Cristobalite), onye mgbanwe okpomọkụ dị na mpaghara kwụsiri ike nke quartz; N'okpuru ọnọdụ nke granulite facies metamorphism, cristobalite precipitated si ọgaranya Na Al Si gbazee, dị na garnet dị ka nsonye na coexisted na albite, na-akpụ a okpomọkụ na ọnọdụ nrụgide nke 800 ℃, 01GPa, nakwa na kwụsiri ike mpaghara nke quartz. Na mgbakwunye, a na-etolitekwa cristobalite metastable n'ọtụtụ ihe ịnweta mineral na-abụghị ọla n'oge ọgwụgwọ okpomọkụ, na nguzobe okpomọkụ dị na mpaghara nkwụsi ike nke thermodynamic nke tridymite.
Usoro nhazi
Diatomite na-agbanwe ghọọ cristobalite na 900 ℃ ~ 1300 ℃; Opal na-agbanwe ghọọ cristobalite na 1200 ℃; A na-emepụtakwa quartz na kaolinite na 1260 ℃; MCM-41 mesoporous SiO2 molecular sieve sịntetị gbanwere ka ọ bụrụ cristobalite na 1000 ℃. A na-etolitekwa cristobalite metastable na usoro ndị ọzọ dị ka seramiiki sintering na nkwadebe mullite. Maka nkọwa nke usoro nhazi metastable nke cristobalite, a kwenyere na ọ bụ usoro thermodynamic na-abụghị nke na-enweghị nha, nke kachasị na-achịkwa usoro mmeghachi omume kinetics. Dị ka usoro nhazi nke cristobalite nke a kpọtụrụ aha n'elu si kwuo, ọ fọrọ nke nta ka ọ bụrụ otu onye kwenyere na cristobalite na-agbanwe site na amorphous SiO2, ọbụlagodi na usoro ọgwụgwọ okpomọkụ kaolinite, nkwadebe mullite na seramiiki, cristobalite na-agbanwekwa site na amorphous SiO2.
Ebumnuche
Kemgbe mmepụta nke ụlọ ọrụ mmepụta ihe na 1940s, a na-eji ngwaahịa ojii carbon ọcha mee ihe n'ọtụtụ ebe dị ka ihe na-agba ume na ngwaahịa rọba. Na mgbakwunye, a pụkwara iji ha na ụlọ ọrụ ọgwụ, pesticide, ink, agba, agba, ntacha eze, akwụkwọ, nri, nri, ihe ịchọ mma, batrị na ụlọ ọrụ ndị ọzọ.
Usoro kemịkalụ nke ọcha carbon ojii na usoro mmepụta bụ SiO2nH2O. N'ihi na ojiji ya yiri nke carbon ojii ma na-acha ọcha, a na-akpọ ya ọcha carbon black. Dị ka usoro mmepụta dị iche iche si dị, enwere ike kewaa carbon ojii na-acha ọcha n'ime oji carbon ojii na-acha ọcha (precipitated hydrated silica) na fumed white carbon black (silica fumed). Ngwaahịa abụọ ahụ nwere ụzọ mmepụta dị iche iche, ihe onwunwe na ojiji. Usoro nke gas na-ejikarị silicon tetrachloride na silicon dioxide enwetara site na combustion ikuku. Ihe irighiri ihe ndia di nma, na nha nha nke etiti nwere ike idi ihe na-adighi 5 microns. Usoro mmiri ozuzo bụ ịkwanye silica site n'ịgbakwunye sulfuric acid na sodium silicate. Ogo urughuru etiti bụ ihe dịka 7-12 microns. Silica fumed dị oke ọnụ ma ọ dịghị mfe ịmịkọrọ mmiri, n'ihi ya, a na-ejikarị ya eme ihe dị ka onye na-emepụta ihe na mkpuchi.
Ihe ngwọta enyo mmiri nke usoro nitric acid na-emeghachi omume na nitric acid iji mepụta silicon dioxide, bụ nke a na-akwadebe ya n'ime silicon dioxide ọkwa eletrọnịkị site na nchacha, pickling, nchacha mmiri na akpịrị ịkpọ nkụ.
Oge nzipu: Nov-17-2022