nūhou

Hoʻolauna
ʻO Cristobalite kahi ʻano homomorphous haʻahaʻa haʻahaʻa haʻahaʻa SiO2, a ʻo kona ʻano paʻa thermodynamic he 1470 ℃ ~ 1728 ℃ (ma lalo o ke kaomi maʻamau). ʻO β Cristobalite kona māhele wela kiʻekiʻe, akā hiki ke mālama ʻia ma ke ʻano metastable i kahi wela haʻahaʻa loa a hiki i ka hoʻololi ʻana o kahi ʻano hoʻololi ma kahi o 250 ℃ α Cristobalite. ʻOiai hiki ke hoʻoheheʻe ʻia ka cristobalite mai ka hoʻoheheʻe ʻana o SiO2 i loko o kāna wahi kūpaʻa thermodynamic, ʻo ka hapa nui o ka cristobalite i ke ʻano i hana ʻia ma lalo o nā kūlana metastable. ʻO kahi laʻana, hoʻololi ka diatomite i loko o ka cristobalite chert a i ʻole microcrystalline opal (opal CT, opal C) i ka wā o ka diagenesis, a ʻo kā lākou mau mineral nui ʻo α Cristobalite), nona ka mahana hoʻololi i loko o ka stable zone of quartz; Ma lalo o ke kūlana o ka granulite facies metamorphism, cristobalite precipitated mai ka waiwai Na Al Si hehee ai, i noho i loko o ka garnet e like me ka inclusion a coexisted me albite, e hana ana i ka wela a me ke kaomi kūlana o 800 ℃, 01GPa, no hoi i loko o ka stable wahi o quartz. Eia kekahi, hoʻokumu ʻia ka metastable cristobalite i loko o nā mea mineral non-metallic i ka wā o ka mālama ʻana i ka wela, a aia ka mahana hoʻokumu i ka thermodynamic stability zone o tridymite.
Mekani formative
Hoʻololi ka Diatomite i cristobalite ma 900 ℃~1300 ℃; Hoʻololi ʻo Opal i cristobalite ma 1200 ℃; Hoʻokumu pū ʻia ka Quartz i kaolinite ma 1260 ℃; Ua hoʻololi ʻia ka sieve molecular MCM-41 mesoporous SiO2 i cristobalite ma 1000 ℃. Hoʻokumu ʻia ka cristobalite metastable i nā kaʻina hana ʻē aʻe e like me ka sintering seramika a me ka hoʻomākaukau ʻana i ka mullite. No ka wehewehe ʻana i ke ʻano hana metastable o ka cristobalite, ua ʻae ʻia he kaʻina thermodynamic non-equilibrium, i hoʻomalu nui ʻia e ke ʻano kinetics reaction. E like me ka metastable hoʻokumu 'ano o ka cristobalite i oleloia maluna, ua aneane lokahi i ka cristobalite ua hoololiia mai amorphous SiO2, a hiki i ke kaʻina hana o kaolinite wela lapaʻau, mullite hoomakaukau a me ka ceramic sintering, cristobalite ua hoololiia mai amorphous SiO2.
Ke kumu
Mai ka hana ʻana i ka ʻenehana i nā makahiki 1940, ua hoʻohana nui ʻia nā huahana kalapona keʻokeʻo e like me nā mea hoʻoikaika i nā huahana lāʻau. Eia kekahi, hiki ke hoʻohana ʻia i loko o ka ʻoihana lāʻau lapaʻau, pesticide, inika, pena, pena, toothpaste, pepa, meaʻai, meaʻai, nā mea hoʻonaninani, nā pihi a me nā ʻoihana ʻē aʻe.
ʻO ke ʻano kemika o ke kalapona ʻeleʻele keʻokeʻo ma ke ʻano hana ʻo SiO2nH2O. No ka mea, ua like kona hoʻohana ʻana me ke kalapona ʻeleʻele a keʻokeʻo, ua kapa ʻia ʻo ia keʻokeʻo kalapona ʻeleʻele. Ma muli o nā ʻano hana hana like ʻole, hiki ke hoʻokaʻawale ʻia ke kalapona ʻeleʻele keʻokeʻo i ke kalapona ʻeleʻele keʻokeʻo keʻokeʻo (precipitated hydrated silica) a me ka carbon black fumed (fumed silica). Loaʻa i nā huahana ʻelua nā ʻano hana hana, nā waiwai a me nā hoʻohana. Hoʻohana nui ke ʻano hana kinoea i ka silicon tetrachloride a me ka silicon dioxide i loaʻa ma ka hoʻopau ʻana i ka ea. Maikaʻi nā ʻāpana, a hiki ke emi mai ka nui o ka median ma mua o 5 microns. ʻO ke ʻano o ka ua ka hoʻoheheʻe ʻana i ka silica ma ka hoʻohui ʻana i ka waikawa sulfuric i ka sodium silicate. He 7-12 microns ka nui o ka nui median. He pipiʻi ka silica fumed a ʻaʻole maʻalahi ke komo i ka makū, no laila hoʻohana pinepine ʻia ʻo ia ma ke ʻano he mea moena i nā uhi.
Hoʻopili ka wai aniani wai o ke ʻano waikawa nitric me ka waikawa nitric e hoʻohua ai i ka silicon dioxide, a laila hoʻomākaukau ʻia i loko o ka silicon dioxide papa uila ma o ka holoi ʻana, pickling, holoi wai deionized a me ka wai.