Influence of Silicate Substance on Pyrochlore and Tantalite Solubility in Fluoride Aqueous Solutions (Experimental Studies)
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Experimental results of behavior of natural minerals of pyrochlore and tantalite in solutions KF, NaF and LiF in the presence of quartz (granite) at T = 550°–850 °C, P = 1 kbar are presented. The considerable influence of silicate substance presence on mineral solubility in water solutions of alkali metal fluorides in hydrothermal conditions is shown. The study of fluid inclusions in quartz showed that under experimental conditions (heterogeneous state of the fluid) the reactions of high-temperature hydrolysis KF: KF + H2O = KOH + HF, with the separation of acid and alkaline components between the immiscible phases of the fluid are intensive. In this case, the interaction of alkaline components with quartz occurs: SiO2 + 2KOH = K2SiO3 + H2O, with the formation of a phase of silicate glass (aqueous solution-melt). This phase of silicate alkaline melt enriched with fluorine concentrates tantalum and niobium (up to 8% of Ta2O5 and 16% of Nb2O5) and can serve as a phase—a concentrator of ore elements in the formation of tantalum-niobate deposits at the last low-temperature stages of crystallization of rare-metal granites.
KeywordsNiobium-tantalum deposits Experimental modeling Hydrothermal fluoride fluid Pyrochlore solubility Tantalite solubility Alcaline-silicate melt-concentrator
This work was supported by the grant of the Russian Foundation for Basic Research № 15-05-03393-a.
Theme # AAAAA-A18-118020590151-3.
- Aksyuk AM (2002) Experimentally established geofluorimeters and the fluorine regime ingranite-related fluids. Petrology 10(6):557–569Google Scholar
- Aksyuk AM (2009) Fluorine regime in deep hydrothermal fluids and near-surface waters. Doctoral dissertation. Moscow, 166 p. (in Russian)Google Scholar
- Beus AA, Severov EA, Sitnin AA, Subbotin KD (1962) Albitized and Greisenized Granites (apogranites). Akad Nauk SSSR, Moscow, 196 p. (in Russian)Google Scholar
- Chevychelov VYu (1998) The influence of the composition of granitoid melts on the behavior of ore metals (Pb, Zn, W, Mo) and petrogenic components in the melt—water fluid system. Experimental and theoretical modeling of mineral formation processes. Nauka, Moscow, pp 118–130Google Scholar
- Chevychelov VYu, Zarayskiy GP, Borisovskii SE, Borkov DA (2005) Effect of melt composition and temperature on the partitioning of Ta, Nb, Mn and F between granitic (alkaline) melt and fluorine-bearing aqueous fluid: fractionation of Ta and Nb and conditions of ore formation in rare-metal granites. Petrology 13(4):305–321Google Scholar
- Doroshkevich AG, Sharygin VV, Seryotkin YV, Karmanov NS, Belogub EV, Moroz TN, Nigmatulina EN, Eliseev A, Vedenyapin N, Kupriyanov IN (2016) Rippite. IMA 2016-025. CNMNC Newslett (32):919: Min Mag 80:915–922Google Scholar
- Gramenitskiy EN, Shchekina TI, Devyatova VN (2005) Phase relationships in fluorine-containing granite and nepheline-syenite systems and the distribution of elements between phases (experimental study). GEOS, Moscow, p 188Google Scholar
- Kotelnikov AR, Korzhinskaya VS, Kotelnikova ZA, Suk NI, Shapovalov YuB (2018b) Tantalite and pyrochlore solubility in fluoride solutions at T = 550-850°C and P = 1 kbar in presence of silicate material. Exp Geos 24(1):177–180Google Scholar
- Kotelnikova ZA, Kotelnikov AR (2002) Synthetic NaF-bearing fluid inclusions. Geochem Intern 40(6):594–600Google Scholar
- Kovalenko VI (1977) Petrology and geochemistry of rare metal granitoids. Nauka, Sibirian Devision Novosibirsk, p 207Google Scholar
- Marakushev AA, Shapovalov YuB (1994) Experimental study of ore concentration in fluoride granite systems. Petrology 2(1):4–23Google Scholar
- Reed SJB (2005) Electron microprobe analysis and scanning electron microscopy in geology. Cambridge University Press, CambridgeGoogle Scholar
- Rub AK, Rub MG (2006) Rare metal granites of Primorye. VIMS, Moscow, p 86Google Scholar
- Ryabchikov ID (1975) Thermodynamics of the fluid phase of granitoid magmas. Nauka, Moscow, p 232Google Scholar
- Shapovalov YuB, Kotelnikov AR, Suk NI, Korzhinskaya VS, Kotelnikova ZA (2019) Liquid immiscibility and problems of ore genesis (according to experimental data). Petrology 27(5)Google Scholar
- Zarayskiy GP (2004) Conditions of formation of rare-metal deposits associated with granitoid magmatism. Smirnovsky digest-2004 Moscow: Fund named after acad Smirnov, pp 105–192Google Scholar
- Zarayskiy GP (2009) The relationship of magmatism, metasomatism and ore formation in rare metal deposits of apogranite type. In: Paragenesis and ore formation ekaterinburg: ural branch RAS, pp 105–109Google Scholar