Research output: Contribution to journal › Article › peer-review
Three-D mineralogical mapping of the kovdor phoscorite-carbonatite complex, NW Russia : III. Pyrochlore supergroup minerals. / Ivanyuk, Gregory Yu; Konopleva, Nataly G.; Yakovenchuk, Victor N.; Pakhomovsky, Yakov A.; Panikorovskii, Taras L.; Kalashnikov, Andrey O.; Bocharov, Vladimir N.; Bazai, Ayya A.; Mikhailova, Julia A.; Goryainov, Pavel M.
In: Minerals, Vol. 8, No. 7, 277, 07.2018.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Three-D mineralogical mapping of the kovdor phoscorite-carbonatite complex, NW Russia
T2 - III. Pyrochlore supergroup minerals
AU - Ivanyuk, Gregory Yu
AU - Konopleva, Nataly G.
AU - Yakovenchuk, Victor N.
AU - Pakhomovsky, Yakov A.
AU - Panikorovskii, Taras L.
AU - Kalashnikov, Andrey O.
AU - Bocharov, Vladimir N.
AU - Bazai, Ayya A.
AU - Mikhailova, Julia A.
AU - Goryainov, Pavel M.
PY - 2018/7
Y1 - 2018/7
N2 - The pyrochlore supergroup minerals (PSM) are typical secondary phases that replace (with zirconolite–laachite) earlier Sc-Nb-rich baddeleyite under the influence of F-bearing hydrothermal solutions, and form individual well-shaped crystals in surrounding carbonatites. Like primary Sc-Nb-rich baddeleyite, the PSM are concentrated in the axial carbonate-rich zone of the phoscorite-carbonatite complex, so their content, grain size and chemical diversity increase from the pipe margins to axis. There are 12 members of the PSM in the phoscorite-carbonatite complex. Fluorine- and oxygen-dominant phases are spread in host silicate rocks and marginal carbonate-poor phoscorite, while hydroxide-dominant PSM occur mainly in the axial carbonate-rich zone of the ore-pipe. Ti-rich PSM (up to oxycalciobetafite) occur in host silicate rocks and calcite carbonatite veins, and Ta-rich phases (up to microlites) are spread in intermediate and axial magnetite-rich phoscorite. In marginal (apatite)-forsterite phoscorite, there are only Ca-dominant PSM, and the rest of the rocks include Ca-, Na- and vacancy-dominant phases. The crystal structures of oxycalciopyrochlore and hydroxynatropyrochlore were refined in the (Formula Presented) space group with R1 values of 0.032 and 0.054 respectively. The total difference in scattering parameters of B sites are in agreement with substitution scheme BTi4+ + γOH- = BNb5+ + γO2-. The perspective process flow diagram for rare-metal “anomalous ore” processing includes sulfur-acidic cleaning of baddeleyite concentrate from PSM and zirconolite–laachite impurities followed by deep metal recovery from baddeleyite concentrate and Nb-Ta-Zr-U-Th-rich sulfatic product from its cleaning.
AB - The pyrochlore supergroup minerals (PSM) are typical secondary phases that replace (with zirconolite–laachite) earlier Sc-Nb-rich baddeleyite under the influence of F-bearing hydrothermal solutions, and form individual well-shaped crystals in surrounding carbonatites. Like primary Sc-Nb-rich baddeleyite, the PSM are concentrated in the axial carbonate-rich zone of the phoscorite-carbonatite complex, so their content, grain size and chemical diversity increase from the pipe margins to axis. There are 12 members of the PSM in the phoscorite-carbonatite complex. Fluorine- and oxygen-dominant phases are spread in host silicate rocks and marginal carbonate-poor phoscorite, while hydroxide-dominant PSM occur mainly in the axial carbonate-rich zone of the ore-pipe. Ti-rich PSM (up to oxycalciobetafite) occur in host silicate rocks and calcite carbonatite veins, and Ta-rich phases (up to microlites) are spread in intermediate and axial magnetite-rich phoscorite. In marginal (apatite)-forsterite phoscorite, there are only Ca-dominant PSM, and the rest of the rocks include Ca-, Na- and vacancy-dominant phases. The crystal structures of oxycalciopyrochlore and hydroxynatropyrochlore were refined in the (Formula Presented) space group with R1 values of 0.032 and 0.054 respectively. The total difference in scattering parameters of B sites are in agreement with substitution scheme BTi4+ + γOH- = BNb5+ + γO2-. The perspective process flow diagram for rare-metal “anomalous ore” processing includes sulfur-acidic cleaning of baddeleyite concentrate from PSM and zirconolite–laachite impurities followed by deep metal recovery from baddeleyite concentrate and Nb-Ta-Zr-U-Th-rich sulfatic product from its cleaning.
KW - Crystal structure
KW - Kovdor phoscoritecarbonatite complex
KW - Pyrochlore supergroup minerals
KW - Typochemistry
UR - http://www.scopus.com/inward/record.url?scp=85049256863&partnerID=8YFLogxK
U2 - 10.3390/min8070277
DO - 10.3390/min8070277
M3 - Article
AN - SCOPUS:85049256863
VL - 8
JO - Minerals
JF - Minerals
SN - 2075-163X
IS - 7
M1 - 277
ER -
ID: 49682164