Nano- to atomic-level analysis of heavy metals in pyrite

• Project/Area Number: 20840035
• Research Category: Grant-in-Aid for Young Scientists (Start-up)
• Allocation Type: Single-year Grants
• Research Field: Petrology/Mineralogy/Science of ore deposit
• Research Institution: Kyushu University
• Principal Investigator: UTSUNOMIYA Satoshi Kyushu University, 大学院・理学研究院, 准教授 (40452792)
• Project Period (FY): 2008 – 2009
• Project Status: Completed (Fiscal Year 2009)
• Budget Amount: ¥3,276,000 (Direct Cost: ¥2,520,000、Indirect Cost: ¥756,000); Fiscal Year 2009: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2008: ¥1,716,000 (Direct Cost: ¥1,320,000、Indirect Cost: ¥396,000)
• Keywords: パイライト / TEM / arsenian pyrite / Carlin-type deposit / Nano-scale / Toxic metals

Research Abstract

Arsenian pyrite is an important host of Au in the Carlin-type deposit, whereas it always contains significant amount of heavy metals. In order to understand the formation process and the impact to the ambient environment, a detailed examination utilizing a variety of electron microscopy techniques was carried out on the arsenian pyrite collected from various epithermal deposits. New type of arsenian pyrite that contains As^<3+> was characterized in the sample from the Yanacocha deposit. The amounts of defect and the content of other toxic metals increases as the particle size decreases to nanometer size <10 nm. The other finding is a decoupled formation of As and Cu rich pyrite, indicating mixing of two distinct fluid conditions during its formation. In addition, an experimental study revealed the specific As-bearing minerals in the interaction between mackinawite and aqueous As under anoxic condition. Consequently, this project successfully covered a wide range of crystallochemical characteristics of pyrite in the ore deposit.

Research Products

• [Journal Article] Chemical and structural characterization of As immobilization by nanoparticles of mackinawite (FeSm) (2009)
  • Author(s): D. Renock, T. Gallegos, S. Utsunomiya, K. Hayes, R.C. Ewing, U. Becker
  • Journal Title: Chemical Geology 268 Pages: 116-125
• [Journal Article] Decoupled geochemical behavior of As and Cu in hydrothermal systems. (2009)
  • Author(s): A.P. Deditius, S. Utsunomiya, R.C. Ewing, S.L. Chryssoulis, D. Venter, S.E. Kesler.
  • Journal Title: Geology 37 Pages: 707-710
• [Journal Article] & S.E. Kesler. Nanoscale "liquid" inclusions of As-Fe-S in arsenian pyrite. (2009)
  • Author(s): A.P. Deditius, S. Utsunomiya, R.C. Ewing, S.E. Kesler
  • Journal Title: American Mineralogist 94 Pages: 391-394
• [Journal Article] Decoupled geochemical behavior of As and Cu in hydrothermal systems (2009)
  • Author(s): A.P.Deditius, S.Utsunomiya, R.C.Ewing, S.L.Chryssoulis, D.Venter, S.E.Kesler
  • Journal Title: Geology 37 Pages: 707-710
  • Peer Reviewed
• [Journal Article] Chemical and structural characterization of As immobilization by nanoparticles of mackinawite(FeSm) (2009)
  • Author(s): D.Renock, T.Gallegos, S.Utsunomiya, K.Hayes, R.C.Ewing, U.Becker
  • Journal Title: Chemical Geology 268 Pages: 116-125
  • Peer Reviewed
• [Journal Article] Nano-scale “liquid"inclusions of Fe-As-S in arsenian pyrite (2009)
  • Author(s): Deditius A. P., Utsunomiya S., Ewing R. C., Kesler S. E.
  • Journal Title: American Mineralogist 94 Pages: 391-394
  • Peer Reviewed
• [Journal Article] Decoupling of arsenic and copper in hydrothermal systems (2009)
  • Author(s): Deditius A. P., Utsunomiya S., Ewing R. C., Chryssoulis S. E., Venter D., Kesler S. E.
  • Journal Title: Geology (In press)
  • Peer Reviewed
• [Journal Article] A proposed new type of arsenian pyrite: composition, nanostructure and geological significance. (2008)
  • Author(s): A.P. Deditius, S. Utsunomiya, D. Renock, R.C. Ewing, C.V. Ramana, U. Becker, S.E. Kesler
  • Journal Title: Geochimica et Cosmochimica Acta 72 Pages: 2919-2933
• [Journal Article] A proposed new type of arsenian pyrite : composition, nanostructure andgeological significance (2008)
  • Author(s): Deditius A. P., Utsunomiya S., Renock D., Ewing R. C., RamanaC. V., Becker, U., Kesler S. E.
  • Journal Title: Geochimica et Cosmochimica Acta 72 Pages: 2919-2933
  • Peer Reviewed
• [Presentation] Behaviour of trace elements in arsenian pyrite in ore deposits. (2009)
  • Author(s): Deditius A.P., Utsunomiya S., Kesler S.E., Ewing R.C., Walshe J.
  • Organizer: he 10th Biennal Meeting of SGA, Townsville
• [Presentation] Behaviour of trace elements in arsenian pyrite in ore deposits (2009)
  • Author(s): Deditius A.P., Utsunomiya S., Kesler S.E., Ewing R.C., Walshe J.
  • Organizer: The 10th Biennal Meeting of SGA
  • Place of Presentation: Townsville
• [Presentation] Decoupling of Cu and As in Magmatic-hydrothermal systems : Evidencefrom the Pueblo Viejo Au-Ag Deposit, Dominican Republic. INVITED (2008)
  • Author(s): Deditius A. P., Utsunomiya S., Kesler S. E.
  • Organizer: Goldschmidt Conference
  • Place of Presentation: Vancouver, Canada
  • Year and Date: 2008-07-15
• [Presentation] Decoupling of Cu and As in Magmatic-hydrothermal systems: Evidence from the Pueblo Viejo Au-Ag Deposit, Dominican Republic. Goldschmidt Conference (2008)
  • Author(s): Deditius A.P., Utsunomiya S., Kesler S.E.
  • Organizer: nvited. Geochim. Cosmochim. Acta 72, A206
  • Place of Presentation: Vancouver, Canada
• [Presentation] Nanoscale geochemistry and mineralogy of arsenian pyrite in ore deposits. (2008)
  • Author(s): Deditius A.P., Utsunomiya S., Renock D., Reich M., Ewing R.C., Chryssoulis S.L., Venter D., Ramana C.V., Becker U., Kesler S.E.
  • Organizer: Gordon Research Conference: Geochemistry of Mineral Deposits
  • Place of Presentation: Il Ciocco, Italy