HRTEM/AEM and SEM study of fluid-rock interactions: Interaction of copper, silver, selenium, chromium, and cadmium-bearing solutions with geological materials at near surface conditions, with an emphasis on phyllosilicates

Technical Report · Fri May 01 04:00:00 EDT 1992

DOI:https://doi.org/10.2172/7075474· OSTI ID:7075474

Veblen, D R; Ilton, E S

Biotite has been reacted with acidic solutions, at 25'' +/-3''C, bearing silver (Ag{sub 2}SO{sub 4}), selenium (selenite), chromium (hexavalent Cr), and copper (CuSO{sub 4}). The experiments were open to the atmosphere. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) show that biotite sorbs and reduces Ag+(aq) to metallic silver. Polygonal precipitates and inclusions of metallic silver (with diameters ranging from 10's of angstroms to > {ge} {mu}m) are concentrated on the edges of the biotite flakes and also in the interlayer region. X-ray photoelectron spectroscopy (XPS) of biotites reacted with selenite-bearing solutions show that the oxidation state of selenium sorbed on the surface of biotite is Se{sup 4+}. XPS of biotites reacted with Cr{sup 6+}-bearing solutions show that the oxidation state of chromium sorbed on the surface of biotite is Cr{sup 3+}. Copper-bearing solutions were reacted with low-F biotite in contrast to our previous work with high-F biotite (Olden et al., in press). Results indicate that low-F biotite absorbs more readily and extensively than high-F biotite. Further work on copper-enriched biotite from the chrysocolla zone has revealed that the mode of copper incorporation in biotite is more complex than previously described.

• Research Organization: Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Earth and Planetary Sciences
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: FG02-89ER14074
• OSTI ID: 7075474
• Report Number(s): DOE/ER/14074-4; ON: DE92040456
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
152003* -- Geothermal Data & Theory-- Rock-Water-Gas Interactions
BIOTITE
CADMIUM
CHEMICAL REACTIONS
CHROMIUM
COPPER
DOCUMENT TYPES
ELECTRON MICROSCOPY
ELECTRON SPECTROSCOPY
ELEMENTS
Geothermal Legacy
METALS
MICA
MICROSCOPY
MINERALS
OXIDATION
PHOTOELECTRON SPECTROSCOPY
PROGRESS REPORT
REDUCTION
ROCK-FLUID INTERACTIONS
SCANNING ELECTRON MICROSCOPY
SELENIUM
SEMIMETALS
SILICATE MINERALS
SILVER
SPECTROSCOPY
TRANSITION ELEMENTS
TRANSMISSION ELECTRON MICROSCOPY