Environmental Mineralogy

Oxford
Miami Chief Little Turtle 1795
Miami University, Oxford, Ohio
Miami University, Oxford, Ohio
9-Mar Environmental Mineralogy Lecture (overview with case studies, methods
applied, etc.)
23-Mar Sediment hosted U & V deposits of the Colorado Plateau
30-Mar Heavy metals in soils: Solid phase characterization: Overview and XRD
13-Apr Heavy metals in soils: synchrotron methods
20-Apr Heavy metals in soils: synchrotron methods
11-May Mineral water interface processes
25-May Mineral water interface processes
1-Jun
Pb, Zn, F contamination from MVT deposits (Missouri, Olkush, Illinois)
15-Jun To be announced
20-Jun To be announced
Go to
www.cas.muohio.edu/~rakovajf/AGH.html
For lecture slides and associated readings.
Environmental Mineralogy: Studies of the dynamic interaction
of minerals and the environment and their affect on
environmental chemistry, water quality, human health,
contaminant remediation, microbial processes, etc.
Environmental Mineralogy is a multidisciplinary endeavor
that encompasses mineralogy, geology, biology, medicine, materials
science and engineering.
The intersection of the biological,
geological, and material sciences
is exemplified no better than in the
importance and interest in the
structure, chemistry, and
environmental significance of the
phosphate mineral apatite.
Apatite
Ca5(PO4)3(F,OH,Cl)
Fluorapatite*
Hydroxylapatite
Chlorapatite
* The most common variety
Ca5(PO4)3F
Ca5(PO4)3OH
Ca5(PO4)3Cl
Apatite
Ca5(PO4)3(F*,OH,Cl) + REE, Mn, Sr, Pb, U,…
Geologic Apatite
• Igneous Rocks
• Metamorphic Rocks
• Sedimentary Rocks
• Hydrothermal Deposits
Environmental Mineralogy
of Apatite Group Minerals
[IX]X1 [VII]X2 ([IV]YO ) [III-IV]Z
4
6
4 6
2
The foundation of the natural
global P cycle
P Cycle
Weathering of
PO4 from rocks
apatite
transport
animal
uptake
Soluble PO4
Plant
uptake
precipitation
decomposition
sedimentation
of particulate PO4
rock formation
Environmental Mineralogy
of Apatite Group Minerals
[IX]X1 [VII]X2 ([IV]YO ) [III-IV]Z
4
6
4 6
2
Major part of the anthropogenic
influence on the global P cycle
Major Ore
of PO4
Eutrophism
Environmental Mineralogy
of Apatite Group Minerals
[IX]X1 [VII]X2 ([IV]YO ) [III-IV]Z
4
6
4 6
2
Biomineralogy and Medical Mineralogy
Biologic Apatite
• Bones and Teeth
Enamel
Dentin
Bone
Carbonatehydroxylapatite
TEM photomicrographs of carbonatehydroxylapatite from rat enamel.
Magnification = 150,000x
From Nylen et al. (1963)
Synthetic Apatite
Materials Applications
• Prosthetic Coatings
Biologic Apatite: Calculi
CaOX – hydroxylapatite kidney stone
Biologic Apatite: Calculi
Amorphous Ca-phosphate & apatite
Components in arterial plaque.
Environmental Mineralogy
of Apatite Group Minerals
[IX]X1 [VII]X2 ([IV]YO ) [III-IV]Z
4
6
4 6
2
The apatite structure allows for
a large number of elemental substitutions
[IX]X1 [VII]X2 ([IV]YO ) [III-IV]Z
4
6
4 6
2
Ca10(PO4)6(F,OH,Cl)2
Ca
P
O
F, OH or Cl
(001)
Cation Sites
X1 site
Y site
[IX]X1 [VII]X2 ([IV]YO ) [III-IV]Z
4
6
4 6
2
X2 site
Major and Trace Substituents
Over half of the elements in the periodic
table have been found in apatite at
concentrations from 10’s of wt% to parts
per million.
Common substitutions in apatite
Ca5(PO4)3(F,OH,Cl)
Sr, Ba, Na, Y,
Mn, REE, U, Th,
etc.
As, V, Si, S,
CO3, etc.
Apatite group minerals
Minerals with the apatite structure but different major
element chemistry.
Most common
Pyromorphite
Pb5(PO4)3Cl
Mimetite
Pb5(AsO4)3Cl
Vanadinite
Pb5(VO4)3Cl
Other apatite group minerals
ALFORSITE
BELOVITE-(Ce)
BELOVITE-(La)
BRITHOLITE-(Ce)
BRITHOLITE-(Y)
CARBONATEFLUORAPATITE
CARBONATEHYDROXYLAPATITE
CESANITE
CHLORELLESTADITE
CLINOMIMETITE
FERMORITE
FLUORBRITHOLITE-(Ce)
FLUORCAPHITE
FLUORELLESTADITE
HEDYPHANE
HYDROXYLELLESTADITE
JOHNBAUMITE
MATTHEDDLEITE
MORELANDITE
STRONTIUMAPATITE
SVABITE
TURNEAUREITE
Ba5(PO4)3Cl
Sr3Na(Ce,La)(PO4)3(F,OH)
Sr3Na(La,Ce)(PO4)3(F,OH)
(Ce,Ca)5(SiO4,PO4)3(OH,F)
(Y,Ca)5(SiO4,PO4)3(OH,F)
Ca5(PO4,CO3)3F
Ca5(PO4,CO3)3(OH)
Na3Ca2(SO4)3(OH)
Ca5(SiO4,PO4,SO4)3(Cl,F)
Pb5(AsO4)3Cl
(Ca,Sr)5(AsO4,PO4)3(OH)
(Ce,La,Na)5(Si,P)3O12F
Ca(Sr,NaCa)(Ca,Sr,Ce)3(PO4)3F
Ca5(SiO4,PO4,SO4)3(F,OH,Cl)
Pb3Ca2(AsO4)3Cl
Ca10(SiO4)3(SO4)3(OH,Cl,F)2
Ca5(AsO4)3(OH)
Pb5(SiO4)1.5(PO4)1.5(Cl,OH)
(Ba,Ca,Pb)5(AsO4,PO4)3Cl
(Sr,Ca)5(PO4)3(OH,F)
Ca5(AsO4)3F
Ca5[(As,P)O4]3Cl
Environmental Mineralogy
of Apatite Group Minerals
[IX]X1 [VII]X2 ([IV]YO ) [III-IV]Z
4
6
4 6
2
Utilization of the a large number
of elemental substitutions:
Dating
Apatite
Ca5(PO4)3(F,OH,Cl)
+ many substituents (I.e. U*, Th*, REE*, Sr*, Y*)
(*important radionuclides)
Environmental Mineralogy
of Apatite Group Minerals
[IX]X1 [VII]X2 ([IV]YO ) [III-IV]Z
4
6
4 6
2
Utilization of the a large number
of elemental substitutions:
Solid Nuclear Waste Forms
Radioactive Waste
SNF storage pools
Dry cask storage
www.ocrwm.doe.gov
Synthetic Apatite: Materials Applications:
• Solid nuclear waste form
U-fluorapatite
Desired properties of a solid nuclear waste form
1) Low Solubility
a) Apatite is very insoluble Ks of FAP ≅ 1 x 10-60
2) High affinity for the incorporation of radionuclides
a) Apatite readily incorporates U, Th, 90Sr, 90Y, REE
3) Thermal stability
a) Apatite forms and is stable under conditions present from
the earths surface to deep in the mantle.
4) Low propensity for Metamictization
a) Thermal annealing temperatures for apatite as low as 70OC
Environmental Mineralogy
of Apatite Group Minerals
[IX]X1 [VII]X2 ([IV]YO ) [III-IV]Z
4
6
4 6
2
Utilization of the a large number
of elemental substitutions:
Sequestration and stabilization
of heavy metal contaminants
Permeable Reactive Barriers
AFM images of Pb interactions with apatite (From Lower et al. 1998)
apatite Ca5(PO4)3(OH)
pyromorphite Pb5(PO4)3(OH)
on apatite
0.5 μm
In situ precipitation
PIMS
Conclusions
The intersection of the biological, geological, and material sciences
is exemplified no better than in the importance and interest in the
structure, chemistry, and environmental significance of the
phosphate mineral apatite.
Environmental Mineralogy of Apatite
1)
2)
3)
4)
5)
6)
Dominant source of P in the environment
Ore of PO4
Biomineralization (Bones and teeth)
Contaminant Barrier
Metal Sequestration Agent
Potential solid nuclear waste form
Apatite, Paraiba, Minas Gerais, Brazil