Bingham Canyon Copper Mine, Utah
Mineral Resources
Questions for Discussion
What is meant by
renewable resources?
Examples?
What does it mean
to recycle a resource?
Examples?
LR
RR
What is meant by
non-renewable
resources? Examples?
What is an ore?
LF
RF
Mineral Resource Categories
• Renewable Fresh Water
• Non-renewable
Recyclable / Abundant
Iron
Gold
Copper
Iron
Rock
Sand
• Non-renewable
Non-recyclable
Fossil Fuels
Soils
Phosphate
Fresh Water
Fresh water is a
renewable
resource if it is
used
sustainably.
Free-flowing artesian well
EPA “Superfund” sites - sources of groundwater
and surface water contamination
Rock-Forming
Minerals
Silicates
Labradorite Quartz
K-Feldspar Kaolinite
Albite
Hornblende
Garnet
Augite
Muscovite
Olivine
Biotite
Mineral Families
Silicate Anion
SiO4-4
e
oxygen
e
e
e
e
silicon e
e
e
oxygen e
e oxygen
e
e
oxygen
Tetrahedron
How silicate tetrahedra
Fe
bond together
O
Bonding to
intermediate cation
(relatively weak bond)
Direct bonding
of tetrahedra
O
Fe
O
O
O
O
Fe O
O
O
O
Shared oxygen
O
(relatively strong bond)
O
• Olivine – a principle
•
constituent of the upper
mantle and oceanic crust.
(Mg, Fe)2 SiO4
Nesosilicates
• The Garnet Group
• Common in metamorphic rocks.
• High hardness (6.5-7), used as
•
an industrial abrasive.
(A3, B2) SiO4
• A = Mg2+, Mn2+, Fe2+, Ca2+
• B= Al3+, Fe3+, Cr3+
Augite
Pyroxene
Inosilicates: common
in igneous and
metamorphic rocks
Hornblende
Amphibole
Phyllosilicates: mica and clay minerals
Muscovite
Biotite
Kaolinite
Mica and clays are soft, flaky minerals because of
their sheet silicate structure.
Tectosilicates
(3-dimensional framework)
• Quartz (SiO2)
– all tetrahedra are
interconnected
(no cations)
– mineral fractures
- all bonds are
the same
– most common
surface mineral,
found in sand and
gravel
Quartz
Tectosilicates
(3-dimensional framework)
• Feldspars
– similar to quartz, but with Al3+ replacing some Si4+
– cations needed to balance Al3+, can be K+, Na+ or Ca2+
– Al3+ ions create weakness in the crystal lattice,
resulting in cleavage (2 directions)
Feldspars
Ca
K
Labradorite
Na
Albite
K-feldspar
Sand, Gravel, Clay, Stone
Non-renewable / Abundant
★
Low value, high volume commodities
★
Local sources preferred due to high cost of
transportation.
★
Sand and gravel for construction in USA app.
790 million metric tons = $6 billion in 2011.
★
Clays are quarried for use in ceramics, brickmaking.
★
Stone is quarried for construction material and
road-building aggregate.
Steers Pit sand mine, Northport, NY circa 1960
Other Mineral Resources
• Native elements - natural occurrences of
single element minerals (eg. Gold).
• Simple compounds (eg. NaCl)
• Other complex ions (eg. CaCO3)
• Less common than silicates, but many are
economically important.
Native Elements
• Minerals composed of a single element.
• ex. Gold, Copper, Silver, Platinum, Sulfur
Gold Nugget
Panning for gold in Alaska
Panning for gold in Alaska
Panning for gold in Alaska
Native Elements
Platinum nuggets
Native Elements
Copper
Native Iron
(only found in meteorites and the Earth’s Core)
Widmanstatten lines
Iron meteorite on the
surface of Mars
Precious Metals Resources
Non-renewable / Recyclable
★
High value, low volume commodities
★
Native sources are very rare - most occur as
simple compounds (except for Gold / Platinum)
★
Ore deposits contain high amounts of metal
elements due to concentration by igneous or
weathering processes.
★
Whether or not a body of rock is an ore
depends on the price of the metal commodity.
★
Low grade deposits become ores if the price is
high enough.
Current Price
Simple Compounds
• Ore minerals - mined to obtain valuable
elements.
– Ratio of valuable to non-valuable elements
in compound is high.
– Easy to separate valuable and non-valuable.
– Economically feasible to mine and process.
• Oxide family - valuable element +
oxygen.
• Sulfide family - valuable element +
sulfur.
Iron Oxides
Hematite (Fe2O3)
Magnetite (Fe3O4)
Which is more valuable, a ton of
hematite or a ton of magnetite? Why?
Banded Iron
Formations
Enormous quantities of iron oxide were
deposited around the world between 3.0
and 2.0 billion years ago, forming our
richest deposits of iron ore.
Dissolved iron pumped into the oceans by
volcanism along mid-ocean ridges reacted
with oxygen being produced by
photosynthesizing bacteria, precipitating
out layers of magnetite (Fe3O4).
Copper Oxide
Titanium Oxide
Cuprite (Cu2O)
Ilmenite (FeTiO3)
Uranium Oxide
Nuclear
Fission
Uraninite (UO2)
Uranium 235 is the fuel
used in nuclear fission reactors.
Copper Sulfides
Bornite (Cu5FeS4)
Chalcopyrite (CuFeS2)
Lead Sulfide
Iron Sulfide
Galena (PbS)
Pyrite (FeS2)
Other Simple Compounds
• Halides - compounds with
Halogens
– Fluorine
– Chlorine
– Bromine
– Iodine
Halite (NaCl)
• Halite - (NaCl) rock salt.
• Fluorite - (CaF) fluorescent.
Fluorite (CaF)
Most salt is mined from
ancient deposits of rock salt,
although some is harvested
from salt lakes and the sea.
Salt Mine near Geneseo, NY
Aluminum Ore
Bauxite (AlOH3)
Bauxite being loaded for export from the Dominican Republic
Are we running out of metals?
★
There are vast quantities of useful metals in
the crust of the Earth.
★
Shortage of a metal drives up the price, which
makes it economically feasible to mine lower
grade ores.
★
Mining has environmental costs - traditionally
these have not been factored into the cost of
the commodity.
★
Metals are usually not consumed - they can be
recycled. Economics of recycling would be
better if environmental costs were factored in.
Complex Ion Mineral Families
• Phosphates - (PO4)3- tetrahedron
• Sulfates - (SO4)2- tetrahedron
• Carbonates - (CO3)2- triangle
Question:
Why don’t these
structures allow for
as many different
kinds of minerals as
the silicate
tetrahedron?
Phosphates (PO4)3-
• Apatite - Ca5(PO4)3F
• Apatite is secreted by vertebrate organisms
to construct bones and teeth.
• Important source of agricultural fertilizer.
• Phosphates are non-renewable, by mid-21st
century half of reserves will be used up!
Phosphate Mine
Apatite
Turquoise
Sulfates (SO4)2• Most common sulfates are
calcium sulfates anhydride and gypsum.
• Both are formed from the
evaporation of seawater.
• Gypsum is an important
economic mineral because
of its use in plaster and
wall board materials.
• Alabaster - fine-grained
gypsum, used for sculpting.
Gypsum (CaSO4 2H2O)
Carbonates (CO3)2Limestones - CaCO3
Dolostones - CaMgCO3
Carbonate minerals form in tropical, marine
environments.
Most carbonate mineral is produced
biologically by coral, bacteria, algae, and
phytoplankton.
Cement and Concrete
Limestone heat Calcium Oxide Carbon dioxide
+
(CaC03) 1450°C
(CaO)
(CO2)
Water
+
Cement + Aggregate
Concrete
Cement Mine
sand
gravel
Limestone is abundant in the crust of the
Earth, but there are sometimes environmental
costs associated with quarrying it. Cement
production also produces about 5% of the CO2
gas added to the atmosphere each year by
human activities.
Mineral Families Overview
• Silicates
– Nesosilicates
– Sorosilicates
– Cyclosilicates
– Inosilicates
– Phyllosilicates
– Tectosilicates
• Carbonates
Rock-forming minerals
• Oxides
• Sulfides
Ore minerals
• Native elements
• Halides
• Phosphates
Other useful minerals
• Sulfates
plaster
• Silicates
steel
• Carbonates
copper
• Oxides
• Sulfides
glass
• Native elements
• Sulfates
fertilizer
clay
salt
ceramics
• Halides
• Phosphates
graphite
aluminum
gold
concrete
• Silicates
glass ceramics clay
• Carbonates
concrete
• Oxides
steel aluminum
• Sulfides
copper
• Native elements
graphite gold
• Halides
salt
• Phosphates
fertilizer
• Sulfates
plaster