SOIL AND SOLID NON-FUEL MINERAL RESOURCES
Au
Cu
How are solid non-fuel mineral resources formed and concentrated?
SnO2
• Internal Processes (magma generation, hot water circulation,
pressure & heat)
– Magmatic deposits
– Hydrothermal deposits
– Metamorphism
Gabbro
Rare Earth Elements
• External Processes (weathering, erosion, transport and deposition
Marble
Slate
The Rare Earth Elements
“REE”
by wind and water; evaporation)
– Sedimentary deposits: wind, water, placers
– Evaporites
– Secondary Enrichment
Web Link
The 17 Rare Earth Elements
http://en.wikipedia.org/wiki/Rare_earth
_element
Ru Ruthenuim
Rh Rodium
Pd Palladium
Os Osmium
Ir Iridium
Pt Platinum
Se Selinium
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Bastnäsite: a fluorocarbonate mineral
(Ce,La,Y)CO3F
Monazite: a phosphate mineral, 4 different types
monazite‐Ce (Ce, La, Pr, Nd, Th, Y)PO4
monazite‐La (La, Ce, Nd, Pr)PO4
monazite‐Nd (Nd, La, Ce, Pr)PO4
monazite‐Sm (Sm, Gd, Ce, Th)PO4
Wide Variety of uses: medical (MRI), military, missiles, clean
energy technology, catalytic converters, magnets, hybrid car
batteries.
Consumer Products: cell phones, computer hard drives, monitors,
power tools, sun glasses, wine bottles, fluorescent light bulbs, TVs,
automobiles, SUV’s
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• Also used in Cell Phones
Until the mid 1980’s, US led the world in REE production; has ~13% of world reserves. China has ~48% of world reserves, but supplies ~97% of the world’s needs. Russia, Canada and Australia also have large deposits.
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Over 3 Square miles
In 2015, global industry forecast is to consume
185,000 tons of rare earth’s
Mountain Pass Rare Earth Mine in Mountain Pass California, Mojave Desert. Environmental Concerns
Closed in 2002, re‐opened in August 2012
• Need to excavate a lot of earth / dig huge holes / takes a lot of energy + a lots of solid waste rock. • Some elements associated with the REE are radioactive such as Uranium and Thorium. They end up in slurry pools and can enter groundwater.
• Toxic acids and chemicals are required during the refining process, often end up in slurry pools and can enter groundwater. • Baotou, a city in China where ~80% of REE are mined produces ~10 million tons of wastewater/year.
• Birth defects and Leukemia have been linked to rare earth refinery in Malaysia and China
• In 2008, ~1/3 of REE in China were mined illegally by heavy polluting, violent criminal gangs.
Web Link: The Only American Mine for Rare Earth Metals
http://www.theatlantic.com/technology/archive/2012/02/a-visit-to-the-onlyamerican-mine-for-rare-earth-metals/253372/
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How are solid non-fuel mineral resources formed and concentrated?
Most of the world’s major metal deposits occur at past or present plate
boundaries. Surface processes also play an important role in
concentrating nonmetallic minerals and rocks.
• Internal Processes (magma generation, hot water circulation,
The Lynas Plant in Malaysia is
the world's largest processing
facility of rare earths.
Metamorphism
pressure & heat)
– Magmatic deposits
– Hydrothermal deposits
– Metamorphism
• External Processes (weathering, erosion, transport and deposition
by wind and water; evaporation)
– Sedimentary deposits
– Evaporites
– Water / Placer deposits
– Secondary Enrichment
How are solid non-fuel mineral resources formed and concentrated?
Most of the world’s major metal deposits occur at past or present plate
boundaries. Surface processes also play an important role in
concentrating nonmetallic minerals and rocks.
• Internal Processes (magma generation, hot water circulation,
pressure & heat)
– Magmatic deposits
– Hydrothermal deposits
– Metamorphism
• External Processes (weathering, erosion, transport and deposition
by wind and water; evaporation)
– Sedimentary deposits: wind, water, placers
– Evaporites
– Secondary Enrichment
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Sand Mining in Monterey Bay has been occurring
since 1906, ~150,000 – 250,000 cubic yards/yr,
with no regulation until 1960s.
3 companies for ~80 years, only one is left.
Sedimentary Deposits: Sand and gravel accumulate in river
A connection between mining and shoreline erosion
was determined in the mid
1980s, but still 1 company
mines ~200,000 cubic yards
each year.
water filtration, glass production…..
channels and bars, coastal offshore bars, sand dunes, beaches and
glacial outwash plains.
After deposition sediments lithify by compaction and cementation.
Materials used for: road beds, cement production, bricks, tiles, abrasives,
Sand Mining in Monterey Bay
http://coastalcare.org/2014/09/monterey-bay-california-beach-sand-mining-from-a-nationalmarine-sanctuary-by-gary-griggs/
(web link)
“Point Bars”
Placer Deposits
Read this slide over very carefully.
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Evaporites: (Salts: halite, gypsum, borates) water evaporates
from shallow inland seas or lakes in warm arid climates.
Materials used in: making glass, ceramics, metals, preservatives,
cleaning agents, water softeners……..
How are solid non-fuel mineral resources formed and concentrated?
Most of the world’s major metal deposits occur at past or present plate
boundaries. Surface processes also play an important role in
concentrating nonmetallic minerals and rocks.
• Internal Processes (magma generation, hot water circulation,
pressure & heat)
– Magmatic deposits
– Hydrothermal deposits
– Metamorphism
• External Processes (weathering, erosion, transport and deposition
by wind and water; evaporation)
– Sedimentary deposits: wind, water, placers
– Evaporites
– Secondary Enrichment
How are mineral resources found?
Understand the geologic/plate tectonic history of an area
Make Maps: rock formations, faults, structure
Drill, extract and analyze rock/sediment samples
Aerial photos and satellite images,
reveals outcrops and types of rock types
Seismic & gravitational surveys give
info about buried rock layers
Chemical analysis of water and plants
to detect minerals leached into water and
absorbed by plants
Remote sensing: (detect /analyze wave
transmitted energy) reveals outcrops and
types of rock
Secondary Enrichment
Measure radiation, magnetism to detect
radioactive metals, iron and other
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How are Mineral Resources Extracted?
Bingham Copper Mine, Utah
>4km wide, 1.2 km deep, >6 billion tons of rock mined since 1906
Surface Mining
machines strip away millions
of tons of “Overburden”
(rock/earth covering ore) and pile
it up as waste material
sometimes called “Spoil”
1) Open-pit mining:
commonly used surface
mining technique; used for
mining most major metal
deposits, also sand, gravel and
stone.
The Palabora open pit in NE South Africa. The hard rock
allows the pit walls to be cut much steeper than is
normal in open-pit Copper mining.
More Surface Mining
2) Hydraulic Mining: wash away overburden on hillsides;
mine uplifted placer deposits. In CA huge volumes of sediment
washed into SF-San Joaquin delta harming navigation and
agriculture, ~ 1850’s – 1890’s.
3) Dredging: used on underwater mineral deposits;
gold mining of CA riverbed sediments until 1960s;
leaves great piles of spoil alongside channels called
spoil banks/dredge fields.
~13 billion cubic
yards of sediment
have been washed
away from the
Sierra Nevada
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Smelting or “Extractive Metallurgy”
How are ores processed?
• Remove undesired parts of ore (gangue)
is the practice of extracting metal from ore, purifying it, and recycling it
Separation
of ore from
gangue
Melting
metal
• Smelting extracts metals from other elements
• Pure metal is then converted to desired product by manufacturing
companies
Drawbacks? Results in air, water, soil pollution; solid and liquid
hazardous wastes; safety and health hazards
Metal ore
Start Here:
Surface
Mining
Recycling
Conversion
to product
Discarding
of product
Scattered in environment
Why do we mine?
Concerns? Environmental degradation from mining and processing, depletion
time, economic depletion, exhaustion, import dependence, high cost
Supply and Consumption of Mineral Resources
• Economic Depletion
– Costs more to find, extract, transport and process mineral than
deposit is worth.
– Options: 1) recycle or reuse existing supplies, 2)waste less, 3) use
less, 4) find substitute, 5) do without.
• Depletion Time:
– time it takes to use up 80% of reserves of a mineral at a given rate
of use.
• US currently imports ~50% of its most important non-fuel minerals.
– Used faster than they can be produced here
– Foreign ores are higher grade and can be extracted cheaper than
US reserves
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A
Mine, use, throw away;
no new discoveries;
rising prices
Production
B
Present
Recycle; increase reserves
by improved mining
technology, higher prices,
and new discoveries
Recycle, reuse, reduce
consumption; increase
reserves by improved
mining technology,
higher prices, and
new discoveries
C
Depletion
time A
Depletion
time B
Depletion
time C
Time
Mineral and Soil Resources
• Greatest concern about
mining solid non-fuel mineral
resources is environmental
degradation caused by
extracting, processing and
manufacturing.
• Soil is a renewable resource if
sound, sustainable agricultural
practices are used. When soil is
depleted of its nutrients or topsoil
erodes faster than it is replenished,
soil becomes a nonrenewable
resource.
• As resources become depleted
• Soil loss seriously compromises
and lower grade ores are
our ability to grow food necessary
mined, environmental
to feed an expanding human
degradation increases.
population.
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