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Mineral Resources


Mineral Resources
• Backbone of modern societies
• Availability of mineral resources as a measure of
the wealth of a society
• Important in people’s daily life as well as in
overall economy
• Processed materials from minerals account for 5%
of the U.S. GDP
• Mineral resources are nonrenewable


Mineral Value

• Direct value

– Raw, recycles
– Import, export

• Indirect value
– Processes

• Value added
– E.g., agriculture


Common Use of Mineral
Products

METALLIC
HYDROCARBON
NON-METALLIC


Mineral Resources and Reserves
• Mineral resources: Usable economic commodity
extracted from naturally formed material
(elements, compounds, minerals, or rocks)
• Reserve: Portion of a resource that is identified
and currently available to be extracted legally and
profitably
• Defining factors: Geologic, technological,
economic, and legal factors


Reserves vs. Resources
• Reserves
– Natural resources that
have been discovered &
can be exploited
profitably with existing
technology
– Oil – 700 billion barrels

• Resources
– Deposits that we know
or believe to exist, but
that are not exploitable
today because of

technological,
economical, or political
reasons
– Oil – 2 trillion barrels



Mineral Resources Problems
• Nonrenewable resources
– Finite amount of mineral resources and growing demands for the
resources

• Supply shortage due to global industrialization
– More developed countries consuming disproportionate share of
mineral resources

• Erratic distribution of the resources and uneven
consumption of the resources.
– Highly developed countries use most of the resources; supply
varies


Major Import Sources (Table 14.2)
• Friends
– Canada: Metals
– United Kingdom: platinum, rare earths

• Other
– China: graphite, tin, tungsten…
– South Africa : platinum, fluorspar

– Chile: arsenic, iodine


Responses to Limited
Availability
•
•
•
•

Find more sources
Find a substitute
Recycle
Use less and make more efficient use of
what is available
• Do without


Responses to Limited
Availability

Figure 14.3


Geology of Mineral Resources
• Metallic ore: Useful metallic minerals that can be
mined for a profit
• Technology, economics, and politics
• Concentration factor: Concentration necessary
for profitable mining

– Variable with types of metals
– Variable over time


Genesis of Mineral Resources


Some Important Minerals and there Uses
•
•

Galena [PbS] – source of lead – car batteries
Magnetite, Hematite [FexOy] – iron ore

•

Bauxite [Al2O3*2H2O] – aluminum ore

•

Chalcopyrite [CuFeS2] – copper ore

•

Quartz [SiO2] – glass and electronic components

•

Gypsum [CaSO4*2H2O] – sheetrock, plater of paris

•
•

Sphalerite [ZnS] – zinc ore
Calcite [CaCO3] – portland cement, soil conditioner, antacids

•

Garnet [Al2(SiO4)3+other metals] – abrasives

•

Olivine [(Fe,Mg)2SiO4] – silicon chips for computers

•
•
•
•
•
•

Sulfur [S] – insecticides, rubber tires, paints, papermaking, etc.
Halite [NaCl] – Table salt
Graphite [C] – lubricant, pencil lead
Feldspars [K,Ca,Na,Al, silicates] – porcelain, source of K
Any other element that is not a major component of a mineral
Gold [Au], Silver [Ag], Platinum [Pt], Titanium [ Ti], Tin [Sn], etc .


Plate Tectonics and Mineral

Resources
• Plate boundaries are related to the origins of
many ore deposits
• Plate tectonic processes (high temperature, high
pressure, and partial melting) promote release
and enrichment of metals along plate
boundaries
• Common metal ores along plate boundaries are
Fe, Au, Cu, and Hg, etc.


Daily Questions
• Within your groups, identify one task you
all have completed today. Collectively
think about the task and brainstorm.
Produce a list of all of the mineral resources
that were used in that task.


Geochemically Abundant Elements
(GAE)
• Elements comprise > 0.1% (by
weight) of the crust
• Form as principal component
in minerals within common
rocks – i.e. iron (Fe) Fe2O3
• Form very large deposits
• Form rock deposits

Geochemically Scarce Elements
(GSE)
• Elements that comprise < 0.1% (by weight) of the
crust
• Do not form as principal component in minerals
within common rocks, usually occur as a
substitute in rock forming minerals
• Form small deposits
• Ore minerals include sulfides, native elements,
etc.


Mineral Deposits
• Elements need to be concentrated
• Minimum Grade - minimum amount of element
necessary to economically mine element
• Minimum Concentration Factor (MCF) –
Minimum Grade divided by the Crustal
Abundance
– GAE have MCF < 100
– GSE have MCF > 100


Comparison of Concentrations of Elements in the
Earth’s Crust with Concentrations needed to operate
a Commercial Mine
Element

Natural
Concentration in

Crust (% by Weight)

Concentration Required
to Operate a commercial
mine (% by Weight)

Enrichment
Factor

Aluminum

8

24-32

3-4

Iron

5.8

40

6-7

Copper

0.0058

0.46-0.58

80-100

Nickel

0.0072

1.08

150

Zinc

0.0082

2.46

300

Uranium

0.00016

0.19

1200

Lead

0.00010

0.2

2000

Gold

0.0000002

0.0008

4000

Mercury

0.000002

0.2

100,000


Process that concentrate elements
• Igneous Processes
– Hydrothermal
– Magmatic

• Sedimentary Processes
– Mechanical
– Chemical

• Metamorphism Processes
• Groundwater Processes


Hydrothermal Processes
• Precipitation of metallic
ions from hot, ion-rich
fluid
• Fluid could be
– Magmatic
– Groundwater
– Oceanic water

• Magmas heat up the water
• Water flows into fractures,
faults, joints, etc. where it
cools and precipitates
(deposits) the metals


Magmatic Processes
• Gravity Settling
– Dense, early-crystallizing
minerals sink to the bottom
of the magma chamber

• Filter Pressing
– Tectonic force compress a
magma chamber and force

the still-liquid portion into
fractures, creating large
crystals

• These processes have
produced large bodies of
iron, chromium, titanium,
and nickel


Sedimentary Processes
• Clastic
– Weathering of
rock also weathers
out elements of
interest
– Generally, the
elements are heavy
and are deposited
when a streams
competence is
low.
– Placer deposits,


Placer Gold