Transcript Mineral Resources - EHS

The Costs & Benefits of
MINERAL RESOURCES
Mineral Resources and Reserves
Resource = 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
– Geology, technology, economy, and legality
Problems with Resources
• LIMITED AVAILABILITY!
– Nonrenewable resources
• Finite amount but growing demand
– Supply shortage due to global industrialization
• More Developed Countries consume a disproportionate
share of existing resources
– Erratic distribution and uneven consumption
• Highly developed countries use most of the resources;
supply varies
Responses to Limited Availability
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Find more sources
Find a substitute
Recycle
Use less and
make more
efficient use of
what is available
• Do without
Major Import Sources
• Friends
– Canada: Metals
– United Kingdom: platinum, rare earths
• Other
– China: graphite, tin, tungsten, rare earths
– South Africa : platinum, fluorspar, diamonds
– Chile: arsenic, iodine
Mineral Resources
• Backbone of modern societies
• Availability = a measure of a society’s wealth
• 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, mined minerals
– Recycled, reused, and repurposed
– Imports vs. exports
• Indirect value
– Processing and manufacturing of resources
and goods
• Value added
– Agriculture and Sales of goods
Common Use of Mineral Products
NON-METALLIC
METALLIC
HYDROCARBON
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, e.g., for gold is about 5000
• Variable with types of metals
• Variable over time
Genesis of Mineral Resources
Plate Tectonics and Mineral Resources
• Plate boundaries
– related to the origins of many ore deposits
• Plate tectonic processes
– high temperature & pressure
– partial melting
– promote release and enrichment of metals
along plate boundaries
• Metal ores are common at plate
boundaries
– Iron, Copper, Zinc, Lead, Gold, Silver
Example: Mid-ocean ridge
• Circulation of sea
water
– Salty and metallic
• Heated, then
cooled
– Precipitates ores
• Can we mine MOR deposits?
• What happens at subduction zones?
What explains Urals, S. Africa?
Intrusive Igneous Deposits (Silverton)
• Major source of metals and mineral wealth
Mineral Resources and
Environmental Impact
• Environmental impacts …
– From mineral exploration and testing
– From mineral mining
– From mineral resources refining
– From mining waste disposal
Environment Impact of Mineral
Development
• The impact depends upon many factors:
– Mining procedures
– Hydrologic conditions
– Climate factors
– Types of rocks and soils
– Topography
• Role of Culture
– NIMBY (not in my back yard)
– Need/desire for jobs
Impact of Mineral Exploration and Testing
• Mineral exploration and testing
– Surface mapping, geochemical, geophysical,
and remote-sensing data collection
– Test drilling
• Impact
– Generally minimal impact
– More planning and care needed for sensitive
areas (arid, wetlands, and permafrost areas)
Impact of Mineral Extraction
and Processing
General impact
• Direct impact on land, water, air, and
biological environment
• Indirect impact on the environment:
Topographic effect, transportation of
materials, etc.
• Impact on social environment: Increased
demands for housing and services
Impact of Mineral Extraction
& Processing
• Land disturbances
• Waste from mines:
– Area required for waste
disposal = 40% all mine area
– Mining waste makes up 40%
of all solid wastes
• Special mining, cyanide
leaching from gold mining
• Mining acid drainage,
during mining and postmining
Impact of Mineral Extraction
and Processing
• Water pollution
– Trace elements leach
into water
• Cd, Co, Cu, Pb, Mo, Zn
– Flooding of abandoned
mines
• oxidation of sulfide ores
= sulfuric acid
– Acid mine drainage from
tailings
Minimizing the Impact of Mining
• Transfer knowledge and technology from
developed countries  developing countries
• Strengthen Environmental Regulations
– Forbid bad mining practices
– Clean Air Act
– on- and offsite treatment of wastes
• Land reclamation
– ~50% of land used in mining industry reclaimed
• Use of new biotechnology in mining
– Bio-oxidation, bioleaching, bio-absorption, genetic
engineering
Minimizing the Impact of Mining
Recycling Mineral Resources
• Why recycle? Consider the impact of the
wastes
– Toxic to humans
– Dangerous to natural ecosystems
– Degradation of air, water, and soil
– Use of land for disposal
– Aesthetically undesirable
Recycling Mineral Resources
• Almost all waste contains recyclable
materials
• Recycling saves money
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land and ecosystems
Water and air
Energy
Raw minerals from more mining
• Saves energy and money when recycling
instead of refining raw ore materials
• Recycling has been proven to be profitable
and workable
Recycling Mineral Resources
• Amount of Metal used in the U.S.
• 134 million metric tons (Mt)
• $32 billion
• Iron and Steel 88.6% weight and 27.7% value
• Aluminum 38.0% value
• Recycling scrap requires 1/3 the energy
compared to refining virgin ore
• Recycling contributed 76.9 Mt of metal
• $14.2 billion or 58% of metal’s weight
• Most recycled: Pb 65%, Fe 60%, Cu 48%
• Least recycled: Zn 26% and Sb 27%
Minerals and Sustainability
• Sustainability = long-term strategy for consuming the
resources
• Find an alternative material for metal, ex: glass
fiber cable for copper wires
• Use raw materials more efficiently
• More Research & Development
• Innovative substitutes
• Ways to maintain the Resource : Consumption
• A solution to the depletion of nonrenewable resources
Questions…
1. Considering the fact that mineral resources are
nonrenewable:
a) Do you believe that technology will eventually
help to meet the growing demand for mineral
resources?
b) If yes, explain.
2. Biotechnology shows the potential for cleaner
minerals extraction and waste disposal.
a) Could biotechnology bring about any
environmental problems?
3. What types of environmental impact would occur if
we increasingly extract more mineral resources from
the seafloor?