impacts of mining & distribution of fossil fuels RQ-+

p. 342-347, 425-432

crustal abundance

The average concentration of an element in Earth’s crust (oxygen, silicon, aluminum, iron)

ore

concentrated accumulation of minerals from which economically valuable materials can be extracted (presence > abundance)

metal

element with properties that allow it to conduct electricity and heat energy and perform other functions

why do nonmetallic resources like clay occur in concentrated deposits

• physical/chemical separation from other materials by water

how do we generally decide to mine and why

• mine most accessible and high concentration first

  • less concentration and availability → more energy, disturbance, air pollution, etc.

reserve

the public known quantity of a resource that can be economically recovered

what is an economically recoverable resource

• concentration high enough to be profitably mined; otherwise, recycle and substitute to fix depletion

4 surface mining techniques

• strip

• open-pit

• mountaintop

• placer

strip mining

removal of overlying vegetation and “strips” of soil and rock to expose underlying ore

overburden

• overlying soil, rock, vegetation

describe the process of strip mining 2

• mine parallel to surface → remove large volume of material, extract resources, return unwanted stuff

• erosion increase

mine tailings

Unwanted waste material from mining; chemical and rock residues left behind after the desired ore is removed

open pit mining

A mining technique that creates a large visible pit or hole in the ground

• for close to surface ores that extend vertically and horizontally, like copper

mountaintop removal

A mining technique in which the entire top of a mountain is removed with explosives, deposit tailings in low rivers

placer-mining

The process of looking for minerals, metals, and precious stones in river sediments

subsurface mining

Mining techniques when the desired resource is more than 100m below the surface of Earth

describe how subsurface mining works 3

• economically more expensive

• horizontal dig into side of mountain, then vertical shifts with elevators

• coal, diamond, gold

surface v. subsurface effects on air

dust from equipment v. minimal dust but significant emissions for equipment

surface v. subsurface effects on water

percolation via tailings v. acid mine drainage and percolation

surface v. subsurface effects on soil

most soil removed from site, unless reclamation occurs

surface v. subsurface effects on biodiversity

habitat destruction v. habitat fragmentation

surface v. subsurface effects on human

minimal but bad air and water quality nearby v. occupation hazards

why is mountaintop removal for coal mining safer

• companies make efforts to restore land and tailings r in water, debate over efficacy of reclamation

  • damage to streams and groundwater

describe placer mining negatives

contaminates a lot of water and adjacent areas with sediment and chemicals

• mercury is volatile and harmful

describe 2 ways acid mine drainage can occur in subsurface mining

• water passes through tailings, becomes acidic, contains metals leached

• pumps must always drain mines → lowers pH of nearby soil

4 mining effects on humans

• respiratory diseases

• methane between coal deposits is explosive and suffocating

• burial

• death

3 mining effects on humans

• demand for certain increases, but coal is decreasing

• efforts become more expensive economically and more tailings

• design systems that reuse and use mineral sources → protect environment and humans and lower costs

describe coal formation 2

• organic matter to make coal must not decompose → buried quickly without air exposure

  • tropical locations, wetlands deltas

describe oil formation 3

• deposits of phytoplankton found where porous sedimentary rocks r capped by nonporous rocks, so after millions of years, crude oil fills the porous spaces

• fossilized organic matter that becomes oil becomes less dense → up to highest point of porous, blocked by nonporous

• sometimes flows similarly to how water comes from artesian wall, but mostly, need drill well and refined via pipeline

describe natural gas formation 2

natural gas in crude oil separates naturally and floats to top

• oil workers burn off natural gas to capture it for fuel

• transportation, petrochemicals, plastics, lubricants

4 advantages of coal

energy dense and abundant

• provides heat for industrial processes and electricity generation

• low economic costs and tech demand (surface)

• easy transportation, easy use

3 disadvantages of coal

• combustion can release air pollutants and impurities of sulfur

• wash coal w organic compounds → leaks can contaminate water and cause residual ash

• lots of air pollution

3 advantages of oil

easy transportation and use

• slightly more energy dense and cleaner, good for mobile combustion engines

• produces less co2

3 disadvantages of oil

• contains trace metals that when burned, release greenhouse emissions and air pollution

• leaks from extraction, transportation, esp runoff and airplanes

• habitat interference, railing accidents

2 advantages of natural gas

• powers half of homes in the US

• fewer impurities, emits less particles during combustion and less co2

2 disadvantages of natural gas

releases less co2 when burned compared to other fossil fuels but

• methane leaks are highly effective greenhouse gases and contribute to climate change

fracking

oil and gas extraction that uses high-pressure fluids to force open existing cracks in rocks deep underground at a lower cost and more reliance on domestic industries

3 problems with fracking

• large amounts of water used, potential contamination

• chemicals are added to fracking → water well gas contamination

• linked to increased earthquake activity

5 steps of fracking

1. water acquisition

2. chemical mixing

3. well injection

4. flowback and wastewater

5. wastewater treatment

volatile organic compounds

An organic compound that evaporates at typical atmospheric temperatures

explain methane and fracking 2

• natural gas escapes during fracking and extraction as fugitive emissions

• methane’s high heat trapping ability makes leakage a serious climate concern

turbine

• A device that can be turned by water, steam, or wind to produce power such as electricity

describe the 5 steps for a coal power plant (or any) to work

1. coal is burned as the fuel source

2. energy of fuel transfers to water to become steam

3. energy of steam turns turbine

4. turbine turns generator that produces electricity

5. condenses back to water → cooling tower or discharged in water body

how to calculate energy efficiency

• coal to electricity x transport of electricity x light bulb efficiency = overall efficiency

energy quality

The ease with which an energy source can be used to do work

• high = concentrated and convenient, gasoline > wood