exam 3, energy & mineral resources

Question 1

What are mineral reserves?

Answer 1

Known & identified deposits where materials can be extracted for profit with existing technology & under present economic & legal conditions

Question 2

What are mineral resources?

Answer 2

Reserves and other deposits that may become profitable in the future

Question 3

What are mineral deposits?

Answer 3

A place in the crust where minerals are concentrated in greater abundance than in average places

Question 4

What is kimberlite and why is it important for mineral resources?

Answer 4

• An igneous intrusive body that contains diamond crystals disseminated throughout
• Kimberlite plays a large role in the movement of diamonds up toward the crust, intrusive breccia carries it up

Question 5

What are placer deposits and to what types of rock do they pertain?

Answer 5

• Placer deposits are deposits created when placers are put in rivers to catch large deposits of valuable materials
• ‘49 gold rush in CA

Question 6

How do mining operations impact water quality?

Answer 6

Acid rain resulting from mining decreases water quality, cyanide contamination in bodies of water from gold dissolution, surface runoff contaminates rivers, and mountaintop mining explosions release toxins into waterways

Question 7

How do smelter emissions influence the environment?

Answer 7

Smelting releases particulates like asbestos or heavy metals, sulfur dioxide, and generally creates air pollution

Question 8

What is surface mining and why is it used?

Answer 8

• Process of removing large volumes of rock to recover materials of interest
• Used due to it being easier & safer than traditional mining, less expensive, and faster

Question 9

How do we obtain gold from mining and what chemicals are used?

Answer 9

Gold is mined through leeching, where gold ore is spread out and sprayed with a cyanide solution. The gold dissolves and the slurry is collected, leaving behind tailings contaminated with cyanide

Question 10

Why is recycling important and which metals are the most recycled?

Answer 10

• Recycling reduces waste, protects the planet, conserves natural resources, reduces emissions, and saves energy
• Steel, aluminum, copper, brass, and zinc are the 5 most recycled metals

Question 11

Why is coal more likely to be used more in the future?

Answer 11

Coal reliance will increase as natural gas prices go up & energy crisis continues

Question 12

What are the types of coal, the basis for classification, and their properties?

Answer 12

• Coal is classified based on type & sulfur content
  Type (% carbon) from low to high
• Lignite, sub bituminous, bituminous, anthracite
  Sulfur content
• Low-medium (0-3%), high (>3%)

Question 13

How has energy consumption changed in the U.S. in recent decades?

Answer 13

Human energy consumption has been steadily increasing and is at an all-time high

Question 14

Will oil be used more in the future?

Answer 14

Oil use will likely decrease in the future as demand will outweigh the amount of available oil

Question 15

What are methane hydrates?

Answer 15

Large amounts of methane trapped in ice from bacterial decomposition of organics in water >300m (can’t be accessed)

Question 16

What are hydrogen fuel cells?

Answer 16

A form of renewable energy where hydrogen gas reacts with oxygen in an electron bath to generate electricity, heat, and water (used in motor vehicles)

Question 17

What are photovoltaic cells?

Answer 17

Way to use solar energy in which sunlight strikes the cell & photons knock off electrons (low efficiency 20-30%)

Question 18

What effects does acid rain produce?

Answer 18

Produces bicarbonate buildup in rivers & has many negative environmental effects

Question 19

What is geothermal energy and how does it work?

Answer 19

• Heat from the core releasing E through the earth
• Harvested at divergent & convergent boundaries where higher heat flow is released at the surface
• Hydrothermal convection & groundwater system

Question 20

What is wind energy and how does it work?

Answer 20

• Taking advantage of winds to store energy through mills, pumps, and turbines
• Winds produced by differences in heat & densities

Question 21

What is nuclear fission and what materials can be used as energy sources?

Answer 21

• Splitting of an atom by neutron bombardment
• Elements used: U-234, 235, 238 & Pu-239

Question 22

How is nuclear waste stored and what are the risks?

Answer 22

• Low-level waste: small radioactive waste stored as solids or packed with liquid absorbing materials (isolation is 500 years)
• Transuranic waste: human-made, heavier than uranium (isolation is 250,000 years)
• High-level waste: a large amount of radioactive waste (isolation is over 250,000 years)
• Risks - not long-term viable, radiation emission, more waste than energy produced, national security (?)

Question 23

What is hydrothermal energy and advantages and trade-offs?

Answer 23

• Water taken from groundwater to produce steam that power turbines before being condensed & reused
• Advantages - naturally occurring
• Disadvantages - slow groundwater recharge, uncommon