exam 3, energy & mineral resources Flashcards
What are mineral reserves?
Known & identified deposits where materials can be extracted for profit with existing technology & under present economic & legal conditions
What are mineral resources?
Reserves and other deposits that may become profitable in the future
What are mineral deposits?
A place in the crust where minerals are concentrated in greater abundance than in average places
What is kimberlite and why is it important for mineral resources?
- 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
What are placer deposits and to what types of rock do they pertain?
- Placer deposits are deposits created when placers are put in rivers to catch large deposits of valuable materials
- ‘49 gold rush in CA
How do mining operations impact water quality?
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
How do smelter emissions influence the environment?
Smelting releases particulates like asbestos or heavy metals, sulfur dioxide, and generally creates air pollution
What is surface mining and why is it used?
- 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
How do we obtain gold from mining and what chemicals are used?
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
Why is recycling important and which metals are the most recycled?
- 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
Why is coal more likely to be used more in the future?
Coal reliance will increase as natural gas prices go up & energy crisis continues
What are the types of coal, the basis for classification, and their properties?
- 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%)
How has energy consumption changed in the U.S. in recent decades?
Human energy consumption has been steadily increasing and is at an all-time high
Will oil be used more in the future?
Oil use will likely decrease in the future as demand will outweigh the amount of available oil
What are methane hydrates?
Large amounts of methane trapped in ice from bacterial decomposition of organics in water >300m (can’t be accessed)
What are hydrogen fuel cells?
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)
What are photovoltaic cells?
Way to use solar energy in which sunlight strikes the cell & photons knock off electrons (low efficiency 20-30%)
What effects does acid rain produce?
Produces bicarbonate buildup in rivers & has many negative environmental effects
What is geothermal energy and how does it work?
- 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
What is wind energy and how does it work?
- Taking advantage of winds to store energy through mills, pumps, and turbines
- Winds produced by differences in heat & densities
What is nuclear fission and what materials can be used as energy sources?
- Splitting of an atom by neutron bombardment
- Elements used: U-234, 235, 238 & Pu-239
How is nuclear waste stored and what are the risks?
- 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 (?)
What is hydrothermal energy and advantages and trade-offs?
- Water taken from groundwater to produce steam that power turbines before being condensed & reused
- Advantages - naturally occurring
- Disadvantages - slow groundwater recharge, uncommon
