3) energy & mineral resources Flashcards
mineral reserve
known & identified deposits where materials can be extracted for profit with existing technology & under present economic & legal conditions
mineral resource
reserves and other deposits that may become profitable in the future
mineral deposit
a place in the crust where minerals are concentrated in greater abundance than in average places
kimberlite: definition & importance
Kimberlite - 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
placer deposits: definition & use
Placer deposits are deposits created when placers are put in rivers to catch large deposits of valuable materials
‘49 gold rush in CA - gold trapped in bedrock in rivers & streams
mining operations & 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
surface mining: definition & why
Surface mining is the process of removing large volumes of rock to recover materials of interest
It’s used due to it being easier & safer than traditional mining, less expensive, and faster
smelter emissions & environment
Smelting releases particulates like asbestos or heavy metals, sulfur dioxide, and generally creates air pollution
weathering & ores
oxygen can oxidize ores and alter their makeup or value
water can convert minerals to clay or dissolve minerals
Intensive weathering (bauxite)
Rising water table carries elements closer to surface
Leaves behind a ring of deposited iron & aluminum
gold mining process
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
mineral concentration in the environment
gold —- 0.0000004
mercury – 0.00001
lead ——— 0.0015
copper ——- 0.005
iron —————– 5
aluminum ——— 8
recycling: importance & common metals
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
(likely) future of coal
Coal reliance will increase as natural gas prices go up & energy crisis continues
coal classification
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%)
US E consumption in recent decades
Human energy consumption has been steadily increasing and is at an all-time high
Natural gas, oil, and coal are the top 3
Coal has had the most consistent increase
Oil is the most used
(likely) future of oil
Oil use will likely decrease in the future as demand will outweigh the amount of available oil
methane hydrate
large amounts of methane trapped in ice from bacterial decomposition of organics in water >300m (can’t be accessed)
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)
photovoltaic cell
way to use solar energy in which sunlight strikes the cell & photons knock off electrons (low efficiency 20-30%)
acid rain: causes & effects
Acid rain is caused by the interaction of SO2 & NOX with water that then turns into precipitation
It produces bicarbonate buildup in rivers & has many negative environmental effects and previous response effects
geothermal E
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)
wind E
taking advantage of winds to store energy through mills, pumps, and turbines
(Winds produced by differences in heat & densities)
nuclear E: fission & E sources
Nuclear fission - splitting of an atom by neutron bombardment
Elements used: U-234, 235, 238 & Pu-239
nuclear waste storage & 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 (?)
hydrothermal E: definition & pros/cons
Hydrothermal energy - water taken from groundwater to produce steam that power turbines before being condensed & reused
Advantages - naturally occurring
Disadvantages - slow groundwater recharge, uncommon
