APES Ch 16 Study Guide Minerals: A Nonrenewable Resource
Vocabulary
Minerals- naturally occurring elements or compounds that are found in Earth’s crust (ex: quartz –
SiO2)
Rocks- mixtures of minerals (ex: granite)
Ore- rock containing a high enough concentration of a particular mineral to make it profitable to
mine and extract the mineral
High-grade ore- contains high concentrations of particular minerals and is therefore more profitable
to mine
Smelting- process of separating valuable minerals from impurities in ore by heating it at high
temperatures
Acid mine drainage- pollution resulting from sulfuric acid and dissolved toxins such as lead,
arsenic, and cadmium flowing from the mine into nearby lakes and streams
Tailings- piles of waste rock left over after ore is processes
Mineral Reserves- mineral deposits that have been identified and are currently profitable to mine
Mineral Resources- undiscovered mineral deposits and deposits that are low-grad ore that are
currently unprofitable to mine
1.
What was the purpose of the General Mining Law of 1872? To encourage settling of the
western frontier
What happens to profits from hardrock mining on federal land? The person who has
purchased the mineral claim keeps 100% of the profits
2.
Describe the characteristics of metals and give three examples.
Good conductors of heat and electricity, malleable, lustrous
Iron, copper, nickel, lead, chromium…..
3.
Describe the characteristics of nonmetals and give three examples.
Poor conductors of electricity, nonmalleable, not lustrous
Sulfur, phosphorus, fluorine, sand, stone, salt…
4.
Describe one of the processes by which mineral deposits form.
Magmatic Concentration- heavier elements (Fe, Mg, Ni) in magma tend to settle to toward the lower
mantle and lighter elements (Si, O) tend to be a high percentage of the magma higher in the mantle
Hydrothermal Process- heated water from deep in the Earth’s crust seeps through cracks and
fissures in the crust. As the water moves through the crust, minerals dissolve in the water. If the
water contains high concentrations of F or Cl, metals will dissolve more readily so the concentration
of dissolved metals will increase. If the hot water contains sulfides, the metals will react with sulfides
but metal sulfides are not soluble in water so they settle out of solution forming metal sulfide deposits
(iron sulfide, copper sulfide….).
Sedimentation- chemical and physical weathering breaks rocks into smaller fragments. Water
carries the sediments away (erosion). Finer particles dissolve more readily than coarse material
(think about fine sugar vs sugar cubes) so some of the minerals will dissolve in the water and
eventually settle out of solution. Much of the sedimentation occurs where rivers empty into cold
ocean water…..solids are more soluble in warm water than in cold water.
Evaporation- enclosed inland seas or lakes with no outlets may eventually dry up. The dissolved
minerals are deposited on the lake or sea bed….. often the source of table salt, borax (minerals
containing sodium and boron), potassium salts and gypsum (calcium sulfate).
5.
Describe one method of locating mineral deposits.
Aerial or satellite photos may reveal geologic formations associated with mineral
deposits….equipment in airplanes and satellites may measure Earth’s magnetic field and gravity
Once possible sites are located, the site may drill or tunnel to collect samples for analysis
Detailed 3-D maps of the ocean floor produced with depth measuring devices help reveal manganese
nodules and other ocean floor deposits
6.
What is overburden?
Rock and soil that lies over the rock containing ore
7.
What is a spoil bank?
Hill of loose rock created when overburden from a new trench is put into an already excavated
trench during strip mining
8.
Why is land that has been surface mined particularly vulnerable to erosion?
The vegetation has been removed
9.
Explain how mining can affect local water supplies both in terms of quantity and quality.
Open pit mining uses huge quantities of water. As mines go deeper and deeper, groundwater must be
pumped out to keep the mine form flooding. This causes the local water table to drop
Rocks rich in minerals often contain high concentration of toxins such as lead, arsenic, and
cadmium. Metals in ores are often metal sulfides and other sulfur compounds. When the rock is
exposed to the elements, some of the sulfur dissolves reacting to form sulfuric acid. This acid mine
drainage is not only acidic and directly harmful to life, it also increases the solubility of lead, arsenic
and other toxins in water flowing out of mined areas.
10.
What are some of the factors that should be considered when completing a cost-benefit
analysis for a proposed mine?
-value of minerals being mined
-dollar value of keeping the land intact for wildlife, ranchers, farmers, indigenous people, watershed
protection and recreation
-Should consider the benefits of the mine will only last the number of years the mine is in operation
while the benefits of leaving the land intact are perpetual and will grow in value as open land
becomes an increasingly scarce commodity
11.
List three toxic substances often found in tailings.
Heavy metals including lead, cadmium, arsenic and zinc
NOTE statistic: for every 2000 pounds of rock mined from low-grade ore in Nevada, as little as
0.7 g or 0.025 ounces of gold is refined.
12.
Why are smelters a major source of sulfur oxides unless adequate pollution control
technology is used?
Most metal ores contain metal sulfides
13.
Why is reclaiming derelict lands a challenging problem?
Often the topsoil is completely gone or contains toxic levels of metals
14.
What is the purpose of the Surface Mining Control and Reclamation Act of 1977?
Requires reclamation of land surface mined for coal
What is a very serious limitation of this act?
Does not cover land mined for minerals other than coal
15.
Describe how phytoremediation can help reclaim derelict land.
Select plants may be able to absorb and store toxic substances such as nickel
16.
Why is it challenging to predict future supplies of mineral resources?
It depends on the market (demand), the development of new technology which may make it profitable
to mine ore that was not previously economically feasible to mine, political stability of countries that
are major suppliers of a mineral, discoveries of new ore deposits, changes in technology that may
result in substitution of materials (ex: substituting plastics for metals)
17.
What is the purpose of the Environmental Protection Protocol to the Antarctic Treaty?
International agreement to ban mineral exploration and development in the Antarctic for a minimum
of 50 years (until 2040)….designated “Antarctica and its marine ecosystem as a natural reserve
dedicated to peace and society”
18.
Why is mining of the ocean floor controversial?
Dredging manganese nodules and other ore from the ocean floor would be harmful to sea life;
(currently this is not profitable using current technology but changes in technology or the value of
the ore could change this)
19.
What is biomining?
Using microorganisms to extract minerals from low-grade ores… currently used in mining low-grade
copper ore. Thiobacillus ferroxidans promotes a chemical reaction when mixed with sulfuric acid
that increases the solubility of copper….copper is separated more efficiently from the ore
20.
What is dematerialization?
Decreasing the weight of products by making them smaller or with thinner layers, lighter materials..
21.
Why are minerals classified as nonrenewable resources?
They are not replaced during a human lifetime by nature