Chapter 16 Mining and Mineral Resources

Describe the steps involved in smelting ore.

1. Fluxing- to remove impurities 2. Roasting- drives off unwanted carbons 3. Reducing- high temperature phase used to create the elemental metal

Name four federal laws that regulate mining activites in the U.S.

1. General Mining Law of 1872 2. Mining Leasing Act of 1920 3. Amending the General Mining Law 4. Subsurface Mining Control and Reclamation Act

Describe two ways in which state governments regulate mining.

1. Obtain permit before mining may begin 2. Bond forfeiture program must be submitted

Describe three methods of subsurface mining.

1. Room and Pillar- network of entries are cut into a seam, a horizontal layer of coal 2. Longwall- machine called a shearer moves back and forth along the face of a coal seam 3. Solution Mining- ore is dissolved by injecting it with hot water. compressed air is then pumped into the dissolved ore, and air bubbles lift it to the surface

List seven potential environmental impacts of mining.

1. air and noise pollution 2. water contamination 3. displacement of wildlife 4. erosion and sedimentation 5. soil degradation 6. subsidence 7. underground mine fires

List the steps in mineral exploration.

1. area selection 2. target definition 3. resource evaluation 4. reserve definition and extraction

Describe three processes by which minerals form.

1. can form under a variety of conditions during the evaporation of liquids, 2. the cooling of liquids 3. at high temperatures and pressures new crystals may grow in solid materials

List five properties that make metals economically and industrially important.

1. good conductors of electricity 2. generally strong 3. can be melted down in order to make other things 4. malleable: can be bent into required size and shape 5. magnetic: can be used to move things around

Describe two methods of surface mining.

1. open-pit mining: ores are mined downward layer by layer 2. Coal surface mining: top layers removed to reach coal near surface

Where could placer deposits form?

Along coastlines from heavy minerals that wash down to the ocean in streams

How do evaporites form?

Dissolved salts are washed into seas or inland lakes. When the water in these seas or lakes evaporates, salt deposits called evaproites are left behind.

How might exposing deep soil layers to the air prevent plants from growing?

Minerals that contain sulfur may be found in deeper soil layers. If these minerals are exposed to water and oxygen in the atmosphere, chemical reactions result in the release of acid. It's difficult for plants to grow in acideified soil.

List three characteristics of all minerals.

Naturally occurring Characteristic chemical composition Orderly internal structure

Why does surface mining cause animals to leave an area?

Removing soil from a surface mine site strips away all plant life. With their natural habitat removed, animal will leave area.

How are metals shaped?

Some metals can be pounded or pressed into various shapes or stretched very thinly without breaking.

Why are alloys important?

They often combine the most desirable properties of the metals use to make them

compounds

atoms of two or more elements chemically bonded together

smelting

crushes ore is melted at high temperatures in furnaces to separate impurities from molten metal

gangue minerals

extracted from the host rock

How do metallic minerals form?

form below ground when magma cools and hardens tend to form early in the cooling process and sink to lower part of magma body because they are dense

native elements

gold, silver, copper

hydro-thermal solutions

hot, subsurface waters that contain dissolved minerals

flux

materical that bonds with imputies and separates them from molten metal

open-pit mining

method that is often used to mine large quantites of near surface ore

placer deposits

minerals are concentrated by wind and water into surface deposits

ore minerals

minerals that are valuable and economical to extact

subsurface mining

mining method in which ore is extracted from beneath the ground surface

surface mining

mining method in which soil and rocks are removed to reach underlying coal or minerals

Longwall mining

more efficient way to remove coal from a subsurface seam

mineral

naturally occurring, usually inorganic solid 1. has a characteristic chemical composition 2. orderly internal structure 3. characteristic set of physical properties

veins

new minerals crystallize out of these solutions and then fill fractures to form ore deposits

gemstones

nonmetallic minerals prized for their beauty, rarity, or durability

How are planes used to find rich ore deposits?

planes carry instruments that identify patterns in gravity, magnetism, or radioactivity. planes fly over and collect data and image of an area.

reclamation

process of returning land to its original or better condition after mining is completed

overburden

rock that covered near-surface coal seams

aggregates

sand, gravel, and crushed rock

Describe what happens to the overburden once all the coal has been taken out of a surface coal mine.

the overburden is used to refill the pit. the soil that has been set aside is laid on top of the overburden.

subsidence

the sinking of regions of the ground with little or no horizontal movement

alloys

two or more metals are combined

evaporites

when the water in these seas or lakes evaporates, deposits of these salts are left behind