3.2.2 Ore Extraction

Ore Extraction

3.2.2

Objectives

Learners can:

• describe the steps involved in extracting minerals from the Earth

• explain the potential negative impacts of ore extraction

• compare the benefits of ore extraction with its environmental potential

• mineral

• ore

• sustainable

Prerequisite Vocab

• extraction

• mine

• refining

New Vocab

Vocabulary

the action of taking something

Extraction

dig into the earth for resources

Mine

removing unwanted components from a substance

Refining

Match

Match the vocabulary word to its definition.

• ore

• mineral

• sustainable

valuable material found within rock

solid substance found in rocks

able to continue

• valuable material found within rock

• solid substance found in rocks

• able to continue

Common Mineral Usage

Iron is used for cast iron cookware and is one of the minerals used to make steel.

Iron

Gold is most commonly recognized as a valuable mineral used for jewelry. However, gold also has properties that make it useful in many electronics, such as phones and computers.

Gold

Lead is a very heavy metal. A common use of lead is for the aprons that are worn at dentist's offices during X-rays.

Lead

Geologists study geologic formations to locate possible ores and determine their concentration. If the mineral deposit is found to be profitable, that resource will be mined and the ore will be extracted. Mine means to dig into the earth for resources. Extraction is the action of taking something.

​

Mining

• ​effective for ores close to Earth's surface

• explosives are used to break up rock

• ex. open-pit mining, mountaintop removal, and strip mining

​​Surface Mining

• collect ores found deep below the Earth's surface

• miners use tunnels to access the ores

Underground Mining

​Mining Methods

While mining is a standard method for obtaining mineral resources, some ores are easily accessed at Earth's surface without significant digging. Placers are valuable minerals found in stream gravels. Much of the gold collected in California during the gold rush in the mid-1800s was discovered by prospectors panning for gold in local waterways. Panning uses a pan and water to separate sediment from placers, like gold.

​

The process of open-pit mining involves removing vegetation, soil, and rock, which can severely impact the land, air, and water of the local ecosystem.

Vegetation

Mountaintop removal involves clearing trees, blasting away large areas of rock, and digging to remove ore. These processes all have a big impact on the air and water quality.

Pollution

Like open-pit mining, strip mining involves clearing large areas of land and often leads to soil erosion and water pollution.

​Mining Concerns

Erosion

Mines that are not properly supported may cave in, trapping miners below ground. Extreme temperatures and poor air quality in underground mines pose health risks for miners. Fresh air and lights must be brought into the tunnels for the miners. Even with safety precautions, accidents are still a common occurrence.

Underground Mining

Categorize

Options (2)

Ecosystems are destroyed as land is cleared for mining.

Miners are put in danger of possible cave-ins.

Match the impact with the type of mining process that would most likely cause that impact.

surface mining

underground mining

​Refining Ore

Once the ore leaves a mine, it begins the process of becoming a usable mineral. Rocks are crushed so that the valuable minerals can be separated from the waste rock. Refining is removing unwanted components from a substance. There are a few methods that are used for refining ore:

• heap leaching;

• flotation; and

• smelting.

• involves adding chemicals like cyanide to remove ore

• usually done on a mass scale

Heap Leaching

• adding a compound that attaches to valuable mineral and floats

• used for gold and copper

Flotation

• uses heat to separate minerals from excess rock

• creates new materials like steel

​​Smelting

​Refining Ore Methods

The process of refining metal ores is very energy intensive. Some metals require temperatures greater than 900 degrees Celsius. The energy costs of refining is why it is important to recycle materials such as aluminum cans that have already been refined. For example, it is estimated that recycling just 40 aluminum cans can save an amount of energy equivalent to one gallon of gasoline.

Multiple Choice

Why does recycling aluminum cans help save energy?

• The metal in the cans is of higher quality than the metal in ore deposits.

• 
  The material from the cans has already been refined.

• 
  The metal in the cans is no longer able to be found.

• 
  The material from the cans is a better type of metal than what can be mined.