slide1 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Exploiting the lithosphere or earth’s crust PowerPoint Presentation
Download Presentation
Exploiting the lithosphere or earth’s crust

Loading in 2 Seconds...

play fullscreen
1 / 15

Exploiting the lithosphere or earth’s crust - PowerPoint PPT Presentation


  • 450 Views
  • Uploaded on

Exploiting the lithosphere or earth’s crust. Early man. Stone age: 1.6 million to 2000 years ago people in SA made stone implements – choppers, hand axes & scrapers. Iron Age: 2000 – 500 years ago people in SA were mainly farmers – cattle, sheep, goats & planting seeds.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Exploiting the lithosphere or earth’s crust' - joan-gross


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

Exploiting the lithosphere or earth’s crust

Early man

Stone age: 1.6 million to 2000 years ago people in SA made stone implements – choppers, hand axes & scrapers.

Iron Age: 2000 – 500 years ago people in SA were mainly farmers – cattle, sheep, goats & planting seeds.

Gold was originally found in riverbeds in Limpopo 1000 years ago & was traded with ivory to China, India & Egypt.

Discovery of gold in Limpopo

slide2

Earth’s crust as source of materials

Earth's crust

Elements are usually found in the form of gases in the atmoshpere and in the form of ores of the various substances, in the Earth’s crust.

Ores are mined and then the various elements extracted.

slide3

Common elements in earth’s crust.

Seldom are these elements in pure state.

Most often they are in the forms of the various ores compounds & minerals i.e. metal oxides, nitrates, carbonates etc.

These need to be extracted by chemical means.

Elements from the ground

slide4

Mineral distribution in Southern Africa

Gold fom our mine dumps

Indication of mineral distribution in Southern Africa.

Mining is a very important source of income in SA.

However, people must not be exploited in this industry.

slide5

Mineral distribution in SA

Besides these elements, diamonds, platinum & uranium are also mined in these areas.

Note how most of the minerals are found in the North & North Eastern parts of SA.

SA gold production has decreased from 68% of world’s gold in 1970 to only 8% in 2009.

slide6

Mining

Mining iron-ore

Mining gold-ore

Coal mining

In general, rocks containing the minerals & ores must be extracted from the mines, crushed and then often chemically extracted from the crushed rocks.

You can elect to study any one of the following major SA mining industries:

Gold, iron, phosphate, coal, diamond, copper, platinum, zinc, chrome, asbestos & manganese.

Gold mining in SA

slide7

Questions that need to be asked about mining in SA.

  • What is available?
  • Where is it found?
  • How is it found?
  • How are the precious materials recovered & processed?

Platinum Diamonds Gold Coal

slide8

Gold mining

The gold industry has been one of the most important industries in SA since alluvial gold was first found in riverbeds and streams at Langlaagte farm in 1886.

After that, deep, underground mines were started and developed in Gauteng & the Free State.

slide9

Gold bars, nuggets & coins

Gold bars or bullion

Gold nuggets

Quartz, granite & gold in rocks

Extracting and producing gold

Gold jewellery

Gold coins – printed by the SA Mint – often to commemorate important occasions.

Making a gold bar

slide10

Processing gold ore.

A very important process in SA mining.

slide11

Old method of gold recovery from ore.

Redox reaction:

4Au + 8Na(CN)2 + 2H2O + O2→ 4NaAu(CN)2 + 4NaOH

Recovery by precipitation method:

Zn + 2NaAu(CN)2 → 2Au + Zn (CN)2 + 2NaCN

These days, mines use activated carbon smelting.

slide12

PGMs (Platinum group metals)

PGMs in SA

SA produces 94% of the world’s Pt – mainly in the Rustenburg area. Pt is used for jewellery, motor vehicle exhausts & for technology.

slide13

Pollution

Air pollution - chemical processing

Dust from mine dumps

Open-pit mining

Acid water pollution

slide14

Pollution

Air pollution from burning coal for the generation of electrical power in SA.

The burning of fossil fuels – coal, oil, petrol & gas, releases incredible amounts of greenhouse gases into the atmosphere & many scientists believe this will lead to global warming.

Pollution from mining

slide15

Research pollution in SA

Pollution is already a problem in South Africa and it is set to become an even bigger problem – unless we seriously do something about it – NOW!

Research and write an essay on current pollution and possible future pollution and its effect in our country.