Mining of Minerals and Methods of Extracting of Metals 

6. Environmental Impact and Economics of Metal Extraction

Scroll down for revision notes on extraction procedures and theory

Useful for school/college assignments/projects on ways of extracting metals from their ores

1. Introduction to Metal Extraction * 2. Extraction of Iron and Steel Making

3. Extraction of Aluminium and Sodium * 4. Extraction and Purification of Copper

5. Extraction of Zinc, Titanium and Chromium * 6. Economic & environmental Issues - metal extraction

GCSE Multiple choice Quizzes on metal extraction: Foundation (easier) or Higher (harder) and word-fill

Revision Notes KS4 Science IGCSE/O level/GCSE Chemistry Information Study Notes for revising for AQA GCSE Science, Edexcel 360Science/IGCSE Chemistry & OCR 21stC Science, OCR Gateway Science  (revise courses equal to US grades 9-10)

There are several limestone quarries in the limestone country of the Yorkshire Dales. The quarrying does present a scar on the landscape BUT limestone is a very useful mineral and used as a building stone, in iron extraction in the blast furnace and for making lime for agricuture and kitchen garden. There often has to be a compramise somewhere along the line since many of a countries important mineral resources and rocks are in some of the most beautiful scenic parts of the country!

Other associated KS4 Science GCSE/IGCSE chemistry web pages on this site

• Reactivity of metals : all the reactions of metals with oxygen (air), water and acids, displacement reactions.

• Oxidation-reduction explained (redox theory)

.

• Group 1 Alkali Metals: chemical and physical properties

• Extra Industrial chemistry : properties and uses of metals including titanium and aluminium

• Transition metals : properties and uses

• Extra Electrochemistry-electrolysis : electrolysis theory, experiment designs and links to all electrolysis section on this site.

6. Environmental Impact and Economics of Metal Extraction

mineral extraction economic, sociological, environmental issues etc.

• One of the problems of metal or mineral extraction is balancing ecological, environmental, economic, social advantage factors.

• It doesn't matter whether you are mining and processing iron ore or limestone, many of the advantages and disadvantages are common to these operations.

• Examples of advantages of a country exploiting it's own mineral resources:

  • Valuable revenue if the mineral or its products are exported.

  • Jobs for people, especially new sources of employment in poor countries or areas of high unemployment in developed countries.

  • Wages earned go into the local economy.

  • Increase in local facilities promoted e.g. transport systems, like roads, recreational and health social facilities.

• Examples of disadvantages of a country exploiting it's own mineral resources and reduction of its social and environmental impact:

  • Dust from mining-quarrying or processing can be reduced by air filter and precipitation systems and even hosing water on dusty areas or spoil heaps or carried away to somewhere else via tall chimneys.

  • Noise from process operation or transport of raw materials and products (lorries/trucks/wagons).

    • Difficult to deal with, sound-proofing often not practical, but operations can be reduced for unsociable hours e.g. evening movement.

  • Pollution can be reduced by cleaning the 'waste' or 'used' air, water and waste gases etc. of toxic or acidic materials e.g.

    • Toxic carbon monoxide from the blast furnace extraction of iron, it can be burnt as a fuel, but it must not be released into the air unless converted to biologically harmless carbon dioxide.

    • Sulphur dioxide gas from copper extraction of its sulphide ore is an irritating poisonous gas which can also cause acid rain, but it can be converted to the useful, therefore saleable, industrial chemical concentrated sulphuric acid, so you can remove a harmful pollutant and recover back some of the metal extraction costs, good green economics?

    • Acidic gases like sulphur dioxide can be removed by bubbling through an alkali solution such as calcium hydroxide solution ('limewater') where it is neutralised and oxidised to harmless calcium sulphate. Cleaning a gas in this way is called 'gas scrubbing'.

  • Mining operations will disfigure the landscape BUT it can be re-claimed and 'landscaped' in an attempt to restore the original flora and fauna. However in the case of a limestone quarry, I'm afraid there is no way round the fact that huge chunks of beautiful hills get carted away if we want to use it as useful mineral.

• The cost of extracting and purifying metals is quite varied for several reasons.

  • If the ore is plentiful it is cheaper e.g. iron ore, but silver ores and gold are much rarer and on that basis alone they would be a more valuable commodity.

  • Reduction of ores using coke (e.g. iron), made from cheap coal, is cheaper than the electricity bill for extracting aluminium from its molten oxide by electrolysis, but different metals have different properties best suited for particular and different uses.

  • Generally speaking, more reactive metals (like Al) are more costly to extract than less reactive metals (like Fe) because of the different energy demands and ease of extraction, which may sometimes be due to more costly technology.

The haze of pollution from Redcar Steelworks on the North Sea coast of North East England. It is an important source of employment and income into towns like Redcar. This steel works is likely to close in 2010 and in an area already hard hit by the decline of traditional heavy industry over the last fourty years.

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