Extracting Ore (AQA A Level Geography)
Revision Note
Written by: Robin Martin-Jenkins
Reviewed by: Bridgette Barrett
Impacts of Ore Extraction
As with any resource that is extracted from the ground, careful consideration needs to be given to how it impacts the environment
Mineral ores are often extracted using open-pit mines
These have a large impact on habitats and groundwater
Processes used to refine the ore can introduce toxic chemicals into the area
Copper extraction has a large impact due to the fact that it is mostly extracted and processed in one place
CASE STUDY - Copper mining in Chile
Chile is the top copper producer globally with 29% of market share
Production is mainly located in the northern part of of the county
Chile’s largest copper producing companies are the state-owned Codelco and British multinational Antofagasta
Due to exports, Chile is now one of two high-income Latin American economies
However, copper mining impacts the environment, through sheer size, water and air pollution
Vast areas are deforested, with open cast mining extending to several kms in width and depths can exceed thousands of kms
The sloping nature of the open mines, along with exposed topsoil increases mass movement
Mining dust increases respiratory disease and high levels of arsenic have been found in the blood of workers
Environmental regulations surrounding operations of Codelco are poor, resulting in heavily polluted mining environments
Extraction of copper from its ore involves crushing, dissolving, filtering and smelting
These processes produce large quantities of of contaminated waste water and frequently washes into local watercourses affecting drinking water and ecosystems
Large amounts of energy is needed and many of the mines have their own power stations running on coal, increasing greenhouse gas emissions
Processing requires quantities of water, but most of the mines are in high altitude deserts and water has to be pumped to the site
Seawater is desalinated at an environmental and economical cost and then piped to the mine, increasing costs
Acid rain is produced as a result of smelting, which releases sulphur dioxide into the atmosphere
Over-extraction of water from underground aquifers, lowering the water table and denying local rural communities source of water from wells
Contaminated water discharged into local drainage systems: large volumes of water, required for processing copper ore are contaminated with rock waste and toxic minerals
Coastal pollution: pollution of coastal waters from blown dust, transfer spills and oil discharge from the ore carriers loading up for export
Air contamination from dust: dust from waste piles lead to breathing issues in the dry air of the Andes
Emissions from transport of ore to docks: can create significant amounts of dust, noise, congestion and vehicle emissions
Due to the intensity of pollution around the Chuquicamata mine, the settlement housing workers and families of the mine was closed in 2003 and residents transferred to the town of Calama,16 km away
Sustainability of Ore
Sustainability of copper ore
Copper is easily recyclable
More than one third of copper used each year is from recycled sources
The most productive reserves have already been exploited, so new mines tend to use lower-grade ores
These produce a greater proportion of waste that has be to dealt with in some way
Large open cast mines reach the end of their economic viability
Can remain as scars on the landscape
Very slow colonisation by vegetation
Issues and Solutions of Copper Ore Security
Sustainability issue | Possible solution |
|---|---|
Use of land – the land area used is larger than the mine itself. This can result in considerable loss of habitat | Restoration and rehabilitation plans, involving replanting and reintegration of plant and animal species |
Pollution: visual, noise and air | Use of baffle mounds to absorb some sound and also to act as visual screens. Dust can be reduced by using water spraying |
Water turbidity – fine deposits in water courses can block sunlight for aquatic plants and choke some of them | The use of holding ponds or lagoons to enable the suspended load to settle |
Leaching of toxic materials – some toxic minerals mobilised by mining can kill both flora and fauna | The use of limestone filters to neutralise acid waters from mines. This can also immobilise some toxic metals |
Disposal of spoil and wastes. Spoil heaps can have the potential for mass movement to create flows and slides | Good quality drainage systems that are constantly monitored to reduce the water content of the spoil heaps |
Sustainable trade patterns – there are concerns that some countries concentrate on meeting demand from other countries for minerals at the expense of the environment | Proposal for a Green Trade Alliance (GTA) between producers and importers. This would enforce protectionist trade to encourage non GTA countries to comply with environmental standards |
Recycling is a key sustainability theme – around 34% of copper is recycled in the world today. Other metals have varying levels of recycling, e.g. aluminium (50%), tin (90%). However, this is not always easy to achieve (transport and labour costs are high) and the use of mixed minerals in products makes recycling difficult | Government legislation can enforce recycling (e.g. the EU has a number of directives). Financial penalties also exist (e.g. landfill taxes in the UK). Promotional campaigns can encourage more recycling, reusing and redesigning |
Examiner Tips and Tricks
When thinking about sustainability of mineral ores, consider social, political, environmental and economic issues. There is no point being environmentally sustainable if the costs are prohibitive, for example. Recycling an ore uses less energy than extracting and processing and it also means that money doesn't need to be spent on finding and extracting new sources, so it is a sustainable strategy on more than one level.
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