Minerals, Wealth and Progress - Mining and the Environment: From Ore to Metal - page 8

FIGURE 1.2
The Mineral Cycle

Return to the
environment

The Earth is a closed material system,
which means that there are fi rm limits
on natural resource use.
Source:
MMSD 2002

Society's need for
minerals and metals

Disposal

Consumption/
use

Re-use

Incorporation
into products

Recycling

Exploration

Re-manufacture

Semi-fabrication
and fabrication

Mine
development

Extractive
metallurgy
and refining

Mine closure
and rehabilitation

Extraction
mining

Milling, washing,
grading,
concentrating

Wastes

Emissions

Some industrial
minerals sold directly
(such as salt and sand)

emissions. The Earth is a closed material system, which means that there are firm limits on
natural resource use. Some limits are clearly related to availability, which is closely related to
price. For some non-renewable resources including many metals and construction minerals,
security of supply does not currently give cause for concern; for others, such as oil and land,
availability is already a problem that is almost certain to grow. There are also limits related
to the ability of the environment to act as a 'sink', that is, to absorb discharges and emis-
sions of pollutants and wastes without serious damage, illustrated most recently by Al Gore's
(2006) topic on anthropogenic carbon dioxide emission and its relation to global warming.
Minerals generally have a long life-cycle, and only a small fraction of the minerals put
into use each year ends up in the waste stream; those that do include metals in short-life
products such as packaging material (e.g. aluminium cans). Most minerals in final prod-
ucts are stocked within the economy for at least several years, since they are used mainly in
durable consumer goods, e.g. automobiles, and infrastructure, including the capital stock
of industries (e.g. machinery, equipment, and industrial buildings). Gold is an extreme
case in that most of the gold that has been extracted throughout history, remains in use or
in storage. Similarly, valuable gemstones are seldom discarded.

There are limits related to the
ability of the environment to
act as a 'sink', that is, to absorb
discharges and emissions of
pollutants and wastes without
serious damage.

Recycling - Extending the Life-Cycle of Minerals

Recycling is the most common way of extending the life-cycle of minerals. It saves primary
raw material inputs, and reduces the need for new mines with associated environmental
impacts. Also, in many cases, processing secondary raw minerals is less environmentally