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MINING FOR CLOSURE
pass items such as the consequences of an event or
set of circumstances and the likelihood of particular
consequences being realised. Exposure pathways
– that is, the manner in which people, property, or
the biophysical, social, or cultural environment are
exposed to a source of potential harm or a situation
with a potential for harm are important is important
when considering the likelihood of harm.
Harm
Any damage to people, property, or the bio-
physical, social, or cultural environment.
Likelihood
A qualitative term covering both probability
and frequency. The use of this termcan avoid problems
caused by using frequency of defined events and prob-
ability of specific outcomes interchangeably. Exposure
pathways – that is, the manner in which people, prop-
erty, or the biophysical, social, or cultural environment
are exposed to a source of potential harm or a situation
with a potential for harm are important is important
when considering the likelihood of harm.
Hazard
A source of potential harm or a situation with
a potential for harm, thus a potential cause of harm.
Consequence(s)
The intermediate or final outcome(s)
of an event or situation. Consequence is a term that
contains elements of the social as well as biophysical
world thus system response factors such as stake-
holder reactions (e.g. outrage) to an event or situa-
tions are highly relevant here.
Sulphuric Acid (H2SO4)
Acid commonly used in industry
for the refining of metals, solvent extraction of uranium
and in the manufacture of chemicals and fertiliser.
Sulphur Dioxide (SO2)
A gas that contributes to climate
effects, acidification and other air quality problems.
Salinization
The accumulation of salts in soil that can
eventually make the soil unable to support plant growth.
Salinity
Amount of various salts dissolved in a given vol-
ume of water.
Surplus Rock or Waste Rock
Rock that must be extracted
to reach economic ore but does not contain significant
commercial mineralization.
Tailings
Residue from metallurgical processing, mainly
comprising finely ground rock. Tailings may contain
process chemical residues.
Tailings Retention System
Holding areas for process
wastes (tailings), also referred to as Tailings Storage Facili-
ties, Tailings Dams, and Process Waste Storage Facilities.
Topsoil
The upper layer of soil which supports plant
growth. Generally the layer containing nutrients, organic
matter and seeds.
Toxic Chemical
A chemical compound that is fatal to hu-
mans in low doses, or fatal to over 50% of test animals at
stated concentrations.
Toxicity
Measure of how harmful a substance is.
Units
k = kilo (thousands – 10
3
) as in kilogram (kg); G =
giga (billions – 10
9
) as in gigajoule (GJ); M = mega (mil-
lions – 10
6
) as in megajoule (MJ); T = tera (one million
million or 10
12
) as in terajoule (TJ); ppm = parts per mil-
lion; ppb = parts per billion.
VOCs
Volatile Organic Compounds. Organic compounds
(i.e. compounds of carbon) which evaporate at normal
ambient temperatures. In addition to hydrocarbons (i.e.
compounds of carbon and hydrogen) VOCs include oxy-
genated compounds and compounds containing sulphur
and halogens. Methane (CH
4
) is treated separately by
convention. VOCs contribute to the formation of ground
level ozone through reaction with NO
x
and sunlight.
VOCs can include toxics such as benzene and 1,3-buta-
diene.
Waste Rock
see
Surplus Rock
Water Table
Upper surface of the zone of saturation, in
which all available pores in the soil ands rock in the sub-sur-
face are filled with water. Also called the phreatic surface.