Sustainability Report - Antofagasta PLC

Air quality and dust management
Our approach
Air quality management, including particulate matter emissions, is a
priority for Antofagasta Minerals. All operations use dust monitoring
stations and have implemented a number of dust prevention methods
such as:
– Continuous watering of the roads leading to the mining pit to
prevent dust being stirred up.
– The use of sprinklers and dust suppressant (foam) applied to the
ore when it travels on conveyor belts from the crusher to the mill.
Protecting air quality is particularly important at Los Pelambres due
to its proximity to local communities. The site uses an online system
to monitor air quality and early warning alerts are issued when
climatic and meteorological conditions increase the possibility of
exceeding the company’s dust level. The system issues predictions
five days in advance, allowing time for the operation to adjust its
activities. When needed, different functions of the mine work
together to prevent rising dust levels, including the planning,
operation, environmental and community functions. A joint companycommunity
committee monitors compliance with these measures.
Performance in 2011
Air quality is measured as the average concentration of particulates in
the air measuring 10 micrometres or less (PM10). Air quality remained
within the legal limit at all sites in 2011. As well as a monitoring station
at its central camp facility, Los Pelambres has four monitoring stations
closer to the communities for which the company has set targets well
below the legal limit. In 2011 the company met these targets at the
monitoring stations located near the communities, with air quality results
between 22ug/m 3 and 36ug/m 3 ; but it failed to meet the target set for
its central camp facility. The company continues to invest in measures to
improve air quality such as: asphalting 14km of main roads and ramps
which is estimated to reduce traffic-related particulate emissions from
these roads by approximately 90%, and using foam which has reduced
particulate emissions from the site’s main crusher by 95%.
In El Tesoro, the increase in PM10 concentration was due to a temporary
increase of road traffic while its new sports facilities were constructed.
In 2011 the company began to monitor particulate matter below 2.5ug/
m 3 to prepare to meet new regulations under discussion that would
impose stricter dust emission standards. El Tesoro is planning a study in
2012 into the technical and economic feasibility of implementing an air
quality prediction model based on weather and operating parameters.
What is the issue?
Mining operations involve moving large
amounts of earth, which causes dust,
impacting local air quality. For mines with
operations in close proximity to communities,
such as Los Pelambres, dust control is a
critical issue.
Los Pelambres (camp facility)
Esperanza
El Tesoro
Michilla
2011
51.0
50.6
42.7
44.9
Antofagasta Minerals 59
Annual average concentration of PM 10* (micrograms (ug) per m 3 )
2010
41.8
68.2
32.8
47.8
* The figures in this table are an annual average for air quality at the monitoring stations
located at the main camp for each monitoring station.
2009
40.0
54.7
35.8
64.8
Overview
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