It is on this basis that new brine
minimisation or treatment technologies
are needed to address the brine in a
consumptive manner to extend the life
of current and new brine ponds, as well
as to eliminate the need for construction
of additional brine storage facilities. A
number of brine treatment or
minimisation technologies, such as
Eutectic Freeze Crystallisation,
HybridIce and Ion Exchange
technologies have been developed and
tested on a laboratory/pilot scale under
the auspices of Coaltech, a collaborative
coal research association in South Africa.
Brine treatment, as opposed to brine
minimisation technology, also has the
potential to produce revenue from the
pure salt byproducts generated; this
mitigates some of the operating costs.
Passive water treatment
Recently, there has been a significant
drive in the development of
cost-effective passive treatment systems
for the treatment of mine-impacted
water or minimisation/prevention of
acid mine damage (AMD) generation as
long-term sustainable solutions that can
be implemented. These technologies
mitigate the requirement for major
infrastructure or sophisticated levels of
operational maintenance. They minimise
waste generation and have reduced
energy requirements, thereby reducing
the carbon footprint of the process.
Passive treatment systems utilise the
chemical, biological and physical
removal processes that occur naturally
in the environment to modify the mine
water characteristics.
Avariety of passive treatment
systems, particularly constructed
wetlands, anoxic limestone drains,
vertical flow systems, such as successive
alkalinity producing systems and open
limestone channels, have been
developed that do not require
continuous chemical inputs and that
take advantage of naturally occurring
physical, chemical and biological
reactions to treat AMD in a controlled
environment.
Frequently, more than one type of
passive treatment or an integrated
system of passive treatment technologies
is employed to treat mine drainage in
order to achieve the required discharge
criteria. For example, ecologically
engineered ecosystems, such as
constructed wetlands, have been shown
to remediate contaminated mine water
but need to be properly planned,
designed, constructed and monitored.
These systems emulate the assimilative
properties of natural wetland in an
environment that can be controlled and
manipulated to ensure treatment
objectives are achieved. These systems
are, however, mostly designed to deal
with metal loads and pH rather than
sulfate removal; therefore, research is
required to address that particular
aspect of treatment.
Water stewards
Mining has received negative publicity
in recent years because of a legacy of
mismanagement of contaminated mine
water and AMD. As such, mining
companies need to take a leadership
role in water stewardship, preventing
impacts where possible, mitigating
impacts that cannot be prevented and
being innovative about solutions to
the issues that the industry has
created.
Peterson Filters Corporation
designs and manufactures high quality
industrial vacuum filtration equipment
for the mining and process industries,
including innovative custom accessories
that enhance their operation.
CorPorate oFFiCe
801-487-7761
PO Box 606
Salt Lake City, UT 84110
eastern Field oFFiCe
304-469-2978
PO Box 48
Oak Hill, WV 25901
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New Solutions to Old Problems
Continuous filters and processes for industrial liquid-solid separation
