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MASSIVE ACID MINE DRAINAGE
PROJECT STIMULUS FOR LOCAL BENEFICIATION
Mining Weekly [ 31st July 2009]
By: Brindaveni Naidoo
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Help is at hand to assist South Africa’s
rising mine water dilemma. It has come in the form of Western
Utilities Corporation (WUC), a wholly owned subsidiary of
Aim-listed Watermark Global, which aims to turn the acid mine
drainage (AMD) scourge into a beneficiation opportunity.
The WUC project, aimed at the reclamation of excess mine water
from underground workings in the Western, Central Rand and
Eastern basins of the Witwatersrand, has the potential to create
thousands of new jobs and become a beacon of hope for the
unemployed.
Such a future would entail the treatment of decanted water to an
acceptable level for industrial and potable purposes. The
industrial water would be cheaper than potable water and would
be reticulated for beneficiation to industry. WUC MD Jaco
Schoeman tells Mining Weekly that the aim is to produce
industrial water to be consumed by the mines within the three
basins. “Excess water will be converted to potable quality and
sold to bulk producers,” he adds.
Political scientist Dr Anthony Turton says that the issue of
mine water should not be considered a mining challenge, but
rather a resource that can be used as the basis of a new
value-added beneficiation economy.
Turton, also the director of Touch-Stone Resources, a company
committed to uplifting South Africans’ survival and health, says
that this can be achieved by, firstly, replacing the tens of
thousands of jobs being lost in mining, because the AMD issue is
being framed as a mine closure problem.
Secondly, he explains the economics of water as an input to a
beneficiation industry: “We know that water is going to become
more expensive and thus deter future economic growth. We,
therefore, need to think of two water streams. One stream is
potable water sold at a high price and escalating over time. The
second stream is industrial-grade water, which is cheaper than
potable water and escalates at a lower rate over time. This
massive volume of lower-grade industrial process water can be
combined with a strategic vision of a beneficiation economy, in
which human skills development is a key component.”
However, he points out that the issue is that the paradigm in
which the question is framed dictates the final answer. “Hence,
the WUC solution is a logical answer to a question framed in the
paradigm of mining. It is, thus, suboptimal at a national level,
even if it is optimal at a mine level. Under the current
thinking, no space has been given to the assessment of an alter-
native model to WUC’s. We are locked into a suboptimal solution
forever,” he says.
The acid mine water from the WUC project will be treated in a
chemical precipitation process to South African National
Accreditation Standards (Sanas) class 2 standards and sold to
the mines for industrial use, which is about 60-million litres a
day. The excess water will be treated to Sanas Class 1 potable
standard and sold to Rand Water.
However, the key to the success and sustainability of this
solution rests in the project’s ability to produce water of a
suitable quality at a cost-effective price for high-volume
industrial water and potable water users.
Another sustainable benefit of using rehabilitated water to meet
industrial demand is the positive impact it will have on the
availability of potable water for the surrounding communities,
as pressure on potable resources will be significantly reduced.
“This is a bold and creative response to a serious environmental
challenge and we are confident that not only can we provide a
sustainable solution to the issue of contaminated water in the
Western Basin but that the same solution can also be rolled out
elsewhere, in South Africa and around the world, to effectively
overcome the damage inadvertently caused by mining activity,”
says Schoeman.
But this is a pretty picture of a directive issued by the
previous Department of Water Affairs and Forestry to the mining
industry to find a long-term sustainable solution for AMD over
almost 200 km of the country’s landscape.
It is a possibility with immense potential and hope for a future
in which AMD is not a serious environ- mental threat but one
that gives rise to a new value-added bene- ficiation economy.
While the WUC project has attracted its fair share of criticism,
it does promise enormous potential in solving the country’s AMD
challenge and is supported by an MD who is con- fident of the
fruitful results of this project.
However, there are many challenges in the pipeline that threaten
to hinder the project, which, currently, appears to be the only
long-term sustainable solution for AMD in South Africa. And
this, in itself, is significant cause for concern.
Solution to the Rising Tides of AMD
WUC reports that the level of ingress water in the Central Rand,
East Rand and West Rand Basins is 54-million litres, 82-million
litres and 15-million litres respectively.
The water levels in the Western Basin have risen to the surface,
and the AMD has entered the dolomite aquifers and is now moving
rapidly. There is also the potential for the water to also enter
the 3,5-million-year-old Cradle of Humankind.
The Central Rand Basin is filling up with water and within a few
years it will decant. In 2011, the environmental-critical level
will be reached in the Central Rand Basin, and failure to tackle
this will result in decanting in the South East vertical shaft
at Boksburg, in January 2012.
The Eastern Basin is currently being maintained at 720 m below
the surface but, if not managed, this basin could flow within
three years and will decant in Nigel and flow into the
Blesbokspruit and then into the Vaal.
The WUC water-treatment plant is in development phase and pilot
operations were concluded in October, last year, after an
extensive six-month evaluation period at gold-miner Harmony’s No
8 shaft near Randfontein, in the Western Basin.
The water plant is expected to reach its commercialisation phase
in December 2010, treating 75-million litres a day of AMD in the
Central Rand Basin. The project plan has been developed to
provide a regional closure solution to government for AMD.
Expansion of the project is expected around 2014 and will treat
some 200-million litres a day of AMD.
The mining industry has invested significantly in this project,
which needs an additional R1-billion for its first phase.
Finance will be raised on a 50% debt and 50% equity basis. The
raising of capital for the debt portion will be done through
South African banks. The Development Bank of Southern Africa has
provided a R10-million nonrecourse loan for the completion of
the bankable feasibility study.
To reduce capital expenditure, the mines will also contribute or
lease existing assets, such as pumpstations, pipelines servitude
and treatment plants to Section 21 companies, namely the Eastern
Basin Environmental Corporation, the Central Basin Environmental
Corporation and the Western Basin Environmental Corporation. The
company is in the process of finalising the heads of agreement.
The AMD water will be collected to produce industrial-quality
(IQ) water and potable water. About 60-million litres a day of
IQ water and 75-million litres of potable water will be
produced.
Schoeman says that the mines located in the surrounding areas
will use the IQ water. This, he adds, will be beneficial as
there is more potable water available for sale to bulk
distributors.
The price of the water will be linked to prices of Rand Water,
which is regulated by government.
The technology to be used in this project is the Council for
Scientific and Industrial Research’s alkaline barium calcium
process.
The potable water produced by the water treatment plant may be
distributed to the Klipriviersberg reservoir through a 20-km
distribution pipeline. The distribution pipeline, will, where
possible, follow existing servitudes.
Significant Challenges
Schoeman says that an integrated regulatory process is being
undertaken, and will tackle, besides other issues, the
environ-mental-impact assessment, an integrated water-user
licence application that is required by the National
Environ-mental Management Act (Nema), an air emissions
assessment in terms of the the Air Pollution Prevention Act, an
assessment of any radiological issues required by the National
Nuclear Regulator Act, and heritage assess- ments required by
the South African National Resource Heritage Act, as well as
investigating other legal issues and entering into contracts,
registering as a water services provider in terms of the Water
Services Act, and ensuring clients comply with the Municipal
Services Act.
These processes are all running in parallel to meet project
timelines.
“We are running against a massive timeline with this project,
which is driven from an environmental perspective and not for
financial gain. If we do not implement this project by 2011, we
are going to contaminate our water resources,” says Schoeman.
If the plant is not in full production by the first quarter of
2011, the high-density sludge plant in place at East Rand
Proprietary Mines will be used.
However, if the project is to progress as scheduled, processes
will still be followed expeditiously in accordance with the law.
But one has to question, given the time that government takes to
approve such processes, whether it will be possible to meet the
necessary deadlines required for the WUC project.
One such decision required from the Department of Water and
Environment Affairs is the approval of an offtake agreement for
the supply of this treated water to Rand Water. The concern, in
this regard, is when Minister Buyelwa Sonjica will proceed with
a public consultation process before signing the offtake
agreement.
There is a possibility that such processes might also delay the
project and result in the unleashing of one of the country’s
worst environmental disasters. And failure to follow through
with a public consultation process might expose the Minister to
political risk. It may appear that Sonjica may be caught between
a rock and a hard place.
After a month of significant effort from Mining Weekly, the
Department of Water and Environmental Affairs did not make any
attempt to respond to questions regarding the WUC project or to
validate or clarify any concerns or misconceptions regarding the
signing of the offtake agreement with Rand Water.
However, Schoeman emphasises that WUC is following the public
participation process dictated by Nema and encourages all
regulators, including the Minister, to follow the correct
procedure. “But if the regulators drag their heels, it will
result in unnecessary delays,” he adds.
But Turton says that the only benefit of the WUC project that
will accrue to the mining industry is the externalisationing of
the cost of water production.
“The benefits they are selling are false benefits because the
law that states the polluter pays, but WUC is asking Rand
Water’s consumers to pay for what the mining industry is legally
obliged to pay. This is sleight of hand. WUC is selling the
benefit based on the sense of urgency: if you do not do things
the WUC way, there will be a disaster. This is flawed logic,” he
says.
He adds that it is not a “benefit” when the mining sector is
evading its legal respons-ibility for averting a disaster that
it created.
“The only benefit, as WUC now stands, is to the mining industry,
where they find a source of cash to pay for their externalised
costs of production. It is scandalous. It is like allowing an
arsonist to say you will benefit by his not burning a building,
so you must pay him not to burn that building,” he comments.
But Schoeman says: “We are not saying this is the beginning and
the end, and the only solution. This is [an effort] by all the
mines in the three basins, and if the Minister decided not to
implement this project, then the mines cannot be held liable.
This is a solution proposed by the mines from which the mines
will not generate an income. If this project does not work, the
mining industry is still liable.”
Meanwhile, the plethora of proposals from private industry or
government to deal with the challenge is either nonexistent or
looming in the shadows.
There is more to contaminated water resources than just toxic
water. This water, in itself, could give rise to disease, which
is often not discussed in the public domain.
While there is time to debate the issues, positive or negative,
which in itself is always necessary and healthy in any
democracy, one issue remains certain, the country’s water
resources will be contaminated by October 2011, if nothing is
done.
Given climate change, coupled with seismicity activity, the
timing of the country’s worst environmental disaster could
change, but the reality is that probably it will happen. And
what is needed right now is a plan of action to prevent it.
Read article online at
Mining Weekly
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FACTS
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Environmental impact assessment to be
completed in August 2009 -Bankable feasibility study to be
completed by end of August 2009
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Record of decision expected in November 2009
-Construction to start in December 2009 -Construction period
of one year
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Three month ramp-up period from December 2010
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Full production expected in first quarter of
2011 -During commercialisation phase, the mines responsibility
to pump AMD to surface will stop. -When the plant has proven
to be entirely profitable after two years in operation, the
mines can hand in the project as a closure rehabilitation
strategy, stepping down from the environmental liabilities and
transferring onus to the rest of the structure.
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WUC will sell the water.
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The treated water is sold to industrial users
in the Rustenburg and Venderbijlpark areas -Reduced offtake in
potable water for processing by industry leads to an increase
in availability to communities.
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The acidity of the mine-affected water is
neutralised by adding limestone. Heavy metals are removed by
adding lime, which causes the metals to precipitate as the pH
is raised. The metal-containing precipitate is removed in a
clarifier. -Sulphate is removed from the water by contracting
it with barium carbinate, which results in insoluble barium
sulphate and calcium carbonate being formed.
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The water is then clarified, filtered and
disinfected and tested for final compliance with the
applicable potable water standards before distribution.
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Barium carbonate, calcium carbonate, calcium
oxide (lime) and elemental sulphur will be recovered for reuse
or for sale as commercial by-products of the process.
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