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Global Best Practices in Cyanide Management: The International Cyanide Management Code (ICMC) and Turkish Experience

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October 2014
18
GENERAL BACKGROUND ON
CYANIDE AND ITS USE IN
PRECIOUS METALS MINING
Cyanide is a general term for a group
of chemicals containing carbon
and nitrogen. There are about 2,000
natural sources of cyanide, however,
the principal man-made forms of
cyanide are hydrogen cyanide gas and
solid sodium and potassium cyanide.
Over one million tonnes of cyanide,
representing about 80% of annual
production, are used annually in the
production of organic chemicals such
as nitrile, nylon, and acrylic plastics.
Other industrial applications include
electroplating, metal processing, steel
hardening, photographic applications,
and synthetic rubber production.
Cyanide is also used in minute quantities
in pharmaceutical applications. The
remaining 20% of cyanide production
is used to manufacture sodium cyanide,
a solid form of cyanide that is relatively
easy to handle. About 90% of the sodium
cyanide produced internationally (i.e.,
about 18% of total global cyanide
production) is used in mining around
the world, mostly for the recovery of
gold and silver. Cyanide is particularly
well suited for extraction of gold (and
silver) from low-grade ores and ores that
cannot be readily processed through
simple physical methods such as gravity
separation. The first commercial-scale
cyanidation plant used in gold mining
began operation at the Crown Mine in
New Zealand in 1889, and proved to be
so successful that by 1904 cyanidation
processes were also established at mine
sites in South Africa, Australia, United
States, Mexico, and France.
Gold mining operations use very dilute
solutions of sodium cyanide in active
separation process (100 - 500 ppm).
When dissolved in water, under mildly
oxidizing conditions, sodium cyanide
solution readily dissolves the gold
contained in the ore. The resultant
gold-bearing solution is described as
“pregnant. Zinc metal or activated
carbon may be added to recover
the gold from solution. The residual
(“barren”) cyanide solution is typically
replenished with fresh cyanide and re-
circulated to extract additional gold,
or when the ore resource is depleted,
may be routed to a waste pond.
After gold has been extracted, three
principal types of cyanide compounds
may be present in wastewater or
process solutions: free cyanide, weakly
complexed cyanide, or strongly
complexed cyanide. Together, the
three cyanide compounds constitute
“total cyanide. “Free cyanide” is a term
used to describe both the cyanide
ion (CN-) that is dissolved in process
water, and any hydrogen cyanide
(HCN) that is formed in solution. Under
normal conditions of temperature and
pressure, the concentrations of HCN
and CN- are equal at a pH value of
approximately 9.4.
While cyanide-bearing solutions are
used in mining because they react with
gold, they also react with other metals
such as Fe, Cd, Cu, Zn, Ni, and Ag to
form weak cyanide complexes. These
complexes, often referred to as “weak
acid dissociable” (WAD), can dissociate
in solution to produce environmentally
significant concentrations of free cyanide.
The rate at which these complexes
dissociate depends on several factors,
including the initial concentration of
the cyanide complex, temperature, the
pH of the solution, and the intensity of
sunlight, as ultraviolet (UV) light tends to
accelerate breakdown effects.
THE INTERNATIONAL CYANIDE
MANAGEMENT CODE (ICMC)
FOR THE MANUFACTURE,
TRANSPORT AND USE OF
CYANIDE IN THE PRODUCTION
OF GOLD
Although cyanide is a common
industrial chemical, concerns over
potential danger to people and
the environment have the highest
profile in relation to the gold mining
industry.xi Following a spill of cyanide
from the overtopping of a tailings
reprocessing operation in 2000 in Baia
Mare, Romania, the United Nations
Environment Programme (UNEP) and
the International Council on Metals
and the Environment (ICME) sponsored
a workshop “to review recent
accidents involving cyanide, and
ways to improve the management of
cyanide at gold mining operations.”xii
The workshop led to a decision to
undertake a multi-stakeholder process
under the aegis of UNEP and a multi-
stakeholder Steering Committee
to develop a voluntary code of
technical practice focused on the
Global Best Practices in Cyanide
Management: The International
Cyanide Management Code
(ICMC) and Turkish Experience
Article
www.miningturkeymag.com
CONTACTS
Professor Ata Akcil, Ph. D.-Eng.
ICMC Technical Expert Auditor, Gold Mine
Verification Audits
S.D. University, Isparta, Turkey
E-Mail: ataakcil@sdu.edu.tr
Glenn Mills, EP (CEA)
Principal Consultant
ICMC Lead Auditor/Technical Expert Auditor,
Gold Mine Verification Audits
ENVIRON International Corp., Seattle, WA, USA
E-Mail: gmills@environcorp.com
October 2014 19
gold mining industry. An independent
International Cyanide Management
Institute (ICMI) was created to develop
and manage the International Cyanide
Management Code (ICMC). The
ICMC was established as an entirely
voluntary standard, and is intended
to complement existing obligations
to comply with the applicable laws
and regulations of the political
jurisdictions in which the operation
is located. The specific objective
of the ICMC is toprotect workers,
communities and the environment
from the adverse effects of cyanide
use in mining; and to improve the
management of cyanide by cyanide
producers, transporters, and mining
companies. Cyanide producers,
transporters, and mining operations
that adopt the ICMC must have their
cyanide-related operations audited
by a qualified and independent third
party to determine ICMC compliance.
Summary versions of audit reports
as well as the credentials of the third
party auditor are made public by
the ICMI in order to openly inform
stakeholders of the status of cyanide
management practices at specific
certified operations. xiii, xiv As of the
publication date of this article, the
ICMC has been adopted by many
international mining companies,
cyanide chemical producers, and
transportation companies. The
challenge that the ICMI now faces is
to gain the participation and support
of the remaining large, medium
and small producers, especially in
developing nations.
BECOMING AN ICMC SIGNATORY
Gold mining companies with either
single or multiple operations, and
the producers and transporters of
cyanide used in gold mining may
choose to become ICMC signatories.
By becoming a signatory, a company
commits to follow the ICMC Principles
and applicable Standards of Practice,
and to undertake independent audits
of such commitments at least every
three years, so long as operations
continue. When becoming a signatory,
a gold mining company must specify
which of its operations it intends to
seek certification for, as only those
facilities that use cyanide mining are
subject to certification. A company
that does not have these operations
audited within 3 years of signing the
ICMC will lose its signatory status.
ICMC IMPLEMENTATION
As it applies to gold mining operations,
the ICMC is comprised of two major
elements: Principles and Standards
of Practice. There are nine Principles,
focused on cyanide production, trans-
portation, handling and storage, opera-
tions, decommissioning, worker safety,
emergency response, training, and
public dialog. The Principles broadly
state the commitments that signatories
make to manage cyanide in a respon-
sible manner. Standards of Practice fol-
low each Principle, and, as summarized
below, identify the specific perfor-
mance goals and objectives that must
be met in order to achieve compliance
with the governing Principle.
1.PRODUCTION: Encourage responsi-
ble cyanide manufacturing by purchas-
ing from manufacturers who operate in
a safe and environmentally protective
manner.
Standard of Practice
1.1 Purchase cyanide from manu-
facturers employing appropriate
practices and procedures to limit ex-
posure of their workforce to cyanide
and to prevent releases of cyanide to
the environment.
2. TRANSPORTATION: Protect com-
munities and the environment during
cyanide transport.
Standards of Practice
2.1 Establish clear lines of responsibil-
ity for safety, security, release preven-
tion, training and emergency response
in written agreements with producers,
distributors and transporters.
2.2 Require that cyanide transporters
implement appropriate emergency
response plans and capabilities, and
employ adequate measures for cyanide
management.
3. HANDLING AND STORAGE: Protect
workers and the environment during
cyanide handling and storage.
Standards of Practice
3.1 Design and construct unloading,
storage and mixing facilities consis-
tent with sound, accepted engineer-
ing practices and quality control and
quality assurance procedures and spill
prevention and containment measures.
3.2 Operate unloading, storage and
mixing facilities using inspections,
preventive maintenance and contin-
gency plans to prevent or contain
releases and control and respond to
worker exposures.
4. OPERATIONS: Manage cya-
nide process solutions and waste
streams to protect human health
and the environment.
Standards of Practice
4.1 Implement management and op-
October 2014
20
erating systems designed to protect
human health and the environment in-
cluding contingency planning and in-
spection and preventive maintenance
procedures.
4.2 Introduce management and oper-
ating systems to minimize cyanide use,
thereby limiting concentrations of cya-
nide in mill tailings.
4.3 Implement a comprehensive wa-
ter management program to protect
against unintentional releases.
4.4 Implement measures to protect
birds, other wildlife and livestock from
adverse effects of cyanide process solu-
tions.
4.5 Implement measures to protect fish
and wildlife from direct and indirect
discharges of cyanide process solutions
to surface water.
4.6 Implement measures designed to
manage seepage from cyanide facilities
to protect the beneficial uses of ground
water.
4.7 Provide spill prevention or contain-
ment measures for process tanks and
pipelines.
4.8 Implement quality control/quality
assurance procedures to confirm that
cyanide facilities are constructed ac-
cording to accepted engineering stan-
dards and specifications.
4.9 Implement monitoring programs
to evaluate the effects of cyanide use
on wildlife, surface and ground water
quality.
5. DECOMMISSIONING: Protect com-
munities and the environment from
cyanide through development and
implementation of decommissioning
plans for cyanide facilities.
Standards of Practice
5.1 Plan and implement procedures for
effective decommissioning of cyanide
facilities to protect human health, wild-
life and livestock.
5.2 Establish a financial assurance mech-
anism capable of fully funding cyanide-
related decommissioning activities.
6. WORKER SAFETY: Protect workers’
health and safety from exposure to cya-
nide.
Standards of Practice
6.1 Identify potential cyanide exposure
scenarios and take measures as neces-
sary to eliminate, reduce and control
them.
6.2 Operate and monitor cyanide facili-
ties to protect worker health and safety
and periodically evaluate the effective-
ness of health and safety measures.
6.3 Develop and implement emergen-
cy response plans and procedures to
respond to worker exposure to cyanide.
7. EMERGENCY RESPONSE: Protect
communities and the environment
through the development of emergen-
cy response strategies and capabilities.
Standards of Practice
7.1 Prepare detailed emergency re-
sponse plans for potential cyanide re-
leases.
7.2 Involve site personnel and external
stakeholders in the planning process.
7.3 Designate appropriate personnel
and commit necessary equipment and
resources for emergency response.
7.4 Develop procedures for internal and
external emergency notification and
reporting.
7.5 Incorporate monitoring elements
and remediation measures into re-
sponce plans that account for the ad-
ditional hazards of using cyanide treat-
ment chemicals.
7.6 Periodically evaluate response pro-
cedures and capabilities, and revise
them as needed.
8. TRAINING: Train workers and emer-
gency response personnel to manage
cyanide in a safe and environmentally
protective manner.
Standards of Practice
8.1 Train workers to understand the
hazards associated with cyanide use.
8.2 Train appropriate personnel to
operate the facility according to sys-
tems and procedures that protect
human health, the community and
the environment.
8.3 Train appropriate workers and per-
sonnel to respond properly to patential
worker exposures or environmental re-
leases of cyanide.
9. DIALOGUE Engage in public consul-
tation and disclosure.
Standards of Practice
9.1 Provide stakeholders the opportu-
nity to communicate issues of concern.
9.2 Initiate dialogue describing cyanide
management procedures and respon-
sively address identified concerns.
9.3 Make appropriate operational and
environmental information regarding
cyanide available to stakeholders.
ICMC VERIFICATION AUDITS
AND CERTIFICATION
Verification Protocols based on the Prin-
ciples and Standards of Practice have
been separately developed for mining
operations, transporters, and producers,
and form the basis for an independent
third-party audit process. The Verification
Protocols are very detailed and transpar-
ent, and are openly posted on the ICMI
website; see http://www.cyanidecode.
org/sites/default/files/pdf/ RevisedAudi-
torGuidance.pdf for an example.
Audits are conducted every three years
by independent, third-party profes-
sionals who meet rigorous qualifica-
tions and experience requirements
defined by the ICMI. Auditor criteria
include requisite levels of experience,
specifically in conducting environmen-
tal, health, or safety audits; certification
as a professional health, safety or envi-
ronmental auditor by a self-regulating
organization; and confirmation that no
material conflicts of interest exist with
respect to the audited operation(s).
For gold mining operations, an on-site
audit is required within one the opera-
tion’s first receipt of cyanide at the site.
The audit is considered to be complete
(and the three-year period before the
next required audit must be conducted
begins) on the day ICMI takes formal
certification action based on the audi-
tor’s findings. Operations are obliged to
provide access to all cyanide facilities
and make all relevant records and data
available to the auditors in order to be
considered for certification.
During an initial verification audit, an
operation’s compliance at the time of
the audit will be evaluated. Subsequent
re-verification audits will also evaluate
compliance during the period between
the preceding and current audits.
Upon completion of the audit, the au-
ditor must review the findings with
the operation to ensure that the audit
is factually accurate. The auditor must
prepare a Detailed Audit Findings Re-
port addressing all applicable criteria
in the Verification Protocol as well as a
Summary Audit Report that includes
the conclusion regarding the opera-
tion’s compliance with the ICMC. These
reports are submitted to the signatory
and the signatory’s mining operation
October 2014 21
for resolution of outstanding issues
prior to submittal to ICMI. The opera-
tion maybe considered to be certified
with respect to ICMC compliance if the
auditor concludes that it is in full com-
pliance with the relevant Principles and
Standards of Practice. The Detailed
Audit Findings Report is the confiden-
tial property of the operation and is
not released or published by the ICMI;
however, the Summary Audit Report
for certified operations will be made
openly available to the public on the
ICMI website.
Operations that are in substantial com-
pliance with the ICMC may be condi-
tionally certified, subject to the suc-
cessful implementation of a Corrective
Action Plan. Substantial compliance
means that the operation has made a
good-faith effort to comply with the
ICMC and that the deficiencies identi-
fied by the auditor can be readily cor-
rected, and do not present an immedi-
ate or substantial risk to employee or
community health or the environment.
Operations that are found to be in sub-
stantial compliance must develop and
implement a Corrective Action Plan to
resolve the deficiencies identified by
the verification audit. The operation
may request that the auditor review the
Corrective Action Plan or assist in its de-
velopment so that there is agreement
that its implementation will bring the
operation into full compliance. The Cor-
rective Action Plan must include a time
period mutually agreed to with the au-
ditor, but in no case longer than one
year, to bring the operation into full
compliance with the ICMC. The Auditor
must submit the Corrective Action Plan
to ICMI along with the Audit Findings
Report and Summary Audit Report.
The operation must provide evidence
to the auditor demonstrating that
it has implemented the Corrective
Action Plan as specified and in the
agreed-upon time frame. In some
cases, it may be necessary for the au-
ditor to re-evaluate the operation to
confirm that the Corrective Action
Plan has been implemented. Upon
receipt of the documentation that the
Corrective Action Plan has been fully
implemented, the auditor must pro-
vide a copy of the documentation to
the Institute along with a statement
verifying that the operation is in full
compliance. Operations cannot be
certified if the auditor concludes that
it is neither in full compliance nor in
substantial compliance with any one
of the applicable Standards of Prac-
tice. An operation that is not certified
based on its initial verification audit
can be verified and certified, however,
once it has brought its management
programs and procedures into compli-
ance with the ICMC.
All ICMC-certified operations are noted
on the ICMI website, which provides
publically accessible links to the rel-
evant Summary Audit Report as well
as a notarized summary of the auditors’
credentials at the time of the audit. Cur-
rent statistics on ICMC certifications are
provided in Table 1.
THE VALUE FOR THE ICMC TO
SIGNATORY ORGANIZATIONS
The programs and procedures identi-
fied by the ICMC Principles and Stan-
dards of Practice and associated Veri-
fication Protocols can be developed
separately from other management
programs, or can be integrated into
a site’s overall health, safety, and en-
vironmental management programs.
Regardless of the management ap-
proach selected, achieving or maintain-
ing compliance with the ICMC provides
signatories a substantially greater mea-
sure of control over the use of cyanide,
which otherwise might well be a sig-
nificant environmental, occupational
health and safety, or social (community
relations) risk. ICMC compliance also
enhances the risk management profile
of a project from the perspective of
major financial lenders. For example,
the International Finance Corporation
(IFC) Performance Standards (IFC, 2012)
and the IFC Environmental, Health and
Safety (EHS) EHS Guideline for Mining
(IFC, 2007) recognize the ICMC as the
preferred good international industrial
practice (GIIP) for all mines using cya-
nide-based mineral extraction process-
es. The IFC Performance Standards and
the sector-specific EHS guidelines refer-
enced therein also form the conceptual
basis for the Equator Principles, which
have been adopted by 80 of the world’s
major private financial institutions; see
http://www.equator-principles.com/
index.php/members-reporting/mem-
bers-and-reporting.
TURKISH GOLD MINING AND
ICMC EXPERIENCE
Turkey is one of the fastest growing
economies in the world, and the fast-
est growing economy in Europe, with
an average annual real GDP growth
rate of 5% over the past decade. Tur-
key has a population of 77 million with
half under the age 30; it is the 16th
largest economy in the world with a
gross domestic project (GDP) greater
than USD 1 trillion. Turkey also has sig-
nificant mineral wealth; it ranks 28th in
the world for mineral production and
is the 10th most diverse producer of
minerals. Turkey has also emerged as
Europe’s largest gold producer.
In 2013, gold production was about 35
tons, but the Turkish Gold Miners’ Asso-
ciation expects production to increase
to 50 tons per year by 2015. This would
put Turkey among the 15 top gold pro-
ducing nations in the world. Turkey
may contain many other economic
gold deposits, and it is expected that
gold production will continue to be a
very positive contributor to the Turkish
mining industry in the years to come.
The Kışladağ Gold Mine (see Figures
1 and 2) is owned by Eldorado Gold
Corp. of Canada, who are an ICMC
signatory. Kışladağ is 35 km south-
west of Usak and is the largest Turk-
ish gold mine now in production.
Mine construction began in 2004
and was completed in 2006; commer-
cial gold production commenced in
July of that year. Kışladağ is a mod-
Item Mining Companies
& Countries
Cyanide
Producers &
Countries
Cyanide
Transporters
& Countries
Totals
Signatory Companies 39 19 112 170
Individual Operations or Facilities of Signatory
Companies 133/41 29/15 156/40 318/51
Certified Sites 89/25 25/13 98/34 212/39
Recertified Sites 63/19 16/10 35/17 114/25
Sites Recertified Twice 16/4 10/6 3/2 29/6
Table 1. Number of ICMC signatory companies, including producers, transporters, and mining operations
(Source: ICMI, July 2014)
October 2014
22
ern conventional open pit mine and
heap leach operation comprised
of a three-stage crushing plant, an
overland conveyor that transports
crushed or to the heap leach pad sys-
tem, mobile conveyors and a stacker
for placing crushed ore on the heap,
a composite liner system underlying
the leach pads, lined emergency so-
lution handling ponds, leach solution
pumping and distribution piping; a
carbon based gold adsorption, de-
sorption, and recovery (ADR) plant,
and supporting infrastructure. The fi-
nal commercial product of the mine is
gold doré bullion. The mine’s current
throughput production is 12.5 million
tonnes/yr. Gold production in 2013
was 8680 kg (306,182 oz).
A Cyanide Management Plan based on
ICMC requirements has been prepared
and implemented at Kışladağ. Secure
dedicated depots are provided for the
storage of cyanide that are fitted with
HCN detectors and alarms. Leak detec-
tion systems are incorporated into the
composite liner system for the heap
leach pads, along with barriers to pre-
vent access by wildlife or domestic ani-
mals. The mineral separation process is
designed as a closed system, with no
discharge to the environment in normal
operating conditions. Water manage-
ment features have been designed to
accommodate a theoretical 100 year, 24
hour storm event, and diversion ditches
have been constructed along the pe-
riphery of the heap leach pad to divert
surface water away from the facility.
Operational water balance models are
used to evaluate heap leach pad per-
formance, to determine makeup water
requirements, and to estimate both
the frequency and size of future storm
events; this permits the mine to adjust
its solution volumes and water use to
prevent any potential discharge to the
environment. An emergency hydrogen
peroxide detoxification plant has also
been constructed that is capable of
reducing the cyanide content of pro-
cess solution to safe levels, in the event
discharge should become necessary
as the result of an unusually extreme
storm event. The process ponds have
a double high-density polyethylene
(HDPE) liner and are fitted with leak de-
tection systems and solution recovery
pumps. Process pond surfaces are cov-
ered with floating plastic balls in order
to reduce evaporation and to discour-
age birds from landing on pond sur-
faces. The heap leach pad and ponds
will be progressively decommissioned
and closed as each respective leach-
ing phase is completed. Kışladağ also
maintains very close, collaborative, and
responsive relations with regulatory
authorities and local communities in
order to resolve any concerns over cya-
nide delivery, storage, and use.
The Kışladağ Gold Mine was certi-
fied in December, 2013 on the basis
of a determination of full compliance
with the detailed requirements of the
ICMC. Kışladağ is the first Turkish mine
achieve such status, and was the first
mine tobe certified in Eldorado Gold’s
international operations. The Summary
Audit Report is published on the ICMI
website (see http://www.cyanidecode.
org/signatory-company/eldorado) as
well as the credentials of the certifica-
tion audit team. As noted previously
the operation must be re-audited every
three years hereafter through the end
of mine life, in order to verify continu-
ing compliance with the ICMC.
LAST WORD
In summary, the ICMC is one of the
most rigorous voluntary auditing
benchmarks ever to be applied in any
international industry. ICMC auditing
protocols are exacting, detailed, and
transparent, and third party auditors
Figure 1. Kışladağ Gold Mine, view to the west-northwest; active leach pad is shown, along with emergency
and process solution ponds and ADR plant in foreground (Source: Kışladağ Gold Mine, 2014)
Figure 2. Kışladağ Gold Mine, aerial view to the southeast; active leach pad is shown in foreground, with open
pit shown left of center (Source: Kışladağ Gold Mine, 2014)
October 2014 23
are held to a very high standard with
respect to their independence, audit-
ing capabilities, and technical experi-
ence. Moreover, the IFC, the Equator
Principles Financial Institutions, and
other multilateral and private lenders
often invoke the ICMC as part of the
environmental, health, safety, and so-
cial conditions of the loans they make
to mining projects that use cyanide-
based mineral extraction processes.
In achieving ICMC certification, the
Kışladağ Gold Mine and its parent
company have demonstrated to regu-
latory authorities, non-governmental
organizations, lending institutions,
and other stakeholders that it is fully
capable of managing its use of cya-
nide to the highest and most widely
recognized international standards.
The successful certification of Kışladağ
is also a demonstration to the Turkish
mining industry that the adoption of
EHS and community relations practic-
es that are consistent with the themes
of the ICMC will enhance the percep-
tion of mining as not only a viable and
vital part of the Turkish economy, but
also as an environmentally and socially
responsible – and internationally com-
petitive – industry.
ACKNOWLEDGEMENTS
This review article was partially pro-
duced from the authors’ audit experi-
ences and the authors wish to thank
the Tüprag Metal Madencilik Sanayi ve
Ticaret AS Eldorado Gold Corporation/
Kışladağ Gold Mine, Turkey for permis-
sion to publish the paper.
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Küresel ekonomideki dalgalanmaların en önemli tetikleyicilerinin başında, hammadde tedariğinden dolayı, madencilik sektörü gelmektedir. Bu durum, aynı zamanda, madencilik sektörünü kamuoyu gündeminde tartışmaların arttığı bir konuma oturtmaktadır. Ülkemizde olduğu gibi, küresel anlamda da madencilik sektörü içinde İş Sağlığı ve Güvenliği tedbirlerinin uygulanmasına en hassas olan Altın ve Gümüş madenciliğidir. Bunun ana sebebi; çok ince boyutta serbestleştirilmesi gereken cevher tipinden ve de çok düşük tenörlerin işlenmesinden dolayı bu değerli metallerin kazanımında siyanür kimyasalının kullanılmasından ileri gelmektedir. Bilindiği gibi, altın ve gümüş madenciliğinde siyanür kullanımı zorunluluğu bu konuda 120 yılı aşkın süren araştırma ve bilimsel gerekçelere dayanmaktadır. Siyanürün yerine kullanılabilecek başka kimyasallar üzerine 80’li yıllardan bu yana ciddi araştırmalar yürütülmektedir. Ancak siyanürün etkinliği, ekonomisi yanında, insan sağlığı ve çevre üzerinde bilinen risk ile birlikte kullanılabilirliğinden dolayı madencilik endüstrisinde kullanımı halen devam etmektedir. Dünya’da altın ve gümüş üretiminin % 90’ınında halen bu değerli metallerin kazanımı için etkin bir kimyasal olarak siyanür kullanılmaktadır. Şehir efsanelerinin aksine kanserojen etkisi olmayan bu kimyasalın küresel olarak yönetimi, 2000 yılındaki Baia Mare (Romanya) altın madenindeki kazadan sonra Birleşmiş Milletlerinde aralarında olduğu kuruluşlar tarafından ele alınmıştı ve 2002 yılından itibaren siyanür yönetiminin anayasası olarak bilinen “Uluslararası Siyanür Yönetim Kodu” (International Cyanide Management Code-ICMC) tüm dünyada yaygın olarak uygulanmaya başlandı. Dolayısı ile, siyanür kullanılan altın ve gümüş madenciliğinde 15 yıldır bu tür bir bağımsız dış denetleme aracının küresel düzeyde uygulanmasıyla iş sağlığı, güvenliği ve çevre konularında en üst seviyede yeni ama normal bir yaklaşım sergilenmektedir. Bu konuda dünyadaki en üst düzey denetleme şekli olmasına rağmen, bağımsız dış denetleme süreçlerine girmek istemeyen bazı şirketler ileri düzeyde yönetim uygulama kriterleri nedeniyle çekingen davranarak bu sürece girmemektedirler. Ülkemizde ise konuya uzak yakın birçok şirket için ilk örnek uygulama 2012 yılında başlamıştır (Kışladağ Altın Madeni, Uşak). Ülkemizde madencilik faaliyeti yapan birçok şirketlerinde önemli ölçüde Siyanür Koduna uyumlanma ve bağımsız dış denetleme sürecine katılmak için; eğitim, boşluk analizi ve ana denetleme (ICMI sertifikasyonu) çalışmaları yaklaşık 7 yıldır devam etmektedir.
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Chemical replacements for cyanide have been investigated for decades; however cyanide remains the exclusive lixiviant of choice in the mining industry due to a combination of its availability, effectiveness, economics and ability to use it with acceptable risk to humans and the environment. About 90% of the significant gold producing operations worldwide currently utilize cyanide for gold and silver extraction. Despite the number of cyanide-related mining operations, there have been no documented accounts during the previous three decades of the death of humans due to cyanide as a direct consequence of major mining-related environmental incidents. Major mining-related environmental incidents have not been concentrated in any geographic location, may occur regardless of the size of the company and do not occur more frequently with a specific type of mining activity. The main aspects of cyanide management that should be addressed at mining operations include transportation of cyanide to site, process solution conveyance, worker health and safety training, water management and treatment, emergency response and preparedness, workplace and environmental monitoring, and community relations. If these aspects of cyanide management are integrated into an overall cyanide management plan, dramatic reductions in risk and potential incidents at mine sites will be realized.
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There are several water and tailings treatment processes that have been successfully used worldwide for cyanide removal at mining operations. The key to successful implementation of these processes involves consideration of the following:•Site water and cyanide balances under both average and extreme climate conditions.•Goals to be adopted for cyanide levels in treated effluent, including the form of cyanide to be regulated (free vs. WAD vs. total cyanide).•The range of cyanide treatment processes available and their ability to be used individually or in combination to achieve treatment objectives.•Proper treatability testing, design, construction, maintenance and monitoring of both water- and cyanide-management facilities.By carefully considering these aspects of water and cyanide management before, during and after mine operation, operators can reduce the potential for environmental impacts associated with the use of cyanide. Another aspect of cyanide treatment to be considered is the potential environmental impact of the cyanide-related compounds - cyanate, thiocyanate, ammonia, nitrate and nitrite. These compounds may be present in mining solutions to varying extents and may require treatment if water is to be discharged. Each of these cyanide-related compounds is affected differently in the treatment processes discussed, and this should be considered when evaluating cyanide-treatment alternatives for a given site. Table 13 provides a simplified summary of the general applications of various treatment technologies for the removal of iron cyanide and WAD cyanide. This table represents a very simplified summary, but can be used as a conceptual screening tool when evaluating cyanide-treatment processes.
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The International Cyanide Management Code was developed to improve the management of cyanide at gold mines. Spills and other incidents involving cyanide solutions at gold mines such as the January 2000 incident at a Romanian gold mine (Baia Mare) demonstrated to the gold mining industry, governments, and the public that better management of cyanide was needed, particularly at operations with limited experience or in countries lacking adequate regulatory programs. In 2001, the Code was underwritten by a group of gold companies and cyanide producers from around the world. The Gold Institute was instrumental in organizing this financial and technical support and provided the administrative and logistical support necessary to successfully complete the project. This effort represents one of practical action that an industry has worked with mining companies and producers including UNEP, World Banks, and Environmental Groups to develop an international voluntary industry Code of Practice.The regional and national environmental management criteria of cyanide are different in various countries. Thus, a common language should be applied as a global perspective which is provided by the Cyanide Code Management. In this review article, a general and brief introduction on Cyanide Code Management is presented.
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In the history of Turkey the first use of cyanide for gold recovery has been at the Ovacik Gold Mine. During one-year test period, this mine has successfully been mining and processing after a complicated and extensive environmental impact procedure. In Turkey about 2500 ton of sodium cyanide are used with about 240 ton of sodium cyanide being used at this mine annually. During the test period, it has been shown that an effluent quality (CNWAD) between 0.06 ppm (min) and 1 ppm (max) was achievable after cyanide destruction with the Inco Process. It was also found that treated effluent values (CNWAD) of process water (decant) were between 0.04 ppm (min) and 0.59 ppm (max). This paper presents a review of the cyanidation and cyanide destruction processes at the Ovacik Gold Mine.
A history of gold mining in Turkey over the last three decades
  • Ü Akdur
Akdur, Ü., A history of gold mining in Turkey over the last three decades. Turkey & Central Asia Investment Summit (Mines & Money), İstanbul, January 27-30, 2014.
Cyanide and society: a critical review The International Cyanide Management Code
  • T Mudder
  • M Botz
Mudder, T. and Botz, M., 2004, Cyanide and society: a critical review, The European Journal of Mineral Processing and Environmental Protection, 4, pp.62-74. www.cyanidecode.org, 2014, The International Cyanide Management Code.
Agency for Toxic Substances and Disease Registry (ATSDR)
Agency for Toxic Substances and Disease Registry (ATSDR). 2006. Toxicological profile for Cyanide. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service. p.298.