Cyanide Management Cyanide Management

Going Beyond the Mine

Sodium cyanide is the most effective chemical known for the extraction of gold and silver from rock. The use and management of cyanide is an important part of Newmont's operational success. However, at high concentrations, sodium cyanide can be dangerous to human and animal health. Newmont is committed to the safe and responsible management of all chemicals used at our operations, including cyanide. This means that we have a responsibility to provide a safe work environment for our employees and contractors, and to protect the environment and surrounding communities.

Operations: How cyanide is used

Heap Leach - In heap leach operations, the cyanide solution is filtered through heaps of gold-bearing ore to extract the gold. The heaps have high-density polyethylene (HDPE) liners underneath them to capture the cyanide solution as it percolates through the ore. Underneath the liners are leak detection and collection systems to alert personnel to any leaks and to capture any cyanide solution and direct it to a central collection area. The cyanide solution containing the gold is collected in HDPE-lined drains and directed to centralized HDPE-lined ponds. The ponds also have leak detection and collection systems.

Carbon in Pulp (CIP) / Carbon in Leach (CIL) - With this type of gold extraction, the crushed gold-bearing ore, water, cyanide solution and fine-grained activated carbon are added to large extraction tanks. The tanks are within a contained area designed to capture any spills or leaks, which, if they occur, are collected in a central area and pumped back to the process tanks. The tanks also have overfill alarms. The gold and the cyanide form a very strong bond and are attracted to the carbon in the tanks, which is removed from the tanks and washed to separate the gold and cyanide into a concentrated gold/cyanide solution.

Gold Refining - Gold from the concentrated gold-bearing solution, from both the heap leach and CIP/CIL processes, is removed by either electrowinning or by using the zinc precipitation process. The resulting gold sludge is then placed into a small furnace where liquid gold/silver is formed and poured into ingots.

All solutions that have had gold extracted from them are recycled back into the process.

Disposal of 'Spent' Ore after the Extraction of Gold - In the heap leach process, the 'spent' ore is left on the pad and more gold-bearing ore is placed on top of it, and the filtration and leaching processes are repeated.

In the CIP/CIL processes, the gold-depleted ore slurry (a mixture of finely crushed ore, water and cyanide) is pumped to a tailings storage facility (TSF). These facilities are designed taking into consideration local seismic conditions, climate and groundwater regimes. Controls are implemented to manage any potential seepage from these facilities. As the crushed ore settles out in the tailings impoundment, the solution on top of the facility is recycled back to the process.

All of Newmont's operations have in place environmental monitoring programs for surface and groundwater.

Newmont's Approach to Safe Management

We are a signatory to the International Cyanide Management Code (the Code) and we use the Code as the framework for responsibly managing cyanide at our operations.

Newmont's approach to safe cyanide management at all of its operations includes:
  • Requiring that our suppliers of cyanide become signatories to the Code or demonstrate compliance with the Code via supply chain certification audits.
  • Requiring that our transporters are in compliance with the Code and through contractual agreements become signatories to the Code or demonstrate compliance with the Code through supply chain certification audits.
  • Implementing handling and storage control procedures for containment of both liquid and solid forms of cyanide.
  • Implementing control procedures for use of cyanide in leaching and refining processes.
  • Including cyanide-related components in our emergency response, worker safety, and training procedures.
  • Including financial assurance and provisions within site closure plans for the decommissioning of all cyanide-related infrastructure.
  • Engaging with local communities to provide information about Newmont's management of cyanide and providing opportunities for community members to raise questions or concerns.
Snapshot: Management of Cyanide at Newmont

2010 Overview

Newmont completed certification with third-party audits of all of its operations against the requirements of the Code in 2009, except Boddington, our newest operation, which will finish the certification process in 2012. Two sites, Lone Tree and Twin Creeks, were recertified in 2010 in accordance with the Code's recertification requirement. Site audits were performed at the two sites by the 3-year anniversary of the original certification date. The auditors then had 90-days to write the audit reports and submit them to the ICMI for review and final approval. The actual published recertification date is therefore subject to the timing of the audit within the 3-year period, and the duration of the report preparation, review and approval process. A summary of the certifications are provided below:

Operation Date of Initial ICMC Certification Date of Required Recertification
Lone Tree February 2007 May 2010
Twin Creeks April 2007 August 2010
Yanacocha April 2008 Planned April 2011
Ahafo March 2008 Planned March 2011
KCGM September 2008 Planned September 2011
Midas September 2008 Planned September 2011
Phoenix December 2008 Planned December 2011
Tanami March 2009 Planned March 2012
Jundee March 2009 Planned March 2012
Carlin May 2009 Planned May 2012
Waihi November 2009 Planned November 2012
Boddington Planned December 2012

Activities to maintain certification initiated in 2010 include:
  1. Decided that the regions should form Regional Cyanide Code Compliance teams to support ongoing continued best practice sharing and recertification. By year end, the Asia Pacific region was successful at implementing their team. North America, South America, and Africa will follow in 2011.
  2. All certified operations have been provided a copy of the Cyanide Code Plus Working Group incident lessons learned review and are conducting internal reviews to evaluate 2010 cyanide incidents and design continual improvements to prevent these incidents from reoccurring.
  3. All certified operations have multi-department Cyanide Code Compliance teams that meet regularly.
  4. All certified operations are looking to map the Cyanide Code requirements to the ISO 14001 Environmental Management System requirements.
  5. Regions are developing internal and outside auditing teams to review site compliance with the Cyanide Code between the three-year audit cycles.
  6. Cyanide Code training programs are being evaluated and developed at the certified operations to support consistency and to develop the resources to sustain compliance.
  7. Certified operations are having regular meetings with our cyanide suppliers to ensure compliance throughout the supply chain.
  8. Recertification strategies are being developed and implemented at the certified operations. The Cyanide Code Plus Working Group is compiling the various recertification strategies developed at the site and regional levels to provide as a resource back to the Certified Operations.
Data
  • 2010: 47.8 thousand tonnes NaCN (52.7 thousand tons) used
  • 2009: 42.9 thousand tonnes NaCN (47.3 thousand tons) used
  • 2008: 40.7 thousand tonnes NaCN (44.9 thousand tons) used
In 2010, no significant Sodium Cyanide incidents were recorded at any of Newmont's operations. A summary of the Cyanide Code Reporting data is provided below.

Cyanide Code Reporting
Site Incidents of cyanide exposure resulting in hospitalization Incidents where releases off the mine site required response or remediation Incidents where releases on or off the mine site resulted in significant adverse effects to health
Ahafo 0 0 0
Boddington 0 0 0
Carlin 0 0 0
Granites 0 0 0
Jundee 0 0 0
KCGM 0 0 0
Lone Tree 0 0 0
Midas 0 0 0
Phoenix 0 0 0
Twin Creeks 0 0 0
Waihi 0 0 0
Yanacocha 0 0 0
Total 0 0 0


Cyanide Code Reporting, Continued
Site Incidents where releases on or off the mine site resulted in significant adverse effects to the environment. Incidents where a release on or off the mine site required reporting under applicable regulations.1 Incidents where releases caused exceedances of applicable limits for cyanide.
Ahafo 0 6 0
Boddington 0 4 0
Carlin 0 4 0
Granites 0 0 0
Jundee 0 0 0
KCGM 0 0 0
Lone Tree 0 0 0
Midas 0 2 0
Phoenix 0 1 0
Twin Creeks 0 8 0
Waihi 0 0 0
Yanacocha 0 0 0
Total 0 25 0

1 Reporting requirements differ between regulatory regimes.

Cyanide Code Summary Data
Total
Incidents of cyanide exposure resulting in hospitalization 0
Incidents where releases off the mine site required response or remediation 0
Incidents where releases on or off the mine site resulted in significant adverse effects to health 0
Incidents where releases on or off the mine site resulted in significant adverse effects to the environment 0
Incidents where a release on or off the mine site required reporting under applicable regulations1 25
Incidents where releases caused exceedances of applicable limits for cyanide 0

1 Reporting requirements differ between regulatory regimes.



Past Cyanide Management reviews:
Beyond the Mine 2009: Cyanide Management PDF
Beyond the Mine 2008: Cyanide Management PDF

Back to top of page

© Copyright 2011 Newmont Mining Corporation www.newmont.com