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KCGM is committed to a process of continual improvement to fully meet and uphold the policies and standards of the two Joint Venture Owners, Barrick Gold of Australia Limited and Newmont Australia Limited, with regard to management of workplace safety, health and environmental management.
KCGM is also fully supportive of the Joint Venture owner commitments to the principles of practices of the Gold Institute and the Australian Mining Industry Code for Environmental Management.
The requirements and expectations of the two Joint Venture Owner policies and standards will prevail in the management of KCGM operations. The documents of the two Owners are formatted differently and offer various explanatory notes or cross references to other Standards and Guidelines. The Inside KCGM intranet provides access to the policies and standards of Newmont, Barrick and KCGM.
An important process of management of systems and operational performance is that of Audit. Regular auditing is carried out by the Joint Venture Owners for Safety, Health and Environment, including both internal and external Auditors to verify the auditing process and outcomes. In addition, KCGM and the Owners will commission subject specific-Audits to support this program as required.
Russell Cole
KCGM General Manager
November 2010
In 2005 Newmont and Barrick (our JV owners) signed up to the International Cyanide Code as managed by the International Cyanide Management Institute (ICMI) and on the 26th September 2008, KCGM was also certified as being officially compliant with Code. This was a significant moment as the Super Pit Operation was the second Barrick site and the first Newmont site in Australia, to be compliant with the Code.
The International Cyanide Management Code is a voluntary code where by mining and other related companies manufacturing or using cyanide could accept and adhere to a very strict set of Principles for the manufacture, transport, use and disposal of cyanide products. All companies are audited against nine principles by specially certified auditors within three years of signing up to the code. In making a commitment to the Code, KCGM effectively had to transform the way it approached the management of Cyanide in order to bring the Operation into line with benchmark standards.
Such a commitment included the design, construction and decommissioning of site facilities to be compliant with the Code Standards of Practise, and being subjected to a regular inspection by an independent third party auditor.
As it has now been three years since KCGM was recognised as being compliant with the Code, in 2011 we will be undergoing a full recertification process to ensure that we are still compliant with the Code's Principles and Standards of Practice.
What is cyanide?
The term ‘cyanide’ (chemical name ‘sodium cyanide’) can refer to a range of different chemicals which may contain cyanide in many different forms. Typically in modern gold processing, cyanide is received as sodium cyanide in either the solid form, which is then dissolved in water prior to use, or as the liquid form, in which the dissolving step is carried out before reaching the mine site. Sodium cyanide and potassium cyanide are both white solids with a bitter, almond-like odour in damp air. Cyanide can occur in many other forms as a by-product of its reaction with other metals and or reagents these can include ‘black cyanide’, calcium cyanide, cupric cyanide, ferrocyanide, Prussian blue, thiocyanate, cyanate and the gaseous form, hydrogen cyanide.
In certain plant foods, including almonds, millet sprouts, lima beans, soy, spinach, bamboo shoots, and cassava roots (which are a major source of food in tropical countries), cyanides occur naturally as part of sugars or other naturally-occurring compounds. As a matter of interest, smoking cigarettes and breathing smoke-filled air during fires is also a major source of cyanide exposure.
Where does KCGM use cyanide?
Sodium cyanide is the most effective chemical known for the extraction of gold and silver from rock. Cyanide is received at KCGM in the liquid form which is placed into large tanks containing the gold bearing rock, and is added using specially designed dosing equipment which eliminates human interaction. The gold and cyanide form a strong bond which is then removed from the solution. Dose rates are controlled automatically to ensure that rates are optimised for the extraction process and to ensure worker safety. The main storage tank is fully contained in a lined bund to ensure there is no release of the solution to the environment.
Why does KCGM need to use cyanide?
Gold is one of the ‘noble’ metals which means it is not soluble in water. Therefore Cyanide is used in the extraction process to dissolve gold after which it is collected on granular activated carbon in the leach tanks. The process of extracting gold from ore with cyanide is called cyanidation. It is also used in the elution process where gold is re-dissolved from granular activated carbon into solution as a preparation step for electrowinning to the final solid gold form.
What are the risks with cyanide?
The main risks associated with cyanide are exposure of workers to concentrated hydrogen cyanide gas, leaking of cyanide into the environment and exposure of surrounding communities to cyanide due to accidental releases.
How can communities be exposed to cyanide?
The cyanide used at the mine site is transported from the manufacturing plant to the mine site. If there was a major road or rail accident involving the container there could be a risk of exposure. The liquid cyanide is transported in “isotainers” which have been designed and constructed to withstand severe damage without rupturing. The transportation of Dangerous Goods such as Cyanide are controlled by the Dangerous Goods Act and strict controls and safety measures are applied to the transport of cyanide.
What happens to cyanide if it gets into the environment?
Cyanide quickly breaks down in sunlight to its core elements of carbon dioxide and nitrogen. When exposed to air and in surface water cyanide may form hydrogen cyanide and evaporate. This is a concern if the concentration in the air exceeds 10 parts per million. It is not known to build up in the tissue of living creatures (does not accumulate). Governments enforce strict surface and ground water limits for cyanide. Any spills to the environment are typically small, and are cleaned up and returned to processing facilities quickly.
How can workers be exposed to cyanide?
Workers at gold mining operations can be exposed to cyanide during the tank extraction process if conditions are allowed to become too acidic. Further, direct contact with strong cyanide solutions can cause skin adsorption, and of course drinking any cyanide solution can be quite harmful. Strict safety procedures are in place to ensure workers are not exposed to concentrated levels of hydrogen cyanide or to cyanide solutions.
Why is cyanide dangerous?
In significant amounts, cyanide is very harmful to people and is a fast acting poison in the human body. Severe breathing difficulties develop very rapidly if cyanide is swallowed, inhaled or absorbed through the skin. If people are exposed to concentrated levels of cyanide this could be lethal. Generally, indications are that 0.25 grams of sodium cyanide may be fatal to a person if not promptly treated. Breathing HCN at concentrations over 200 ppm may also be fatal. Cyanide has not been reported to directly cause birth defects but in tropical regions where mothers have been known to eat cassava root some children have been born with thyroid disease. There have been no reports that cyanide can cause cancer in people or animals.
Are there any alternatives to cyanide?
Although research is continuing into alternatives for the extraction of gold, no current environmentally acceptable or economically feasible alternatives exist to the use of cyanide in the gold extraction process. Cyanide is essential to KCGM’s ongoing viability.
What is KCGM doing to reduce the risks of cyanide use?
The actions taken by KCGM for the management of cyanide include:
• Ensuring that manufacturers, suppliers and transporters maintain standards consistent with the cyanide code. This identifies Best Practice methods for safe handling and transport.
• Regular maintenance of plant and equipment used in the handling of cyanide.
• Exclusion of fauna from open water containing harmful levels of cyanide.
• Minimising use of the cyanide through ongoing testwork and optimisation programs.
• Minimising risk of exposure to employees by proactive controls such as area exclusions, alarms and protective alkalinity.
• Communicating with the community any concerns regarding the use of cyanide and providing assistance with emergency response training for the unlikely instance of a leak or spill.
• Putting controls in place to ensure workers are not exposed to cyanide
What is KCGM doing to prevent impacts of cyanide on the environment?
All cyanide management facilities are designed to protect against environmental releases.
Protective measures include:
• Double containment for liquids that contain cyanide
• Double containment for gold processing facilities.
• Excess capture and storage capacities in preparation for extreme storms
• Regular and frequent inspections
• Instrumentation and monitoring
The manufacture and transport of cyanide are not in the immediate control of KCGM operations but KCGM is working in partnership with manufacturers and transporters to ensure responsible management of cyanide. This, in part includes:
• Planning transportation routes.
• Using transportation equipment designed to withstand incidents
• Regular tracking during shipment
• Emergency response procedures.
How do I inform KCGM of any concerns I have with cyanide?
The Public Inquiry line, 9022 1100 is available 24 hours a day seven days a week for all queries regarding our operations. You can also drop into the Super Pit Shop located off the Goldfields Highway Kalgoorlie to talk with our Community Relations team, or email crelations@kalgold.com.au
Where can I get further information on cyanide and its use?
For more information on the Code please visit the International Cyanide Management Code website www.cyanidecode.org or read Edition 5 of KCGM's News & Views Newsletter outlining our approach to the use of Cyanide on site. Additional information can also be found at Barrick Cyanide Information.
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