Cyanide Management

One of the most critical materials to our operations – and one often associated with communities’ concerns – is cyanide. Cyanide is commonly used in the gold mining industry, and three of our four operations (Cerro San Pedro, Mesquite and Peak Mines) use cyanide to extract gold and silver from the ore. At those operations, the responsible use and management of cyanide are of critical importance.

While cyanide has inherently toxic properties, its safe transport, handling, storage and use are well understood and manageable. All three New Gold operations that use cyanide in the gold-extraction process follow procedures that are guided by the International Cyanide Management Code (ICMC). The ICMC is a voluntary initiative for the gold mining industry and is intended to complement an operation’s existing regulatory requirements. The ICMC provides an international benchmark for transporting, storing and using cyanide for the safety of personnel, surrounding communities and the environment.

In October 2010, New Gold was accepted by the International Cyanide Management Institute (ICMI) as a signatory to the International Cyanide Management Code (ICMC). Cerro San Pedro and Mesquite Mines were first certified in 2013. Cerro San Pedro achieved recertification under the ICMC in 2015, joining the Mesquite Mine, which was recertified during the same period. Although Peak Mines was temporarily withdrawn from the certification program in 2014, they are guided in their management practices by the ICMC as part of our New Gold Environmental Management Standards, and have robust procedures in place to lessen the risks to wildlife.

Performance in 2016

The following summarizes our performance in regards to cyanide management in 2016:

  • New Gold sites collectively consumed 16,364 tonnes of sodium cyanide, about 10% more than last year. The Mesquite and Cerro San Pedro Mines saw increases of 71% and 2% respectively.
  • Ten cyanide-related wildlife deaths occurred. While none of the species were listed as threatened or subject to special protection status, each of these cases was reported internally and to regulatory agencies as required. Each case was investigated and our processes were reviewed and improved to reduce the risk to fauna in the future.
  • Two spills of materials containing cyanide occurred at Cerro San Pedro: a solution spill at the refinery and a sludge spill at emergency pond during clean-up activities. In both cases, cyanide did not leave the site. Clean up proceeded immediately. Investigations and root-cause analyses were completed and corrective actions have been implemented.
Sodium Cyanide Consumption (tonnes) 2014 2015 2016
Mesquite Mine 1,812 1,481 2,533
Peak Mines 1,573 1,204 1,027
Cerro San Pedro Mine 12,139 12,574 12,804
Total 15,224 15,259 16,364

While we seek continuous improvement in order to find optimal application strength and reduce the use of cyanide, the amount of cyanide used at our operations constantly varies to reflect the volume of ore processed as well as changes in ore composition and associated leaching requirements. At Mesquite, a significant increase of cyanide use resulted from recontouring of existing heap leach areas, the establishment of a new heap leach area and a change in ore composition requiring increased cyanide use for the leaching process. On the other hand, at Peak Mines, we continue to reduce the use of cyanide by optimizing processes – a 23% reduction in 2015 was followed by a further 30% reduction in 2016.

New Gold takes all cyanide-related incidents very seriously and works to improve practices by assessing and controlling identified risks and through investigation and corrective actions once an incident is recorded. We train our staff to look for and report conditions that may result in wildlife deaths, such as ponding on our heap leach pads or irregular fluctuations in cyanide concentration in process solutions. These steps ensure that we learn from incidents and make our processes safe for wildlife.

Wildlife Mortalities from Cyanide Exposure

Wildlife 2014 2015 2016
Birds 6 9
Mammals
Reptiles 2
Amphibians 1
Total 2 6 10
ICMI