Cyanide Management

Cyanide is a critical input for New Gold operations and across the gold mining industry; yet given its toxic nature if not managed correctly, cyanide is also a topic of great interest for our local communities of interest.

Since the late 19th century, use of cyanide to extract gold from ore has been the dominant method across the mining industry. This is because gold typically occurs at low concentrations in ores and chemical extraction processes using cyanide is the only economically viable method of extracting the gold from the ore.

In 2017, four of five New Gold operations (Cerro San Pedro, Mesquite, Rainy River and Peak Mines) used cyanide to extract gold and silver from the ore. The responsible use and management of cyanide is critically important at these operations. New Gold is a signatory to the International Cyanide Management Code which aims to uphold best practice in the gold and silver mining industries.

Description of Impacts

While cyanide has inherently toxic properties1, when done properly, it is safe to transport, handle, store and use in carefully managed situations.

The proper use of cyanide results in negligible impacts: it is handled and used in a way that prevents its release to the surrounding environment. Potential impacts can occur in cases when the environment interacts with the cyanide, such as when birds land in areas of our operations that cyanide is being used, or when cyanide is accidentally released to the environment due to emergency circumstances such as a vehicle accident during transport. It is therefore imperative that we have emergency contingencies and training of personnel to cover all of the risks that cyanide can cause to the environment and local communities.

Management Approach

All three New Gold operations that use cyanide follow procedures in alignment with the International Cyanide Management Code (the Code). The Code is a stringent international best-practices standard developed to complement and add to operations’ existing regulatory requirements. To be certified under the Code requires the adoption and maintenance of the highest standards of care for transporting, storing, and using cyanide. In 2013, Cerro San Pedro and Mesquite Mines achieved certification under the Code, and both mines achieved re-certification in 2017.

Despite conforming with all but one requirement of the Cyanide Code Standards of Practice, Peak Mines was temporarily withdrawn from the certification program in 2014. Peak Mines was found non-compliant with the standard that deals with preventing wildlife contact with cyanide at site. While historically the site can prove extremely low incidence of wildlife mortality and a robust procedure to further decrease risk to wildlife, the criteria that the International Cyanide Management Institute has adopted meant that Peak could not be certified. In 2017, Peak Mines continued to be guided by the Code in their management practices, as part of our New Gold Environmental Management Standards, and have robust procedures in place to minimize cyanide-related risks to wildlife.

2017 Cyanide Management Performance Spotlight

  • New Gold sites collectively consumed 17,490 tonnes of sodium cyanide, an increase from last year mostly because of a significant increase in cyanide use at Mesquite to improve the recovery of gold from the leach pad.
  • Six spills of materials containing cyanide occurred across New Gold. Two at Cerro San Pedro, one at Rainy River, and three at Mesquite. Details on these spills are provided in the Appendix.
  • Fourteen cyanide-related wildlife mortalities 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 individually, and processes were reviewed and improved to reduce risks to wildlife. Further details on these wildlife mortalities are provided in the Appendix.

We seek to continuously improve efficiency in our cyanide use as it is not only a potential source of environmental or health and safety risk, but it is also a major cost driver. We always look for efficiencies in in the amount used, but in the end the amount of cyanide used remains tied to ore.

Sodium Cyanide Consumption (tonnes)
Sites 2015 2016 2017
Mesquite Mine 1,481 2,533 6,223
Peak Mines 1,204 1,027 1,148
Cerro San Pedro Mine 12,574 12,804 10,119
Total Consumption 15,259 16,364 17,490

 

Wildlife Mortalities from Cyanide Exposure
Wildlife 2015 2016 2017
Birds 6 9 10
Mammals 2
Reptiles
Amphibians 1
Total 6 10 12

Most of the cyanide-related wildlife mortalities were birds (8) at the Cerro San Pedro heap leach. The identified cause of these was ponding of cyanide solution on the surface of the heap leach, with which the birds then came into contact. To reduce the risk of further bird fatalities at Cerro San Pedro, several corrective actions were put in place. These included regular inspections of the heap leach pad perimeter, the identification and elimination of ponding on the heap leach surface, the increase of berm height in relevant areas, and the construction of freshwater reservoirs to attract wildlife to a safe place to drink. In addition, workers were re-trained to use sonic cannons to chase birds off the area of most risk to them.

New Gold takes all cyanide-related incidents very seriously. When an incident occurs, we assess what happened and ensure that identified root causes are addressed with corrective actions. We train our staff to look for and report conditions that may result in wildlife deaths. These steps ensure that we learn from incidents and make our processes safe for wildlife.

A comprehensive table with details of all cyanide-related incidents is available in the Appendix.