The planetGOLD programme and the entire ASGM development community worldwide are eager to support alternatives to mercury amalgamation. Given that cyanide is the current large-scale mining industry standard for gold extraction from milled ore, it may seem obvious that we should carefully consider its potential for ASGM as well. But can cyanide be a responsible alternative for ASGM?
This is a challenging, sensitive, and often politically charged question to wade into, so let’s start with some context. Worldwide, cyanide (CN) compounds (which are made of carbon and nitrogen molecules) are the primary method for extracting gold using a process called cyanidation. While cyanidation can be conducted safely and without harm to the environment if conducted with rigorous safeguards, in practice the process presents considerable safety and environmental risks to workers, communities and the environment.
The risks for communities can be very serious and we have terrible accounts of impact from cyanide spills (e.g. Omai gold Mine in Guyana in 1995; Aural Gold Mine spill in Baia Mare, Romania, in January 2000). When the associated risks are studied and analysed, it becomes clear that these risks can be compounded and dispersed in the artisanal and small-scale gold mining sector.
They can be compounded because ASGM operations are typically undercapitalized and lack formal safety training and environmental management policies (e.g. mine site water management plan; mine site waste management plan). And the risks can be dispersed because ASGM CN operations exist in remote and unpredictable (in some cases unacceptable) locations, near waterbodies, peri-urban living centers, agricultural spaces, etc.
What about the International Cyanide Management Code (ICMC)?
It is clear that the International Cyanide Management Code - developed and used by industrial operators to ensure safe use of cyanide - has limitations on its direct transferability to small-scale gold processing operations. It is also clear that small-scale cyanide processors, both for ore processing and processing of gold-rich tailings, have been spreading like wildfire through some ASGM countries while in others, regulatory mandates or local customs have slowed the spread. The important question for regulators and ASGM stakeholders becomes if and how the risks of cyanidation can be better managed in the ASGM sector.
Where national regulatory frameworks authorize CN use in ASGM, it is imperative that the risks of CN are well understood and that regulators and CN operators are provided with information, guidance, and training to ensure their compliance with regulations formulated to mitigate the health, safety, social, and environmental risks. In an effort to address this critical need, planetGOLD and the international NGO Pact have produced a guidance document on CN management written specifically for the actors in the ASGM sector, worldwide.
In addition to presenting clear points of guidance which are aligned to the International Cyanide Management Code (but directed at ASGM CN operators), the guidance document also presents two national case studies from countries where CN has been in widespread for several decades - to help contextualize the challenges which must be faced and resolved.
It is important to note that using cyanidation on mercury-contaminated ASGM tailings constitutes a “worst-practice” as defined in the Minamata Convention. CN operators should not use cyanide on mercury-contaminated tailings without removing/addressing the mercury first. Refer to the planetGOLD cyanide report and UNEP Guidance document on the management of artisanal and small-scale gold mining tailings for more discussion of this matter.
planetGOLD is not advocating for cyanidation
This planetGOLD document must not be interpreted as advocating for the adoption of cyanidation. Similarly, the document does not wish to sideline or overshadow potentially impactful non-toxic leaching alternatives to cyanide. A relevant note here is that many of the nascent non-toxic/less toxic leaching technologies use similar or the same leaching mechanics/ operations/ infrastructure as cyanidation, and thus key aspects of this guidance are equally applicable to these new (less-toxic) leaching systems.
As the Minamata Convention implementation moves forward, with support from the planetGOLD programme, it is important for stakeholders to continue evaluating regionally appropriate and acceptable alternatives to mercury amalgamation.
Cyanidation can potentially provide an effective alternative to mercury amalgamation but only if CN operators are effectively regulated and CN operators employ sound chemicals management systems which provide effective risk mitigation for occupational health and safety, and environment hazards. Policymakers and regulators, as well as planetGOLD country teams around the world, stand to benefit from an improved understanding of responsible and safe CN management.