Inside of a gold kacha concentrator

Technical Solutions

Reducing mercury use and improving efficiency with better practices and technologies

The planetGOLD programme is promoting and piloting alternative technologies and better practices with artisanal and small-scale gold miners. That means more money for miners and their families and fewer risks to their health, their communities, and the environment.

Better Practices - Higher Yields

When used properly, technologies and practices that reduce or eliminate the use of mercury can extract a greater amount of gold than traditional methods using mercury amalgamation. The appropriate technologies will depend on the ore type, available resources, and social and economic factors. There is no single technology appropriate to every artisanal and small-scale gold mining (ASGM) situation, but successful approaches often include some combination of:

  • Improved crushing and milling
  • Gravity concentration tools such as sluicing and shaking tables
  • Flotation
  • Chemical leaching
  • Eliminating the Worst Practices


Eliminating the Worst Practices

The best place to start reducing mercury use and exposure in ASGM is by eliminating the four worst practices, as defined by the Minamata Convention on Mercury.

  • Whole ore amalgamation
  • Open burning of amalgam or processed amalgam
  • Burning of amalgam in residential areas
  • Cyanide leaching in sediment, ore, or tailings to which mercury has been added without first removing the mercury

In communities where these practices are utilized, the planetGOLD country projects are promoting adoption of the better practices outlined below.

graphic showing ASGM worst practices and better practices


Why is Mercury Used?

If miners can often get better results by using other methods, why is mercury use still so widespread in the ASGM sector? Extracting gold using mercury is quick and easy, and it can be used by a single person. Mercury can also be cheaper in the short term, and it is easy to transport anywhere, whereas other technologies sometimes require large equipment that cannot be moved easily. There are also more complex socioeconomic reasons where mercury plays a role in how profits are shared. For example, miners may need to extract gold every day to meet subsistence needs and may not have the time required for technologies that take longer to work. And finally, miners may simply not be aware of the alternatives or have the capital required to pursue them.

why mercury


Beyond Technical Solutions

Focusing on technical solutions alone is rarely sufficient to reduce mercury use in ASGM on a sustainable basis. With greater awareness and formalization of the sector comes more opportunities to access finance. Access to finance makes possible safer solutions to gold processing, which in turn improves the livelihoods of the mining communities.