Remediation of mercury polluted tailings

The majority of small-scale gold miners use mercury to capture their gold. The mercury is subsequently burned off and the gold is ready for selling. Unfortunately a large part of the mercury containing gold ends up in tailings as tiny drops called mercury flour. Mercury flour slowly evaporate and accounts for 37 % of global mercury pollution. Mercury flour contain high amounts of gold which is lost for the miners. It is thus a lose-lose situation.

In 2014 Danish Ministry of Environment rewarded Danish Elplatek and Appelglobal a grant to determine possibilities to extract mercury flour from tailings from small-scale gold mining. The processing plant consist of two unites Mercury Recovery Plant (MRP) producing a heavy mineral concentrate including mercury and Peter Plates capturing mercury flour. Two sessions of testing were carried out in Northern Nicaragua. In 2015 follow up financing was rewarded from the Danish Ministry of Environment. The project was terminated October 2016. Follow-up test programme in Nicaragua took place February 2017. The project is carried out in cooperation with Oro Industries, California. The processing plant has the capacity of extracting mercury and gold from 20 tons per hour 24/7. Up to 40 percent of mercury and 75 percent gold can on test runs be extracted from the tailings.

Appel, P.W.U., Na-Oy, L. D., Hatsukawa, Y., Osawa, T., Kystol, J. & Sørensen, L.L. 2011: Cleaning mercury polluted mine tailings in the Philippines. Danmarks og Grønlands. Geol. Unders. Rap. 2011/127, 39

Appel, P. and Esbensen, K: Reducing global mercury pollution with simultaneous gold recovery from small-scale mining tailings. TOS Forum. Special issue June 2019.

Mercury flour in tailings

Mercury recovery plant (MRP)

 

 

 

 

 

 

 

Mercury flour captured on Peter Plates