According to the United Nations Environment Program (UNEP) Global Mercury Assessment, the artisanal and small-scale gold mining (ASGM) sector is the largest source of anthropogenic mercury emissions, with 53% of these emissions originating in the region of Latin America and the Caribbean. The ASGM sector is also recognized globally as an important source of livelihood for local and rural communities in over 80 countries. As such it is crucial to support the elimination of the use of mercury in the sector and ensure socially and environmentally responsible practices within countries legal frameworks. Responding to its obligations under the Minamata Convention on Mercury, Brazil is currently developing its National Action Plan (NAP), which will provide the country's roadmap for the gold mining sector transformation and strategies to mitigate the risks and impacts arising from the use of mercury.
Miners’ organization as a driver for change
Vale do Rio Peixoto Cooperative (COOGAVEPE), located in the north of the Mato Grosso state, is the largest mining cooperative in the country. It operates in eight municipalities and counts around 7 thousand members. COOGAVEPE is an exemplary model of the ASGM sector organization. Efforts undertaken by the cooperative, such as reducing mercury use, post-mining land restoration, technical and legal support provided to members, and investment in research and development of local mercury-free alternatives, position COOGAVEPE as an example of progressive ASGM organization that could be promoted at local, regional and global levels.
Land restoration practices: paving the way for sustainable mining
A key aspect of COOGAVEPE's operations is the use and the recycling of mercury in a closed circuit. This practice significantly reduces environmental releases and potential risks of contamination of nature and people. The cooperative also developed expertise and technical competence for opening and closing pits. During the excavation phase, the fertile soil layer is set aside and put back during the mine closing stage. This approach helps to re-gain the soil richness after the mining operation ceased, which in turn allows the return of other economic activities, such as soybean planting or livestock farming, strengthening the local economy. Alternatively, the areas are being reforested, with seedlings provided free of charge by the cooperative's nursery.
COOGAVEPE mining representatives welcomed the development of the NAP and underlined that synergetic approach joining the efforts of academia, industry and public authorities will result in sound national strategies to achieve the goal of reducing and, and when possible, eliminating mercury from artisanal and small-scale gold mining in Brazil.
Green and Sustainable Chemistry as a vehicle for more reponsible gold mining
In a pioneering effort to trasition away from mercury, a consortium of institutions including Embrapas Florestas and Agrosilvipastoril, the University of Campinas (UNICAMP), the Federal University of Mato Grosso (UFMT), the State University of Maringá (UEM) and COOGAVEPE, work on a study to test the effectiveness of four bioextracts produced from a native Amazonian tree, known as Pau de Balsa (scientifical name Ochroma pyramidale) - as a potential mercury free technology in gold mining.
The plant is already used as an alternative to amalgamation process in ASGM in other countries, such as in the Chocó region, in Colombia. The researchers' objective is to elaborate a more sustainable product that can be applied in broader ASGM context and is attractive to miners in terms of price and ease of use.
The researchers from Embrapa Florestas stated that if viability of the extracts is confirmed in the laboratory setting, the process will need to be carried out in the field with the miners who intend to use the technology to gain their trust and provide training.
The logistic arrangements necessary to produce Pau de Balsa and to build bio-refineries for processing the extract at a scale that can support the ASGM sector transformation are still to be determined. The bio-refineries will allow for the creation of autonomous systems and strengthen a cycle of plant cultivation and processing, which also creates other jobs and makes the technology economically viable. Moreover, the collaboration between miners and researchers is a rare example of mercury free solution being developed and financed by a small-scale mining sector.
For more information please visit the Ouro sem Mercurio website dedicated to the Minamata NAP development in Brazil: https://www.ourosemmercurio.com.br
