Indonesia – ASGM Mercury-Free Technology
Yayasan Tambuhak Sinta (YTS), Geological Survey of Denmark and Greenland (GEUS), and Emerald Mt.
In Indonesia, up to 300,000 small-scale miners rely on various methods for gold extraction and processing for income. Mercury-use has increased within the past 20 years, in part due to a process called “whole-ore amalgamation.” Capturing gold using mercury amalgamation is preferred among gold processors as the technique is relatively easy and can generate income quickly to cover miners’ daily expenses.
Blacksmith Institute and its implementing partners have introduced the ‘Manado Method’ of gravity concentration to ASGM communities throughout Indonesia. The Manado Method is a highly effective gravity concentration that eliminates the need for mercury during the gold extraction process. The Manado Method makes use of natural and abundant resources, namely sugar palm fibers, located within the region.
The pilot project focused on three main components of development: technology, society/community and political involvement. Solutions included the introduction of mercury-free technology in ASGM communities, community outreach and education, and capacity building among stakeholders and governments.
Field-level project implementation began in March 2013. Gadjah Mada University and the Islamic University in Yogyakarta hosted presentations on the following: project details, health and sustainability benefits to mercury mitigation, and existing barriers to intervention.
The project also used existing materials from previous projects in Indonesia and supplemented materials from the Philippines, adapted to the local context to raise awareness regarding the health risks of mercury and to the benefits of mercury-free practices.
The results were promising, by the end of June, teams were able to get detailed and reliable gold recovery data from one shed that has already converted to the Manado Method. This operation is run by a small group of miners from Tasikmalaya. They provided the following information on their gold recovery:
|Gold Recovery Process||Recovery Using Mercury||Recovery Without Mercury|
|Primary Process (Mercury)||0.3g Au per sack||1.2g Au per sack|
|Secondary Process (Cyanide)||1.6g Au per sack||3.6g Au per sack|
From the data above, we can see that their primary gold recovery of gold has now increased to 400% of previous recovery. Considering that their profit margin was previously slim, the profitability of their gold mining activity has increased enormously as a result, perhaps by as much as ten times.