|Abstract Title:||Emissions, releases, and fate of Hg from Artisanal Small Scale Gold Mining in tropical and subtropical Countries|
|Presenter Name:||Francesco De Simone|
|Session:||Mercury in Artisanal Gold Mining|
|Co-Authors:||Francesco De Simone,Delia Evelina Bruno|
Abstract Information :
Artisanal and small scale gold mining (ASGM) occurs mainly at sites located in tropical and subtropical belt, and often in regions with sensitive ecosystems. In some of these highly vulnerable contexts, mining activities have been present for millennia, contributing to damage to the landscape both for geomorphological and geochemical reasons . Large quantities of mercury used for Concentration Amalgamation and Whole Ore Amalgamation processes are released both to the atmosphere and to soils and waters. The Minamata Convention entered into force in 2017 binding the adhering Countries to limit mercury use. This work attempts to refine the estimates of mercury losses from ASGM in 56 countries where it is practised. The work was performed starting from gold production on the basis of: i) official databases from 2006 to 2019; ii) estimates of reserves based on petrographic and mineralogical characteristics . Data on the mining history of each country was collected to construct a database covering ASGM activity from the start of extraction activities until 2019. Based on production of gold for the period 2006-2019, in Asia, China and Papua New Guinea emitted 1665 and 1174 tons of Hg to the atmosphere, in Africa, Rwanda emitted 1099 tons and in Latin America Peru 1003 tons. Considering the extended period , apart from China where emissions to the atmosphere and releases to soil and water have long been significant, the countries with the greatest quantities of Hg lost emitted to the environment are, Per u, Rwanda, Indonesia, Colombia and Egypt with over 10K tons. To estimate future emissions 6 scenarios were constructed to simulate Hg release up to 2050, considering variation mercury use with amalgamation in the processes, the extent of ASGM , and the introduction of Hg recovery techniques . The modelling tools included in the GOS4M knowledge hub (https://gos4m.org/kh) were used to investigate the fate of mercury emitted under these scenarios and compared with scenarios planning reduction from other industrial sectors.