Mercury and cyanide in gold mining

将调查金矿开采的汞排放及其知识缺口，以便创造必要的知识，建立工具，以了解和减少排放并改进金矿开采做法。金矿开采——特别是手工和小规模金矿开采（ASGM）——释放的汞的命运和影响仍然知之甚少。尽管这些排放是即将到来的全球汞条约（联合国）的一个关键问题。2009年2月，在内罗毕召开的联合国环境规划署理事会一致同意制定一项具有法律约束力的条约（第25/5号决议）。根据拟议的条约，反舰导弹是最受关注和最需要关注的领域之一。这主要是因为据估计，ASGM每年向环境释放1200吨汞，仅次于燃煤。在我已确定并向国际社会提出的关于汞和金矿开采的12个关键知识空白中，我要求提供资金，支持对改进做法最关键和对条约制定最具协同作用的两个方面进行基础科学研究。它们是(i)汞和氰化物的相互作用；（ii）释放的命运。值得注意的是，尽管汞和氰化物经常在ASGM中一起使用，但人们对氰化汞的化学性质知之甚少。什么是氰化物-汞配合物？它们会持续多久？怎样才能最有效地摧毁它们？腐烂产物的命运如何？氰化物能促进汞的生物积累吗？什么技术可以最好地取代这种做法？氰化物如何增加空气排放？关于金矿开采释放的汞的命运，金矿开采排放了多少汞？直接进入大气和水圈的有多少？它能走多远？尾矿的潜在排放量有多大？ASGM排放的汞是什么种类？这项研究的部分成果将与联合国环境规划署合作，编入www.mercurywatch.org全球汞排放数据库。

Emissions of mercury from gold mining and the knowledge gaps about them will be investigated in order to create the knowledge needed to build tools to understand and reduce emissions and improve gold mining practices. The fate and effects of mercury released from gold mining - particularly Artisanal and Small Scale Gold Mining (ASGM) - remains poorly understood. This is despite the fact that these releases are a key concern of the forthcoming global mercury treaty (UN). The creation of a legally binding treaty was unanimously agreed to by the world's governments in February 2009 by the Governing Council of the United Nations Environment Program in Nairobi (Decision 25/5). Under the proposed treaty, ASGM is one of the areas receiving and needing the most attention. This is mainly because ASGM is estimated to release 1200 tonnes of mercury to the environment each year, second only to coal burning. Of the 12 key knowledge gaps about mercury and gold mining that I have identified and presented to the international community, I am asking for funding to support basic scientific research into the two most critical to improving practices and most synergistic to the development of the treaty. These are (i) Mercury and Cyanide interactions; and (ii) the fate of releases. Remarkably, despite the fact that mercury and cyanide are often used together in ASGM, very little is known about mercury-cyanide chemistry. What are the cyanide-mercury complexes? How long do they persist? How can they most efficiently be destroyed? What are the fate of the decay products? Can cyanide enhance mercury bioaccumulation? What technologies can best replace this practice? How does cyanide enhance air emissions? Regarding the fate of mercury released from gold mining, How much mercury is emitted from gold mining? How much of it directly enters the atmosphere versus hydrosphere? How far does it travel? How large are latent emissions from tailings? What is the speciation of mercury emitted from ASGM? Part of the outcomes of this research will populate the www.mercurywatch.org database on global mercury emissions in collaboration with the United Nations Environment Program.