Showing posts from 2011

Fifty thousand gold shops in the world's artisanal gold supply chain

There are approximately 50,000 small gold shops serving artisanal and small scale gold miners worldwide. They are a doorway to engaging artisanal gold mining communities and they are the first link of many in the artisanal gold supply chain to consumers. by Kevin Telmer, Artisanal Gold Council Gold shops and the supply chain  Small informal gold shops are common in artisanal and small scale mining communities. After the miners, they are the next link downstream in the informal gold supply chain. They process raw gold or gold-mercury amalgam and then buy the raw gold product from miners at a price that is typically based on the London fix. This price is well known by both the miners and the shop owners due to mobile phones. Some shop owners will also refine the gold to close to 24 k purity (>99%) before selling it to the next level up in the supply chain. This is often done using the quartering technique which involves creating an alloy with silver and then digestion in nitri

World Artisanal Gold Production

How much artisanal gold is produced per year is an interesting and important question. It defines the size of the artisanal and small scale gold mining (ASGM) economy. This is an informal economy that mainly serves the important role of supporting rural development in developing countries - just as it did in western North-America 100 years ago. Typically around 70% of the value of the gold remains with the miners and in-country. However, due to the informal nature of artisanal and small scale gold mining, a good estimate of annual gold production is not possible. The most recent robust estimate may be the one included in Telmer and Veiga (2009) World emissions of mercury from Artisanal and small scale gold mining. In N. Pirrone and R. Mason (eds.), Mercury Fate and Transport in the Global Atmosphere, Springer Science . This is available at Springer Link . The estimate is 330 tonnes of gold per year or 12% of official world production. The estimate considers a variety of types of data

Silver Causes Huge Increase in Mercury Use in Artisanal Gold Mining

Although gold is the primary target of most Artisanal and Small-scale Gold Miners (ASGM) that use mercury, the role of silver on mercury use can be astonishing. When mercury is applied to ores that contain both gold and native silver, in order to get all the gold, enough mercury must be used to amalgamate both the gold and the silver. Because silver is less rare than gold, some ores can contain ten times as much silver as gold or more - silver to gold ratios of 10:1 or 20:1. So more mercury must be added to these ores to capture all the gold. However, because silver forms a weaker amalgam than gold, the situation is even worse than these numbers imply. A typical mercury-gold amalgam formed by small scale miners contains roughly 50% mercury and 50% gold. Mercury-silver amalgam formed under similar conditions however is closer to 70% mercury and 30% silver. In the case of an ore that contains 10 times more silver than gold, about 20 times more mercury is added in order to capture the gol