Sustainable development of small-scale mining
Fact sheet, About small-scale mining. Services offered by GEUS within small-scale mining.
Small-scale mining provide sources of income for many people
Small-scale/artisanal mining for gold is a world-wide phenomenon, which directly and indirectly supports in excess of 100 million people. Small-scale gold mining provides jobs in remote villages, reduces migration of ablebodied people to urban areas, and helps fight poverty, but may also involve considerable risks for the environment and people's health. It is thus important to create the best working conditions for small-scale miners.
Small-scale mining can be carried out as a sustainable activity, but is unfortunately mostly carried out by non-educated people with little knowledge of the environmental and health hazards related to small-scale mining.
Effects on environment and health
One obvious environmental problem is deforesting of vast areas, where the wood is used for processes related to small-scale mining. Tunnelling and digging of numerous pits in unconsolidated river sediment releases large amounts of fine-grained material, which tend to clog up the rivers and increase the risk of flooding. Gold extraction by amalgamation without use of retorts releases thousands of tonnes of mercury to the environment in metallic form. After some time metallic mercury is converted to methylated mercury, which is even more toxic than metallic mercury. It then enters the food chain. At the top of the food chain are people, who by eating the polluted fish gradually accumulate large amounts of very toxic methylated mercury in their bodies. This result in a number of diseases.
Apart from mercury poisoning and collapse of unsupported tunnels, the health risks includes silicosis from crushing of gold-bearing quartz, rheumatism from standing in cold water without proper boots and clothing and severe lung problems from the use of nitric acid for purifying gold concentrates.
How to improve small-scale mining
Most of these problems can fairly easily be avoided through dedicated teaching programmes for the small scale/artisanal miners themselves.
Many small-scale miners work with techniques, which only allow them to recover a small percentage of the gold in either placer deposits or hard rock. Training courses in the use of inexpensive equipment and better understanding of basic geology will certainly increase the recovery of gold significantly and reduce the risks involved.
Experience within Small Scale Mining
The Geological Survey of Denmark and Greenland (GEUS) is the national agency advising the Government of Denmark and the Homerule Government of Greenland in a number of aspects related to mineral exploration and exploitation.
GEUS has worked with problems associated with small-scale mining in Tanzania, Lao PDR, Kyrgyz Republic and Greenland.
The work in Tanzania was carried out for Danida and comprised a study along lake Tanganyika where extensive small scale mining involving widespread amalgamation created severe mercury pollution of the environment and resulted in high concentrations of mercury in the bodies of the small scale miners.
In Kyrgyz Republic a baseline study of small-scale mining was carried out for the World Bank. It comprised detailed work in the field to evaluate, which of the methods actually applied could be improved, and also included a socio-economic assessment of artisanal mining in Kyrgyzstan in general. This study was followed up by several training courses and a distant learning programme for the small-scale miners. During our work in Kyrgyzstan we became aware of yet another technique within small-scale mining, the so-called acid treatment. The process produces highly toxic nitrous oxides. A joint project of GEUS, the World Bank and WHO has now been established to teach small scale miners how to work properly with nitric acid.
In Greenland GEUS has been involved in evaluating projects for possible small scale mining projects.
Services offered by GEUS within small-scale mining
Recognising that small-scale mining can be an effective activity towards the alleviation of poverty in poor areas, GEUS is prepared to offer the following services in projects related to small scale mining, aimed at improving the conditions for the people involved and increasing the economic benefit by better recovery:
Assessment of conditions for artisanal and small-scale mining
Training courses for small-scale miners so they can improve the recovery of gold with less damaging impact on environment and health.
Legal advice to Governments and local authorities to support the activities of small-scale miners.
Training courses in basic geology to facilitate improved recovery of gold and other precious metals.
Small-scale gold mining - high mercury risk, Tanzania