Oceneni zdroju zlata v odpadech po domorode tezbe v Burkine Faso a moznosti jejich dalsiho vyuziti: vysledky projektu v roce 2004

Burkina Faso represents one of developing countries in West Africa and only during the past 10 years it has been classified by leading world financial institutions as a country with prospective mineral resources (especially gold). Gold has been mostly primitively mined and processed at many places. At present, around 150 000 individuals of whom around 40 % are female are involved in seasonal gold mining, which in combination with agricultural activities represents one of the most important sources of income for people living in countryside. The Czech technical assistance programme on the "Evaluation of gold sources in waste material after artisanal exploitation in Burkina Faso and possibilities of their further economical use"(2003-2005) with a total budget of about 130 000 EUR (about 40 000 EUR in 2004) was focused on the technical-economical evaluation of gold potential in waste material after exploitation and processing of gold ores in selected regions with the aim to contribute to their industrial development, thus minimizing their poverty. Sustainability of the project is justified by a transfer of "know-how" through organizing workshops and field trainings with the aim to facilitate possible future feasible process of gold extraction from waste materials in Burkina Faso. During the second year of the project (2004), tailing material from the Boutouonou 1 and mine waste from Boutouonou 2 and 3 localities (Fada N'Grourma region in the eastern part of Burkina Faso) were studied in more detail with the aim to evaluate their tonnage, characterize their technological properties and calculate the amount of their resources. Special analyses as e.g., yield of Au from variable fractions, output and loss of Au during its separation through gravitation and cyanide leaching methods as well as evaluation of environmental impact of exploitation and processing of Au ores on the quality of surrounding agricultural soil and crop plants were part of this study. Rather low total tonnage of raw material (altogether 19,050 t at all objects) and also pure metal (Au = 64 kg) indicate that these objects do not represent attractive industrial targets. However, they can be efficiently exploited through technologically and methodologically improved primitive artisanal mining. Based on our calculations about 25-37 kg of Au can be extracted from local waste material under present economic conditions in the country. About 3.5-7 kg of Au can be taken out of these waste materials simply using gravitation methods.