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Ghana: Gold Mining Resurgence: Difference between revisions
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Ghana: Gold Mining Resurgence (view source)
Revision as of 12:00, 8 April 2015
, 12:00, 8 April 2015→Alteration of the physical environment
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Even without the use of mercury, the effect of alluvial extraction methods by artisanal miners can be devastating by disturbing the physical characteristics of the environment. Miners are not particularly concerned about water discharge and simply deal with flow as they require for the immediate purposes of their mining activities. They dig pits in or alongside river beds in which they need just enough water for washing the gold (and diamond) bearing gravels. Habitats for aquatic life are therefore greatly disturbed and thus food availability is limited because excavation pits destroy the vegetation cover and aquatic macrophytes, which reduces the amounts of organic matter available to invertebrates and omnivorous fish. <ref name="Rambaud" /> Environmental damage has been exacerbated beyond alluvial mining areas by the expansion of ASM gold mining outside easily accessible diamond-bearing gravels in the proximity of streams. “[M]iners have now moved several kilometres outwards from the low-lying diamond-bearing areas to weathered and primary host rock gold-bearing material in comparatively higher ground”<ref name="Nyame" />(p.168). | Even without the use of mercury, the effect of alluvial extraction methods by artisanal miners can be devastating by disturbing the physical characteristics of the environment. Miners are not particularly concerned about water discharge and simply deal with flow as they require for the immediate purposes of their mining activities. They dig pits in or alongside river beds in which they need just enough water for washing the gold (and diamond) bearing gravels. Habitats for aquatic life are therefore greatly disturbed and thus food availability is limited because excavation pits destroy the vegetation cover and aquatic macrophytes, which reduces the amounts of organic matter available to invertebrates and omnivorous fish. <ref name="Rambaud" /> Environmental damage has been exacerbated beyond alluvial mining areas by the expansion of ASM gold mining outside easily accessible diamond-bearing gravels in the proximity of streams. “[M]iners have now moved several kilometres outwards from the low-lying diamond-bearing areas to weathered and primary host rock gold-bearing material in comparatively higher ground”<ref name="Nyame" />(p.168). | ||
''How artisanal miners extract gold'' | ''How artisanal miners extract gold'' | ||
''In a typical small-scale gold mining operation where hard rock is mined, the ore is excavated manually and size reduction is carried out using a combination of jaw and rocker crushers, hammer, disc and stamp mills. The stamp mills and rockers are manually operated while the others are powered by diesel or electricity. Generally, the milled material is washed in a sluice lined with corduroy, jute material, miner’s moss or astro turf to obstruct the flow of slurry and concentrate gold particles. Alluvial ores do not go through comminution [the reduction of solid materials to smaller sizes] but are scrubbed, screened and concentrated by sluicing. The concentrate in both cases is cleaned in pans and the gold is amalgamated with mercury. The amalgam is then roasted to obtain the gold, which is sold to licensed buyer.'' <ref name="Nyame" />(p.133). | ''In a typical small-scale gold mining operation where hard rock is mined, the ore is excavated manually and size reduction is carried out using a combination of jaw and rocker crushers, hammer, disc and stamp mills. The stamp mills and rockers are manually operated while the others are powered by diesel or electricity. Generally, the milled material is washed in a sluice lined with corduroy, jute material, miner’s moss or astro turf to obstruct the flow of slurry and concentrate gold particles. Alluvial ores do not go through comminution [the reduction of solid materials to smaller sizes] but are scrubbed, screened and concentrated by sluicing. The concentrate in both cases is cleaned in pans and the gold is amalgamated with mercury. The amalgam is then roasted to obtain the gold, which is sold to licensed buyer.'' <ref name="Nyame" />(p.133). | ||
During the days GCD was the leading diamond miner in Ghana it created a 30-metre buffer zone alongside stream channels where mining was prohibited. This was a deliberate strategy to prevent environmental degradation and pollution. With the demise of GCD, artisanal miners felt free to begin mining these areas, leading to increased siltation of waterways, and to divert lengthy sections of stream channels. Such behaviour resulted in the complete diversion, for example, of the Birim River in the Akwatia area of Ghana, and in combination with deforestation and siltation also caused by small-scale miners, it has led to wholescale flooding during the annual rainy season, including loss of life and large-scale displacement of local peoples. | During the days GCD was the leading diamond miner in Ghana it created a 30-metre buffer zone alongside stream channels where mining was prohibited. This was a deliberate strategy to prevent environmental degradation and pollution. With the demise of GCD, artisanal miners felt free to begin mining these areas, leading to increased siltation of waterways, and to divert lengthy sections of stream channels. Such behaviour resulted in the complete diversion, for example, of the Birim River in the Akwatia area of Ghana, and in combination with deforestation and siltation also caused by small-scale miners, it has led to wholescale flooding during the annual rainy season, including loss of life and large-scale displacement of local peoples. | ||
===Weakening of the Kimberly Process=== | ===Weakening of the Kimberly Process=== | ||