| The bucket - put to a novel use by artisanal miners in Central Asia to recover placer gold.... ....eliminating the need for a big sluice and reducing panning effort close to zero... | ABSTRACT The article is a Short Note to draw attention to the use of buckets by artisanal miners to help them to recover placer gold in Kyrgyzstan.
The buckets are normal domestic metal buckets each with a plain handle of a curved piece of solid metal rod. However, without exception, the handle has a sleeve of strong rubber slotted over it to make the handle comfortable for prolonged use. The rubber is a slit open tube from a bicycle tyre or similar.
The gold miner carries a bucket full of slurry to the stream where he stands on his favourite stone for balance. Grasping the bucket in both hands, the miner bends down and submerges the bucket until stream water rushes in, and then commences to twist the bucket in tick-tock fashion by muscular arm movements. A plume of suspended clay and silt ejects downstream and vanishes in the torrent.
At intervals, the gold miner pauses and crouches down to inspect the contents of the submerged bucket, while stirring its contents with a stout thick stick. Oversize pebbles are visually checked and discarded into the stream.
The sequence of tick-tocking the bucket then prodding its contents are repeated until the plume of tailings becomes faint.
The gold miner carries the bucket and pours the contents slowly into a short plain in-stream sluice made of ribbed rubber matting set in a shallow metal trough. No hopper is added. Sluicing continues in the normal manner, pausing only to hand pick oversize for inspection and discarding.
When the tailings cease, the rubber mat is lifted from the sluice and carried to a pan placed on the ground. By bending the rubber mat into a half moon, the mat is slotted inside the rim of the pan. The gold pan is an aluminium frying pan modified by removal of the handle. The gold miner flushes the contents of the mat into the pan with water poured gently from a bucket.
The gold miner decants some of the water from the gold pan and carries it to the stream, and commences gold panning in the traditional 'North American' fashion grasping the gold pan in both hands, tilting the pan away from him, submerging the lowered edge of the pan, and using both hands to impart a slight orbital oscillation of the pan.
With most of the oversize and light particles already removed by the bucket and in-line sluice, the panning effort is minimal and rapid, serving only to remove the last of the light particles and some of the black sand. The particles of placer gold are revealed by a final swirl to leave a smear on the pan. The gold is then removed.
The term 'bucketing' is proposed to give proper recognition to prevent the process being lost in the overused blanket term of panning. Bucketing probably has wide application for artisanal and small-scale miners (ASM) in recovering not only placer gold but also alluvial tin (cassiterite), alluvial diamonds and alluvial gems such as rubies, sapphires and emeralds. Bucketing demands considerable physical fitness, but eliminates the capital cost and effort of making a larger sluice, hopper, screen and larger pan. Bucketing cuts the time for sluicing considerably and cuts the time and effort of panning.
The USA Megabucks rocker bucket is also described.
DOWNLOAD ARTICLE
GO TO NEXT ARTICLE
|
