Impact Factor (2025): 6.9
DOI Prefix: 10.47001/IRJIET
The upper
crust of the Sanoukou area, Kenieba district in the southwest parts of Mali are
well known for the placer gold occurrences. The extraction of the gold by using
primitive tools has been practiced since long period in the region. However,
mining of placer gold in Mali has not been given due consideration so far. The
study of the placer deposit of Sanoukou stream terrace has, therefore, been
carried out to determine the mineralogy their texture, size and shape of these
placer deposits, which help in investigation the source rock for gold and also
to design methods for the extraction of placer gold in more economic manner.
Placer deposits result from weathering and release of the gold from lode
deposits, transportation of the gold, and concentration of the gold dominantly
in stream gravels which composed mainly of laterite-gravels with clay cemented.
Unless preserved by burial, a placer subsequently may be eroded, and either
dispersed or re-concentrated.
The
estimation of mineral resources/reserves together with a quantification of the distribution
of metallurgical attributes provide strong evaluation of the large alluvial
gold deposits within west Sanoukou and its surrounding, which occurs along the
flank of the stream. This reduces the risk arising from uncertainties within
the ore body as far as geological and metallurgical information are concern and also improve decision making
processing during the production stage
of the mining project. Hand-dug pits data formed the basis for the estimation
of the source as well as the determination of the spatial distribution of the
metallurgical parameters of the west Sanoukou gold deposits. A typical grid
density of 50m x 50m was used for the pitting between 2m to 7m depth. Detailed
logging of pit samples together with processing provided first-hand information
concerning the metallurgical behavior of the gold bearing gravels and
subsequent distribution of these parameters. The estimation of the mineral
sources have been based on an initial estimation of the gold grade and gravel
section using the Inverse Distance Weighting (IDW) technique and subsequent
estimation of the sources using the volume and mean grade of the ore. A total
volume of 448,672m3/717875 tones gold bearing gravels were estimated
at average grade of 0.1675g/t and 120,244 grams of the alluvial gold within the
area of 600 x 300m. With 92% purity of gold so the estimate resource will be
110,624.538g equal 3,539.71439oz.
The gold
within the study area are usually fine in nature with majority of the fine to
medium gold occurring at the upstream of the drainage in the area. Clayey
materials also represent large portion of the gold bearing gravels in almost
all the sampled area.
Country : Sudan
IRJIET, Volume 6, Issue 12, December 2022 pp. 19-37