Abstract:
The combination of gold's relative scarcity and its elegant beauty
has made it a very valuable commodity throughout the history of humanity. It is
much evident that Sri Lanka is processing placer type secondary gold occurrences
scattered with most of the alluvial gem gravel deposits in many areas.
Unfortunately discards after panning for gem stones which contain finer particles of
gold together with sand are thrown away as waste or sold out as a substitute to
river sand. Therefore, it is important to find methods of recovering gold from gem
gravel. In this study, Physical separation methods such as Table separation and Jig
concentration were basically used for gem gravel as well as stream bed sediments
from several parts of the country. After samples (about 300Kg) were processed, we
were able to concentrate 71.2mg of gold particles and a relatively high amount of
heavy minerals like Garnet, Rutile, Ilmenite, etc... Though the presence of gold in
placer deposits exhibits relatively a low concentration, the high production cost in
gold industry (630$ per ounce) elsewhere makes it a cheaper method to gold from
gem gravel as a by-product of gem mining.
Citation:
Sampath, J.D.S., Abyegunawardana, P.H., Anojan, R., Gunasekara, R.D.I., Dharmaratne, P.G.R. & Rohitha, L.P.S. (2010). Gold recovery from gem gravel. In A.M.K.B. Abeysinghe, H.M.R. Premasiri & S. Karunaratne (Eds.), Proceedings of the 5th Annual Conference on Earth Resources for National Development (pp. 17-20). Department of Earth Resources Engineering, University of Moratuwa.