Getting Gold: A Gold-Mining Handbook for Practical MenJohnson, J. C. F. (Joseph Colin Francis)
History
Getting Gold: A Gold-Mining Handbook for Practical Men
Johnson, J. C. F. (Joseph Colin Francis)
Gold mines and mining
Another form of “shaking table” is one with a lateral motion, and this,
whether with amalgamated plates, or provided with small riffles, or
covered with blanket, keeps the pulp lively and encourages the retention
of the heavier particles, whether of gold or base metals containing
gold. There has also been devised a rocking table, the action of which
is analogous to that of the ordinary miner’s cradle. This appliance,
working somewhat slowly, swings on rockers from side to side, and is
usually employed in mills where, owing to the complexity of the ore,
difficulties have been met with in amalgamating the gold. Riffles are
provided and even very fine gold is sometimes effectively recovered by
their aid.
The Frue vanner will, as a rule, act well when the pulp is sufficiently
and consistently fine. It is an adaptation of the old simple apparatus
used in China and India for washing gold dust from river sand. The
original consisted of an endless band of strong cloth or closely woven
matting, run on two horizontal rollers placed about seven feet apart,
one being some inches lower than the other. The upper is caused to
revolve by means of a handle. The cloth is thus dragged upwards against
a small stream of water and sand fed to it by a second man, the first
man not only turning the handle but giving a lateral motion to the band
by means of a rope tied to one side.
[Illustration: FIG. 24. FRUE VANNER.]
Chinamen were working these forerunners of the Frue vanner fifty years
ago in Australia, and getting fair returns.
The Frue vanner (Fig. 24) is an endless india-rubber band drawn over an
inclined table, to which a revolving and side motion is given by
ingenious mechanism, the pulp being automatically fed from the upper
end, and the concentrates collected in a trough containing water in
which the band is immersed in its passage under the table; the lighter
particles wash over the lower end. The only faults with the vanner
are--first, it is rather slow; and secondly, though so ingenious it is
just a little complicated in construction for the average non-scientific
operative.
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Elsewhere in the archive
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account