with experience, will assist the battery manager to adopt
the right system.
The crushed stuff--generally termed the "pulp"--passes from the boxes
through the "screens" or "gratings," and so on to the "tables"--i.e.,
sheets of copper amalgamated on the upper surface with mercury, and
sometimes electroplated with silver and afterwards treated with mercury.
Unless the quartz is very clean, and, consequently light, I am opposed
to the form of stamper box with mercury troughs cast in the "lip," nor
do I think that a trough under the lip is a good arrangement, as it
usually gets so choked and covered with the heavy clinging base metals
as to make it almost impossible for the gold to come in contact with the
mercury. It will be found better where the gold is fine, or the gangue
contains much base metal, to run the pulp from the lip of the battery
into a "distributor."
The distributor is a wooden box the full width of the "mortar," having
a perforated iron bottom set some three to four inches above the first
copper plate, which should come up under the lip. The effect of this
arrangement is that the pulp is dashed on the plate by the falling
water, and the gold at once coming in contact with the mercury begins
to accumulate and attract that which follows, till the amalgam becomes
piled in little crater-shaped mounds, and thus 75 per cent of the gold
is saved on the top plate.
I have tried a further adaptation of this process when treating ores
containing a large percentage of iron oxide, where the bulk of the gold
is impalpably fine, and contained in the "gossan." At the end of the
blanket table, or at any point where the crushed stuff last passes
before going to the "tailings heap," or "sludge pit," a "saver" is
placed. The saver is a strong box about 15 in. square by 3 ft. high,
one side of which is removable, but must fit tight. Nine slots are cut
inside at 4 in. apart, and into these are fitted nine square perforated
copper plates, having about eighty to a hundred 1/4 in. holes in each;
the perforations should not come opposite each other. These plates are
to be amalgamated on both sides with mercury, in which a very little
sodium has been placed (if acid ores are being treated, zinc should be
employed in place of sodium, and to prevent the plates becoming bare, if
the stuff is very poor, thick zinc amalgam may be used with good effect;
but in that case discontinue the sodium, and occasionally, if required,
say once o
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