TOR

The mercury extractor or amalgam separator is a machine which is very
simple in construction, and is stated to be most efficient in extracting
quicksilver from amalgam, as it requires but from two to three minutes
to extract the bulk of the mercury from one hundred pounds of amalgam,
leaving the amalgam drier than when strained in the ordinary way by
squeezing through chamois leather or calico. The principle is that
of the De Laval cream separator--i.e., rapid centrifugal motion.
The appliance is easily put together, and as easily taken apart. The
cylinder is made of steel, and is run at a very high rate of speed.

The general construction of the appliance is as follows: The casing or
receiver is a steel cylinder, which has a pivot at the bottom to receive
the step for an upright hollow shaft, to which a second cylinder of
smaller diameter is attached. The second cylinder is perforated, and
a fine wire cloth is inserted. The mercury, after passing through the
cloth, is discharged through the perforations. When the machine
is revolved at great speed, the mercury is forced into the outside
cylinder, leaving the amalgam, which has been first placed in a calico
or canvas bag, in a much drier state than it could be strained by hand.
While not prepared to endorse absolutely all that is claimed for this
appliance, I consider that it has mechanical probability on its side,
and that where large quantities of amalgam have to be treated it will be
found useful and effective.

SLUICE PLATES

I am indebted to Mr. F. W. Drake for the following account of sluice
plates, which I have never tried, but think the device worth attention:

"An addition has been made to the gold-saving appliances by the placing
of what are called in America, 'sluice plates' below the ordinary table.
The pulp now flows over an amalgamating surface, 14 ft. long by 4 ft.
wide, sloping 1 1/2 in. to the foot, and is then contracted into a
copper-plated sluice 15 ft. long by 14 in. wide, having a fall of 1 in.
to the foot. Our mill manager (Mr. G. C. Knapp) advocated these sluice
plates for a long time before I would consent to a trial. I contended
that as we got little or no amalgam from the lower end of our table
plates there was no gold going away capable of being recovered by copper
plates; and even if it were, narrow sluice plates were a step in the
wrong direction. If anything the amalgamating surface should be widened
to give the particles of gold