Improvements in or relating to Mixing or Aerating Apparatus for Use in the Extraction or Recovery of Gold and other Metals.
Year: 1899

page_text: Date of Application, 19th June, 1899-Accepted, 3rd Feb., 1900
Improvements in or relating to Mixing or Aerating Apparatus for Use
in the Extraction or Recovery of Gold and other Metals.
I, WILLIAM DUNCAN, of Day Dawn Ridge, Charters Towers, in the Colony of
Queensland, Engineer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and as-
certained in and by the following statement:
Numerous attempts have, from time to time, be made to secure the thorough
mixing of sands and tailings, including slimes with the solvent while under treat-
ment, and also to prevent that close packing which prevents the percolation of
the solvent and wash liquors. For this purpose vertical vessels with vertical
agitators, revolving barrels, air, steam, and water jets, have been used but these
means have not been as efficient as they might be.
My invention. relates to improved mechanical means for mixing and aerating
sands or tailings, by which terms I include slimes, sludges and concentrates,
while under the action of solvents, whereby time is saved and a better extraction
is obtained, and consists of a semi-circular vat provided with a revolvable agitator
composed of arms arranged helically on a shaft running the length of the vat.
At one end of the vat is placed the fast and loose pulleys and gear for slowly
rotating the agitator, while at the opposite end a series of taps are provided con-
nected to the vat at various heights and to pipes so that the liquor can be drawn
off at any desired point and either run direct to the sump or through a filter to
the sump.
In order that my invention may be clearly understood I will now describe it,
with the aid of the accompanying drawings, in which,
Fig.
represents a side elevation of the plant.
Fig. 2 is one end elevation of same.
Fig. 3 is a view of the opposite end showing decanting cocks.
A is the vat made preferably of iron or steel, semi-circular in section and of
any convenient length; it is carried in a framework of wood, which framework
is extended to carry the driving gear.
Over the top of the vat A is a shaft B (having its centre somewhat below the
centre of the vat), carrying wooden.arms in metal sockets arranged helically on
said shaft. The shaft B is carried in bearings C and has on one end the spur
wheel D into which gears the pinion 12 on the counter shaft B1; this shaft B' also
carries the belt pulleys D³.
At the end of the vats opposite to the gearing I arrange on a diagonal line a
number of taps E (see Fig. 4) secured to the end plate and connected to a common
discharge pipe F which leads direct to the sump, but, by shutting the tap G and
opening the tap G¹ the liquors may be diverted through a filter J and thence on
to the
sump.
The sluice K is fitted for discharging the contents of the vat, after treatment,
by the addition of water.
Although this invention is designed primarily for the treatment of slimes and
sludges it will be understood that it is useful as a most efficient washer and
"

page_text: puddler, and can also be used for treating alluvial; for the latter purpose the
vat would be divided into compartments so that the material could pass from
one to the other and thus permit of continuous treatment...
When working on slimes or sludges the following is the most definite instruc-
tion of the best method to proceed; but, it is obvious that the hereinafter de-
The
scribed treatment must be varied to suit the material under treatment.
solution is first put into the vat and the agitator set in action at the rate of 5 io
12 revolutions per minute, and while in action the material to be treated is
shovelled into the vat in an unscreened condition, the lumps being broken up by
the agitator and liquor, and the whole becomes thoroughly intermixed with the
solution. After the full charge of solids has been shovelled in, the agitator is
kept at work for such time as is necessary for the solvent to act, and eventually
stopped to allow the contents to settle. The clear liquor is drawn off through
the taps E and pipes connected therewith; a weak wash, or, if preferred, a water
wash is added and the agitator revolved again for a short time. The contents
are allowed to settle, the clear liquor being again drawn off and this operation
repeated until the solvent and its contents are washed out completely. To empty
the vat after the last wash has been drained off, water is added, the agitator set
in action and the sluice K opened so that water and slimes are discharged to-
gether, the shaft being kept in motion until all is discharged.
The
The gold in solution is then recovered by any of the well known means.
bottom of the vat may be perforated and provided with an outer case so that the
contents may in some cases be leached, as in an ordinary vat, after agitation.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:
-
1. Improved means for mixing and aerating sands or tailings consisting of a
semi-circular vat, a horizontal revolvable shaft, having arms arranged helically
thereon, gearing at one end of said vat for actuating said shaft, at the opposite
end an arrangement of taps for withdrawing liquor at varying levels and pipe to
convey same to filter and sump as herein described and for the purpose set forth.
Dated this 10th day of Luna 1800
BOULT & WADE,
Agents for the Applicant.