AU765186B2 - An improved gold sluice - Google Patents

Description

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

TO BE COMPLETED BY APPLICANT Name of Applicant: MINTRAP PTY LTD Actual Inventors: Douglas Gordon Westbury; and Courtney James Field *o Address for Service: CALLINAN LAWRIE, 711 High Street, Kew, Victoria 3101, Australia Invention Title: AN IMPROVED GOLD SLUICE The following statement is a full description of this invention, including the best method of S performing it known to us:- *go• *o* *•g 08/07/03,jbl 3178.spe,1 -2- AN IMPROVED GOLD SLUICE This invention relates to apparatus used for the concentration of gold and/or other heavy minerals contained in alluvial deposits or crushed mineralised ore.

BACKGROUND TO THE INVENTION Precious minerals, such as gold are extracted from alluvial or placer deposits or milled ore, etc, by known processes which generally use water for washing the material and to transport it through a system. Such processes involve panning, sluicing, shaking tables, jigs, spinning bowls and amalgamation. These washing processes are well known to the mining and extractive mineral industry. Vibration or agitation of some sort is commonly used to aid the work of gravity and fluid motion.

The present invention differs from known devices because:- Water does not flow through the device nor does it act as a transporting medium, although water is used to immerse and wash the material.

The present invention makes use of known principles:- Firstly, it is known that loose, free material will be levelled when it is subjected to motion, especially, such as shaking or vibration.

Secondly, when a circular pan is oscillated by a shaking or vibratory motion in a horizontal plane around a vertical axis, the rotation (to and fro) of the pan keeps the particles in motion and causes the heaviest minerals to settle to the bottom.

20 SUMMARY OF THE INVENTION The present invention provides apparatus for wet or dry separation of minerals from a mixture of particulate minerals of different densities, comprising: Refer Fig 1. A doughnut shaped pan, the outer side of which is higher than the inner side. The bottom of S" the pan is made using any known means to trap the densest particles. A round table (2) is fixed to the top of the pan at its outer upper edge, so as to form an annulus shaped gap. A t;bar and shaft is fixed to the central axis of the table and pan by which they are suspended in water and can be oscillated in short arcs so as to provide a circular jigging motion in a horizontal plane to material that is placed on the table.

An improved method of hand sluicing gold is disclosed.

Gold or other precious minerals can be collected from a mixture of wet particular by the following procedure:- Refer to Fig 1. The present invention is suspended in water and is jigging by an oscillating movement around its central vertical axis so as to move the particulate. A mixture of particulate is put on the round table and is slung outward by the centrifugal force and is made to pass over or through the annulus shaped gap which 08/07103,jb1 31 78.spe,2 -3acts as a screen. The particles that drop into the pan beneath it flow inward and the densest particles settle to the bottom where they are trapped, while the lighter particles at the surface flow over to the outlet at the centre of the pan. The bottom of the pan can trap a large amount of concentrate that is easily removed for collection.

For large powered plants, see Fig 2, it would be convenient to continuously rotate the pan in one direction and fix circular hoops to the underside of the table and form circular grooves in the bottom of the pan so that a hoop divides each groove into two.

The pan is rotated so that the grooves moving past the stationary hoops stir the mixture of particulate. A sufficient number of wiper blades are attached to the rotating pan and they sweep off material that is placed on the stationary table. Material can be continuously moved off the table into or over the annulus shaped gap between the edges of the table and pan.

The slicing/rubbing action which occurs between the surfaces of the grooves and rotating hoops moves the material over the entire floor of the circular pan causing the material to level out and flow horizontally in a spiralling course inwardly to a discharge opening at the centre of the pan.

An alternative arrangement is to rotate the hoops and keep the pan stationary. The collection pan (see Fig has a series of concentric grooves in the bottom of it. These grooves may be rounded, flat bottomed, wide or narrow. The groove walls can be shaped 20 in any way so that a suitable depression is formed to trap heavy minerals. The hoops are conveniently made of hard wearing, rigid material and can be flat or shaped so as to increase its ability to drag material around.

All of the hoops are attached to each other, yet are free enough to rise or sink and move in the grooves. A variation may be made to the bottom of the pan so it may be conical to increase the flow rate of the material passing through the pan toward the centre.

Also, to improve the movement of wash dirt from the spreader table it may also be shaped in a conical configuration, somewhat like a china man's hat. The screening ability of the aperture presented by the gap between the table's edge and the rim of the bowl may be changed by widening or narrowing to allow the passage of any size of material to pass into 30 the pan.

This present invention moves the wash dirt in a horizontal, circular direction. The movement allows the lighter fractions to be displaced by the heavier minerals which gravitate into the bottom trapping grooves. The water cannot move the wash dirt as it does not flow. The wash dirt "flows" because it is being constantly moved and leveled as it is 08/07/03,jbl3178.spe,3 -4brushed between the stationary concentric hoops and the moving grooves. Any number of hoops and grooves can be used.

The method of operation is as follows: Refer to Fig 2.

The pan is immersed in water. Wash dirt is placed on the stationary table by some known means and is swept off into the pan by spreader bars which are attached to the rim of the rotating pan, through the gap between the table and the rim of the pan which acts as a screen. The hoops are suspended from the table into the grooves of the pan A preferred arrangement is to rotate the pan, or jig it whilst the table and the concentric hoops are kept stationary. A mincing/slicing action is generated between the walls of the grooves and the sides of the hoops The movement of material between the hoops and groove sides enables the lighter particles to be moved and displaced by the heavier particles. The lighter particles rise to the surface and are moved horizontally around the pan The levelling effect of this action moves the lighter surface material to the centre of the pan where they are discharged.

The heavier particles gravitate into the grooves where they are trapped. Separation proceeds in every groove. The hoops and ridges work like the baffles in a sluice. The mincing/slicing action between the groove wall and hoop edge, levels the wash dirt and makes it flow away from the source of the wash dirt, toward the centre of the pan.

20 ADVANTAGES OF THIS SYSTEM:- Less aeration means less gold flotation and loss of fine gold.

Water only washes and stirs the surface of the material.

The doughnut shaped pan can hold a large amount of concentrate.

Work may continue a long time between cleanups.

Efficiency and flow rates are controlled by pan speed.

Rate of radial movement slows down in proportion to the radius.

Units can be light and portable so as to be portable and easily operated by S"hand.

The product can be highly concentrated.

S...va This invention can work as part of a continuous process.

s 08/07/03,jbl 3178.spe,4

Claims (14)

1. An apparatus for wet or dry separation of minerals from a mixture of particulate minerals of differing densities including an annular pan having an inner wall and an outer wall, said outer wall being higher than said inner wall, the inner bottom of said pan being provided with means to trap the denser or densest particles in said mixture, a circular table adjacent to but displaced from the upper edge of the outer wall of the annular pan, the diameter of said table being less than the diameter defined by the inner side of the outer wall of the annular pan but greater than the diameter defined by the inner side of the inner wall of the annular pan, thereby providing an annular gap, and a shaft mounted to the web and table.

2. The apparatus as claimed in Claim 1 wherein the axes of the pan and table are concentric and said shaft is aligned along said concentric axes.

3. The apparatus as claimed in either Claim 1 or Claim 2 wherein said table is fixedly mounted to said shaft with respect to said annular pan.

4. The apparatus as claimed in either Claim 1 or Claim 2 wherein said table is rotatably mounted to said shaft with respect to said pan.

The apparatus as claimed in either Claim 1 or Claim 2 wherein said pan is rotatably mounted to said shaft with respect to said table.

6. The apparatus as claimed in any one of Claims 1 to 5 wherein the said 20 means to trap the densest particles includes a plurality of circular grooves formed in the bottom of the annular pan.

7. The apparatus as claimed in Claim 6 wherein a plurality of downwardly extending circular hoops is provided on the underside of said table, each of said hoops S• being sited so as to extend at least part way into one of said plurality of circular grooves.

An apparatus for wet or dry separation of minerals from a mixture of particulate minerals of differing densities including an annular pan having an inner wall and an outer wall, said outer wall being higher than said inner wall, the inner bottom of said pan being provided with a plurality of circular grooves to trap the denser or densest particles in said mixture, a circular table relatively rotatable with respect to said annular 30 pan, adjacent to but displaced from the upper edge of the outer wall of the annular pan, the diameter of said circular table being less than the diameter defined by the inner side of the outer wall of the annular pan but greater than the diameter defined by the inner side of the inner wall of the annular pan, thereby providing an annular gap, the underside of said table being provided with a plurality of downwardly projecting circular hoops, each of said 08/07/03,jb1 3178.spe,5 -6- hoops being sited so as extend at least part way into one of said plurality of said circular grooves, and a shaft mounted to the pan and table.

9. The apparatus as claimed in Claim 8 wherein a plurality of blades or fingers mounted on the upper edge of the outer wall of the pan extend inwardly and over the upper surface of said table.

The apparatus as claimed in either Claim 8 or Claim 9 wherein said pan is rotatably mounted to said shaft.

11. The apparatus as claimed in either Claim 8 or Claim 9 wherein said table is rotatably mounted to said shaft.

12. The apparatus as claimed in any one of Claims 8 to 11 wherein said bottom of said pan is generally downwardly conical.

13. The apparatus as claimed in any one of Claims 8 to 12 wherein the upper surface of said table is generally upwardly conical.

14. A mineral separation apparatus as claimed in any preceding claim substantially as hereinbefore described. DATED this 8 th day of July, 2003 MINTRAP PTY LTD i20 By their Patent Attorneys: CALLINAN LAWRIE o* 0* *too *ooo 9* S...o 08/07/03,jbl3178.spe,6