Machine and method for the extraction of gold from gold ore

Abstract

A machine for the extraction of gold from gold ore has a separation bell (24) suitable to rest on a vibrating plate (27). The separation bell (24) has, at the bottom, a porous cap (32) that is convex upwards and is made up of a membrane suitable for allowing the passage of compressed air from a blower (21) through a first delivery pipe (22) to the separation bell (24). A plurality of nozzles (41), being fed by the blower (21), introduces circumferential air into the separation bell (24). At the top, a Y fitting (51) allows the passage of siliceous material in whirling upwards from inside the separation bell (24) to a duct (52), and then to a siliceous material recovery compartment (45), and the suction of concentrated gold material via a rigid tube (54) capable of rotating around a vertical axis.

Description

DescriptionTitle of Invention: MACHINE AND METHOD FOR THE EXTRACTION OF GOLD FROM GOLD ORETechnical Field

[0001] The invention relates to a machine for extracting gold from gold ore. Furthermore, a gold extraction method is described.Background Art

[0002] US 2023 / 072144 describes an apparatus for grinding material by means of a swirling air flow. The apparatus comprises a cylindrical lower chamber with a side wall and a central opening, and a truncated conical upper chamber with an upper opening and a lower opening, the latter being operatively connected and in fluid communication with the central opening of the lower chamber. Groups of compressed air nozzles are operatively connected to the annular side wall of the lower chamber in order to inject air into the lower chamber in order to create a swirling air flow that extends upwards into the upper chamber, in order to achieve the grinding of material.

[0003] The international patent application WO 2023 / 084471 of the same Applicant, claiming the priority of Italian patent no. 102021000028175 granted on 18.11.2023, describes a machine, called GPS (Gold Particle Separator), which replaces the use of mercury for the amalgamation of gold particles contained in gold ore, generally quartz or granite. Gold ore crushed by artisanal miners has particle sizes ranging from 10 microns to 800 microns, or more. According to the cited patent, the machine operates on gold ore particles with dimensions between 10 microns and 74 microns to obtain a satisfactory separation. The machine of the above-mentioned patent includes a truncated cone-shaped compartment, which is converging upwards and is provided at the bottom with an agitator, located above a gold particle recovery drawer, and a blower. The truncated cone-shaped compartment extends into a chimney with a superior end that is upwards truncated cone-shaped to create a Venturi effect. The upper end of the chimney is open and spaced by an interspace from a conical passage converging downwards. This interspace is affected by a jet of compressed air obtained with a pressurized air tube, ending with a flute-shaped end facing a channel communicating with a container for the recovery of light particles.

[0004] The micronized gold ore is inserted by gravity from above into the conical passage with a downward conicity. The light particles of gold ore are pushed upwards into the truncated cone-shaped compartment and into the chimney by means of the pressure and whirling obtained by a stirrer, in the form of a rotating plate, and are diverted into the container for the recovery of the light particles by means of a blower actingtransversely in said interspace. The gold particles, which have a greater weight than the light particles, are deposited in the gold recovery drawer.Summary of Invention

[0005] The Applicant has realized that the GPS machine described in his patent required some improvements to increase its efficiency.

[0006] An object of the invention is to provide a machine that achieves a more efficient separation of gold.

[0007] In particular, an object of the invention is to provide a machine in which the precious part and the siliceous part are sent to further separation means.

[0008] Another object of the invention is to provide a machine in which means are provided for creating compressed air and aspirated air and related circuits that increase the efficiency of the machine.

[0009] Yet another object of the invention is to provide a method for extracting gold using such a machine.

[0010] The above mentioned objects are achieved by the present invention that in a first aspect thereof provides a machine for the extraction of gold from gold ore, comprising in a container cabinet, equipped with a frame, a separation bell having a truncated cone shape tapered towards the top and being equipped with an insertion tube for the gold ore and with a plurality of nozzles for introducing circumferential air into the separation bell individually controlled by solenoid valves and fed by a blower through a compressed air circuit,

[0011] wherein the separation bell, designed to rest on a vibrating plate, includes:

[0012] - at the bottom, a porous cap being convex upwards from a base circumference, the porous cap being made up of a membrane suitable for allowing the passage of compressed air from the blower through a first delivery pipe to the separation bell, and

[0013] - at the top, a Y fitting having:

[0014] - a lateral arm designed to allow the passage of siliceous material in vortical movement upwards from inside the separation bell to a duct, and then to a siliceous material recovery compartment, and

[0015] - a vertical arm for suction of the concentrated gold ore via a rigid tube capable of rotating around a vertical axis by a rotation device and a joint downstream thereof.

[0016] In a second aspect of the invention, there is provided a method for the extraction of gold from gold ore by an extraction machine, comprising the insertion of the gold ore into a separation bell, the method including the following steps:

[0017] - vibrating the separation bell to start the separation of the siliceous material from the concentrated gold material;

[0018] - stopping the vibration for a pre-set period of time, in which what follows is provided:

[0019] - injection of compressed air into the separation bell through a porous cap to create an upward flow of air and siliceous material,

[0020] - injection of compressed air into a rigid tube for suction of the concentrated gold material with the end close to the porous cap so that the rigid tube is kept patent or open, and

[0021] - insufflation of compressed air through a plurality of nozzles into the separation bell to provide a centrifugal force suitable for moving the siliceous material upwards;

[0022] - resumption of the vibration of the separation bell for a predetermined period of time to continue the extraction of the siliceous material;

[0023] - stopping the extraction machine for a fixed period of time;

[0024] - injection of compressed air into the nozzles for a predetermined period of time;

[0025] - extraction of the siliceous material for a predetermined period of time;

[0026] - extraction of the concentrated gold material with the consent of a solenoid valve using a rigid tube and its rotation to extract the concentrated gold material and send it into a cyclone for a predetermined period of time.Brief Description of Drawings

[0027] Further features and advantages of the invention will become more apparent from the description of an embodiment of the machine for extracting gold from gold ore according to the invention, illustrated by way of indicative and non-limiting example in the attached drawings in which:Fig.l

[0028] [Fig.l] is a general assembled perspective three-quarters view of the machine;Fig. 2

[0029] [Fig.2] is a plan view from above of the machine of [Fig.l];Fig. 3

[0030] [Fig.3] is a rear view of the machine of [Fig.l] without doors;Fig. 4

[0031] [Fig.4] is a perspective view similar to that of [Fig.l] without doors;Fig. 5

[0032] [Fig.5] is a perspective view similar to that of [Fig.4] but showing the machine as seen from the rear side, without the support frame;Fig. 6

[0033] [Fig.6] is a perspective view similar to that of [Fig.5] but showing the machine with the separation bell without the cover; andFig. 7

[0034]

[0019] [Fig.7] is an exploded perspective view of the separation bell of the machine according to the invention.Description of Embodiments

[0035] Initially, reference should be made to Figures 1 and 2 which are a general assembled perspective three-quarters view of the machine, and a plan view from above respectively.

[0036] The machine for extracting gold from gold ore, hereinafter referred to simply as the machine, is designed to receive gold ore of dimensions of about 100 p, given that the best release of the particles occurs at 74 p. The machine comprises a frame generally indicated as 1. The frame 1 is equipped anteriorly and superiorly with:- an upper front door 10 including an electrical command and control panel 11;- a lower front door 12 for a compartment in which a blower and a sucking pump, both shown subsequently, are provided;- an upper cover 13 in which a ventilation aperture 14 is obtained; and- a lowered cover 15 from which a tube 16 for the insertion of the gold ore emerges.

[0037] The frame 1 has on the right side thereof, from top to bottom:- a door 17 for a disconnect switch with emergency button and internal lighting switch;- a door 18 for inspection of the ore passage;- a pair of doors 19 for the gold particle recovery compartment; and- a right door 20 for the blower and sucking pump compartment.

[0038] The doors on the left side of frame 1 are not shown but are similar to those on the right side listed above.

[0039] Reference is made now to Figures 3 and 4 which are respectively a rear view and a perspective view similar to that of [Fig.l] but without doors. Located in the lower shelf is a blower 21, having a first delivery pipe 22 and a second delivery pipe 23. The first delivery pipe 22 is connected to a separation bell 24 which will be described later. The second delivery pipe 23 is connected to a pressurized air circuit 25 also described below. A suction pump 26 is positioned in the same lower shelf.

[0040] Positioned behind the upper front door 10 is the separation bell 24 on a vibrating plate 27 resting on a plurality of shock-absorbing feet, indicated as 28. Bored gussets 31 connect the vibrating plate to the top of the shock- absorbing feet 28. The vibrating plate 27 is in contact with a vibrating device 29, preferably provided with a cam.

[0041] As shown in [Fig.7], which is an exploded perspective view of the separation bell 24, the vibrating plate 27 comprises a vibrating plate ring 30, equipped with through holesand a plurality of bored gussets 31, suitable for connecting the vibrating plate ring 30. The vibrating plate ring 30 holds a porous cap 32 made, for example, with a membrane that is convex towards the top. The porous cap 32 is represented with intersecting concentric lines; obviously, the porosity does not correspond to the distance between the lines which are only representative of a membrane that lets the air pass without being crossed downwards by the gold ore. The free end of the first delivery pipe 22 from the blower 21 is below the porous cap 32. The first delivery pipe 22 is drawn in the [Fig.7] with dotted line.

[0042] The separation bell 24 comprises a base 33 and a cover 34. The base 33 has a cup ring 35 that delimits a cup 36 at the bottom and an upper support edge 37.

[0043] The cover 34 of the separation bell 24 has a lower support edge 38 and a hood 39.In the hood 39 there is an inlet channel 40 for the ore to be separated. Furthermore, in the hood 39, peripherally in the vicinity of the lower support edge 38, a plurality of nozzles, generically indicated as 41, are provided for air coming from the pressurized air circuit 25. The nozzles 41 are positioned tangentially to the hood 39.

[0044] The hood 39 ends at the top with a ring nut 42, which has a connecting function as will be explained later.

[0045] From [Fig.7] it is clear that the lower support edge 38 of the cover 34 and the upper support edge 37 of the base 33 are provided with corresponding through holes for the integral union of the cover 34 with the base 33 by means of threaded coupling means. In turn, the cup ring 35, the vibrating plate ring 30 and a retaining ring 43 are provided with corresponding through holes for their union by means of bolts. The retaining ring 43 is suitable for retaining the vibrating plate 27 in a sandwich with the cooperation of the cup ring 35.

[0046] In Figures 3 and 4, it is also shown that, on the sides of the separation bell 24, there are a compartment 44 of the separated concentrated gold material, which is closed by means of the aforementioned pair of doors 19, and a compartment 45 for the recovery of the siliceous material. At least one cyclone indicated as 46 is coupled to the compartment 44 ([Fig.l]) for the collection of the gold material. Advantageously but not necessarily, a cyclone 47 for the recovery of the siliceous mineral is also provided in the compartment 45.

[0047] Also, reference is made to [Fig.5] which is a perspective view similar to that of [Fig.4] but showing the machine without the support frame 1 and seen from the rear side; further reference is made to [Fig.6], which is a schematic perspective view similar to that of [Fig.5] but showing the machine with the separation bell 24 without its cover 34 and other parts, for clarity of exposition.

[0048] In Figures 5 and 6 it is schematically shown that the pressurized air circuit 25, fed by the blower 21, has a multiplicity of branches indicated generically as 48, each beingcontrolled by a nozzle solenoid valve 49. There is also a branch with an air injection solenoid valve 50 whose function will be explained below.

[0049] Mounted on the ring nut 42 of the hood is a Y-fitting 51 that allows the connection of the inside of the separation bell 24 with the at least one cyclone 47 for the removal of the siliceous mineral from the inside of the separation bell 24 towards the filtration of the siliceous material. This connection is made by means of a duct 52. Mounted on the Y-fitting 51 is a rotation device 53 for a rigid tube 54 for sucking the gold material as shown in [Fig.6]. The rigid tube 54 has a vertical section 55 and an inclined section 56 configured so that its lower end moves close to the periphery of the porous cap 32. The vertical section 55 of the rigid tube 54 passes through the ring nut 42 and is integral with a toothed wheel 57 engaged with a pinion 58 mounted on the shaft of a motor 59.

[0050] A joint 60 allows a non-rotating coupling with a flexible tube 61 connected to a suction pipe 62 for the gold material, i.e. concentrated in gold ore. Mounted on the suction pipe 62 is a suction solenoid valve 63 for opening and closing the suction pipe 62.

[0051] As shown in [Fig.5], the suction line 62 leads to the at least one cyclone 46 for the gold material used for recovering the gold.

[0052] The branch with air injection solenoid valve 50 for injecting air from the pressurized air circuit 25 is also connected to the flexible tube 61.

[0053] The above-mentioned components have functions that are explained below with direct reference to the separation bell 24, which is shown in the assembled condition in Figures 3, 4 and 5. It is designed to be loaded with gold ore of adequate fineness, about 100 p through the inlet channel 40, provided inclined upwards in the hood 39 of the cover 34 of the separation bell. The separation bell 24 has the base 33 connected to the cover 34 by means of the threaded means passing through the respective upper support edges 37 and lower support edges 38. The base 33 is also connected, as explained above, to the vibrating plate 27, resting on the shock- absorbing feet 28 and stressed by the vibrating device 29.

[0054] Thanks to the vibration, the gold ore with the highest concentration of gold tends to distribute itself on the periphery of the porous cap 32, shown in Figures 6 and 7. Below the porous cap 32 is the end of the first delivery pipe 22 for compressed air coming from the blower 21. The compressed air, pushed from below, tends to lift the lighter siliceous mineral upwards in the separation bell 24, separating it from the concentrated gold ore and from the gold particles which is susceptible to moving towards the circumference of the base 3 of the porous cap 32.

[0055] On the hood 39 of the cover 34 of the separation bell 24, the plurality of nozzles 41 arranged tangentially on the periphery near the upper support edge 37, are connected to the pressurized air circuit 25 which is supplied with compressed air by the blower21 through the second delivery pipe 23. The connection of the plurality of nozzles 41 with the pressurized air circuit 25 takes place by means of the branches 48 with the interposition of the nozzle solenoid valves 49. The compressed air coming from the pressurized air circuit 25 in the separation bell 24 is able to create a whirling of the lighter siliceous mineral that is helped to move upwards up to the ring nut 42 of the hood 39. Provided on the ring nut 42 of the hood 39 is the Y fitting 51. The whirling is favoured by a subsequent activation of groups of the nozzle solenoid valves according to a protocol for opening and closing the nozzles. The Y fitting 51 has a lateral arm 5 connected to the duct 52, through which the siliceous material is able to reach the recovery compartment 45 of the siliceous material ([Fig.3]), where the cyclone 47 shown in [Fig.5] can be provided.

[0056] The Y fitting 51 has a vertical arm 6 which serves to move the concentrated gold material coming from the porous cap 32. This movement is achieved through the rigid tube 54 for sucking the ore material by means of its inclined section 56 and the vertical section 55. The rigid tube 54 is rotated so that the lower end of its inclined section 56 closely follows the base circumference 3 of the porous cap 32. This rotation is allowed by the rotation device 53 comprising the toothed wheel 57 and the pinion 58 rotated by the motor 59. To limit the rotation to the rigid tube 54 only, the joint 60 connected to the flexible tube 61 is provided downstream of the rotation device 53. The flexible tube 61 serves to move the concentrated gold material upwards from the porous cap 32 of the separation bell 24 by means of the rigid tube 54, but also to introduce compressed air through the branch with air solenoid valve 50, the branch being also connected to the pressurized air circuit 25. In fact, when the concentrated gold material does not move upwards through the rigid tube 54, the latter could become clogged with siliceous material present at the bottom of the separation bell 24. It is, therefore, advisable to introduce compressed air into the rigid tube 54 to keep the latter patent or open. When the suction of the concentrated gold material is decided, the suction solenoid valve 63 is activated, which allows the rigid tube 54 to be connected to the suction pipe 62 for the separated concentrated gold material, connected to the suction pump 26. The concentrated gold material thus reaches the first cyclone and the second cyclone if any for gold material, both indicated as 46, as shown in Figures 5 and 6.As regards the method of separating the concentrated gold material from the siliceous material, the time periods are determined by various factors such as the quantity of ore treated, the size of the machine and others. In general, the method according to the present invention provides that the finely ground gold ore is inserted through the insertion tube 16, and is deposited on the porous cap 32. The separation cycle begins with a vibration of the vibrating plate so that the particles of the concentrated gold material, heavier than the particles of siliceous material, such as quartz and granite,move on the circumference 3 of the porous cap 32, which, as already mentioned, could be a membrane. Subsequently, for a period of time, the following actions are simultaneously provided.

[0057] A jet of compressed air enters the separation bell 24 through the first delivery pipe 22 to start the raising of the lighter particles of siliceous material, such as quartz and granite.

[0058] Compressed air is injected into the rigid tube 54 to keep it patent or open;

[0059] Compressed air is blown through the nozzles 41 which, by providing centrifugal force, allow to increase the sending of the siliceous material particles towards the compartment 45 for recovering the same.

[0060] Subsequently, the vibration of the separation bell 24 is added for a predetermined period of time to continue the extraction of the siliceous material particles.

[0061] There is a period of stopping the machine, after which compressed air is blown into the nozzles 41 for a period of time until the siliceous material is extracted. The compressed air is blown through the nozzles 41 by commanding the nozzle solenoid valves 49 according to a protocol that permit that a vortex motion is achieved in order to favour the separation of the concentrated gold material from the siliceous material.

[0062] At this point, the extraction of the concentrated gold material occurs, thanks to the opening of the suction solenoid valve 63 and to the suction with air coming from the suction pump 26 in the rigid tube 54 and its rotation. The concentrated gold ore is sent to the at least one cyclone 46.

[0063] As regards the manufacturing material of the separation bell 24, a transparent material may be chosen which allows the separation process to be checked. However, any other suitable material may be used for its manufacturing.

[0064] It should be understood that the separation method is controlled by an electronic processing unit which is not mentioned in this description. The electronic processing unit supervises the operation of all the components of the machine and their operating times depending on the gold ore being treated.

Claims

Claims

1. 1. A machine for the extraction of gold from gold ore, comprising in a container cabinet, equipped with a frame (1), a separation bell (24) having a truncated cone shape tapered towards the top and being equipped with an insertion tube (16) for introducing gold ore and with a plurality of nozzles (41) for introducing circumferential air into the separation bell (24), each nozzle being controlled by a solenoid valve (49) and fed by a blower (21) through a pressurized air circuit (25), the machine being characterised in that the separation bell (24), designed to rest on a vibrating plate (27), includes:- at the bottom, a porous cap (32) being convex upwards from a base circumference (3), the porous cap (32) being made up of a membrane suitable for allowing the passage of compressed air from the blower (21) through a first delivery pipe (22) to the separation bell (24), and- at the top, a Y fitting (51) having: a lateral arm (5) designed to allow the passage of siliceous material in whirling upwards from inside the separation bell (24) to a duct (52), and then to a siliceous material recovery compartment (45), and a vertical arm (6) for suction of concentrated gold material via a rigid tube (54) capable of rotating around a vertical axis by a rotation device (53) and a joint (60) downstream thereof.

2. 2. The machine according to claim 1, wherein the rigid tube (54) is in communication with a suction pipe (62) for suction of the concentrated gold material connected to a suction pump (26) by a suction solenoid valve (63), the rigid tube (54) being further in communication with the pressurized air circuit (25) via a branch with air injection solenoid valve (50).

3. 3. The machine according to claim 2, wherein the suction pipe(62) for suction of the concentrated gold material leads to at least one gold concentrated material cyclone (47).

4. 4. The machine according to claim 1, wherein the rigid tube (54) includes a vertical section (55) and an inclined section (56) having a free end near the base circumference (3) of the porous cap (32).

5. 5. The machine according to claim 1, wherein the vibrating plate(27) includes a vibrating plate ring (30), suitable for retaining said porous cap (32), and a plurality of bored gussets (31) for fixing the vibrating plate (27) on respective shock- absorbing feet (28) connected to the frame (1) of the container cabinet, the vibrating plate (27) being able to vibrate by a vibrator device (29).

6. 6. The machine according to claim 5, wherein the separation bell(24) is made in two pieces, consisting of:- a base (33), including a cup (36), equipped with a cup ring (35) and an upper resting edge (37), and- a cover (34), comprising a hood (39) and a lower support edge (38), the upper resting edge (37) and the lower support edge (38) being joined by threaded coupling means.

7. 7. The machine according to claim 6, wherein the hood (39) has:- an inlet channel (40) for the gold ore into the separation bell (24) in communication with said insertion tube (16) for the gold ore, and- said plurality of nozzles (41) arranged peripherally in a tangential horizontal position with respect to the hood (39).

8. 8. The machine according to claim 6, wherein the vibrating plate ring (30) is sandwich joined with the cup ring (35) by a retaining ring (43) and threaded coupling means.

9. 9. A method for the extraction of gold from gold ore by an extraction machine, comprising the insertion of the gold ore into a separation bell (24), characterised in that the procedure includes the following steps:- vibrating the separation bell (24), to start the separation of the siliceous material from the concentrated gold material;- stopping the vibration for a pre-set period of time, in which what follows is provided:- injection of compressed air into the separation bell (24) through a porous cap (32) to create an upward flow of air and siliceous material, injection of compressed air into a rigid tube (54) for suction of the concentrated gold material with the end close to the porous cap (32) so that the rigid tube (54) is kept patent or open, and- insufflation of compressed air through a plurality of nozzles (41) into the separation bell (24) to provide a centrifugal force suitable for moving the siliceous material upwards;- resumption of the vibration of the separation bell (24) for a predetermined period of time to continue the extraction of the siliceous material;- stopping the extraction machine for a fixed period of time;- injection of compressed air into the nozzles (41) for a predetermined period of time;- extraction of the siliceous material for a predetermined period of time;- extraction of the concentrated gold material with the consent of a suction solenoid valve (63) using a rigid tube (54) and its rotation to extract the concentrated gold material and send it into a cyclone (46) for a predetermined period of time.

Images