WO2017027937A1

WO2017027937A1 - Ore concentrator

Info

Publication number: WO2017027937A1
Application number: PCT/BR2015/050124
Authority: WO
Inventors: Cordoval Geraldo DA CRUZ
Original assignee: Da Cruz Cordoval Geraldo
Priority date: 2015-08-18
Filing date: 2015-08-18
Publication date: 2017-02-23

Abstract

The present invention refers to an ore concentrator was capable of yielding another crushing operation as it can treat fines sized between 0.01 and 12 millimeters, separating them in a single operation, with a concentration level of 90% of ore content in treated slurries, comprising an equipment intended for the separation of iron and manganese ores from their sands, through gravity, based on the behavioral difference between the materials that form the particulates to be treated due to the different densities of such materials as they are subjected, simultaneously, to gravitational effects and alternating water blasts both upward and downward, in order to separate the ore from its gangs that usually comprise silica, silicate, and minerals, with the latter being denser than the former, basically comprising a tank (4) equipped with, at least, a bed area (7) which, in turn, is formed by: a classifying (8) lower surface (5) set in such a way as to allow the passage of concentrated ore within a pre-determined size range, and a number dividing walls (9), set on the classifying lower surface (8), with said number of dividing walls (9) forming a number of spaces (10) that hold part of the ore fed to the concentrator (1 ). The bed area (7) is submerged into water, and its lower portion is coupled to a vertical axle (16) that is responsible for moving the bed area (7) both upward and downward. This movement is characterized as a thrust, which was discovered by the Greek mathematician, physicist, engineer, inventor, and astronomer, Archimedes of Syracuse.

Description

ORE CONCENTRATOR

Applications of the present invention

The present invention refers to an ore concentrator aimed to the separation of ores and their gangs, comprising particulates with sizes ranging from 0.01 to 12 millimeters; recovery and reclaiming of ore fines, especially in the case of iron and manganese, from waste stocked in yards and containment dams of mining companies; separation of sands and ores from waste slurries in ore concentration plants; environmental security; productivity in mining and ore concentration treatment. State of the art

Ore concentration occurs when the ore of interest is to be separated from unwanted ores. For this separation to take place, the ore of interest must be physically disaggregated from unwanted ores. Furthermore, there must be a physical or a physicochemical difference between the mineral of interest and unwanted minerals. This separation may be easy to be accomplished or a complex task, depending on the type or ore.

In the case of iron ore, for instance, it may undergo beneficiation through diverse processes, from comminution to classification down to concentration. Concentration is divided into physical and chemical. The physical method is characterized by gravity concentration, which is the method used for the separation of mineral particles of different densities. In most gravity concentration processes, in addition to gravity, resistance to motion is another force used, which is made possible by the medium that carries the properties of the fluids. The choice of an appropriate physical method for the concentration of a given ore depends, but is not limited to, the resulting size and on the differentiating property that makes for the separation.

The gravity concentration method benefits the environment as it generates low environmental impact when compared to other methods, given that it does not use any chemical reagent. Furthermore, it may also contribute to low production and installation cost, which are advantages not found in other traditional equipment available in the market.

Jig is one of such concentration equipment. The jigging process is probably the most complex gravity concentration method due to its continuous hydrodynamic variations. In this process, the separation of minerals of different densities is accomplished in a bed dilated by a pulsating current of water, thereby causing the stratification of the minerals.

In such a context, an important variable is process water, which is added in the tank at the lower part of the jig under the screen. There should be no alteration in the water flow as it could hamper the concentration status on the jig's bed. Water process piping for each jig or even for each of the jig's chamber should, preferably, be fed separately by gravity from a water reservoir. Brazilian gravity concentration facilities, however, often fail to give due attention to this aspect. Nevertheless, this state of the art concentrator has a number of disadvantages. First, this concentrator needs a large volume of water in the tank, so as to act on the bed, while the tank needs great volume and pressure to keep the bed soft. Furthermore, whenever the level of concentrate on this concentrator's bed is too high the machine has to be stopped, mainly in the case of heavy ore concentration, as the water pressure is no longer capable of keeping a soft bed and, therefore, needs to be emptied. Depending on the concentrate content and the size of the ore to be treated, this operation tends to be repeated at short intervals, thereby losing its efficacy and safety.

Therefore, one of the objectives of the present invention is to provide an ore concentrator that demands less water, thereby resulting in a considerable reduction in water consumption.

Another objective of the present invention is to provide a concentrator whose bed is never blocked and whose operation does not need to be stopped due to excessive volume of ore on its bed.

The objective of this invention is to separate iron and manganese ores from their sands, with particles size ranging from 0.01 to 12 millimeters, given that, in addition to treating hundreds of millions of tons of concentrate a year, this mining operation is of paramount economical importance and highly impacts the environment.

Iron and manganese ores mining and crushing operations always generate what is called "fines", that is to say, smaller ore sizes than those required by blast furnaces that must be fed ore ranging from 8 to 34 mm so that heated gases may be able to find small clearances to percolate the ores and reduce them to the desired metal.

Ore sizes smaller than those mentioned above do not allow for the operation of blast furnaces that are predominantly used to reduce iron and manganese by means of highly heated carbon.

Each ore and manganese mine generates ores with specific physical properties that, markedly, tend to generate fines.

This sector's average production from crushing is:

A - Between 35% to 40% of ore sizes that meet blast furnaces needs, between 8 and 34 mm;

B - Between 30% and 35% of sinter feed, with sizes ranging from 0.106 to 8 mm; and

C - Between 30% and 35 of pellet feed, with sizes being smaller than 0.106 mm. This ore size profile shows that between 35% and 40% may be promptly used to feed blast furnaces. The remainder of smaller ore sizes are still either piled up on mining companies' stockyards or thrown into containment dams, thereby creating great environmental and occupational hazards. In other words, basically, from 60% to 65% of the ore involved in expenses related to extraction, transport and crushing are disposed of. This alone drastically reduces the mining company's earnings since ores are considered commodities whose prices are set by international competition mechanisms.

As far as the state of the art is concerned, what matters the most is that, so far, there is no ore concentrator available in the world market that is capable of providing the separation of ores ranging in size from 2 to 12 millimeters. Advances in the State of the Art

Advances in the State of the Art brought by this patent were clearly demonstrated by an experiment conducted for a whole year with the object of this invention, capable of treating 100 tons per hour.

Simply by changing screens, the object of this invention was capable of yielding another crushing operation as it can treat fines sized between 0.01 and 12 millimeters, separating them in a single operation, with a concentration level of 90% of ore content in treated slurries.

Based on the following premises, the object of this Report improves the State of the Art:

1 ^st - It separates ores and their gangs formed by particulates sized between 0.01 and 12 millimeters, and, based on proven practice, is capable of recovering 90% in weight of the ore content in slurries at a production rate of 100 tons per hour. 2^nd - It is more productive because it prevents the build up of material along the course of sand-carrying water, thereby, avoiding technical stoppages for the removal of such buildup.

3^rd - It uses less water during the process due to the manner through which sand- laden water is removed, as per item 2, thereby avoiding clogs as it needs less water for sand-carrying.

4^th - With less pressure auxiliary water being used in the process, the consumption of electric energy is also reduced.

Description of the Invention

In order to bypass, without limitation to, the aforementioned inconveniences of the state of the art, the present invention comprises an equipment intended for the separation of iron and manganese ores from their sands, through gravity, based on the behavioral difference between the materials that form the particulates to be treated due to the different densities of such materials as they are subjected, simultaneously, to gravitational effects and alternating water blasts both upward and downward, in order to separate the ore from its gangs that usually comprise silica, silicate, and minerals, with the latter being denser than the former, basically comprising a tank equipped with, at least, a bed area, which, in turn, is formed by: a classifying lower surface set in such a way as to allow the passage of concentrated ore within a pre-determined size range, and a number dividing walls, set on the classifying lower surface, with said number of dividing walls forming a number of spaces that hold part of the ore fed to the concentrator. The bed area is submerged into water, with its lower portion being coupled to a vertical axle that is responsible for moving the bed area both upward and downward.

Based on additional or alternative embodiments of the present invention, the following characteristics and their potential variables may be present, either singly or as a combination:

- the tank comprises a conical lower section and a cylinder-shaped upper section;

- the upper portion of the tank comprises a resilient member, on its side wall, that is set below the bed area and configured in such a way as to allow the bed area to move vertically in relation to the remainder of the tank;

- the bed area is set on the tank's upper portion;

- the vertical axle is coupled to the bed area through a base located outside the tank and associated to a moving and movement transmission mechanical system;

- the spaces formed by the dividing walls are open on its upper portions;

- the concentrator is also fitted with an ore feeding duct that discharges the ore on the bed area;

- the ore feeding duct discharge is set on the center of the bed area;

- a distributing container, set on the center of the bed area, receives the ore discharged by the feeding duct; and

- the cylinder-shaped distributing container extends vertically from the bed area and is set in such a way as to spread the ore discharged by the feeding duct over the bed area.

Brief description of drawings

The objectives, functional improvements to and advantages of the ore concentrator as per this invention shall be clearly identified by those skilled in the art based on the description provided below in relation to a particular embodiment that refers to attached figures. The figures are schematic and their dimensions or proportions may not translate the reality as their purpose is to present only a description of the invention in a didactic way, without imposing limitations other than those set out in the claims. As for these figures:

Figure 1 shows a front view of a particular embodiment of the ore concentrator described in this present invention;

Figure 2 shows an upper section of the embodiment illustrated in Figure 1 ;

Figure 3 shows a schematic front section of an alternative embodiment; and

Figure 4, based on Figure 2, shows an aerial schematic view of the proposed alternative embodiment.

Description, illustrations and how the invention works

The description provided hereinafter shall approach the invention's specific applications, including references to the attached figures. Similar parts are pointed out both in the descriptive report and figures with equal reference numbers. The figures are not, necessarily, provided to scale. Specific characteristics, therefore, may be overscaled or shown in a somewhat schematic way, while other details of conventional elements may have not been depicted for the sake of better clarity and concision. The invention may be applied in different ways. Specific embodiments are described in detail and shown in the figures, with the understanding that these embodiments should be viewed as examples of their principles, and not as a way to limit the invention to what is only illustrated and described in the present descriptive report. It should be acknowledged that the different embodiments discussed hereinafter may be deployed separately or in whatever combination that may be deemed fit to yield the same desired results. As it can be seen in Figure 1 , this present invention's concentrator (1 ) comprises a supporting structure (2) that supports the tank (4) plus a mechanical system (5) for moving and transmitting movement. Furthermore, this supporting structure (2) is provided with a lid (6). It's worth pointing out that the supporting structure (2) may comprise variable formats and components within the scope of the present invention. Therefore, depending on the embodiment of the present invention, the supporting structure (2) may comprise a diverse number of beams and crossbeams also in diverse positions.

The tank (4) comprises a cone-shaped lower section (4A) and a cylinder-shaped upper section (4B), with the lower section (4A) being concentric in relation to the upper surface (4B). One should be able to notice that the diameter of these two sections, the lower one (4A) and the upper one (4B), may vary depending on the embodiment of the present invention. Furthermore, the tank (4) may also be embodied in different formats such that the upper section (4B) is not concentric in relation to the lower section (4A), provided that the expected effects proposed by the present invention are met. One should also note that the tank (4) in Figure 1 is positioned on the center portion of the supporting structure (2) at a certain height in relation to the base (3).

Additionally, the tank (4) also comprises, at least, a bed area (7) set on the lower portion of the tank (4) on which the ore to treated is discharged. This bed area (7) is fitted with a lower classifying surface (8), set in such a way as to allow the passage of concentrated ore within a pre-determined size range.

Based on the embodiment depicted by the figures, this lower classifying surface (8) is a screen. The ore size to be classified by such screen (8) depends on specific conditions related to design and implementation of this present invention, so that its exact value is not a factor that could impair the scope of protection of the present invention.

A number of dividing walls (9) are set on the lower classifying surface (8), such walls forming a number of spaces (10) that are capable of holding part of the ore fed into the concentrator (1 ), since these spaces are opened without their respective upper portions. As shown in the figures, each of such spaces (10) is substantially circular in format which, depending on an alternative embodiment, may have a different format without prejudice to the protection of the present invention. The tank (4) is also fitted with a resilient member (1 1 ) on its side wall, which is set, more precisely, under the bed area (7). Said resilient member (1 1 ) may be composed, for instance, of a polymer with elastic properties, with the choice of material in this case varying within the scope of protection of the present invention. Also, this resilient member (1 1 ) must be set in such a way as to allow for the bed area (7) to move freely vertically in relation to the tank, as per details provided hereinafter.

Furthermore, in addition to being fitted with, at least, one exit for concentrated ore (12) which is set on its lower section (4A), more precisely, next to its lower surface, the tank (4) is also fitted with a water feeding pipe (13). It should also be worth noting that the tank (4) is surrounded by a clearance (14) that is coupled to a waste exit (15).

An ore feeding duct (17) is set above the bed area (7), with said duct being fitted with a discharge over the bed area (7), preferably over the center of the bed area (7). It should also be worth noting that the lid (6) may be fitted with a hole through which the feeding duct (17) may have access to the inside of the concentrator (1 ). Furthermore, the center portion of the bed area (7) comprises a distributing container (18), naturally, underneath the ore feeding duct exit (17). As it can be observed in Figure 1 , the distributing container (18) is cylinder-shaped and extends vertically from the bed area (7), said distributing container (18) being set out to spread the ore that is discharged from the feeding duct (17) over the bed area (7).

As mentioned before, the present invention's concentrator (1 ) comprises a mechanical system (5) for movement and the transmission of movement set on the base (3) of the supporting structure (2). This mechanical system (5) may be composed of diverse components, depending on the manner through which the present invention will be embodied. So, for instance, in the preferred embodiment depicted in the figures, the mechanical system (5) comprises a driving set, a motor, a gearbox and an eccentric axle plus a vertical axle (16).

This vertical axle (16) is coupled to the lower portion of the bed area (7). More precisely, the vertical axle (16) extends all the way until it is coupled to the bed area (7) from the base (3) of the supporting structure (2).

As to how the invention works, the ore to be concentrated enters the ore feeding duct (17) and is discharged into the distributing container (18), which, as the name implies, distributes the ore to be treated over the bed area (7), and, more precisely, among the spaces (10) formed by the dividing walls (9). That way, the mechanical system (5) makes the vertical axle (16) to move the bed area (7) by means of upward and downward movements. As mentioned before, this movement is made possible by the action of the resilient element (1 1 ), given that the bed area (7) is kept submerged into water. In many aspects, this movement resembles the way artisanal miners toss their mining pan beneath the water. Over time and with these repeated upward and downward movements, the concentrated ore flows by gravity through the classifying lower surface (8) towards the concentrate exit (12). The coarse portion of the ore, by its turn, is directed to the waste exit (15) without entering the classifying lower surface (8). Additionally, as it can be observed, with such upward and downward movements on the bed area (7), the concentrator (1 ) employs Archimedes' principle by exerting an upward thrust. As a result, even if the bed area (7) has already been filled with the concentrate, it is still possible to keep the concentrator (1 ) functioning, given that the movements on the bed area (7) prevents or, at the very least, considerably delays the clogging of the lower classifying surface (8). It is worth remembering that, in the case of conventional concentrators, the operation can hardly be kept going on in a satisfactory manner when too much concentrate is accumulated on the bed area (7). As a result, another advantage in relation to this fact is that the present concentrator can work with any desired ore size.

It is important to point out that the amplitude and force used in both upward and downward movements may vary within the scope of the present invention, while its specific values depend on how the present invention will be used.

Additionally, it is also worth highlighting that the present concentrator uses much less water in relation to the state of the art concentrators and, therefore, it needs less volume and pressure due to the fact that it uses a submerged bed area (7). Furthermore, given that the ore feed is spread over the center portion of the bed area (7), the ore is moved towards the tank's edge (4), favoring an outstanding increase of the concentration area and reduced speed of the slurry in the bed area (7).

Another advantage of the present invention lies in the fact the concentrated ore is not retained in the bed. All the produced material is continually discharged from a pipe connected to the concentrate (12) exit. As a result, it makes concentration both easier and faster without the need to stop the equipment to discharge the treated ore.

Still another advantage of the present invention has to do with the concentrator's greater efficiency if compared to other conventional concentrators of the state of the art. This efficiency stems from the fact that the bed area (7) movement covers all the concentration area, with no dead areas.

Finally, it should be noted that the present invention may be used for the concentration any type of ore.

Though the present invention is particularly useful for the concentration of ore, the ore concentrator of the present invention may be manufactured to meet other applications and may feature alterations to meet the intended use, so that the scope of the protection for this invention is solely limited by the content of the attached claims, including possible equivalent variations.

Below is an example of another variant embodiment.

Figure 3 (based on Figure 1 ) shows a frontal and schematic cross view that illustrates, through vectors and in a dynamic, synthetic, summarized, and sufficient way the principle of how the aforementioned variant embodiment works, in addition to adding to the understanding of the innovations introduced herein; figure 3 shows the movement of the water containing a mixture of sands and ores, from where it enters the concentrator, object of the present invention, down to the place where, after being separated from the sand, the ore-containing waters exit the concentrator, and while these waters move along inside the concentrator, solids of different densities contained in the water are separated, providing a vertical direction to ores - which are heavier -, and a predominantly horizontal direction to sands, that are lighter; the arrows show the effects of horizontal and radial and vertical drifting, both brought about by the existing different densities among ore particles and sands as these are subjected to a fluidized bed condition that is formed by the upward and downward water blasts, as well as by the water's horizontal flow, the waters - or slurries -, containing sands an ores, enter the concentrator making downward vertical movements, in the direction indicated by the bold arrow (19), which is seen in Figure 3 inside the feeding duct (17); the indication (20) shows that the continuous provision of water - or slurries - breaks down the bold arrow (19) into downward vertical branches represented by arrow 21 and the horizontal flow, as indicated (20); according to Figure 1 , the set composed by the bed (7) that is formed by the lower classifying surface (8) and a number of dividing walls (9) that define a number of spaces (10), with said bed area (7) being surrounded by particulate-containing water while it goes up and down; these water blasts are responsible for making only dense ore particles to keep a downward movement while the sands' less dense particles keep moving in the opposite direction, namely, upward, with a predominantly horizontal movement through which both waters and sands - devoid of 90% in weight of their original ore content - leave the bed area (7) as they flowing through the space (14) of the cone-shaped lower section (4A) of the tank (4), exiting the inner side of the object of this invention through the duct (15), while ore particles (22) that are also carried away by the water, fall inside the cone-shaped lower section (4A) of the tank (4) and exit through the duct (12), with sand- and ore fractions-carrying waters being totally recovered.

One of the innovations presented herein is the wide range of dimensions of particulates with the object of this report work, namely, particulates ranging from 0.01 to 12 millimeters, which has been proven in practice, being logically and easily understood as per Figure 3 in which sand and ore particulates, that may be considered as having equal average dimensions, have their weight directly proportional to their densities; therefore, should the water upward pulsating flow be minimally strong to carry lighter particles upward, heavier particles, due to their weight, will overcome such strength to which they are also subject, and, by means of a vertical movement, will be separated from the sands that are carried away by the process water until they exit the equipment.

Another innovation introduced herein refers to the fact that the equipment in question is more productive as it does not allow for the build up of clogging over the course of the waters that carry away the sands and, therefore, does not need any technical stoppage for the removal of clogging; Figure 4 shows the new shape of the duct through which sand-carrying waters exit the equipment without posing any risk of clogging the space (14) in Figure 1 , reference being also made to Figure 2.

Figure 4, taken from Figure 2, shows a schematic aerial view of the bed area (7) composed of the lower classifying surface (8) and a umber of dividing walls (9) that define a number of spaces (10) to which surface the new indication number was added to its external ring (23), which corresponds, in terms of aerial view, to the space (14) shown in Figure 1 , through which sand-containing waters are dropped, and from which an average of about 90% of ore particulates were recovered. Figure 4 also shows the other elements, namely, the two diametrically opposed barriers (24), as per description in Figure 2, in which the bed area (7) is also described, said barriers (24) dividing up the space (14) into two parts in such a way that the sand-containing waters, which exited radially through the upper portion of said bed area (7), represented by the pair of two arrows (25) and (26) and (27) and (28), run symmetrically and concomitantly, respectively toward the sand-carrying waters exit holes (29) and (30) that are located on the lower cone- shaped part (4A) of the tank (4); which implies that the falling speed through the drainers (31 ), said drainers measuring one quarter of turn of the helicoid, make the sand-carrying waters to move from the edges of the bed area (7) to the sand- carrying water (29 and 30) exit holes, at an increasing speed, thereby not allowing for the settlement of sands over their course, preventing any build up that could stop the production until being properly removed.

So, the arrows (25, 26, 27, and 28) refer to the course of waters that exit the bed area (7) inside the space (14) of Figure 1 , and that run on the helicoidal metal plates that comprise the four drainers (31 ) measuring one quarter of turn of the helicoid, that fill the space (14).

Other proposed innovations are interlinked: the acute angle formed between the helicoid and the right angle, which is part of the second innovation, is far smaller than the wet sand piling bursting angle and, therefore, these waters are not kept from running vertically toward the exit located on the equipment's base - duct (15) -, so that there is no need for any auxiliary water supply, which is managed, under pressure, by the duct (13), thereby, eliminating any expense related to electric energy to power pumps.

Due to its highly effective features in recovering ore fines, within a wide range of sizes, at an average of 90% of the ore contained in treated slurries, the ORE CONCENTRATOR, object of the present invention, not only allows for the reduction of energy consumption and less consumption of process water, in addition to its potential capability of recovering fines from hundreds of thousands of potentially environmentally hazardous tons of waste piles on yards and containment dams of mining companies that have already incurred costs associated with mining, crushing, milling, and concentration, but also plays an important role as an environmentally friendly equipment.

Claims

1 ) ORE CONCENTRATOR (1 ), comprising a tank (4) equipped with, at least, a bed area (7) which, in turn, features a classifying lower surface (8) set in such a way as to allow the passage of concentrated ore within a pre-determined size range, and a number dividing walls (9) set on the classifying lower surface (8), with the number of dividing walls (9) forming a number of spaces (10) that hold part of the ore fed to the concentrator (1 ), characterized by the fact that the bed area (7) is submerged into water, with its lower portion being coupled to, at least, a vertical axle (16) that is responsible for moving the bed area (7) both upward and downward.

2) ORE CONCENTRATOR, according to claim (1 ), characterized by the fact that the tank (4) comprises a conical lower section (4A) and a cylinder-shaped upper section (4B);

3) ORE CONCENTRATOR, according to claim 2, characterized by the fact that the upper portion (4B) of the tank (4) comprises a resilient member (1 1 ), on its side wall, that is set below the bed area (7) and configured in such a way as to allow the bed area (7) to move vertically in relation to the remainder of the tank (4), and by the fact that the bed area (7) is set on the tank's upper portion (4B);

4) ORE CONCENTRATOR, according to claims 1 and 2, characterized by the fact that the vertical axle (16) extends all the way until it is coupled to the bed area (7) through a base (3) located outside the tank (4), with said base (3) being associated to a moving and movement transmission mechanical system (5);

5) ORE CONCENTRATOR, according to claim 1 , characterized by the fact that the spaces (10) formed by the dividing walls (9) are open on its upper portions; 6) ORE CONCENTRATOR, according to claim 1 , characterized by the fact that it is also fitted with an ore feeding duct (17), the exit of which being located on the bed area (7), and also by the fact that the ore feeding duct (17) discharge is set on the center of the bed area (7);

7) ORE CONCENTRATOR, according to claims 1 and 6, characterized by the fact that a distributing container (18), set on the center of the bed area (7), on which is set the ore feeding duct (17) exit; and, further, by the fact that the cylinder-shaped distributing container (18) extends vertically from the bed area (7) and is set in such a way as to spread the ore discharged by the feeding duct (17) over the bed area (7).

8) ORE CONCENTRATOR, characterized by being a variant embodiment, comprising a bed area (7), that is formed by the lower classifying surface (8) and a number of dividing walls (9) that define a number of spaces (10), that work with size particulates ranging from 0.01 to 12 millimeters and also featuring two barriers (25) on its external ring (23), with said barriers being diametrically opposed and dividing up the space (14) into two parts in such a way that the sand-containing waters, which exited radially through the upper portion of said bed area (7), represented by the pair of two arrows (25 and 26) and (27 and 28), run symmetrically and concomitantly, respectively toward the sand-carrying waters exit holes (29 and 30) that are located on the lower cone-shaped part (4A) of the tank (4), and four drainers (31 ) of one quarter of turn of the tank's(4) helicoid, and that fill up the space (14).

9) ORE CONCENTRATOR, according to claim 8, characterized by the fact that the acute angle formed between the helicoid and the right angle is far smaller than the wet sand piling bursting angle.