AU2022287552A1

AU2022287552A1 - Low headroom jaw crushing facility

Info

Publication number: AU2022287552A1
Application number: AU2022287552A
Authority: AU
Inventors: Johan Albertus Luies; Bruno Ruggiero
Original assignee: Lycopodium Minerals Pty Ltd
Current assignee: Lycopodium Minerals Pty Ltd
Priority date: 2020-07-14
Filing date: 2022-12-12
Publication date: 2024-06-27
Also published as: AU2022100178A4; AU2022100178B4; AU2021201301B2; AU2021201301A1

Abstract

A low headroom jaw crushing facility comprising: a structure housing a Run of Mine (ROM) bin 54 for receiving ROM ore from either a dump truck 56 or 10 front-end loader (FEL), and a primary feeder 58 for conveying ROM ore delivered to the ROM bin 54 to an adjacent crushing circuit 60. The crushing circuit 60 comprises: a jaw crusher 62 for crushing coarse oversize ore and, a discharge conveyor 64 for collecting dribble from the primary feeder 58 and discharge product from the jaw crusher 62, and 15 transporting it to a next processing stage. An approach ramp 90 for the dump truck 56 or FEL to deliver ROM ore to the ROM bin 54 is oriented in a direction substantially perpendicular to a longitudinal axis of the primary feeder 58. This has the benefit of facilitating a reduced height of the ROM bin 54 as the ROM bin has end walls that are 20 substantially vertical (rather than inclined), and therefore not a driver in ROM height. Drawing to accompany abstract: Figure 5 3Ji It Figure 4 60 56I III Figure 5

Description

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ORIGINAL AUSTRALIA

Patents Act 1990

COMPLETE SPECIFICATION FOR A PATENT OF ADDITION

Invention title:

"LOW HEADROOM JAW CRUSHING FACILITY"

Applicant:

LYCOPODIUM MINERALS PTY LTD

Associated Complete Application/Parent No.: 2021201301

The following statement is a full description of the invention, including the best method of performing it known to me:

"LOW HEADROOM JAW CRUSHING FACILITY"

Field of the Invention

The present invention relates to an improved low headroom jaw crushing facility and relates particularly, though not exclusively, to such a jaw crushing facility for use in the mining industry.

Patent of Addition

The present invention is an improvement in, or modification of, the "main invention" the subject of co-pending patent application no. 2021201301 (hereinafter "the parent application"). The contents of the specification and drawings of the parent application are incorporated herein by reference.

Background to the Invention

A conventional or low headroom jaw crushing facility is typically rated to approximately 4-6 Million tonnes per annum (Mtpa) maximum capacity (depending on numerous other factors, but not critical for the purposes of this discussion). Historically, should a crusher of greater capacity be required, a gyratory crusher would typically be used. Typically, the smallest gyratory crusher has a capacity of 6-8 Mtpa when selected on the same basis as the jaw crusher alluded to above.

There are two obvious gaps in the current approach to design. These are: (a) There is a void between the 4-6 and 6-8 Mtpa capacity range - the challenge is how to address this gap in the market offerings. (b) A gyratory crusher installation is significantly more capital- and schedule- intensive, and requires significantly more maintenance attention than an equivalent jaw crusher installation.

There is a further problem in that as the capacity of the crushing circuit increases the overall Run of Mine (ROM) height also typically increases. While a low headroom gyratory crusher facility already exists, the inherent characteristics of the gyratory crusher have not lead to the general acceptance of this style of design. The low headroom gyratory crusher design that results is compromised for a number of reasons, including: 1. Inability to evenly feed the gyratory crusher around its periphery (by virtue of having an apron feeder feeding the crusher), leading to preferential wear and wastage of the liners. Some vendors have tried to address this by introducing a means to rotate the concave segments. II. Inability to utilise the full capacity of the gyratory crusher due to inability to evenly feed the crusher around its periphery (by virtue of having an apron feeder feeding the crusher). III. Hydroset maintenance (from below the crusher) causes discharge product to fall a significant distance onto the receiving conveyor, thus posing a considerable, and more often than not unacceptable, risk to the ongoing operation. Some vendors have tried to address this by introducing what is termed a 'top service unit', whereby all maintenance is undertaken from above the crusher.

The present invention was developed with a view to providing a modified low headroom jaw crushing facility that has a ROM height even less than that of the improved low headroom jaw crushing facility of the parent application using the same design basis.

References to prior art in this specification are provided for illustrative purposes only and are not to be taken as an admission that such prior art is part of the common general knowledge in Australia or elsewhere.

Summary of the Invention

According to one aspect of the present invention there is provided a low headroom jaw crushing facility which is permanently fixed, the jaw crushing facility comprising:

a structure housing a ROM bin for receiving ROM ore from either a dump truck or front-end loader (FEL), the structure comprising a concrete ROM foundation, and wherein the ROM bin has end walls that are substantially vertical, to facilitate a further reduction in ROM bin height; a primary feeder for conveying ROM ore delivered to the ROM bin to an adjacent crushing circuit supported on a concrete foundation, wherein the foundation of the crushing circuit and the ROM foundation are at substantially the same level, and wherein an approach ramp for the dump truck or FEL is oriented to permit presentation of the ROM ore to the ROM bin in a direction substantially perpendicular to a longitudinal axis of the primary feeder, the crushing circuit comprising: a jaw crusher for crushing coarse oversize ore; and, a discharge conveyor for collecting dribble from the primary feeder and discharge product from the jaw crusher, and transporting it to a next processing stage.

Typically the ROM bin, when viewed in plan, is longer and narrower than that of the ROM bin of the "main invention", but has a volumetric efficiency that is greater than the ROM bin of the "main invention".

Typically the crushing circuit further comprises a vibrating grizzly for screening the ore ahead of the jaw crusher. Advantageously the discharge conveyor also collects undersize ore from the vibrating grizzly.

Typically the primary feeder is an apron feeder which is used to direct the ore onto the vibrating grizzly. Typically the apron feeder is inclined at 150 - 180 to the horizontal. Alternatively, the primary feeder is a low-profile feeder (LPF). Advantageously the LPF is oriented horizontally under the ROM bin, and is cranked downstream of the ROM bin at 15° - 180 to the horizontal.

Preferably a dribble conveyor is provided to collect dribble from the apron feeder and transfer it via a dribble chute onto the discharge conveyor. Alternatively the discharge conveyor could be used for this purpose, albeit at the penalty of increased ROM height. In one embodiment the structure housing the ROM bin is a concrete vault. Alternatively a structural steel support system with retaining wall can be used in lieu of the concrete vault.

Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. Likewise the word "preferably" or variations such as "preferred", will be understood to imply that a stated integer or group of integers is desirable but not essential to the working of the invention.

Brief Description of the Drawings

The nature of the invention will be better understood from the following detailed description of several specific embodiments of the improved low headroom jaw crusher facility, given by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a plan view of a first embodiment of a low headroom jaw crushing facility according to the present invention;

Figure 2 is an end elevation of the low headroom jaw crushing facility shown in Figure 1;

Figure 3 is a side elevation of the low headroom jaw crushing facility shown in Figure 1;

Figure 4 is a top perspective view from one side of the low headroom jaw crushing facility shown in Figure 1;

Figure 5 is a top perspective view from the other side of the low headroom jaw crushing facility shown in Figure 1;

Figure 6 is a plan view of a second embodiment of a low headroom jaw crushing facility according to the present invention;

Figure 7 is an end elevation of the low headroom jaw crushing facility shown in Figure 6;

Figure 8 is a side elevation of the low headroom jaw crushing facility shown in Figure 6;

Figure 9 is a top perspective view from one side of the low headroom jaw crushing facility shown in Figure 6;

Figure 10 is a top perspective view from the other side of the low headroom jaw crushing facility shown in Figure 6;

Figures 11 (a), (b) and (c) are an end elevation, side elevation and plan view of a ROM bin according to the classical prior art design;

Figures 12 (a), (b) and (c) are an end elevation, side elevation and plan view of a ROM bin according to the modified design of the first embodiment of the present invention; and,

Figures 13 (a), (b) and (c) are an end elevation, side elevation and plan view of a ROM bin according to the modified design of the second embodiment of the present invention

Detailed Description of Preferred Embodiments

In a classical prior art jaw crushing facility the presentation of the feed (ROM ore delivered by dump truck or FEL) to the ROM bin has typically been in-line with a longitudinal axis through the apron feeder - refer Figure 2 of the parent application. This is also the case with the first and second embodiments of the improved low headroom jaw crushing facility in the parent application, shown in Figures 3 and 4 of the parent application, which also follow the classical design.

With reference to Figure 11, in this classical design the height of the ROM bin is largely determined by the bin width Wa, (bin width Wa equals tray width Wal and/or FEL bucket width Wal plus necessary clearances Wa2) combined with the ROM bin critical wall angle (Aa2, noting that the critical wall angle will be the valley angle when the adjacent wall is not vertical) i.e., the inclined side walls of the ROM bin to achieve the tray width and/or bucket width plus necessary clearances, to maintain mass flow. As the critical wall angles increase - a material property and not something that can be modified - the height of the ROM bin, and hence the ROM pad, increases.

In the low headroom jaw crushing facility of the present invention, the presentation of the feed (ROM ore delivered by truck or FEL) to the ROM bin has been modified to be substantially perpendicular to the longitudinal axis (shown as A-A' in Figure 1 of the present application) of the apron feeder. This departure from the classical design is also disclosed in the modified form of the low headroom parallel circuit jaw crushing facility shown in Figure 5 of the parent application. In that case the ROM bin 54 has been modified to allow dual tipping, by providing side approaches to the ROM bin for dump trucks 80a and 80b as shown. This facilitates a higher number of heavy vehicle movements on the ROM pad due to reduced queueing times at the ROM bin 54.

However, it was subsequently found that this modified design, in which a substantially perpendicular approach to the ROM bin is adopted, a further reduction in ROM bin height can be facilitated. A ROM bin can be designed with end walls that are vertical (rather than inclined), and therefore not a driver in ROM height. It turns out that in this modified design, the ROM bin critical wall angles are on the feed side and opposite feed side, and do not impact the height of the ROM to the same extent.

A first embodiment of a low headroom jaw crushing facility according to the present invention will now be described with reference to Figures 1 to 5. Many of the features of the low headroom jaw crushing facility of the present invention are substantially the same as, or similar to, that shown in Figures 3 to 5 of the parent application, and therefore will not be described again in detail here. The same reference numerals as in the parent application will be used to identify the like or similar parts in the present application. The low headroom jaw crushing facility of the first embodiment comprises a structure which is used to house a ROM bin 54. In this embodiment the structure is a concrete vault 52. The ROM bin 54 is used to receive the ROM ore from either a dump truck 56 or front-end loader (FEL) and direct the ore onto a primary feeder 58. The primary feeder, typically an apron feeder 58, is used to direct the ore to an adjacent crushing circuit 60. The primary feeder 58 is inclined at 150 - 180 to the horizontal (as is the bottom of the ROM bin 54, thus impacting the ROM bin live volume). In this embodiment there is no change in the apron feeder angle from the classical design.

As can be seen most clearly in Figure 1, 4 and 5, an approach ramp 90 for the dump truck 56 or front-end loader (FEL) is provided to one side of the jaw crushing facility, to permit presentation of the ROM ore to the ROM bin in a direction substantially perpendicular to the longitudinal axis A-A' (see Figure 1) of the ROM bin 54 and apron feeder 58. The approach ramp 90 is formed with concrete retaining walls 92 and 92a.

The crushing circuit 60 typically comprises a jaw crusher 62 for crushing coarse oversize ore, and a discharge conveyor 64 for collecting dribble from the primary feeder 58 and discharge product from the jaw crusher 62 and transporting it to a next processing stage.

Typically, the crushing circuit 60 further comprises a vibrating grizzly 66 for screening the ore ahead of the jaw crusher 62. The jaw crusher 62 is used to crush the coarse oversize ore from the grizzly 66. Advantageously undersize ore from the grizzly 66 also reports to the discharge conveyor 64. Preferably a dribble conveyor 72 is provided to collect dribble from the apron feeder 58 and transfer it via a dribble chute 73 onto a discharge conveyor 64. A vibrating grizzly may or may not be needed. It is generally included to bypass any material that naturally meets the crushed ore size, thus increasing the capacity of the plant - typically in larger plants.

The ROM bin size in any configuration must accommodate the width of the truck tray or FEL bucket and meet live volume requirements. The side walls (using the primary feeder 58 as reference) of the ROM bin in the classical design (as in the "main invention") are inclined at the critical bin/chute wall angle Aa2 and determine the ROM pad height (see Figure 11 (a)). Angle Aa2 is a material property over which the designer has no control and will typically be in the order of 50-70°. The same walls of the ROM bin 54 in the modified design are in fact end walls, by virtue of the perpendicular approach, and are vertical - this implies the ROM height is driven only by volume as opposed to volume and geometry. ROM bin 54 has end walls 55 (using the primary feeder 58 as reference) that are vertical (rather than inclined as in the classical design), and therefore do not have an impact on ROM height. In this modified design, the ROM bin critical wall angles Ab2 (see Figure 12 (a)) are on the feed side 57 and opposite feed side 59 i.e., the side walls (using the primary feeder as reference), which do not impact the height of the ROM bin to the same extent.

The result is a ROM bin 54 that is longer and narrower than that of the classical design (as in the "main invention"), but whose volumetric efficiency is greater than that of the classical design. This is because the ore is presented (via tray or bucket) along the length Wb of the ROM bin 54 - unlike the classical design where the resulting volumetric efficiency is poor. As can be seen most clearly in Figure 11 (b), in the classical design the natural rill of the material (shown in broken outline) from the tray or bucket tip position of the truck or FEL 56 is such that the bin cannot be filled. There is a large volume along the length Da2 and width Wa of the ROM bin that remains empty, leading to poor utilisation of the bin i.e., poor volumetric efficiency. The bin volume in this case is far in excess of what can be used.

However, with the modified design of the first embodiment of the present invention, as shown in Figure 12 (a), although the natural rill of the material from the tray or bucket tip position of the truck or FEL 56 is the same, there is much better utilisation of the volume within the ROM bin 54. The volume across the width Dbl, Db2 that remains empty is much smaller. Hence for any set of given, fixed design parameters i.e., live volume, bulk density, critical wall angle, angle of repose etc. - the height of the ROM pad in the modified design is less than that of the classical design. In the modified design of the ROM bin shown in Figure 12 it can be seen from Figure 12 (b) that there is still a significant loss of volume as a result of the bottom edge of the bin needing to be inclined at an angle Ab1 to match that of the apron feeder 58 and the resulting upper bend line (to avoid complexity in plate and liner and to maintain a square bin; see also Figures 3 and 5).

A further improvement in volumetric efficiency for the ROM bin 54 is achieved by replacing the apron feeder 58 with the low-profile feeder (LPF) 94 of the second embodiment. In this embodiment the bottom edge of the ROM bin 54 can be substantially horizontal, as shown in Figure 13 (b). The ROM bin 54 of this embodiment is also more efficient in that compared to that of Figures 11 and 12, there is only a single, lower bend line, which is parallel, i.e., horizontal to the LPF 94 at the loading point. There is no upper bend line in this bin, unlike the bin for the apron feeder, which also leads to greater volumetric capacity.

The ROM bin 54 of the modified design has a typical length Wb of 8.2m and width Lb of 4.1m compared to the typical length La and width Wa of a conventional ROM bin of 6.5m and 7.7m respectively (using the primary feeder as reference in both cases and length measured parallel to the primary feeder). The height of the ROM pad for the modified design is typically 10.8m, compared to 12.7m of the classical design.

The low headroom jaw crushing facility of Figures 1 to 5 exhibits several advantageous physical characteristics, these being: A. A ROM height of approximately 'X5' m, where X5 is even less than X4 or X3, the ROM height of the improved jaw crushing facility of the parent application, using the same design basis as that for the conventional jaw crushing facility. B. ROM bin 54 that is longer and narrower than that of the classical design. Other benefits of the low headroom jaw crushing facility compared with the jaw crushing facility of the parent application are therefore: C. A further reduction in the overall construction cost of the facility and its associated construction schedule.

D. A further reduction in working at heights requirements, thus promoting a safer workplace, with significant intangible benefits. E. A further reduction in operating costs, e.g., ore haulage costs. F. Improvement in carbon credits.

A second embodiment of the low headroom jaw crushing facility according to the present invention will now be described with reference to Figures 6 to 10. The low headroom jaw crushing facility of Figure 6 is similar to the low headroom jaw crushing facility of Figure 1, and therefore the like parts will again be identified with the same reference numerals and will not necessarily be described again in detail. In plan view the low headroom jaw crushing facility of Figure 6 looks substantially the same as that shown in Figure 1.

The main difference between the two designs, is that the low headroom jaw crushing facility of Figures 6 to 10 employs a low-profile feeder (LPF) 94 as the primary feeder. The LPF is a modified form of apron feeder that is available commercially from a variety of suppliers. The LPF is similar to an apron feeder in that it is also very heavy duty as it is chain-driven. However, the LPF 94 differs from the apron feeder 58 in that the running surface is a heavy-duty, wear-resistant conveyor belt that is fixed to a continuous support bed, which in turn is mounted to the driven chains. By virtue of its design, a LPF 94 can be cranked (via the use of restraining wheels to prevent uplift of the chains), to achieve any given profile within practical limits.

The presentation of the feed (ROM ore delivered by truck or FEL) to the ROM bin has been modified to be substantially perpendicular to the longitudinal axis A-A' of the LPF 94, similar to the first embodiment described above with reference to Figures 1 to 5. However, in this embodiment the LPF's ability to be cranked is exploited to achieve a further reduction in overall height of the ROM pad. In this embodiment, the LPF 94 is horizontal under the ROM bin 54, thus maximising the available ROM bin volume and enabling the height of the ROM to be minimised, as can be seen most clearly in Figures 8, 9 and 10. The LPF 94 is cranked (inclined upwards) downstream of the ROM bin at 15-18° to the horizontal, in order to transport the ROM ore to the adjacent crushing circuit 60. In other respects, the low headroom jaw crushing facility of this embodiment is the same as the previous embodiment and will not be described again here.

By exploiting the LPF's ability to the cranked, this second embodiment of the low headroom jaw crushing facility, the result is a ROM bin 54 whose end walls are vertical (using the primary feeder as reference), and therefore not a driver in ROM height. Rather, as in the first embodiment, the ROM bin critical wall angles are on the feed side and opposite feed side, and do not impact the height of the ROM to the same extent. The ROM bin 54 is longer and narrower than that of the classical design but has a usable volume that is maximised (see Figures 8-10).

For any set of given, fixed design parameters i.e., feed method (truck size, FEL size), live volume, bulk density, critical wall angle, angle of repose etc., the height of the ROM pad is less than that of the first embodiment of the low headroom jaw crushing facility described above. The height of the ROM pad is also significantly less than that of the classical design, as in the "main invention" described in the parent application.

It will be understood that a LPF can also be used with the classical design of the low headroom jaw crushing facility described in the parent application.

The low headroom jaw crushing facility, illustrated in Figures 6 to 10, exhibits all of the characteristics described for the low headroom jaw crushing facility of Figures 1 to 5, whilst offering further overall benefits when compared to conventional crushing circuits or a gyratory crushing facility, including the following:

A. A further reduction in the overall cost of the facility and its associated construction schedule. B. A ROM height of approximately 'X6 m, where X6 is significantly less than X1 using the same design basis as that for the conventional gyratory crushing facility.

C. A further reduction in working at heights requirements during construction, thus promoting a safer workplace, with significant intangible benefits. D. A further reduction in ore haulage costs. E. A facility which is significantly more cost and schedule effective when compared to a gyratory crushing installation. F. A further improvement in carbon credits as the ore does not need to be lifted as high as previously.

For the examples given in the parent application and above, X1 = >24m; X2 =18m, X3=12m, X4=13m, X5=11m, X6=7m. However, the main point is that for the purposes of comparison, on a like for like basis, X1>X2>X3>X5>X6 (where X3 is approximately equal to X4), i.e., the low headroom jaw crushing facility of the present invention provides a further reduction in overall ROM height compared to both a conventional jaw crusher facility and the improved jaw crushing facility of the parent application.

The capacity of the improved low headroom jaw crusher described above is typically equivalent to that of a conventional or low headroom crusher i.e., approximately 4-6 Mtpa maximum capacity. If two parallel low headroom jaw crusher circuits are constructed side-by-side, as in Figure 5 of the parent application, the overall circuit capacity is equivalent to that of a comparable gyratory crusher i.e., approximately 6-8 Mtpa.

In both embodiments of the improved low headroom jaw crusher described above the structure housing the ROM bin 54 is a concrete vault. Alternatively, a structural steel support system with retaining wall can be used in lieu of the concrete vault. Likewise, in both embodiments the vibrating grizzly and crusher support structure as shown are steel; but the support structure for the crushing circuit could just as easily be concrete. It can be seen in Figures 2 to 5 and Figures 7 to 10 that the support structure for both the ROM bin and the crushing circuit share substantially the same concrete foundation.

Now that preferred embodiments of the modified low headroom jaw crushing facility have been described in detail, it will be apparent that the described embodiments provide a number of advantages over the prior art, including the following:

(i) Significantly reduced overall ROM height compared to both the conventional gyratory crusher facility and the conventional jaw crusher facility. (ii) A significant reduction in working at heights requirements during construction, thus promoting a safer workplace, with significant intangible benefits. (iii) A significant reduction in the overall cost of the facility and its associated construction schedule.

It will be readily apparent to persons skilled in the relevant arts that various modifications and improvements may be made to the foregoing embodiments, in addition to those already described, without departing from the basic inventive concepts of the present invention. Therefore, it will be appreciated that the scope of the invention is not limited to the specific embodiments described, and is to be determined solely from the claims which follow.

Claims

The Claims defining the invention are as follows:

1. A low headroom jaw crushing facility which is permanently fixed, the jaw crushing facility comprising:

a structure housing a ROM bin for receiving ROM ore from either a dump truck or front-end loader (FEL), the structure comprising a concrete ROM foundation, and wherein the ROM bin has end walls that are substantially vertical, to facilitate a further reduction in ROM bin height;

a primary feeder for conveying ROM ore delivered to the ROM bin to an adjacent crushing circuit supported on a concrete foundation, wherein the foundation of the crushing circuit and the ROM foundation are at substantially the same level, and wherein an approach ramp for the dump truck or FEL is oriented to permit presentation of the ROM ore to the ROM bin in a direction substantially perpendicular to a longitudinal axis of the primary feeder, the crushing circuit comprising:

a jaw crusher for crushing coarse oversize ore; and,

a discharge conveyor for collecting dribble from the primary feeder and discharge product from the jaw crusher, and transporting it to a next processing stage.

2. A low headroom jaw crushing facility as defined in claim 1, wherein the ROM bin, when viewed in plan, is longer and narrower than that of the ROM bin of the "main invention", but has a volumetric efficiency that is greater than the ROM bin of the "main invention".

3. A low headroom jaw crushing facility as defined in claim 1 or claim 2, wherein the crushing circuit further comprises a vibrating grizzly for screening the ore ahead of the jaw crusher.

4. A low headroom jaw crushing facility as defined in claim 3, wherein the discharge conveyor also collects undersize ore from the vibrating grizzly.

5. A low headroom jaw crushing facility as defined in claim 1, wherein the primary feeder is an apron feeder which is used to direct the ore onto the vibrating grizzly.

6. A low headroom jaw crushing facility as defined in claim 5, wherein the apron feeder is inclined at 150 - 180 to the horizontal.

7. A low headroom jaw crushing facility as defined in claim 1, wherein the primary feeder is a low-profile feeder (LPF).

8. A low headroom jaw crushing facility as defined in claim 7, wherein the LPF is oriented horizontally under the ROM bin and is cranked downstream of the ROM bin at 150 - 180 to the horizontal.

9. A low headroom jaw crushing facility as defined in claim 5 or claim 6, wherein a dribble conveyor is provided to collect dribble from the apron feeder and transfer it via a dribble chute onto the discharge conveyor.

10. A low headroom jaw crushing facility as defined in claim 1, wherein the structure housing the ROM bin is a concrete vault.

11. A low headroom jaw crushing facility as defined in claim 1, wherein the structure housing the ROM bin is a structural steel support system with retaining wall.

Dated this 12th day of December 2022

Lycopodium Minerals Pty Ltd by its Patent Attorneys WRAYS