WO2001023157A2

WO2001023157A2 - Method and apparatus for quarrying rock

Info

Publication number: WO2001023157A2
Application number: PCT/US2000/041029
Authority: WO
Inventors: Glenn Meinders; Doug Wilson
Original assignee: Vermeer Manufacturing Company
Priority date: 1999-09-29
Filing date: 2000-09-29
Publication date: 2001-04-05
Also published as: AU1494001A; WO2001023157A3

Abstract

The present disclosure relates to a method for quarrying rock. The method includes a first phase in which at least two spaced-apart relief slots are provided in a layer of rock such that a rock piece is defined between the relief slots. The method also includes a second phase in which the rock piece is fractured from between the relief slots. The disclosure also relates to a multiple rock wheel device for concurrently cutting a plurality of slots into a rock formation.

Description

METHOD AND APPARATUS FOR QUARRYING ROCK

Field of the Invention

The present invention relates generally to methods and apparatuses for quarrying rock. More particularly, the present invention relates to non-explosive methods and apparatuses for quarrying rock.

Background of the Invention

The drill and blast method is a common technique for quarrying rock from a rock deposit. The drill and blast method typically involves drilling holes into the rock deposit, loading the drilled holes with explosive material, detonating the explosive material, collecting fractured rock generated by the detonation of the explosive material and processing the fractured rock. One typical processing step includes screening the fractured rock to separate the rock by size. Frequently, larger pieces of rock are pre-processed (e.g., crushed) prior to the screening process. One concern with the drill and blast method of quarry mining is safety. Safety is an issue because, when explosives are detonated, it is difficult to control flying rock. Also, as with any blasting process, there is always the possibility of non-discharged blasting caps and/or explosives remaining in the rock after blasting. Additionally, blasting detonation techniques are frequently subject to outside electromagnetic interference. Moreover, blasting can present a seismic danger to surrounding areas. For example, blasting may cause damage to basements, houses and other buildings. Blasting may also cause avalanches, rock slides and other damage in non-intended areas.

Another concern with drill and blast quarry mining methods is expense. Drill and blast mining operations can be expensive because drill and blast contractors typically have high insurance costs due to the dangers associated with blasting operations. Drill and blast mining operations also can be expensive because the drill and blast method of mining is time consuming, and frequently requires specialized personnel for handling explosives. Moreover, the drill and blast method of mining commonly generates rocks/fragments of many different sizes. Because rocks of many different sizes are generated, significant pre-processing time may be required prior to sizing of the rock.

Still another concern associated with the drill and blast method of quarry mining relates to product quality. Blasting often leaves a large quantity of shot rock that is exposed to weather before further processing. This weathering may have adverse effects on subsequent processing operations such as screening. Also, blasting often mixes rocks from various layers in a rock shelf. This is problematic because undesirable rock from one layer can become mixed with desirable rock from another layer. The various aspects of the present invention address the concerns identified above by providing methods and apparatuses for efficiently quarrying rock from a rock deposit without requiring the use of explosive material.

Summary of the Invention

One aspect of the present invention relates to a method for quarrying rock including providing at least two spaced-apart relief slots into a layer of rock such that a rock piece is defined between the relief slots, and fracturing the rock piece from between the relief slots. By way of non- limiting example, the relief slots can be cut to a depth of at least 12, 18 or 24 inches. A preferred method of fracturing the rock piece involves applying pressure to the rock piece in a direction generally transverse with respect to the slots.

Another aspect of the present invention relates to a quarrying apparatus for quarrying rock. The quarrying apparatus includes a vehicle and means secured to the vehicle for concurrently cutting into the rock at least two spaced-apart slots each having a depth sufficient for allowing a portion of rock between the slots to be effectively fractured from the rock deposit.

A further aspect of the present invention relates to a quarrying apparatus including at least two cutting wheels rotatable about an axis, and an axial spacing gap defined between the cutting wheels. Preferably, the axial spacing gap has a radial depth sufficiently deep for allowing the cutting wheels to cut separate slots into a rock formation. Preferably, the slots are sufficiently deep to generate a strip of rock between the slots that can be fractured from the rock formation. Still another aspect of the present invention relates to a quarrying apparatus including a vehicle, and a boom pivotally secured to the vehicle. The quarrying apparatus also includes a slot cutting arrangement for cutting spaced-apart slots into a rock layer. The slot cutting arrangement includes a shaft aligned along an axis of rotation and secured to the boom; at least two drums rotatably mounted on the shaft and positioned on opposite sides of the boom; and at least four rock wheels fixedly secured to the drums. The rock wheels are preferably separated by axial spacing gaps.

A variety of advantages of the invention will be set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practicing the invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed.

Brief Description of the Drawings The accompanying drawings, that are incorporated in and constitute a part of this specification, illustrate several aspects of the invention and together with the description, serve to explain the principles of the invention. A brief description of the drawings is as follows:

Figure 1 is a perspective view of a rock deposit being quarried by a method in accordance with the principles of the present invention;

Figure 2 is a side elevational view of a quarrying apparatus constructed in accordance with the principles of the present invention, the apparatus includes a boom oriented in a non-cutting position;

Figure 3 shows the quarrying apparatus of Figure 2 with the boom oriented in a cutting orientation;

Figure 4 is a top view of the boom and cutting assembly of the quarrying apparatus of Figures 2 and 3; and

Figure 5 is a front elevational view of the cutting assembly of the quarrying apparatus of Figures 2 and 3.. Detailed Description

Reference will now be made in detail to exemplary aspects of the present invention that are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

One broad aspect of the present invention relates to an efficient technique for quarrying or mining rock. Generally, the technique involves a two phase quarrying process. In the first phase of the quarrying operation, a plurality of spaced-apart slots are formed or otherwise provided in the rock formation desired to be mined. The slots are preferably provided by cutting the slots into the rock formation with a tool such as a rock wheel (i.e., a rock saw), a water jet or a trencher. The slots define or segregate discrete portions of rock located between the slots. During the second quarrying phase, the discrete portions of rock formed between the slots are fractured and removed from the rock formation. One preferred fracturing technique is to apply pressure to the segregated portions or pieces of rock in a direction that is generally transverse with respect to he slots. By way of non- limiting example, the fracturing pressure can be applied by a piece of excavation equipment such as a bulldozer, a back hoe, an end loader, a wheel loader, or a conventional ripper apparatus. Figure 1 illustrates a rock deposit or formation 20 in the process of being mined by a method in accordance with the principles of the present invention. As shown in Figure 1 , a plurality of slots 22 are shown cut through a top surface of the rock formation 20. The slots 22 are shown as being substantially straight and parallel such that a plurality of separate rock pieces 24 are formed between the slots 22. The rock pieces 24 are in the form of substantially parallel strips or ribbons. However, it will be appreciated that alternatively, the slots 22 could be curved or skewed relative to one another so as to form rock pieces having a variety of different shapes. By way of non-limiting example, slots can also be formed in a transverse direction with respect to the slots 22 so as to form a plurality of separate rock squares or cubes that can be fractured from the rock deposit.

After the slots 22 have been provided in the rock formation 20, the rock pieces 24 are preferably fractured from the rock formation 20. For example, the rock pieces 24 can be fractured by applying a fracturing load against the rock pieces

24 in a direction generally transverse to the slots 22. As shown in Figure 1, the fracture loads are illustrated by arrows 26. The application of force (e.g., in the transverse direction indicated by arrows 26) preferably causes the rock pieces 24 to fracture adjacent to the bottom ends of the slots 22. Fracture lines 28 show the desired fracture locations.

It will be appreciated that the rock pieces 24 can be fractured by any number of techniques. For example, conventional excavation equipment such as bulldozers, back hoes or rippers can be used to apply fracture loading to the rock pieces 24 in a direction corresponding to the arrows 26. Alternatively, fracture loading can be applied in a direction parallel to the slots 22, or in a direction skewed relative to the slots 22.

After the rock pieces 24 have been fractured, the rock pieces 24 can be removed from the rock formation 20 with conventional excavation equipment. For example, the rock pieces 24 can be pushed to a processing site with a bulldozer. At the processing site, the rock pieces 24 can be subject to additional processing steps such as crushing or sizing. After a layer of rock has been removed from the rock formation 20 by the method described above, the same process can subsequently be repeated on underlying layers of rock. Referring again to Figure 1, each of the slots 22 has a width w, and a depth d, and each of the rock pieces 24 has a width w₂. It will be appreciated that these dimensions can be varied depending upon the desired size of the rock pieces, and also on the type of rock being quarried. The ability to control the size of the rock pieces 24 assists in making subsequent processing steps more efficient. Preferably, the width w, is 5 inches or less. Preferably the width w, is at least 15 inches, or at least 20 inches. More preferably, the width w₂ is about 28 inches. Preferably the depth d is at least 12 inches, or at least 18 inches, or at least 24 inches. Most preferably, the depth d is about 24 inches. In one particular embodiment suitable for use in mining limestone, the depth d is equal to about 24 inches, the width w, is equal to about 5 inches, and the width w₂ is equal to about 28 inches. As used in this specification, the term "rock" is intended to include any number of different types of geological materials. For example, the term is intended to include softer geologic materials such as sedimentary rock (e.g., caliche, limestone and shale). The term is also intended to include harder geologic materials such as building stone, granite, etc. The term is further intended to include other types of geological material such as hard-packed soil, slate and clay.

Figures 2 and 3 illustrate one type of quarrying apparatus 30 for practicing the method described above. The quarrying apparatus 30 includes a slot cutting arrangement 32 for concurrently cutting a plurality of slots into a rock formation. The slot cutting arrangement 32 is secured to a vehicle 34 by a boom 36. The boom 36 is pivotally movable between a lowered position (shown in Figure 3) and a raised position (shown in Figure 2). Preferably, the boom 36 is raised and lowered by conventional techniques such as one or more hydraulic cylinders 38. The quarrying apparatus 30 also can include optional ripping teeth 40 that are connected to the vehicle 34 at an end opposite from the slot cutting arrangement 32. It will be appreciated that any type of vehicle can be used for moving the slot cutting arrangement 32. A preferred vehicle 34 is a track vehicle such as a track trenching machine. A preferred track trenching machine is a Model No. T- 1055 track trenching machine sold by Vermeer Manufacturing of Pella, Iowa. Referring to Figures 4 and 5, the slot cutting arrangement 32 includes a plurality of rock wheels/rock saws including cutting disks or wheels 42 (e.g., four cutting wheels are shown). The cutting wheels 42 are rotatable about a central axis of rotation 44. Cutting teeth 46 (shown in Figures 2 and 3) are positioned about the peripheries of the cutting wheels 42. The cutting teeth 46 preferably comprise carbide tipped teeth that define a cutting tip diameter of each of the wheels 42. In one particular embodiment of the present invention, each of the wheels 42 has a cutting tip diameter of about 101 inches.

The cutting wheels 42 preferably have a cutting width w, (shown in Figure 5) no greater than 5 inches. Additionally, the cutting wheels 42 are separated by axial gaps 43 having widths w₂ (shown in Figure 5). Each of the widths w₂ is preferably greater than 15 inches, and more preferably at least 20 inches, and most preferably about 28 inches. Each of the axial gaps 43 also has a radial depth d (shown in Figure 5). It is preferred for the radial depth d to be at least 12 inches. It is more preferred for the radial depth d to be at least 18 inches. It is most preferred for the radial depth d to be at least 24 inches. It will be appreciated that the preferred depth d, width w,, and width w₂ will most likely vary depending upon the type of material being quarried.

Referring still to Figures 4 and 5, the slot cutting arrangement 32 also includes two drums 48 positioned on opposite sides of the boom 36. The drums 48 are rotatably mounted on a shaft 50 aligned along the axis of rotation 44. The drums

48 are connected to the shaft 50 by a plurality of bearings 52. The boom 36 is connected to the shaft 50 at a location between the two drums 48. The cutting wheels 42 are fixedly connected (e.g., bolted, screwed, welded, etc.) to outer peripheries of the drums 48. In one particular embodiment of the present invention, the drums 48 have an outer diameter of about 48 inches.

As shown in Figure 4, sprockets 54 for rotating the drums 48 are fixedly moimted at inside ends of the drums 48. Continuous drive chains 56 (cross- sectional views of which are shown in Figures 4 and 5 for clarity purposes) are entrained between the sprockets 54 and drive sprockets 58 (shown in Figure 4). Referring to Figure 3, an entire one of the drive chains 56 is shown entrained about the sprockets 54 and 58. Figures 2 and 3 also illustrate a top shield 64 that covers upper circumferential portions of the cutting wheels 42.

The drive sprockets 58 correspond to a drive assembly 60 (shown in Figure 4) such as a conventional track trencher head shaft arrangement (e.g., the head shaft arrangement of a Vermeer Manufacturing T-1055 trencher). The tension of the drive chains 56 is preferably adjusted by moving the shaft 50 along a longitudinal centerline 51 (shown in Figure 4) of the boom 36. The centerline 51 preferably bisects the vehicle 34, and preferably, the drums and cutting wheels 42 are symmetrically configured relative to the longitudinal centerline 51. The drive assembly 60 includes a motor 62 for driving the drive sprockets 58.

To operate the quarrying apparatus 30, the cutting wheels 42 can be rotated in a clockwise direction (shown in Figure 3 by arrow 66) as the vehicle 34 creeps forward in a direction (shown in Figure 3 by arrow 68). As the cutting wheels 42 rotate, the cutting wheels 42 concurrently cut four separate slots into the rock formation 20. The cutting depth of the cutting wheels 42 (e.g., the depth of the slots) is determined by the stroke of the hydraulic cylinder 38. The cutting depth is also limited by a mechanical stop (not shown) positioned on the vehicle 34 that prevents the boom 36 from pivoting downward beyond a predetermined location. It is also possible for the cutting wheels 42 to be operated in either a clockwise or counterclockwise direction based on desired production rates and the desired product size. It is also desirable for the cutting wheels 42 to include reversible cutting teeth or segments that can be turned relative to the cutting wheels 42. For example, in certain embodiments, to reverse the teeth 46, the drums can be removed from the shaft 50 and turned such that the teeth 46 face in an opposite direction.

After the slots have been cut by the cut slotting arrangement 32, the strips of rock formed between the slots can be fractured with the ripper teeth 40 of the vehicle 34. However, more preferably, the strips of rock are sheared or otherwise fractured by another piece of excavation equipment that impacts the rock strips in a direction generally transverse with respect to the slots.

The cutting wheels 42 of the quarrying apparatus 30 can either be fixed as shown, or can be modified such that the spacing between the cutting wheels 42 is adjustable. By adjusting the axial spacing between the cutting wheels 42, the size of the rock pieces generated by the quarrying operation can be controlled. The axial spacing can also be adjusted to account for varying rock hardness and the ability to fracture the rock between the cut slots. Furthermore, while the cutting wheels 42 are shown mounted on a common axis, it will be appreciated that the wheels 42 could be staggered relative to one another. Additionally, in alternative embodiments, multiple trencher booms having digging chains can be mounted on a common machine.

The various aspects of the present invention provide numerous advantages. For example, certain aspects allow rock to be mined at production rates that can be controlled so as to closely match subsequent processing rates. This helps to ensure that excavated rock is quickly processed. Additionally, rock mined in accordance with the principles of the present invention can have a higher quality with a more dependable gradation as compared to prior art techniques. The present invention also makes it possible to efficiently mine rock on a layer-by-layer basis. This assists in inhibiting different types of rock corresponding to different layers from becoming mixed together.

With regard to the foregoing description, it is to be understood that changes may be made in detail, especially in matters of the size, shape and arrangement of the parts without departing from the scope of the present invention.

It is intended that the specification and depicted aspects be considered exemplary only, with a true scope and spirit of the invention being indicated by the broad meaning of the following claims.

Claims

WHAT IS CLAIMED IS:

1. A method for quarrying rock, the method comprising; during a first quarrying operation, providing at least two spaced-apart relief slots into a layer of rock such that a rock piece is defined between the relief slots; and during a second quarrying operation, fracturing the rock piece from between the relief slots.

2. The method of claim 1, wherein during the first quarrying operation, the relief slots are provided by simultaneously cutting the relief slots into the rock layer.

3. The method of claim 1 , wherein the relief slots are provided by cutting the relief slots into the rock layer with a rock wheel.

4. The method of claim 1 , wherein the relief slots are simultaneously cut with a plurality of rock wheels.

5. The method of claim 1, wherein the relief slots are substantially parallel.

6. The method of claim 1 , wherein the rock piece is fractured by applying pressure to the rock piece in a direction generally transverse with respect to the slots.

7. The method of claim 1, wherein the rock layer comprises sedimentary rock.

8. The method of claim 1, wherein during the first quarrying operation, at least three relief slots are concurrently cut into the rock layer such that separate rock pieces are formed between the relief slots; and during the second quarrying operation, the separate rock pieces are fractured from between the relief slots.

9. The method of claim 1, wherein during the first quarrying operation, at least four relief slots are concurrently cut into the rock layer such that separate rock pieces are formed between the relief slots; and during the second quarrying operation, the separate rock pieces are fractured from between the relief slots.

10. The method of claim 1, wherein during the first quarrying operation, the relief slots are provided by cutting the relief slots into the rock layer.

11. A quarrying apparatus for quarrying rock, the quarrying apparatus comprising: a vehicle; and means secured to the vehicle for concurrently cutting into the rock at least two spaced-apart slots.

12. The quarrying apparatus of claim 11, wherein the means for cutting includes means for concurrently cutting into the rock at least three spaced-apart slots.

13. The quarrying apparatus of claim 11 , wherein the means for cutting includes means for concurrently cutting into the rock at least four spaced-apart slots.

14. A quarrying apparatus for quarrying rock, the quarrying apparatus comprising: at least two rock wheels mounted for rotation about a common axis; and an axial spacing gap defined between the rock wheels.

15. The quarrying apparatus of claim 14, further comprising a boom having a distal end at which the rock wheels are positioned, the boom being adapted to be coupled to a vehicle.

16. The quarrying apparatus of claim 14, further comprising a shaft aligned along the axis, and at least one drum rotatably mounted on the shaft, wherein the rock wheels are secured about a periphery of the drum.

17. The quarrying apparatus of claim 16, further comprising at least one drive sprocket secured to the drum, and at least one continuous drive chain entrained about the sprocket for rotating the drum about the shaft.

18. The quarrying apparatus of claim 14, wherein each of the rock wheels includes a disk-shaped portion and a plurality of cutting teeth positioned about a periphery of the disk-shaped portion.

19. A quarrying apparatus for quarrying rock, the quarrying apparatus comprising: a vehicle; a boom pivotally secured to the vehicle; and a slot cutting arrangement for cutting spaced-apart slots into the rock, the slot cutting arrangement including: a) a shaft aligned along an axis of rotation, the shaft being secured to the boom; b) at least two drums rotatably mounted on the shaft, the drums being positioned on opposite sides of the boom; and c) at least four rock wheels fixedly secured to the drums, the rock wheels being separated by axial spacing gaps.

20. The quarrying apparatus of claim 19, further comprising drive sprockets secured to the drums, and drive chains entrained about the sprockets for rotating the drums about the shaft.