MATERIAL CONVEYOR, SYSTEM AND METHOD FOR THE MOVEMENT OF MATERIAL

Abstract

A material conveyor apparatus is described comprising a conveyer device having a material receiving end suitable for receiving material such as overburden or mineral at a working site, a material discharge end distal of the material receiving end, and a material transport system disposed between the material receiving end and the discharge end so as in use to cause material received at the material receiving end to be conveyed to the material discharge end; an scanning system comprising a scanning device disposed to scan the material being conveyed to the material discharge end and obtain a response from the material from which the material may be classified at least into two classes comprising at least a waste class and a useable ore class based on the response; a chassis supporting the conveyor device and the scanning device; a transport carriage supporting the chassis and adapted to cause the chassis to be movable across a surface for deployment in use.

Claims

1-43. (canceled)

44. A material conveyor apparatus comprising: a conveyer device having: a material receiving end suitable for receiving material such as overburden or mineral at a working site; a material discharge end distal of the material receiving end; a material transport system disposed between the material receiving end and the discharge end so as in use to cause material received at the material receiving end to be conveyed to the material discharge end; and a scanning system comprising a scanning device disposed to scan the material being conveyed to the material discharge end and obtain a response from the material from which the material may be classified at least into two classes comprising at least a waste class and a useable ore class based on the response; a chassis supporting the conveyor device and the scanning device; and a transport carriage supporting the chassis and adapted to cause the chassis to be movable across a surface for deployment in use.

45. The apparatus according to claim 44, wherein the scanning system further comprises a classification module to classify the material at least into two classes comprising at least a waste class and a useable ore class based on the response of the scanning device.

46. The apparatus according to claim 44, wherein the material conveyor apparatus comprises a transport conveyer, an elevating conveyer, a surge conveyer or a combination thereof.

47. The apparatus according to claim 44, wherein the material conveyor apparatus further comprises one or more material processing modules adapted to effect a material processing operation as the material is conveyed from the material receiving end to the material discharge end, including a processing module comprising a mineral breaker or sizer; and the material transport system comprises a plurality of conveyor arrangements successively disposed to convey material received at the material receiving end via the material processing module or modules to the material discharge end.

48. The apparatus according to claim 47, wherein the mineral breaker or sizer has a mineral output positioned before the scanning system in a material transport direction, the material transport system being configured to deliver sized mineral from the mineral output to and through the scanning system.

49. The apparatus according to claim 44, wherein the scanning system is adapted to scan the mineral and monitor some response therefrom, being a response selected to be one which characteristically varies depending upon the level of one or more target minerals present in the material.

50. The apparatus according to claim 44, wherein the scanning system is adapted to classify the material at least into two classes based on predetermined demarcations correlated to levels of target mineral, wherein the predetermined demarcations between the at least two classes are adjustable.

51. The apparatus according to claim 44, wherein the scanning device includes one or more signal emitters to emit a signal in the direction of the material and one or more signal detectors to detect a response signal produced by the material following interaction of the emitted signal therewith.

52. The apparatus according to claim 51, wherein the scanning device includes one or more gamma ray emitters and one or more gamma ray detectors.

53. The apparatus according to claim 44, comprising a scanning conveyor including a first conveyor portion to convey material to and through the scanning system and second conveyor portion to convey the material from the scanning system to a point of delivery, wherein the second conveyor portion is configured to have a combined conveyance speed and length such as to deliver material to the point of deliver after at least a pre-determined acquisition time has elapsed; wherein the material transport system comprises an endless conveyor configured to constitute such a first conveyor portion, or such a first conveyor portion and second conveyor portion.

54. The apparatus according to claim 44, comprising a material sorter in communication with the scanning device, and adapted to physically separate material classified in each one of the classes from material classified in each other of the classes, wherein the sorter is mounted on the chassis and the sorter comprises a material input to receive material, and a plurality of material outputs, including at least one output corresponding an output designated for material classified in each one of the classes, and further comprises a selective diversion system to divert material from the input to a respective output in accordance with its classification.

55. The apparatus according to claim 54, wherein the selective diversion system comprises one or more gates to selectively divert material within the sorter via selective paths from the input to a respective output and/or selectively openable closures for the respective outputs.

56. The apparatus according to claim 53, wherein the sorter is disposed in an elevated position and makes use at least in part of the action of gravity to effect passage of material through the respective outputs and at least a part of the material transport system is an elevating conveyor that raises the material from a first height to a second height at which the sorter is located.

57. The apparatus in accordance with claim 44, wherein the material receiving end of the material conveyor apparatus is a material receiving hopper.

58. The apparatus in accordance with claim 44, wherein the transport carriage comprises one or more ground contactable transport arrangements adapted to effect movement of the chassis across a ground surface in use comprising a pair of parallel, driven, ground-engaging tracks, and wherein the chassis is rotatably supported on the transport carriage to permit rotation of the chassis and apparatus thereon relative to the transport carriage.

59. A system for the movement of material from a working site comprising: a material shovel having a bucket adapted to pick up material and move the material from a work front; a material conveyor apparatus in accordance with claim 44 positioned to receive material discharged from the bucket into the material receiving end of the material conveyor apparatus and to convey the same to the material discharge end of the material conveyor apparatus; and an onward transportation system positioned to receive material from the material discharge end.

60. The system in accordance with claim 59, wherein a separate onward transportation system is provided to receive material classified in each one of the classes separately from material classified in each other of the class, and the apparatus comprises a material sorter in communication with the scanning system, and adapted to physically separate material classified in each one of the classes from material classified in each other of the classes and to distribute material classified in each one of the classes to such respectively separate onward transportation systems.

61. The system in accordance with claim 59, wherein the onward transport system comprises one or more transport trucks and/or one or more overland conveyers.

62. A method for the movement of material from a working site comprising: providing a material conveyor apparatus comprising: a conveyer device having: a material receiving end suitable for receiving material such as overburden or mineral at a working site; a material discharge end distal of the material receiving end; a material transport system disposed between the material receiving end and the discharge end so as in use to cause material received at the material receiving end to be conveyed to the material discharge end; a scanning system comprising a scanning device disposed to scan the material being conveyed to the material discharge end and obtain a response from the material from which the material may be classified at least into two classes comprising at least a waste class and a useable ore class based on the response; a chassis supporting the conveyer device and the scanning device; a transport carriage supporting the chassis and adapted to cause the chassis to be movable across a surface for deployment in use; moving the conveyor apparatus into position at a work front at the working site; picking up material from the work front; transferring material to the material receiving end; conveying material to the discharge end of the conveyor apparatus in such manner that the material is conveyed to and through the scanning device; and operating the scanning device to scan the material and monitor a response from the material, and thereby to classify the material at least into two classes comprising at least a waste class and a useable ore class based on the response.

63. The method in accordance with claim 62, the method comprising: providing a material shovel at a work front; moving the material conveyor apparatus into position with the material receiving end adjacent the material shovel; positioning an onward transportation system positioned to receive material from the material discharge end of the feed device; picking up material from the work front using the bucket of a material shovel; transferring material from the bucket of the material shovel to the material receiving end; and conveying material to the discharge end of the conveyor apparatus and thereby to the onward transportation system.

64. The method in accordance with claim 62, comprising sorting materials as between the respective classes.

65. The method in accordance with claim 64, wherein material is sorted via a binary classification into a waste class in which levels of target mineral are below economically recoverable levels and a useful ore class in which levels of target mineral are above economically recoverable levels.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0140] In the drawings, which illustrate exemplary embodiments of the invention:

[0141] FIG. 1 is a diagrammatic side elevation of the conveyor apparatus of the first aspect of the invention in an example use with other apparatus thereby constituting an embodiment of the system of the second aspect of the invention and illustrative of an embodiment of the method of the third aspect of the invention;

[0142] FIG. 2 is a diagrammatic side elevation of an alternative embodiment of conveyor apparatus of the first aspect of the invention in an example use with an alternative arrangement of other apparatus thereby constituting an alternative embodiment of the system of the second aspect of the invention and illustrative of an alternative embodiment of the method of the third aspect of the invention;

[0143] FIG. 3 is a diagrammatic side elevation of an alternative embodiment of conveyor apparatus of the first aspect of the invention in an example use with an alternative arrangement of other apparatus thereby constituting an alternative embodiment of the system of the second aspect of the invention and illustrative of an alternative embodiment of the method of the third aspect of the invention;

[0144] FIGS. 4 and 5 show alternative arrangements for supply of sized and classified and optionally sorted material to onward transport.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

[0145] Different embodiments of conveyor apparatus according to the first aspect of the invention are shown in an example use in the figures.

[0146] In the illustration in FIG. 1, a possible system embodying the principles of the second aspect of the invention is shown in which the conveyor apparatus is configured as a simple conveyor with a scanner to give a classifying function. A mobile feeder 5 constituting a possible embodiment of the first aspect of the invention, and a truck 15 are shown positioned left to right in series. The system may employ alternative onward transport to the truck, for example including overland conveyers without departing from the principles of the invention. In the illustration in FIG. 2, the system of FIG. 1 is modified by providing the mobile feeder with a material sorter downstream of the scanner.

[0147] In the FIG. 3 arrangement the conveyor apparatus includes a mobile mineral sizer. FIGS. 4 and 5 show alternative arrangements for supply of sized and classified and optionally sorted material to onward transport.

[0148] In all cases trucks are shown but the system may employ alternative onward transport to the trucks, for example including overland conveyers without departing from the principles of the invention. In all cases discussion is of loading using a shovel, but other loading means such as draglines may be used without departing from the principles of the invention.

[0149] Other alternative additional processing apparatus may be provided here or elsewhere within the system without departing from the principles of the invention, or such additional processing apparatus may be dispensed with altogether as shown in FIGS. 1 and 2.

[0150] In the embodiment of FIG. 1 the conveyor apparatus comprises a simple conveyor 5 with a scanner 6 to give a classifying function. Advantageously in the embodiment, the conveyor apparatus is configured as a surge feeder, but this is not a requirement of the invention.

[0151] Overburden/mineral material is removed by a mobile shovel in conventional manner (not shown, but in like manner to that shown in FIG. 3). In an advantageous mode of operation it is passed directly to the surge feeder 5 from the bucket of the mobile shovel directly to the hopper 7 of the surge feeder 5. Overburden/mineral material is supplied by the shovel, directly or indirectly, to the hopper 7 in the apron region of the surge feeder 5. It is conveyed via an endless conveyor belt 9 to a discharge end 11 where a truck 15 waits to receive it into its load volume 16.

[0152] The apparatus is characterized in being mobile, by virtue of being mounted on a chassis 12 and provided with parallel ground engaging tracks 13.

[0153] The apparatus is additionally characterized by the provision of the scanner 6 to give a classifying function. The scanner 6 is positioned part way along the conveyer belt 9 in suitable position to obtain a response from material as it passes along the belt. The scanner has a sensor which is for example a gamma ray sensor, such as will be familiar to the skilled person as being useful for the automatic grading of various ores. The gamma ray sensor for example comprises one or more gamma ray emitters and one or more gamma ray detectors.

[0154] The material to be classified passes through the scanner 6 and through the detection zone of the sensor and is conveyed onward via the endless belt conveyor 9. This serves as a scanning conveyor, a first portion of which conveys material to and through the scanner and a second portion of which conveys material onward to the discharge end 11. This second portion of the conveyor serves not merely to convey the material, but also to take at least a pre-determined time to do. The sensor of the scanner will require an acquisition time in order to make the necessary determination. A suitable acquisition time might for instance be at least 30 seconds. The conveyor 9 operates at a length and speed which are together selected to provide at least this acquisition time as the material passes from the scanner 6 to the discharge end 11.

[0155] The scanner may include a classifier or be in remote data communication with a remote classifier. The classifier is able to classify the material at least into two classes comprising at least a waste class and a useable ore class based on the response of the scanner. It is this at least possible to know the class of the material loaded into the truck 15.

[0156] A development of the FIG. 1 embodiment is shown in FIG. 2 which is of broadly similar arrangement until the discharge end.

[0157] Overburden/mineral material is passed to the feeder 115 from the bucket of the mobile shovel to the hopper 117 of the surge feeder 5. It is conveyed via an endless conveyor belt 119 to a discharge end 111. The apparatus is mobile, by virtue of being mounted on a chassis 112 and provided with parallel ground engaging tracks 113. The scanner 106 gives a classifying function.

[0158] In this case however two trucks 115, 125 wait to receive material it their respective load volumes volume 125, 126.

[0159] The apparatus is distinguished by the provision of a separation module 119 at the discharge end 111 to give a sorting function supplementary to the classification function.

[0160] The material passes through the scanner 106 and through the detection zone of the sensor and is conveyed onward to the separation module comprising a physical material separator via the endless belt conveyor 109. This serves as a scanning conveyor, a first portion of which conveys material to and through the analysing module and a second portion of which conveys material onward to the separator. This second portion of the conveyor serves not merely to convey the material, but also to take at least a pre-determined acquisition time as the material passes from the sensor to the separator.

[0161] In a preferred embodiment, the conveyor 105 is an elevating conveyor, and the separator 119 is provided at an elevated height above that of the scanner. This allows physical separators to be used which make use of the elevated height to sort the material under action of gravity.

[0162] The gradient at which the belt will operate will be dependent on the length of belt as well as height required for bin loading. The gradient may affect the method of conveying the material to the separator. In case of gradient=0-9 degrees a normal troughed belt can be used. For gradient 10-20 degrees a chevron troughed belt should be used. For gradients above 20 degrees, a specialist lift belt should be considered.

[0163] In the embodiment, it is envisaged that material will be sorted in a binary way into one of two classes, for example “accept” and “reject” which will represent economically useful ore from which recoverable quantities of mineral may be economically obtained, and “waste”, being material which does not have such economically recoverable quantities of mineral. A first truck 115 receives the former and a second truck 116 receives the latter. Other transport means could be used.

[0164] The physical separator 119 acts under the control of the scanner 116, and directs material to one or other of these trucks depending on the response of the sensor. In a possible embodiment, the physical separator comprises a gated arrangement which can selectively open one or other of two apertures respectively feeding into the trucks. For example, the physical separator may include separate chutes through which material can fall respectively into the trucks and a gate which selectively opens one and closes the other of said chutes under the control of the analyser in response to the signal detected by the sensor.

[0165] It is the intention that the apparatus in the invention will be used, and the method of the invention thereby performed, at or in the vicinity of the mining or quarrying location, so that waste need not be transported any significant distance, and only economically useful ore need be transported to onward processing. It is particular advantage of the arrangement that it may be possible to adjust the classification parameters of the scanning system so as to produce a variable classification as between economically useful ore and waste which may thus take account of the factors such as economic factors which may vary over time.

[0166] The specification for the final apparatus will vary as per each individual application. The concept will thus have to be scalable for different pits and locations. Design components will be modular to facilitate this.

[0167] In an example use FIGS. 1 and 2 illustrate a truck loading operation. Advantageously in such a case, the conveyor apparatus is configured as a surge feeder.

[0168] The shovel and the truck(s) may be of generally conventional design. Open cast mining operations are constantly seeking more flexible solutions to match truck and shovel capacities and processing rates and to improve fill level accuracy and efficiency in particular. In direct loading systems, where a shovel such as illustrated in the embodiment loads a truck directly batch by batch, trucks rarely reach 90% load and load rates of say 6000 tons per hour might be typical where a shovel might in principle have a capacity of 10000 tons per hour because of delays as each truck is replace. The surge feeder of the invention provides an admirable solution.

[0169] The surge feeder of the embodiments is positioned between the shovel and the truck(s). The surge feeder is able continuously to process overburden/mineral from the shovel and provide it to load a truck. The mobile arrangement of surge feeder enables a truck to drive alongside the surge feeder output end eliminating the need for it to reverse into position directly adjacent the shovel. This potentially improves truck movement efficiency.

[0170] The embodiment provides a surge feeder which is made mobile so that it can move along with the shovel, allowing the operation to use the shovel to its maximum capacity, and which additionally classifies and in the preferred case sorts material as the truck is loaded. The surge feeder is positioned between the shovel and the truck, and is therefore able to continuously to process overburden/mineral supplied by the shovel, whether directly to its apron region or indirectly via intermediate processing equipment. The surge feeder is drivable on its tracks and pivotable on its chassis allowing it to be positioned optimally to feed the trucks progressively. A truck need never to reverse into position. It can merely position itself alongside. The processing capacity of the surge feeder is designed to be greater than that of the shovel, so that the shovel can operate continuously.

[0171] Loading the trucks via the surge feeder offers potential efficiency advantages for a number of reasons. The more steady continuous operation allows for the possibility of more even loading, for higher fill levels, and avoids the shock loading effect of dropping 100 ton batches into the truck bed.

[0172] Advantages of such a system might include the following potential efficiency savings: maximized volume of operation due to improved truck fill factors;

[0173] savings on operating expenses by reduction in unnecessary truck operation; reduction of truck wear and tear and damage;

[0174] cleaner and more precise operation at the processing site, with a possible increase in truck tyre life with cleaner pit floors;

[0175] avoidance of damage to truck bodies by loading buckets.

[0176] Thus, in the FIGS. 1 and 2 embodiments, the material conveyor apparatus of the first aspect of the invention is a simple single conveyor arrangement, in that the material transport system is configured to cause material received at the material receiving end to be conveyed directly to the material discharge end via a suitable scanner and optional sorter.

[0177] Alternatively, the material conveyor apparatus of the first aspect of the invention may further comprise one or more material processing modules adapted to effect a material processing operation as the material is conveyed from the material receiving end to the material discharge end.

[0178] In the FIG. 3 arrangement an embodiment of conveyor apparatus 200 of the first aspect of the invention includes a mobile mineral sizer. The FIG. 3 embodiment is shown in side elevation.

[0179] Overburden/mineral material to be classified and optionally sorted is first sized. The material needs to be appropriately sized to a consistent, reasonably uniform lump size for processing by the scanning device. An example lump size might for example be less than or equal to 150 millimetres. Excessively fine materials could also be removed.

[0180] Overburden/mineral material is supplied by the bucket 204 of the shovel 202 to the hopper 207 in the apron region of the mobile sizer feed conveyer 205. It is conveyed via an endless conveyor belt to a discharge end where it is passed to the sizing module 211.

[0181] To effect this, a sizing module includes a sizer or crusher comprising in the example two contra rotating rollers which will typically be provided with radially projecting breaker teeth (not shown in the figure) in familiar manner.

[0182] Material is supplied to the sizer from a left to right direction in the figure and oversized lumps are broken by the rollers, and in particular in a typical case broken by being gripped between opposed teeth and broken through a tensile snapping action. The sizer is appropriately rated to produce the desired lump size, in the example embodiment to a maximum of for example 150 millimetres.

[0183] It is also desirable to screen out excessively fine material. Again, this may be effected in familiar manner by use of a screen (not shown) through which fines fall to be conveyed away via a fines conveyor.

[0184] It may be desirable to provide a constant feed to and through the ore analyser. This may be achieved using a suitable continuous feeder/loader, such as an apron feeder with a surge loader.

[0185] Suitably sized material lumps are then passed to a material analysing module comprising a scanner 219 positioned about the intermediate conveyor 221 of the sizer. The scanner is conveniently at or closely adjacent to the discharge of the intermediate conveyor 221 which takes the material to and through the scanner.

[0186] The scanner may include a classifier or be in remote data communication with a remote classifier. The classifier is able to classify the material at least into two classes comprising at least a waste class and a useable ore class based on the response of the scanner. It is thus at least possible to know the class of the material being passed via the discharge conveyor of the sizer 223 to be loaded into the truck 225.

[0187] FIGS. 4 and 5 show alternative arrangements for supply of sized and classified and optionally sorted material to onward transport, each in plan view. In each case the system includes the same mobile sizer arrangement as far as the scanner and like numbers are used for like components.

[0188] Overburden/mineral material is supplied by the bucket 204 of the mobile shovel 202 to the hopper 207 in the apron region of the mobile sizer feed conveyer 205. It is conveyed via an endless conveyor belt to a discharge end where it is passed via the sizing module and scanner (not visible in the figures) to a discharge end 221 of the sizer intermediate conveyor.

[0189] At this point the design varies. In each case physical diverters 222A, 222B are used to distribute classified materials between one of two discharge conveyers 223A, 223B. The embodiments of FIGS. 4 and 5 thus have a facility for bulk sorting at the face. The two discharge conveyers 223A, 223B respectively load trucks 225A, 225B. Other transport means such as overland conveyers could be used. The FIG. 4 embodiment loads the trucks directly from the discharge ends of the discharge conveyors. In the FIG. 5 embodiment, intervening surge feeders 227A, 227B are deployed.

[0190] In all embodiments a mobile apparatus is provided that provides for bulk scanning at least for bulk classification and optionally for bulk sorting to take place at the mineral recovery face. Subject to this requirement, features of the various embodiments will be understood to be interchangeable.

[0191] For bulk sorting to take place on the face the apparatus will be adapted to be loaded in the pit by means of shovels, loaders or draglines after blasting. Material sizes will initially range from very coarse to very fine. For sorting to take place the envisaged known sensors require ore to be crushed to <=150 mm. This means a jaw crusher/screen may be employed as above discussed.

[0192] The apparatus or at least some of the modules thereof should be mobile and maneuverable. The apparatus or module may be tracked. Track systems mounted with steel tracks will probably be most resilient.

[0193] The invention thus provides a mobile material classifier, optionally with sorting capability, and optionally with other material processing such as sizing capability. It thus offers a solution which provides much greater flexibility in classifying and optionally sorting of mineral in-situ at or about the vicinity of its mining or quarrying with a potential of avoiding of the economic and technical disadvantages which might be associated with conventional methods where the mineral is sorted and graded at a processing site.