AU2019257540B1

AU2019257540B1 - Mineral sample support bed

Info

Publication number: AU2019257540B1
Application number: AU2019257540A
Authority: AU
Inventors: Kevin Dormer
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-11-01
Filing date: 2019-11-01
Publication date: 2020-08-06
Anticipated expiration: 2039-11-01

Abstract

An insert is provided for raising the level of a surface of a drill core sample to a suitable state for undergoing analytical imaging while still in a core sample holding tray. The insert is extruded and cut to size to fit conveniently into a tray channel between the floor of the channel and the sample to be analysed. The insert is extruded to have an upper surface shaped for supporting the sample in a stable manner and a supporting portion that rests on the tray floor or is splayed out against the side walls of the channel.

Description

MINERAL SAMPLE SUPPORT BED

Field of invention

[01] The present invention relates to the presentation of mineral samples for the capture of images thereof and specifically to the display of drill-core samples in respective individual channels within a core sample tray, so that an axially cross sectioned sample is raised within the tray to a level appropriate to facilitate scanning.

Background to the invention

[02] A core drill is a geological exploration tool that has an annular drill bit, used for extracting intact from a sample site an elongate sample representative of the strata through which the drill has passed. The sample is referred to as a drill core and has the shape of a round-circular cylinder, but is solid throughout, barring irregularities arising in the rock strata from which it is retrieved.

[03] Core-holding trays, referred to simply as core trays, have been developed with a series of parallel channels sized for receiving core lengths and maintaining their separation and structural integrity during transportation off-site and during periods of subsequent storage pending analysis. The parallel channels extend from end to end of the tray.

[04] The following are some of the patent publications that describe the state of the art:

a. AU2013204184, which proposes a handle arrangement to facilitate man-handling of trays;

b. US application 2010/0018886 Al, which is directed to facilitating removal of the core sample from the tray;

c. AU 2013204793, which addresses drainage of fluid accumulating in a tray.

[05] A single core sample is intended to be stored in each channel; that is one sample per channel. The channels are separated by walls to help avoid cross contamination of the core samples. The samples are subjected to various forms of analysis, even while in the channels. Emerging drilling technologies, coupled with developing analytical methods, allow and require mineral assays by means of scanning using electromagnetic radiation, to detect density changes or composition changes, for example. Such technologies may cause a physical response relating to the mineral content, and example of such response being a fluorescent or phosphorescent emission. One form is x-ray fluorescence (XRF) scanning. This form requires a core sample with a circular end profile to be sectioned axially down the middle, providing an exposed central planar surface. The surface is then exposed to x-rays which cause excitation of a fluorescence response, the characteristics of which depend on the mineral composition at the exposed planar surface. Images of the response are captured, typically by using digital photography.

[06] A drawback of currently available core trays is that they are designed for stacking, to save space when transported or stored. The channels are designed to be deep enough for the core samples to lie entirely below the outer rim of the tray to enable stacking of a tray on to it. A sample that has been cut in half axially to expose a generally planar axial cross- section rests well below the upper rim of the tray. Shadows tend to be cast by at least one side of the tray channel in which the sectioned sample is located and this affects photographing of the central plane being exposed.

[07] Another drawback of the current system of tray storage and sample scanning is that in convention XRF imaging processes, the scanner head needs to be brought within a few millimetres of the sample surface. However, in many scanning equipment models, the scanner head too wide to be inserted into the channels.

[08] A need has therefore been recognized for a tray configuration in which the samples are supportively raised in their channels so that the planar cross sectional surface, when horizontally orientated in the channel is free of interference

REPLACEMENT SHEET

by shadows and is approachable by the scanner head, thereby avoiding at least some of the drawbacks of current core tray systems.

Objects of the invention

[09] It is an object of this invention to address the shortcomings of the prior art and, in doing so, to provide a system for presentation of a mineral drill core sample for XRF imaging in a core tray.

[010] It is a further object of the invention to provide a mineral sample supporting bed for insertion into a channel in a core tray of known construction.

[011] The preceding discussion of the background to the invention is intended to facilitate an understanding of the present invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was part of the common general knowledge in Australia or elsewhere as at the priority date of the present application.

[012] Further, and unless the context clearly requires otherwise, throughout the description and the claims, the words 'comprise', 'comprising', and the like are to be construed in an inclusive sense - that is to say, in the sense of "including, but not being limited to" - as opposed to an exclusive or exhaustive sense - that is to say meaning "including this and nothing else".

Summary of invention

[013] The invention provides a mineral sample presentation system in which a a mineral sample in the form of a drill core is arranged in a channel of a core tray for examination by an imaging technique. The system includes means for raising a surface to be imaged to a required level and inhibiting movement of the sample relative to the tray. Conveniently, the tray comprises a series of parallel channels into which respective sample are received.

[014] According to a first aspect of the invention, there is provided a mineral sample-supporting extruded insert configured to fit within a channel of a core tray and comprising a hollow bed and a supporting base.

[015] In a preferred form of the invention, the bed has an axially-extending hollow for receiving an elongate core sample.

[016] Preferably, the base is contiguous and extends the length of the insert.

[017] Further preferably, the base is configured for supporting the bed at a level at which a planar diametric major surface of a drill-core sample is raised to a level at least substantially the same as the level of adjacent channel walls.

[018] In a preferred embodiment, the base comprises a leg for abutting a channel wall.

[019] Preferably, the leg is configured for abutting an inwardly sloping lower portion of the channel wall.

[020] In a further embodiment, the base comprises a pair of legs connected by an arch.

[021] The base may comprise a leg for resting on a floor of the channel into which it is operatively located.

[022] Alternatively, or additionally, the base may comprise a laterally extending leg formation.

[023] According to a second aspect, the invention provides an elongate insert for locating in a channel of a core tray having an elongate channel for receiving a core sample of round cylindrical proportions diametrically sectioned to have a semicircular profile and to display a planar surface, the channel being bounded by opposing side walls having upper rims, the insert comprising an extrudate having first and second axially extending connected sections, the first defining a base for resting within the channel and the second defining an upper bed surface operatively spaced from the bottom of the channel and complementally shaped for supporting a core-drill sample, whereby

when the insert is located within the channel and a core-drill sample is placed thereon with the semicircular surface resting on the bed surface, the semicircular surface is spaced from the bottom of the channel, so that the planar surface is generally horizontally disposed at a level that generally coincides with said wall upper rims.

[024] Preferably, the insert is adapted for snug fitment within an elongate core receiving channel in a core tray.

[025] In a preferred form of the invention, the base is substantially the same length as the channel.

[026] Preferably, the second section defining the bed surface is substantially the same width as the channel at its opening.

[027] In an embodiment, the bed surface is contiguous across its width.

[028] In an alternative embodiment, the bed surface is made up of elongate axially-extending ridges and grooves.

[029] According to a third aspect of the invention, there is provided a method of presenting a planar surface of a core sample for imaging, the method comprising the steps of:

a. locating an extruded insert between a rounded surface of the sample and a lower surface of a core tray channel,

i. the channel being defined by opposing side walls each ending at an upper rim and being connected by a floor,

ii. the insert having an upper section defining a bed adapted for supporting the sample and a base section adapted to rest within the channel,

iii. so that when the sample rests on the bed, the planar surface is located at a level corresponding substantially with the wall rims; and

b. placing the core sample to repose on the bed.

[030] The method preferably includes directing electromagnetic radiation at the planar surface from a position located above the level of the wall rims.

[031] In a preferred form, the method further includes capturing an image of a visual response emanating at the planar surface as a result of excitation caused by the radiation.

[032] In an embodiment of the method, the insert extends from end to end of the channel.

[033] The invention extends in a further aspect to a method of presenting a flat-sided core sample for imaging, the method including the steps of:

a. Providing an elongate insert profiled by extrusion for defining an upper side and a lower side, the upper side having a profile defining a surface for supporting a core sample against rotation and a lower side profiled to rest within a core tray channel;

b. Operatively locating the insert in a core tray channel having side rims; and

c. Disposing a drill-core sample having an axially oriented planar surface on the insert so that the planar surface is operatively located for effective scanning by secondary electromagnetic radiation detecting equipment.

[034] The equipment may comprise known X-ray generating means operable to direct X-rays at the sample and a detector capable of detecting a fluorescence response therefrom.

[035] In a preferred form of the invention, the planar surface, when operatively located for effective scanning, is at a level at which it is free of shadows cast by the walls blocking incident scanning-related radiation.

[036] In a further preferred form of the invention, the level is substantially the same level as that of the side rims.

[037] In a still further preferred form of the invention, the lower side of the insert defines a pair of splayed legs.

[038] Further preferably, the legs are connected by an arch.

[039] In a further preferred form of the invention, the upper side surface is concavely adapted for receiving a rounded surface of the sample.

[040] Still further, the upper side surface may comprise axially parallel ridges and grooves on which the sample is placed.

Brief description of drawings

[041] In order that the invention may be readily understood, and put into practical effect, reference will now be made to the accompanying figures. Thus:

Figure 1 is a perspective view of an insert of the invention and a core sample with which it is intended for use.

Figure 2 shows in an end-on upper perspective view an example of a core tray of the prior art into which the insert of the invention from Figure 1 has been placed for supporting a flat sided sample for imaging.

Figure 3 is an axial cross-section of the core tray taken along line A-A' in Figure 2, containing the insert and sample of Figure 1.

Figure 4 illustrates in end view the profiles of a selection of non-limiting examples of extruded inserts according to the invention, the bed and base portions of each being distinguished by a broken line.

Detailed description of an embodiment of the invention

[042] The invention will now be described using a known design of core tray as the tray on which core-drill samples are supported and presented for imaging, such as by using XRF techniques. The invention should not be construed as limited to having a core tray as the carriage vehicle. It is within the scope of the invention that the extruded support may be provided in sections corresponding to the length of a tray channel of standard length, or of shorter lengths that may be spaced from each other in an axial direction within a channel.

[043] Preferred embodiments of the invention will provide continuous support along the entire length of a sectioned, flat sided core sample. Continuous support helps avoid flexure of the core due to sagging between adjacent support points, even though the sagging may not be evident to the naked eye. Even slight sagging can negatively affect the image capture and especially the quality and accuracy thereof. The support of the invention is therefore in preferred embodiments produced by an extrusion process to be consistent and continuous over their whole length and therefore able to provide consistent support to a core sample that rests thereon.

[044] The extrusion product in preferred embodiments of this invention is manufactured from polyvinylchoride (PVC) using a known process of extrusion. However, any other suitable material may be used. The choice of material is a balance between factors such as price and quality obtainable. In this case, PVC provides sufficient rigidity and compressive strength in the finished elongate product. Manufacturing the insert by extrusion enables a consistent quality and mechanical integrity to be obtained along the entire length of the insert. As noted above, this is a major advantage in regard to the integrity of the surface of the sample to be exposed for imaging.

[045] Figure 1 illustrates in (a) a drill-core sample 20 in round cylindrical form as it is when retrieved from a core bit at a drilling site. In (b) the full core sample is shown axially divided into a half-cylindrical sample 22 so that it has a planar surface 24 that is now suitable for XRF or other imaging. The surface 26, extending from end to end, remains cylindrically rounded, as is confirmed by the semi-circular profile at end 28.

[046] Shown generally located below sample 22 is core tray insert 10 of the invention. The insert comprises extruded polyvinylchloride (PVC) having an axial profile that defines two connected sections: A base 12 and a hollow bed 14. In axial profile, these sections resemble larger and smaller versions of the letter 'C', rotated 900 in respective opposite directions, and placed back to back.

[047] When the insert is operatively located in a core tray channel (see Figure 3) with the base orientated toward the channel floor, the bed is supported by the base to define a concave formation 16 into which the rounded surface 26 of sample 22 can be received to fit snugly by lowering it, as suggested by directional arrow D. When the core section has been operatively located in the hollow concavity 16, it resists rotation, so that planar surface 24 is exposed and is stable for imaging to be performed.

[048] The base of the insert is defined by first and second splayed legs 18, 18'. These extend the length of the extruded insert and are adapted to rest against the sloping sides of the channel, as illustrated in Figure 3. Because they extend end to end, they also substantially prevent axial movement of the insert. The lack of movement relative to the tray increases the stability of the supported sample in the channel and helps reduce risk of degradation or breakage.

[049] Referring to Figure 2, a known core tray is generally denoted by the number 100. The example shown is not to be construed as limiting of the scope of the invention, as the invention may be applied to a wide range of tray configurations. The typical tray is of substantially rigid construction, made of high-density polyethylene (HDPE), injection moulded to shape, but may be made of any other suitable impact resistant substance, including in particular metals and other plastics. The tray has a generally rectangular body, defined by a base 112, which is partially obscured in the drawing, bounded by pairs of opposed longer sides 114, '114, and opposed shorter end walls 116, '116.

[050] In this embodiment, the tray has four core-receiving channels 118 formed in the upper surface of the base. The channels extend longitudinally along the length of the core tray and are closed at their opposite ends by end walls 116, '116. Each channel may receive an insert according to the invention. For convenience, only one is shown in this illustration. It is located in the channel marked 118b.

[051] Channel 118b is defined by side walls 122 extending up from the base, separating it from adjacent channels. At the upper rim 126 of wall 122 is a joining strip

124 which together with the walls 122 of the separate channels forms an intervening dividing wall between them.

[052] The channels have a flat planar underside 130, which is designed to rest in a stable manner with a surface on which the tray is being transported, for example a belt or roller conveyor, or forklift pallet, vehicle load space and the like. The sides 114 and end walls 116 extend downwardly, curving inwardly to a common floor substantially at the level of the floors of the channels. This correspondence in levels assists in stabilising the tray during transportation, especially when loaded with core samples, by increasing the points and lines of support for the base when under load.

[053] Referring to Figure 3, a insert 10 of the invention is shown in cross section, operatively located in a channel 118b defined by a floor 130 and a surrounding upstanding wall 122 terminating with an upper rim 126. The insert legs 18, 18' in this embodiment do not rest on floor 130, but are braced against the inwardly sloping lower portions 128 of walls 122. The arch that separates legs 18, 18' provides structural stability against the legs buckling under the weight of sample 22.

[054] The insert is shaped to fit snugly into the receiving channel so that sample 22 rests in bed 14 so that the planar surface 24 is located at a level at least substantially as high as the rims 126 of the adjacent channel walls. By not being located below the rims of the channel, the insert avoids shadows that may be cast from the channel walls. The elevated surface of the sample is also closely approachable by a scanning head, such as from an XRF scanner.

[055] In a further embodiment, the insert is cut to be in shorter lengths than the length of the channel of a standard tray. When in lengths shorter than 50% of the channel length, two or more inserts may be arranged end to end for supporting a flat surfaced sample. It will be appreciated that although short lengths may be used, undivided sections of extrudate of the length of the channel of the tray for which they are produced will provide effective rigid support for a sample.

[056] It will be appreciated that the channels may be defined by differently shaped profiles on their upper, assay-receiving and -supporting surfaces.

Consequently, the insert of the invention may take different configurations for adapting them to the different channel profiles. Non-limiting examples are presented in Figure 4. It will be apparent that instead of splayed legs in examples (a), (d) and (e), the base portions in illustrations (b) and (c) have a single block-like plinth that fits between the side walls of the channel and rests directly on the floor thereof. The legs in the base portion of (e) are adapted to fit between the inwardly sloping lower parts 128 of channel side walls 122 in Figure 3, with outer surface 32 abutting the walls. Lower toe portions 34 will rest on the channel floor. In example (f), the upper surface on which the rounded side of the sample is disposed to rest comprises axially parallel alternating ridges 36 and grooves 38 extending up from a body 40. The ridges are of different heights to provide a generally hollow axial recess between the outer lateral edges of the insert. The ridges come into contact with the rounded surface of the sample when resting on them and help to prevent the sample rolling sideways.

[057] Various other profile configurations may be conceived of without departing from the essence of the present invention.

[058] In implementing the invention, the insert is operatively located in a channel of a tray with the bed-defining surface exposed and the base section stably located against the floor or inwardly sloping sides of the channel, depending on the channel profile and profile of the insert. Thereafter, the half-core sample to be imaged is placed on the bed, planar surface upwards. Electromagnetic radiation of the kind anticipated to cause a fluorescent or phosphorescent or other response, for example Raman spectroscopic, may then be directed at the surface from a position above the level of the rims of the channel walls. The response is captured by methods well known in the art and analysed for determining the mineral composition of the sample.

[059] Practical considerations would usually require that the radiation source is positioned to one or other side of the tray when the tray is located in a radiation receiving zone. If the planar surface is below the level of the channel wall rims, the risk of the surface being at least partially in shadow is significant. Consequently, incomplete images are obtained. Therefore, the elevating of the sample by using the insert of the invention alleviates and avoids shadows becoming an issue and also facilitates bringing of a scanning head, such as belonging to an XRF scanner into close, operatively effective proximity of the surface

[060] These embodiments merely illustrate examples of the core tray insert of the invention for sample surface lifting. With the insight gained from this disclosure, the person skilled in the art is well placed to discern further embodiments by means of which to put the claimed invention into practice.

Claims

SUBSTITUTE SHEET CLAIMS

1. A drill core sample-supporting extruded non-metallic insert configured to fit within a channel of a core tray, and comprising:

a. a drill core sample-receiving bed portion, and

b. a bed-supporting base portion configured for supporting the bed portion at a level at which a planar diametric major surface of a drill core sample is raised to a level at least substantially the same as the rim level of adjacent channel walls.

2. The extrudate of claim 1, wherein the bed portion has an axially-extending hollow for receiving an elongate core sample.

3. The extrudate of claim 1 or claim 2, wherein the base portion is contiguous and extends the length of the bed portion.

4. An insert according to any one of the preceding claims, wherein the base portion comprises a leg for abutting a channel wall.

5. The insert of claim 4 wherein the leg is configured for abutting an inwardly sloping lower portion of the channel wall.

6. An insert according to claim 4 or claim 5, wherein the base portion comprises a pair of legs connected by an arch.

7. An insert according to any one of the preceding claims, wherein the base portion comprises a leg for resting on a floor of the channel.

8. An elongate insert for locating in a channel of a core tray having an elongate channel for receiving a core sample of round cylindrical proportions diametrically sectioned to have a semicircular profile and to display a planar surface, the channel being bounded by opposing side walls having upper rims, the insert comprising an extrudate having first and second axially extending connected sections, the first defining a base for resting within the channel and the second defining an upper bed surface operatively spaced from the bottom of the channel and complementally shaped for supporting a core-drill sample, whereby when the insert is located within the channel and a core-drill sample is placed thereon with the semicircular surface resting on the bed surface, the semicircular surface is spaced from the bottom of the channel, so that the planar surface is generally horizontally disposed at a level that generally coincides with said wall upper rims.

9. The insert of claim 8 adapted for snug fitment within an elongate core receiving channel in a core tray.

10. The insert of claim 9 wherein the base is substantially the same length as the channel.

11. The insert of any one of claims 8 to 10 wherein the bed surface is contiguous across its width.

12. The insert of any one of claims 8 to 11 wherein the bed surface is made up of elongate axially-extending ridges and grooves.

13. A method of presenting a planar surface of a core sample for imaging comprises:

iii. so that when the sample rests on the bed, the planar surface is located at a level corresponding substantially with the wall rims; and b. placing the core sample to repose on the bed.

14. The method of claim 13 including directing electromagnetic radiation at the planar surface from a position located above the level of the wall rims.

15. The method of claim 14 further including capturing an image of a visual response emanating at the planar surface as a result of excitation caused by the radiation.

16. A method of presenting a flat sided core sample for imaging, the method including the steps of:

b. Operatively locating the insert in a core tray channel having side rims; and

17. The method of claim 16, wherein the planar surface, when operatively located for effective scanning, is at a level at which it is free of shadows cast by the walls blocking incident scanning-related radiation.

18. The method of claim 16 or claim 17, wherein the planar surface, when operatively located for effective scanning, is substantially at the level of the side rims.

19. A method according to any one of claims 16 to 18, wherein the lower side of the insert defines a pair of splayed legs.

20. A method according to any one of claims 16 to 19, wherein the upper side surface comprises axially parallel ridges and grooves and is concavely adapted for receiving a rounded surface of the sample.

SHEET 1 OF 3 01 Nov 2019

20 2019257540

(a)

22 24

26

D

28 10 16

12 14

18 18’ (b)

FIGURE 1

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100 50 10 116

118 2019257540

118b 114 A’ 20

52

114’ 52

A 124 112 48 FIGURE 2 38 54 116’

118b 22 124 122 122

118c 118d 118a 114’ 114

128 18 130 18’ 128 30 10 112

FIGURE 3

SHEET 3 OF 3 01 Nov 2019

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12 14 (a) 14 2019257540

(c) 12

14 12

14 (b) (d)

12

38 36 14 32 34 12

40 (e) 14 (f)

FIGURE 4