BR112017018916B1 - CONTAINER FOR PREPARING A SAMPLE FOR ANALYSIS, METHODS OF PREPARING A SAMPLE FOR ANALYSIS, AND SYSTEM FOR AUTOMATICALLY PREPARING A SAMPLE FOR ANALYSIS - Google Patents

Abstract

The present invention provides a container and a method for preparing a sample for analysis. the container comprises a cavity for receiving a sample, including a collecting material and a precious metal. the cavity is suitable for melting the sample and oxidizing the collecting material. the cavity comprises a first region defined by a porous material that is capable of absorbing the collecting material when oxidized and melted. the cavity comprises a second region defined by a material that is, to a large extent, incapable of absorbing the molten and oxidized collecting material. the second region is capable of holding a volume of the molten sample. the container is arranged and the method is carried out in such a way that, when the sample has melted and reduced in volume due to absorption by the porous material of the first region, at least a part of the remaining sample remains in the second region.

Description

FIELD OF INVENTION

[001] The present invention relates to a method and a container for preparing a molten sample for analysis.

BACKGROUND OF THE INVENTION

[002] Mineral samples containing noble or precious metals often need to be analyzed to determine the amount of noble or precious metals within the mineral samples.

[003] One method of analyzing mineral samples for precious metals involves the use of spectroscopic techniques such as laser ablation or optical emission spectroscopy. In these methods, mineral samples are first melted with a flux before being analyzed. Sample preparation generally involves mixing the samples with a flux material, such as a litharge flux material, and placing the resulting mixture in a crucible and into an oven that is heated to form a melt. The litharge flux material is reduced to molten lead, which collects the precious metal and settles at the bottom of the crucible.

[004] There are several ways to separate lead and precious metals from the resulting slag to form a lead bud. The lead knob is then analyzed to determine the amount of precious metal that is distributed in the lead. The amount of precious metal can be determined by directly analyzing the bud using spectroscopic techniques. Alternatively, the lead button can be placed in a cupola and heated. Lead is absorbed into the cup and the resulting prill can be weighed or analyzed using wet chemistry techniques.

[005] A problem with the sample preparation described above concerns the often inhomogeneous distribution of the precious metal contained in the separate lead button. As spectroscopic analysis techniques generally only detect precious metal content in small areas of the sample, significant errors can occur if the precious metal is not evenly distributed in the lead knob. Spectroscopic techniques are essentially only capable of analyzing the outer surface of the sample. Furthermore, precious metal is often too diluted in lead and falls below the detection limit.

BRIEF DESCRIPTION OF THE INVENTION

[006] In a first aspect, a container for preparing a sample for analysis is provided, the container comprising:

[007] a cavity for receiving a sample including a collector material and a precious metal, the cavity being suitable for melting the sample and oxidizing the collecting material, the cavity comprising:

[008] a first region defined by a porous material that is capable of absorbing the collector material when oxidized and melted; and

[009] a second region defined by a material that is, to a large extent, incapable of absorbing the molten and oxidized collector material, the second region being capable of maintaining a volume of the molten sample;

[0010] wherein the container is arranged in such a way that when the sample has melted and has reduced in volume due to absorption by the porous material of the first region, at least a part of the remaining sample remains in the second region.

[0011] Throughout this specification, unless the context requires otherwise, the term "collecting material" refers to any substance that can form an alloy with a precious metal at suitable temperatures, thereby "collecting" it. Examples of collector materials include base metals such as lead and silver, or nickel sulfite. The terms can also be used to refer to the substance in its oxidized state, eg lead and lead oxide.

[0012] In a specific embodiment of the present invention, the first and second regions of the container are arranged so that the collector material is absorbed by the porous material of the first region, which reduces the amount of sample during co-lation to the sample it remains substantially only in the second region whereby, therefore, further absorption of the collector material is substantially avoided.

[0013] The embodiments of the present invention have the advantage that absorption of the collecting material or "copelling" automatically ceases once the collecting material material in the first region is absorbed and the concentrated sample in the second region is formed.

[0014] The second region may extend from a lower part of the first region. Additionally or alternatively, the second region can be positioned below the first region. The second region can have a smaller volume than the first region.

[0015] The container may be a cup, and the second region may be fully contained within the cup and extend from the first region.

[0016] Throughout this specification, unless the context requires otherwise, the term "copel" refers to a container comprising porous material capable of withstanding temperatures in the order of about 1000-1200 °C. To provide context, cupelas are commonly used in a technique known as fire extraction testing to refine precious metals.

[0017] The porous material of the first region of the container may, for example, comprise bone ash or magnesium oxide. The second region may, for example, be defined by a suitable ceramic material which is to a large extent incapable of absorbing the molten and oxidized collector material, which may be boron nitride, aluminum oxide or glassy carbon.

[0018] The container may comprise an insert that defines the second region and extends from the first region (generally from the bottom of the first region). The insert may be cylindrical in shape having a closed bottom and an open top to receive the sample through the first region. The inset can be surrounded by the material that defines the first region.

[0019] In a second aspect, a method of preparing a sample for analysis is provided, the method comprising:

[0020] providing the container according to the first aspect of the present invention;

[0021] placing a molten sample including a collector material and a precious metal in the cavity of the container; and

[0022] heat the sample in the container to a temperature sufficient to melt the sample and allow a part of the molten sample to be absorbed by the porous material;

[0023] in which the container is arranged and the method is conducted in such a way that a part of the molten sample that remains in the cavity retreats to the second region, preventing any further absorption by the porous material.

[0024] In a specific embodiment of the present invention, the method is conducted in such a way that the collecting material is absorbed by the porous material of the first region, which reduces the amount of the sample until the sample remains substantially only in the second region, whereby further absorption of the collecting material is generally avoided substantially automatically.

[0025] The collector material may comprise silver as a co-collector material. The collector material may comprise a primary collector material which may include lead in the form of litharge.

[0026] The step of heating the sample in the container usually involves oxidizing the collector material.

[0027] The method may comprise modifying a property of an environment surrounding the container during sample heating to increase or decrease a rate at which the container absorbs collecting material. Modification of the environment can include the addition of oxygen to increase the oxidation of the collector material and therefore the rate at which the oxidized collector material is absorbed.

[0028] The method may comprise, after absorption of the collecting material has ceased, pouring the remaining sample into a mold, such as a refrigerated mold. Furthermore, the refrigerated mold can be a sample holder, so that the remaining sample can be further analyzed in the sample holder.

[0029] In a third aspect, a method of preparing a sample for analysis is provided, the method comprising:

[0030] heating a molten sample including a collector material and a precious metal in a cup to a temperature sufficient to melt the molten sample and initiate absorption of at least a portion of the collector material by the cup; and

[0031] automatically stop the absorption of the collecting material by the cup after a predetermined period of time in such a way that the remaining sample comprises a part of the collecting material.

[0032] The step of stopping the absorption of the collecting material by the cup can comprise reducing the oven temperature after the predetermined period of time or removing the cup from the oven after a predetermined time.

[0033] Alternatively, the orifice may be a recess that is located in a lower part of the cupla without protruding from the lower part. The recess may have a diameter that is much smaller than that of the cup. For example, the recess may have a diameter on the order of 5-10 mm or about 5-10%, 10-20% or 20-30% of the cup's diameter. The recess can have an inner volume that is less than 1%, 1-2%, 2-5%, 5-10%, or 10-20% of a cupella's total inner volume. As the sample is absorbed into the cup, an amount of the sample reduces until it is just located in the recess. As the surface area in the recess is significantly less than the total internal surface area of the cup, the cupping (absorption) process is slowed down, making it easier to control the remaining sample volume and sample molding time.

[0034] In a fourth aspect of the present invention, a system for the automated preparation of a sample for analysis is provided, the system comprising:

[0035] an oven having at least one receiving station located within the interior of the oven and an access door to facilitate access to the receiving station;

[0036] the container according to the first aspect of the present invention, further configured to be received by the, or a respective, receiving station;

[0037] a loading mechanism for moving the container with respect to the oven; and

[0038] a controller for controlling the loading mechanism.

[0039] The controller may further be arranged to initiate a change to an operating parameter of the furnace after a predetermined period of time. The change in the oven operating parameter can be a reduction in temperature inside the oven, or it can refer to opening or closing the access door.

[0040] The controller can be arranged in such a way that the container is loaded or unloaded automatically after a predetermined period of time.

[0041] The system can further be configured to decant the contents of the container to another container, such as a refrigerated mold.

The invention will be more fully understood from the following description of specific embodiments of the invention. The description is provided with reference to the attached figures.

BRIEF DESCRIPTION OF THE FIGURES

[0043] Figure 1 is a flowchart illustrating a method according to an embodiment of the present invention;

[0044] Figure 2 is a flowchart illustrating a method according to another embodiment of the present invention;

[0045] Figure 3a is a plan view of a cup in accordance with an embodiment of the present invention;

[0046] Figure 3b is a cross-sectional view of the cupola shown in Figure 3a;

[0047] Figure 3c is a perspective sectional view of the cupola shown in Figures 3a and 3b; and

[0048] Figures 4a and 4b are perspective views of a system according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0049] The present invention relates to a method and a container for preparing a mineral sample for analysis, such as spectroscopic analysis, to determine an amount of a precious metal in the sample.

[0050] Mineral samples for spectroscopic analysis are generally fused with a flow and collector material prior to analysis. The flux can serve to lower the melting point and to provide a level of homogeneous fluidity in the sample. The flux can also include collecting material such as litharge and silver. The mixture of sample and flux is then placed in an oven and heated to about 1000°C to form a melt. The molten slag floats in the melt, and the collector material bonds with the precious metal in the sample and sinks to form an array of collectors and molten precious metals, which is then separated from the molten slag and rapidly cooled to form a homogeneous bud.

[0051] So generally, spectroscopic analysis is performed directly on the knob. Suitable spectroscopy techniques include laser ablation, optical emission spectrometry or X-Ray fluorescence (XRF). However, a problem with this is that the level of homogeneity in the button may be insufficient to produce accurate results, for example if the button was not produced by blast chilling. This can, in turn, present a problem during spectroscopic analysis, which usually measures only small areas of the sample. As a result, significant errors can occur if the precious metal is not sufficiently homogeneous within the knob. Also, impurities in the sample can interfere during the analysis.

[0052] Referring to Figure 1, a method 100 according to an embodiment of the present invention is now described. Method 100 comprises heating the knob in a cup to a temperature sufficient to melt the sample and oxidize a collector material to initiate absorption of at least a portion of the oxidized collector material by the cup (step 102).

[0053] In a specific embodiment of the present invention, the sample is a molten sample containing lead and a precious metal. More specifically, the sample is derived from a melting process, in which a mineral sample is combined with flux and a collector material (lead in the example) and heated in a crucible to melt the sample. During this process, the collecting material (lead) melts and oxidizes, collects the precious metals and settles at the bottom of a crucible. Silver can also be added as a co-collecting material. Lead and precious metals can then be separated from the remaining slag to form a molten sample or "lead knob". Examples of precious metals include, but are not limited to, gold, silver, platinum, palladium, ruthenium and rhodium.

[0054] Method 100 further comprises automatically ceasing absorption of oxidized lead by the cup after a predetermined period of time such that a remaining sample comprises only a portion of the original lead (step 104).

[0055] The cup comprises a porous material such as bone ash or magnesium oxide. In step 102, the cup and knob are heated in an oven to about 1000-1200°C. During this process, lead oxidizes due to a reaction with the oxygen flow in the furnace. The lead oxide then fuses and diffuses into the pores of the cup by capillary action, thus separating from the precious metal. Precious metals are left behind unabsorbed.

[0056] If heating in step 102 is continued for a sufficiently long period of time, eventually all the lead in the sample will oxidize and be absorbed by the cup, and a precious metal prill having a very high percentage purity will remain. However, according to method 100, step 104 is carried out before this can occur, i.e. the lead oxidation is not continued to completion. The absorption of the collecting material by the cup is caused to cease after a predetermined period of time, so that some of the lead collecting material still remains in the cup. In other words, method 100 only allows partial match.

[0057] Thus, method 100 increases the concentration of precious metals, which facilitates the analysis of the sample. Furthermore, when performing a partial cupping process, impurities in the sample and flux mixture (which can cause interference during spectroscopic analysis) are also removed by absorption into the cup material.

[0058] The step 104 of causing the absorption of the collector material (lead oxide) by the cup to cease can be performed by reducing the oven temperature in a predetermined time or the cup can be removed from the oven in a predetermined time.

[0059] In another embodiment, step 102 of method 100 may comprise modifying an environment surrounding the cup during sample heating to increase or decrease a rate at which the cup absorbs lead oxide. In one embodiment, modifying the environment comprises introducing oxygen into the interior of the oven in which the cup is heated, to increase lead oxidation and thus the rate at which lead oxide is absorbed. Introducing oxygen into the furnace may involve injecting a predetermined amount of gaseous oxygen into the furnace, or opening the furnace door for a predetermined period of time to allow additional air to enter.

[0060] In a specific embodiment of the present invention, the cup has a recess that is located in a lower part of the cup. The recess has a diameter that is much smaller than that of the cup. For example, the recess may have a diameter on the order of 5-10 mm. As the sample collecting material is absorbed by the cup, a quantity of the sample is reduced until the sample is exclusively located in the recess. As the surface area in the recess is much smaller, the cupping (absorption) process is slowed down, making it easier to control the remaining sample volume and sample molding time.

[0061] Referring to Figure 2, a method 200 of preparing a sample, specifically a molten sample in the form of a lead button, in accordance with another embodiment of the present invention is now described.

[0062] Method 200 comprises providing a container having a cavity that has a first region defined by porous material that is capable of absorbing a collector material when oxidized and fused, and a second region defined by a material that is, to a large extent, waterproof and capable of holding a volume of a molten sample (step 202). The container will be described in more detail with reference to Figures 3(a), (b) and (c) below. Again, in one modality, the collecting material is lead and the sample is a molten sample or a "lead knob".

[0063] Method 200 also comprises placing the molten sample or lead knob, including the precious metals, in the cavity (step 204).

[0064] In addition, method 200 comprises heating the lead button in the cup to a temperature sufficient to melt the lead button and allow the oxidized lead to be absorbed by the porous cup material, thereby reducing the volume of the lead button, wherein the container is arranged so that the remaining part of the sample completely retreats into the second region, preventing any further absorption by the porous material (step 206).

[0065] Method 200 is similar to method 100 in that both methods involve heating the sample in a container and, at a predetermined time, prematurely causing the absorption of the lead collecting material to cease. Thus, in both methods, the remaining sample to be analyzed still comprises a part of the lead-collecting material, and the precious metal is more concentrated and the sample has less impurities than if this partial co-lation step had not been carried out.

[0066] However, in method 200, it is the configuration of the container that causes the lead collecting material to be prevented from being further absorbed.

[0067] In one modality and as mentioned above, silver may be added to the flux to act as a co-collector during the fusion of the mineral sample with the flux containing the main collecting material, usually lead. Silver can be added as a metal or in the form of a silver salt. At the end of the smelting process, the separate collector material, usually composed mainly of lead, will contain all the silver as well as all the other precious metals collected. For mineral samples that have been fused with a flux containing silver as a co-collector in addition to lead, the cuplation can continue for a period of time sufficient to allow all of the lead to be oxidized and absorbed into the cupella porous body leaving only a silver bead containing the collected precious metal remaining in the cup. This silver bead is then used for analysis, for example using optical emission spectroscopy. Furthermore, when the collecting material comprises lead and silver as a co-collector, method 100 or 200 may further comprise allowing the oxidation of all the lead such that only the silver co-collector remains in the cup with the metals. precious collected. Silver and other precious metals can then be analyzed using spectroscopic techniques such as laser ablation or optical emission spectrometry.

[0068] With reference to Figures 3a to 3c, in one embodiment, a cup 300 that can be used for method 200 is now described. Figures 3b and 3c show sectional views through section A-A shown in Figure 3a. Cup 300 comprises a cavity 302 for receiving a material to be partially cupped. The material to be received may be the lead button, including the collected precious metal, as in the case of method 100 and 200. Cavity 302 comprises a first region 304 and a second region 306.

[0069] The first region 304 is defined by porous material capable of absorbing lead when oxidized and in molten form. The porous material can be the same as the cup material suitable for use in method 100, such as bone ash/magnesium oxide.

[0070] The second region 306 is defined by a material that is, to a large extent, impermeable. In this embodiment, the second region comprises a surrounding wall 308 and a lower portion. The second region 306 is capable of holding a volume of a molten sample.

[0071] The first and second regions 304 and 306 are arranged in such a way that, in use, when the mixture reduces in volume due to absorption of the collector material by the porous material, a remaining part of the molten sample completely retreats to the second region 306. As a result, any further absorption by the porous material of the first region 304 is impeded.

[0072] In this particular embodiment, when cup 300 is placed upright, second region 306 is located below first region 304 and extends from a lower portion of first region 304. In other words, an open bottom 310 of first region region 304 is adjacent to, and in communication with, an open top 312 of second region 306, thus allowing fluid communication between first and second regions 304 and 306. In one embodiment, first region 304 is configured with an inner surface. concavely curved 314, and the second region 304 is cylindrical, as shown in Figures 3a-3c. The second region 306 has a smaller volume than the first region 304.

[0073] Furthermore, the surrounding wall 308 of the second region 306 may be in the form of an insert 316, particularly a cylindrical insert, comprising a base 318 and sidewall(s) 320 extending upwardly therefrom. . Thus, insert 316 can be made separately for a main body of cup 300, and then combined.

[0074] Cup 300 can be formed by first fabricating cup body 300 entirely from bone ash or magnesium oxide, with a portion of cavity 302 molded to receive insert 316. Insert 316 can then be placed in the cup. associated part of cavity 302. Insert 316 may be made of any suitable material, such as ceramic, which can withstand temperatures of about 1000-1200°C and will not absorb or react with the collector material.

[0075] In an alternative embodiment, a container for use in method 200 may be formed from a combination of a cup and a crucible of impermeable material. For example, the cup can have a longitudinal hole drilled to a lower end of the cup. The crucible can then be coupled to the lower end of the cup in such a way as to seal the opening created by the hole. The crucible can be formed to be mounted within the hole such that a lower end of the crucible is flush with the lower end of the cup. Alternatively, the crucible can be attached to an outer surface of the cup, thus forming an appendix to the cup.

[0076] An advantage of using the container arrangements described above for use in method 200 is that a consistent volume or desired amount of sample can be accurately obtained for subsequent analysis. In other words, method 200 can produce multiple samples having the same predetermined volume, thus allowing for a more efficient method of assaying precious metals.

[0077] In other embodiments, methods 100 and 200 may comprise pouring the remaining sample into a refrigerated mold after steps 104 and 206, respectively. Thus, after the absorption of the collecting material has ceased, or in other words, the partial colation process is complete, the remaining sample is then allowed to cool and resolidify in a refrigerated mold before being analyzed for precious metal content . In one embodiment, the cooled mold also functions as a sample holder for further spectroscopic or other analysis. The mold can be any suitable shape.

[0078] Referring to Figures 4a and 4b, a system 400 in accordance with an embodiment of the present invention is now described. System 400 allows automated preparation of a mineral sample for analysis to determine a quantity of a precious metal in the mineral sample. System 400 can be used to perform either 100 or 200 methods.

[0079] The system 400 comprises an oven 402, a charging mechanism 404 and a controller for controlling at least one component of the system, including the charging mechanism.

[0080] The oven 402 comprises receiving stations located within the oven 402. The receiving stations are capable of receiving suitable containers or cups containing the respective samples. For example, each container to be received by a respective receiving station may be in the form of cup 300 as described above and further configured to be received by the stations. Oven 400 also features an access door to facilitate access to the receiving station. For example, the access door can be an entrance.

[0081] A plurality of receiving stations 404 may be provided, such that the automated process can assist in preparing a sample or a batch of samples. It will be appreciated that the number of receiving stations 404 is exemplary only, and any number of receiving stations may be housed by furnace 402.

[0082] The controller is normally capable of controlling various components of the 400 system, but is at least capable of controlling the 404 loading mechanism to perform handling tasks. These tasks include loading, unloading and decanting the contents of the container to another. As shown in Figures 4a and 4b, the loading mechanism 404 is positioned relative to the furnace, but it can also move relative to the furnace in order to accomplish these tasks.

[0083] In one example, the controller is arranged such that the container is loaded or unloaded automatically after a predetermined period of time. In other words, the controller can be programmed to perform predetermined movements relating to loading and unloading the container. For example, mechanism 404 can be programmed to remove a container from oven 402 and decant its contents into a mold after the container and its sample have been heated for a predetermined period of time within oven 402. has cooled in the mold, the sample can then be analyzed for precious metal content. Mechanism 404 can sequentially perform this task for each container in the oven, thus automating the process.

[0084] In another embodiment, the controller is also arranged in such a way to initiate a change in an operating parameter of the furnace after a predetermined period of time or other condition(s) is satisfied. Oven operating parameters can include a reduction in temperature inside the oven, and opening or closing the access door. Furnace 402 may comprise control electronics configured to communicate with the controller such that the controller can initiate these changes. For example, the oven may comprise electronic temperature sensors and/or a timer. Once the pre-selected temperature and/or duration conditions have been satisfied, the controller can automatically cause the oven to reduce or stop heating the vessel and sample. Then the controller can control the loading mechanism to proceed with handling tasks such as unloading and decanting.

[0085] The oven 402 comprises a housing and a heater for heating an interior part of the housing to a temperature sufficient to cause each sample to melt. Furthermore, in one embodiment, the receiving stations are in the form of an opening or indentation located in a platform, being dimensioned to receive the respective containers.

[0086] In a further example, the oven 402 comprises a rotating platform or carousel on or on which the receiving stations are located. The carousel may be configured to receive a plurality of (e.g. six) receiving stations radially disposed about a central longitudinal axis of the carousel.

[0087] The carousel helps to move the containers in relation to the receiving stations, in particular, placing and removing the containers from the oven. Thus, when it is desired to place or remove a container from a particular receiving station, the carousel is rotated such that the receiving station moves to a loading/unloading position with respect to oven 402. accessed, oven 402 may allow mechanism 404 to place or remove the container from the respective receiving station.

[0088] All such modifications and variations together with others that would be obvious to those skilled in the art are considered within the scope of the present invention, the nature of which is to be determined from the above description and the appended claims. For example, the first and second regions 304 and 306 may have an alternative shape and configuration for the specific embodiment described above.

Claims (15)

1. Container for preparing a sample for analysis, CHARACTERIZED in that the container comprises: a cavity for receiving a sample, including a collector material and a precious metal, the cavity being suitable for melting the sample and oxidizing the collecting material, the cavity comprising: a first region defined by a porous material that is capable of absorbing the collecting material when oxidized and melted; and a second region defined by a material that is, to a large extent, incapable of absorbing the molten and oxidized collector material, the second region being capable of maintaining a volume of the molten sample; wherein the container is arranged such that when the sample has melted and has reduced in volume due to absorption by the porous material of the first region, at least a portion of the remaining sample remains in the second region. 2. Container according to claim 1, CHARACTERIZED in that the first and second regions of the container are arranged in such a way that the collecting material is absorbed by the porous material of the first region, which reduces the amount of sample during the cupping up to the sample substantially only remains in the second region, whereby, therefore, further absorption of the collecting material is substantially avoided. Container according to claim 1 or 2, CHARACTERIZED in that the second region extends from a lower portion of the first region and is in use positioned below the first region. Container according to any one of claims 1, 2 or 3, CHARACTERIZED in that the second region has a smaller volume than the first region. 5. Method of preparing a sample for analysis, CHARACTERIZED in that the method comprises: heating a molten sample including a collector material and a precious metal in a cup to a temperature sufficient to melt the molten sample and initiate absorption of at least a part of the collecting material by the cupela; and automatically ceasing absorption of the collector material by the cup after a predetermined period of time such that the remaining sample comprises a portion of the collector material. 6. Method according to claim 5, CHARACTERIZED in that the step of stopping the absorption of the collecting material by the cup comprises reducing an oven temperature after the predetermined period of time or removing the cup from the oven after a predetermined time . Method according to claim 5 or 6, CHARACTERIZED in that the cup has a recess in a lower part. The method of claim 7, CHARACTERIZED in that the method is carried out in such a way that the collector is absorbed until a remaining sample is located substantially uniquely in the recess, whereby a rate of progression of the cupellation is reduced. Method according to claim 7, characterized in that the recess has a diameter of 5-10 mm. The method of claim 7, characterized in that the recess has a diameter on the order of about 5 to 30% of the cup diameter, more preferably 5 to 20% of the cup. The method according to claim 7, characterized in that the recess has an internal volume that is from 1 to 20% of a total internal volume of the cup. 12. System for automatically preparing a sample for analysis, CHARACTERIZED in that the system comprises: an oven having at least one receiving station located within the interior of the oven and an access door to facilitate access to the receiving station; the container as defined in any one of claims 1 to 4 further configured to be received by the or a respective receiving station; a loading mechanism for moving the container with respect to the oven; and a controller to control the loading mechanism. System according to claim 12, CHARACTERIZED in that the controller is further arranged to initiate a change to an operating parameter of the oven after a predetermined period of time. System according to claim 13, CHARACTERIZED in that the controller is arranged to reduce the temperature inside the oven after a predetermined period of time. A system according to any one of claims 11 to 14, CHARACTERIZED in that the controller is arranged such that the container is loaded or unloaded automatically after a predetermined period of time.

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