A method and container for preparing and analyzing fusion samples

Abstract

This invention discloses a method and container for preparing an analytical fused sample. The container includes a cavity for receiving a sample comprising a collection material and a noble metal, the cavity being adapted to melt the sample and oxidize the collection material. The cavity includes a first region defined by a porous material capable of absorbing the collection material upon oxidation and melting. The cavity also includes a second region defined by a material that cannot absorb the molten and oxidized collection material. The second region is capable of accommodating a volume of the fused sample. The container is configured such that when the sample has melted and its volume has decreased due to absorption by the porous material in the first region, at least a portion of the remaining sample remains in the second region.

Description

[0001] This application is a divisional application of patent application No. 201680014097.9 (PCT / AU2016 / 000069) filed by the applicant on March 4, 2016 and entitled “A method and container for preparing fusion samples for analysis”. Technical Field

[0002] The present invention relates to a method and a container for preparing a fusion sample for analysis. Background Art

[0003] In order to determine the content of rare metals or precious metals in a mineral sample, it is usually necessary to analyze the mineral sample containing rare metals or precious metals. One method of analyzing precious metal mineral samples involves the use of spectroscopic techniques, such as laser ablation or optical emission spectroscopy. In these methods, the mineral sample is first fused with a flux before analysis. Sample preparation generally includes mixing the sample with a flux material (e.g., a large amount of flux material), and placing the resulting mixture in a crucible and heating it in a furnace to form a melt. A large amount of the flux material is reduced to molten lead, which collects the precious metal and precipitates to the bottom of the crucible.

[0004] Methods may be employed to separate the lead and precious metals from the resulting slag in order to form lead buttons. The lead buttons are then analyzed to determine the amount of precious metal dispersed in the lead. The amount of precious metal may be determined by directly analyzing the lead buttons using spectroscopic techniques. Alternatively, the lead buttons may be placed in an ash dish and heated, the lead being absorbed by the ash dish, and the resulting particles may be weighed or analyzed using wet chemical methods.

[0005] The above sample preparation problem is related to the fact that the precious metals contained in the separated lead buttons are often unevenly distributed. Since spectroscopic analysis techniques usually only detect the precious metal content in a small area of ​​the sample, if the precious metal is unevenly distributed in the lead button, significant errors may occur. Spectroscopic techniques can basically only analyze the outer surface of the sample. In addition, the precious metal content in the lead is usually too small to be detected. Summary of the invention

[0006] In a first aspect, the present invention provides a container for preparing an analytical sample, the container comprising: the container comprising: a cavity for receiving a sample containing a collection material and a precious metal, the cavity being used to melt the sample and oxidize the collection material, the cavity comprising:

[0007] a first region defined by a porous material capable of absorbing a collection material when oxidized and melted;

[0008] a second region defined by a material incapable of absorbing the molten and oxidized collection material, the second region being capable of accommodating a volume of the fused sample;

[0009] The container is configured such that when the sample has melted and its volume has decreased due to absorption by the porous material of the first region, at least a portion of the remaining sample remains in the second region.

[0010] Throughout this specification, unless the context indicates otherwise, the term "collecting material" refers to any substance that can form an alloy with a precious metal at the appropriate temperature, thereby "collecting" it. For example, collecting materials include base metals such as lead and silver or nickel sulfide. These terms can also be used to refer to substances in an oxidized state, such as lead and lead oxide.

[0011] In a specific embodiment of the present invention, the first area and the second area of ​​the container are configured so that the collection material is absorbed by the porous material of the first area, so that the amount of the sample is reduced during the ash blowing method until the sample is basically retained only in the second area, thereby avoiding further absorption of the collection material.

[0012] Embodiments of the present invention have the advantage that absorption or "ash blowing" of the collection material will automatically stop once the collection material in the first region is absorbed and forms a concentrated sample in the second region.

[0013] The second region may extend from the bottom of the first region. Further or alternatively, the second region may be located below the first region. The volume of the second region is smaller than that of the first region.

[0014] The container may be an ashtray, and the second region may be completely contained within the ashtray and extend from the first region.

[0015] Throughout the specification, unless the context requires otherwise, the term "ashtray" refers to a container comprising a porous material capable of withstanding temperatures of the order of about 1000-1200° C. For ease of context, an ashtray is commonly used in the art of fire refining precious metals.

[0016] The porous material of the first region of the container may comprise bone ash or magnesium oxide. The second region may be defined by a suitable ceramic material that is incapable of absorbing the molten and oxidized collection material, which may be boron nitride, aluminum oxide or glassy carbon.

[0017] The container may include an insert defining the second region and extending from the first region (typically from the bottom of the first region). The insert may be cylindrical, with a closed bottom and an open top for receiving a sample via the first region. The insert may be surrounded by a material defining the first region.

[0018] In a second aspect, the present invention provides a method for preparing an analytical sample, the method comprising:

[0019] Making the container of the present invention as described above;

[0020] placing a fused sample comprising the collection material and the precious metal in a cavity of the container;

[0021] heating the sample in the container to a temperature sufficient to melt it and allowing a portion of the fused sample to be absorbed by the porous material;

[0022] Therein, the container is arranged and the method is performed such that a portion of the fused sample remaining in the cavity is retracted into the second region, thereby preventing further absorption by the porous material.

[0023] In a specific embodiment of the present invention, the method allows the collection material to be absorbed by the porous material of the first region, reducing the amount of the sample until the sample remains substantially only in the second region, thereby avoiding further autoabsorption of the collection material.

[0024] The collecting material may include silver used as a co-collecting material.The collecting material may include a primary collecting material which may include lead in lead oxide.

[0025] The step of heating the sample within the container includes oxidation of the collection material.

[0026] The method increases or decreases the rate at which the container absorbs the collection material by changing the properties of the environment surrounding the container during heating of the sample.

[0027] The changing of the environment includes adding oxygen to increase the degree of oxidation of the collection material, thereby increasing the rate at which the oxidized collection material is absorbed.

[0028] The method pours the remaining sample into a mold, such as a cold mold, after the collection material stops absorbing. Further, the cold mold can be a sample holder, so that the remaining sample in the sample holder can be analyzed later.

[0029] In a third aspect, the present invention provides a method for preparing an analytical sample, the method comprising:

[0030] heating a fused sample comprising a collection material and a precious metal in an ashtray to a temperature sufficient to melt the fused sample so that at least a portion of the collection material is absorbed by the ashtray;

[0031] The ashtray automatically stops absorbing the collection material after a predetermined time, so that the remaining sample contains a portion of the collection material.

[0032] The step of stopping the ashtray from absorbing the collected material comprises lowering the temperature of the furnace after the predetermined time, or removing the ashtray from the furnace after the predetermined time.

[0033] Alternatively, the hole can be a groove located at the bottom of the ash dish, not running through the bottom. The diameter of the groove is smaller than the diameter of the ash dish. For example, the diameter of the groove is about 5 to 10 mm, or about 5-10%, 10-20% or 20-30% of the ash dish. The internal volume of the groove can be 1%, 1-2%, 2-5%, 5%-10% or 10-20% less than the internal volume of the ash dish. As the sample in the ash dish is absorbed, the amount of sample decreases until the sample is only in the groove. Since the surface area of ​​the groove is significantly smaller than the total internal area of ​​the ash dish, the ash blowing method (absorption) is slowed down, making it easier to control the remaining volume of the sample and the time of casting the sample.

[0034] In a fourth aspect of the present invention, there is provided a system for automatically preparing samples for analysis, the system comprising:

[0035] a furnace having at least one receiving station located within said furnace and an entrance facilitating access to said receiving station;

[0036] A container as described above, arranged to be received by said receiving station or a corresponding receiving station;

[0037] a loading mechanism for moving the container relative to the furnace;

[0038] and a controller for controlling the loading mechanism.

[0039] The controller is also configured to change the startup operating parameters of the furnace after a predetermined time. The furnace operating parameters may be changed by lowering the temperature inside the furnace, or opening or closing the inlet.

[0040] The controller is configured to automatically load or unload the container after a predetermined time.

[0041] The system also includes another container, such as a cold mold, into which the contents of the container are poured.

[0042] According to one aspect of the present invention, there is provided a container for preparing an analytical sample, the container comprising: a cavity for receiving a sample containing a collection material and a precious metal, the cavity being used to melt the sample and oxidize the collection material, the cavity comprising:

[0043] a first region defined by a porous material capable of absorbing a collection material when oxidized and melted;

[0044] a second region defined by a material that is substantially incapable of absorbing the melted and oxidized collection material, the second region being capable of accommodating a volume of the fused sample;

[0045] The container is configured 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.

[0046] Optionally, the first and second regions of the container are arranged so that the collection material is absorbed by the porous material of the first region, reducing the sample amount during ashblowing until the sample remains substantially only in the second region, thereby preventing further absorption of the collection material.

[0047] Optionally, the second region extends from a bottom of the first region and, in use, is positioned below the first region.

[0048] Optionally, the volume of the second region is smaller than the volume of the first region.

[0049] Optionally, the container is an ashtray.

[0050] According to another aspect of the present invention, there is provided a method for preparing an analysis sample, the method comprising:

[0051] Providing any of the above containers;

[0052] placing a fused sample comprising a collection material and a precious metal in a cavity of a container;

[0053] heating the sample in the container to a temperature sufficient to melt it and allowing a portion of the fused sample to be absorbed by the porous material;

[0054] Wherein, by arranging the container and performing the method, the portion of the fused sample remaining in the cavity is retracted into the second region, thereby preventing it from being further absorbed by the porous material.

[0055] Optionally, the method is performed such that the collection material is absorbed by the porous material of the first region, reducing the sample volume until the sample is substantially retained in the second region, thereby avoiding further autoabsorption by the collection material.

[0056] Optionally, the collecting material comprises silver used as a co-collecting material.

[0057] Optionally, the step of heating said sample within said container comprises oxidation of said collection material.

[0058] Optionally, the method further comprises increasing or decreasing the rate at which the collection material is absorbed by the container by changing the properties of the environment surrounding the container during heating of the sample.

[0059] Optionally, said changing the environment comprises adding oxygen to increase the degree of oxidation of the collection material.

[0060] Optionally, the method further comprises pouring the remaining sample into a mold after stopping the absorption of the collection material.

[0061] According to another aspect of the present invention, there is provided a method for preparing an analysis sample, the method comprising:

[0062] heating a fused sample containing a collection material and a precious metal in an ashtray to a temperature sufficient to melt the fused sample and absorb at least a portion of the collection material by the ashtray:

[0063] The ashtray automatically stops absorbing the collection material after a predetermined time, so that the remaining sample contains a portion of the collection material.

[0064] Optionally, the step of causing the ashtray to stop absorbing the collected material comprises reducing the temperature of the furnace after the predetermined period of time, or removing the ashtray from the furnace after a predetermined period of time.

[0065] Optionally, the bottom of the ashtray has a groove.

[0066] Optionally, the method is performed such that the collection material is absorbed until the remaining sample is substantially located in the recess, thereby reducing the rate of progression of the soot-blowing melt.

[0067] According to another aspect of the present invention, there is provided a system for automatically preparing an analysis sample, the system comprising:

[0068] a furnace having at least one receiving station located within said furnace and an entrance facilitating access to said receiving station;

[0069] A container as described above, configured to be received by said receiving station or a corresponding receiving station;

[0070] a loading mechanism for moving the container relative to the furnace;

[0071] and a controller for controlling the loading mechanism.

[0072] Optionally, the controller is further configured to initiate a change in an operating parameter of the furnace after a predetermined period of time.

[0073] Optionally, the controller is arranged to reduce the temperature within the oven after a predetermined period of time.

[0074] Optionally, the controller is arranged to automatically load or unload the container after a predetermined period of time.

[0075] Optionally, the system is further configured to pour the contents of the container into a cold mold.

[0076] Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings in order to more fully understand the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 is a flow chart illustrating a method according to an embodiment of the present invention;

[0078] Figure 2 is a flow chart showing a method according to another embodiment of the present invention;

[0079] Figure 3a is a plan view of an ashtray according to an embodiment of the present invention;

[0080] Figure 3b yes Figure 3a A cross-sectional view of the ashtray shown;

[0081] Figure 3c yes Figure 3a and 3b A perspective cross-sectional view of the ashtray shown;

[0082] Figure 4a and 4b is a perspective view of a system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0083] The present invention relates to a method and a container for preparing a mineral sample for analysis, such as spectroscopic analysis, to determine the content of precious metals in the sample.

[0084] Mineral samples for spectroscopic analysis are usually fused with flux and collection materials prior to analysis. Flux can be used to lower the melting point and give the sample uniform fluidity. The flux can also contain collection materials, such as lithium batteries and silver. The sample and flux mixture is then placed in a furnace and heated to about 1000°C to form a melt. The slag floats on the top of the melt, and the collection material alloyed with the precious metals in the sample sinks to the bottom, forming a molten pool of molten collection and precious metals, which is then separated from the slag and rapidly cooled until a homogeneous snap is formed.

[0085] Then, spectroscopic analysis is usually performed directly on the snaps. Suitable spectroscopic analysis techniques include laser ablation, optical emission spectroscopy or X-ray fluorescence (XRF). However, the problem with this is that the inhomogeneity of the snaps can produce inaccurate analysis results, for example if the snaps are not formed by rapid cooling, which can cause problems during spectroscopic analysis, which usually only measures a small area of ​​the sample. As a result, significant errors can occur if the precious metal is not evenly distributed within the snaps. In addition, impurities in the sample may also interfere with the analysis results.

[0086] refer to Figure 1, the method 100 of an embodiment of the present invention is now described. The method 100 includes heating a fusion sample containing a collection material and a precious metal in an ash dish to a sufficient temperature to melt the fusion sample and oxidize the collection material so that at least a portion of the collection material is absorbed by the ash dish (step 102).

[0087] In a specific embodiment of the invention, the sample is a fusion sample containing lead and precious metals. More specifically, the sample comes from a fusion process in which a mineral sample is combined with a flux and a collection material (lead in this embodiment) and heated in a crucible to melt the sample. During this process, the collection material (lead) melts and oxidizes, and the precious metals are collected and precipitated at the bottom of the crucible. Silver can also be used as a co-collection material. The lead and precious metals can then be separated from the slag to form a fusion sample or "lead buckle". The precious metals can include, but are not limited to, gold, silver, platinum, palladium, ruthenium and rhodium.

[0088] The method 100 also includes automatically stopping the process of absorbing lead oxide by the ash dish after a predetermined time so that the remaining sample contains a portion of the original lead (step 104).

[0089] The ashtray includes a porous material such as bone ash or magnesium oxide. In step 102, the ashtray and snaps are heated in a furnace to about 1000-1200°C. During this process, the lead is oxidized due to reaction with oxygen entering the furnace. The lead oxide then melts and diffuses into the pores of the ashtray by capillary action, thereby separating from the precious metal. The precious metal is precipitated because it is not absorbed.

[0090] If the heating in step 102 is continued for a long enough time, eventually all of the lead in the sample will be oxidized and absorbed by the ash dish, thereby forming precious metal "pearls" with extremely high purity. However, as can be seen from method 100, step 104 is performed before this can occur, that is, the oxidation of the lead does not continue. As a result, the process of absorbing the collected material by the ash dish stops after a predetermined time, so that a portion of the collected material remains in the ash dish. In other words, method 100 only allows for a partial ash blowing process.

[0091] Therefore, method 100 increases the concentration of precious metals, which is beneficial for sample analysis. In addition, by performing a partial ash blow process, impurities in the mixture of sample and flux (which may cause interference during spectral analysis) may also be removed by absorbing them through the ash dish material.

[0092] The method for automatically stopping the process of the ashtray absorbing the collection material (lead oxide) in step 104 may be to reduce the temperature of the furnace after a predetermined time or to remove the ashtray from the furnace.

[0093] In another embodiment, step 102 of method 100 may include changing the environment around the ashtray during heating of the sample to increase or decrease the rate at which the ashtray absorbs lead oxide. In one embodiment, changing the environment includes introducing oxygen into the interior of a furnace used to heat the ashtray to increase oxidation of lead, thereby correspondingly increasing the rate at which lead oxide is absorbed. Introducing oxygen into the furnace may inject a predetermined amount of oxygen into the furnace, or open the furnace door for a predetermined time to allow air outside the furnace to flow in.

[0094] In a specific embodiment of the invention, the ash dish has a groove located in the bottom of the ash dish. The diameter of the groove is much smaller than the diameter of the ash dish. For example, the diameter of the groove can be about 5-10 mm. As the collected material of the sample is absorbed by the ash dish, the amount of sample decreases until the sample is completely located in the groove. Since the surface area of ​​the groove is much smaller, the ash blowing process (absorption) is significantly slowed down, making it easier to control the volume of the remaining sample and the time of casting the sample.

[0095] refer to Figure 2 , a method 200 for preparing a sample according to another embodiment of the present invention is now described, specifically relating to a fusion sample in the form of a lead button.

[0096] Method 200 includes providing a container having a cavity, the cavity having a first region defined by a porous material capable of absorbing a collection material when oxidized and melted, and a second region defined by a material that cannot absorb the molten and oxidized collection material, the second region being capable of accommodating a volume of a fused sample (step 202). The container will be described in more detail below with reference to Figures 3(a), (b) and (c). In an embodiment, the collection material is lead and the sample is a fused sample or "lead button".

[0097] The method 200 also includes placing a fusion sample or lead button containing a precious metal in the cavity (step 204).

[0098] In addition, method 200 includes heating the lead buckle in the ashtray to a temperature sufficient to melt the lead buckle and allow oxidized lead to be absorbed by the porous ashtray material, thereby reducing the volume of the lead buckle, wherein the container is arranged in the following manner so that the remaining portion of the sample is completely withdrawn into the second area to prevent further absorption by the porous material (step 206).

[0099] Method 200 is similar to method 100 in that both methods include heating the sample in the container and stopping the absorption of the lead collecting material as early as possible within a predetermined time. Therefore, in both methods of the present invention, the remaining sample to be analyzed still contains a portion of the lead collecting material, the precious metal is more pure, and the impurities in the sample are less than those in the step without the partial ash blowing method.

[0100] However, in method 200, the container is structured to prevent further absorption of the lead collecting material.

[0101] In the embodiment described above, when the mineral sample is fused with a flux containing a main collection material (usually lead), silver can be added to the flux to serve as a co-collection material. Silver can be added in the form of metal or silver salt. At the end of the melting process, the separated collection material, which is usually mainly composed of lead, will contain all the silver and all other collected precious metals. For the mineral sample melted with the flux, the flux contains silver as a co-collection in addition to lead, and the ash blowing method can last long enough so that all the lead is oxidized and absorbed by the porous body of the ash dish until only a silver bead containing the collected precious metals is left in the ash dish. The silver bead is then analyzed, for example, by optical emission spectroscopy. In addition, when the collection material contains lead and silver as a co-collection material, method 100 or 200 can also include allowing all the lead to be oxidized so that only silver co-collection and the collected precious metals remain in the ash dish. Silver and other precious metals can then be analyzed using spectroscopic methods, such as laser ablation or optical emission spectroscopy.

[0102] refer to Figures 3a to 3c , in one embodiment, an ashtray 300 that may be used in method 200 is described. Figure 3b and 3c Shown by Figure 3a The ashtray 300 comprises a cavity 302 for receiving material to be partially ashblown. The material to be received may be a lead button including precious metals that have been collected, as in the case of methods 100 and 200. The cavity 302 comprises a first region 304 and a second region 306.

[0103] The first region 304 is defined by a porous material capable of absorbing the oxidized and molten lead. The porous material may be the same material as the ash tray suitable for use in method 100, such as bone ash / magnesia.

[0104] The second region 306 is defined by a mostly impermeable material. In this embodiment, the second region includes an annular wall 308 and a bottom. The second region 306 is capable of accommodating a certain volume of fusion sample.

[0105] The first region 304 and the second region 306 are arranged in such a way that, in use, when the mixture decreases in volume due to absorption of the collection material by the porous material, the remainder of the fused sample completely retreats into the second region 306. As a result, the fused sample is prevented from being further absorbed by the porous material of the first region 304.

[0106] In this particular embodiment, when the ashtray 300 is erected, the second region 306 is located below the first region 304 and extends from the bottom of the first region 304. In other words, the open bottom 310 of the first region 304 is adjacent to and communicates with the open top 312 of the second region 306, thereby allowing fluid communication between the first region 304 and the second region 306. In one embodiment, the first region 304 is configured to have a concavely curved inner surface 314, and the second region 306 is cylindrical, such as Figure 3a-3c The volume of the second region 306 is smaller than that of the first region 304 .

[0107] In addition, the annular wall 308 of the second region 306 can be in the form of an insert 316, in particular a cylindrical insert, which includes a bottom 318 and a side wall 320 extending upward from the bottom. Therefore, the insert 316 can be manufactured separately from the main body of the ashtray 300 and then assembled together.

[0108] When manufacturing the ashtray 300, the body of the ashtray 300 made entirely of bone ash or magnesium oxide may first be formed with a cavity 302 for receiving the insert 316. The insert 316 is then placed in a corresponding portion of the cavity 302. The insert 316 may be made of any suitable material, such as ceramic, which can withstand temperatures of about 1000-1200° C. and does not absorb or react with the collection material.

[0109] In an alternative embodiment, the container for method 200 can be composed of an ash dish and a crucible made of an impermeable material. For example, the ash dish can have a longitudinal hole running through the bottom end of the ash dish, and the crucible is connected to the bottom end of the ash dish and seals the opening caused by the hole. The crucible can be assembled in the hole so that the bottom end of the crucible is flush with the bottom end of the ash dish. Alternatively, the crucible can be connected to the outer surface of the ash dish to form an additional part of the ash dish. The advantage of using the above-mentioned container assembly in method 200 is that a consistent volume or a required amount of sample for subsequent analysis can be accurately obtained. In other words, method 200 can produce multiple samples with the same predetermined volume, thereby achieving a more effective method for determining precious metals.

[0110] In other embodiments, methods 100 and 200 may include pouring the remaining sample into a cold mold after steps 104 and 206, respectively. Thus, after the absorption of the collected material has ceased, or in other words, after the partial ash blowing process has been completed, the remaining sample is cooled and solidified in the cold mold before being analyzed for precious metal content. In embodiments, the cold mold may also serve as a sample holder for subsequent spectroscopy or other analysis. The cold mold may take any suitable shape.

[0111] refer to Figure 4a and 4b, a system 400 according to an embodiment of the present invention is now described. The system 400 can automatically prepare a mineral sample for analysis to determine the precious metal content. The system 400 can be used in the method 100 or 200. The system 400 includes a furnace 402, a loading mechanism 404, and a controller for controlling at least one component of the system (including the loading mechanism).

[0112] The furnace 402 includes a receiving station located inside the furnace 402. The receiving station can receive suitable containers or ash dishes containing corresponding samples. For example, each container received by the corresponding receiving station can be in the form of an ash dish 300 as described above, and is further configured to be received by the receiving station. The furnace 402 also includes an entrance that is convenient for approaching the receiving station. For example, the entrance can be a door.

[0113] A plurality of receiving stations may be provided so that a sample or a batch of samples may be prepared automatically. It should be noted that the number of receiving stations is only exemplary, and the furnace 402 may accommodate any number of receiving stations.

[0114] The controller can control various components in the system 400, and at least can control the loading mechanism 404 to perform corresponding processing tasks. Tasks include loading, unloading and pouring the contents of a container into another container. Figure 4a and 4b As shown, the loading mechanism 404 can be fixed relative to the furnace or can be moved relative to the furnace to perform the above-mentioned tasks.

[0115] In one example, the controller is configured so that the container can be automatically loaded or unloaded after a predetermined time. In other words, the controller can be programmed and perform predetermined movements related to loading and unloading containers. For example, the loading mechanism 404 can be programmed to remove the container from the furnace 402 and pour the sample in the container into the mold when the container and the corresponding sample have been heated in the furnace 402 for a predetermined time. After the sample cools in the mold, the precious metal content of the sample can be analyzed. The loading mechanism 404 can perform the above tasks for each container in the furnace in sequence, thereby automating the process.

[0116] In another embodiment, the controller is also configured to change the operating parameters of the furnace startup after a predetermined time or other condition is met. The operating parameters of the furnace may include a reduction in the temperature within the furnace, and the opening or closing of the entrance. The furnace 402 may include control electronics to communicate with the controller so that the controller can control these changes. For example, the furnace may include an electronic temperature sensor and / or a timer. Once a predetermined temperature and / or duration condition is reached, the controller may cause the furnace to automatically reduce or stop heating the container and sample. The controller may then control the loading mechanism to perform tasks such as unloading and dumping.

[0117] The furnace 402 includes a housing and a heater for heating the interior of the housing to a temperature sufficient to melt each sample. Further, in one embodiment, the receiving station is a hole or recess located on the platform, which is sized to accommodate a corresponding container.

[0118] In another example, the furnace 402 includes a rotating platform or turntable on or in which the receiving station is arranged. The turntable can be arranged to receive a plurality of (eg, six) receiving stations, the plurality of receiving stations being arranged around the longitudinal center axis of the turntable.

[0119] The turntable facilitates movement of containers relative to the receiving stations, particularly placing and moving containers on the furnace. Thus, when a container needs to be placed in or removed from a particular receiving station, the turntable rotates so that the receiving station moves to a loading / unloading position relative to the furnace 402. The furnace 402 then allows the loading mechanism 404 to drop or remove the container at the corresponding receiving station through the entrance.

[0120] Obvious modifications and changes to the above by those skilled in the art will be considered within the scope of the present invention, the nature of which will be determined from the above description and the appended claims.For example, the first region 304 and the second region 306 can have alternative shapes and configurations to the above specific embodiments.

Claims

1. A method for preparing an analytical sample, characterized in that: The method comprises: heating a fused sample containing a collection material and a precious metal in an ashtray to a temperature sufficient to melt the fused sample and absorb at least a portion of the collection material by the ashtray: The ashtray automatically stops absorbing the collection material after a predetermined period of time so that the remaining sample contains a portion of the collection material. The bottom of the ash dish has a groove, and the diameter of the groove is 5-30% of the diameter of the ash dish. The method is performed such that the collection material is absorbed until the remaining sample is located substantially only in the grooves, thereby reducing the rate of progression of the ashblowing melting.

2. The method according to claim 1, characterized in that: The step of causing the ashtray to stop absorbing the collected material may include reducing the temperature of the furnace after the predetermined period of time, or removing the ashtray from the furnace after the predetermined period of time. The method of claim 1 , wherein the recess is cylindrical.

4. The method according to claim 1 or claim 3, wherein the diameter of the groove is 5-10 mm.

5. The method according to any one of claims 1 to 3, wherein the diameter of the groove is 5-20% of the diameter of the ashtray.

6. The method according to any one of claims 1 to 3, wherein the inner volume of the recess is 1 to 20% of the inner volume of the ashtray.

7. A container for preparing an analytical sample, characterized in that: The container comprises: a cavity for receiving a sample containing a collection material and a precious metal, the cavity being used to melt the sample and oxidize the collection material, the cavity comprising: a first region defined by a porous material capable of absorbing a collection material when oxidized and melted; a second region defined by a material that is substantially incapable of absorbing the melted and oxidized collection material, the second region being capable of accommodating a volume of the fused sample; wherein the container is configured 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, The second area is a groove at the bottom of the container, and the diameter of the groove is 5-30% of the diameter of the container.

8. The container according to claim 7, characterized in that The first and second regions of the container are arranged such that the collection material is absorbed by the porous material of the first region, reducing the amount of the sample during sootblowing until the sample remains substantially only in the second region, thereby substantially preventing further absorption of the collection material.

9. A system for automatically preparing analytical samples, characterized in that: The system comprises: a furnace having at least one receiving station located within said furnace and an entrance facilitating access to said receiving station; A container as claimed in any one of claims 7 to 8, configured to be received by the receiving station or a corresponding receiving station; a loading mechanism for moving the container relative to the furnace; and a controller for controlling the loading mechanism.

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