CN112629963A

CN112629963A - Method and container for preparing analysis fusion sample

Info

Publication number: CN112629963A
Application number: CN202011117117.XA
Authority: CN
Inventors: 特雷-布兰奇.德.容; 皮埃尔.卡雷尔.霍夫迈尔; 阿诺.范德.弗斯特赫伊曾; 博伊恩.弗里德里希.霍恩施泰因
Original assignee: Alfa Smith Co
Current assignee: Alfa Smith Co
Priority date: 2015-03-06
Filing date: 2016-03-04
Publication date: 2021-04-09
Also published as: DE112016001054T5; AU2016228933A1; CA2977255A1; CN107430049A; CL2017002234A1; RU2721764C2; BR112017018916B1; ZA201705903B; MX2017011314A; WO2016141405A1; RU2017132566A; AU2016228933B2; RU2017132566A3; CA2977255C; BR112017018916A2

Abstract

The invention discloses a method and a container for preparing an analysis fusion sample. The container includes a cavity for receiving a sample including a collection material and a precious metal, the cavity adapted to melt the sample and oxidize the collection material. The cavity includes a first region defined by the porous material capable of absorbing the acquisition material when oxidized and melted. The cavity further includes a second region defined by a material that is incapable of absorbing the melted and oxidized collecting material. The second region is capable of holding a volume of the fused sample. The container is arranged such that when the sample has melted and 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.

Description

Method and container for preparing analysis fusion sample

This application is a divisional application of patent application No. 201680014097.9 (PCT/AU2016/000069) entitled "a method and container for preparing an assay fusion sample" filed on day 4/3/2016 by the applicant.

Technical Field

The present invention relates to methods and containers for preparing an analytical fusion sample.

Background

In order to determine the content of rare or noble metals in a mineral sample, it is often necessary to perform an analysis on the mineral sample containing rare or noble 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 fluxing agent prior to analysis. Sample preparation typically involves mixing a sample with a flux material (e.g., a very large flux material) and placing the resulting mixture in a crucible and heating in a furnace to form a melt. A large amount of flux material is reduced to molten lead which collects the precious metals and precipitates to the bottom of the crucible.

Some method may be used to separate the lead and precious metals from the resulting slag to form the lead button. The lead button was then analyzed to determine the amount of noble metal dispersed in the lead. The amount of precious metal can be determined by directly analyzing the lead button using spectroscopic techniques. Alternatively, the lead button may be placed in a cupel and heated, the lead absorbed by the cupel, and the resulting particles may be weighed or analyzed using wet chemistry methods.

The problem with the sample preparation described above relates to the often uneven distribution of precious metals contained in the separate lead buttons. Since spectroscopic analysis techniques typically only detect the precious metal content in a sample over a small area, significant errors can occur if the precious metal is not uniformly distributed within the lead button. Spectroscopic techniques can only analyze substantially the outer surface of the sample. In addition, the noble metal is generally present in too little of the lead, below the detection limit.

Disclosure of Invention

In a first aspect, the present invention provides a container for preparing a sample for analysis, the container comprising: the container includes: a cavity for receiving a sample comprising a collection material and a precious metal, the cavity for melting the sample and oxidizing the collection material, the cavity comprising:

a first region defined by a porous material capable of absorbing the collecting material when oxidized and melted;

a second region defined by a material incapable of absorbing the melted and oxidized collection material, the second region capable of containing a volume of the fused sample;

wherein the container is arranged such that when the sample has melted and 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.

Throughout this specification, unless the context indicates otherwise, the term "collecting material" means any substance that can be alloyed with a noble metal at a suitable temperature, thereby "collecting" it. For example, the collector material comprises a base metal such as lead and silver or nickel sulphide. These terms may also be used to refer to substances in an oxidized state, such as lead and lead oxide.

In a particular embodiment of the invention, the first and second regions of the container are arranged such that the collecting material is absorbed by the porous material of the first region, such that the amount of the sample is reduced during the blowing process until the sample remains substantially only in the second region, thereby avoiding further absorption of the collecting material.

The embodiment of the invention has the following advantages: once the collection material in the first zone is absorbed and a concentrated sample in the second zone is formed, the absorption or "blowing" of the collection material will automatically stop.

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 second region has a smaller volume than the first region.

The container may be a cupel and the second region may be completely contained within the cupel and extend from the first region.

Throughout this specification, unless the context requires otherwise, the term "cupel" refers to a vessel containing a porous material capable of withstanding temperatures on the order of about 1000-. For ease of context, cupels are commonly used in the art of pyrometallurgical refining of precious metals.

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 which is not capable of absorbing the molten and oxidised collecting material, which may be boron nitride, alumina or glassy carbon.

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 through the first region. The insert may be surrounded by a material defining the first region.

In a second aspect, the present invention provides a method of preparing an assay sample, the method comprising:

making the container of the present invention as described above;

placing a fused sample comprising a collection material and a noble metal in a cavity of a container;

heating the sample in the container to a temperature sufficient to melt and allow a portion of the fused sample to be absorbed by the porous material;

wherein 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.

In a particular embodiment of the invention, the method is such that the collecting material is 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 auto-absorption of the collecting material.

The collecting material may comprise silver as a co-collecting material. The collection material may comprise a primary collection material, which may comprise lead from lead oxide.

The step of heating the sample within the container comprises oxidation of the collection material.

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.

The altering of the environment includes adding oxygen to increase the degree of oxidation of the collector material, thereby increasing the rate at which oxidized collector material is absorbed.

The method pours the remaining sample into a mold, such as a chill, after stopping the absorption of the collecting material. Further, the chill may be a sample holder, such that the remaining sample in the sample holder may be subsequently analyzed.

In a third aspect, the present invention provides a method of preparing an assay sample, the method comprising:

heating a fused sample comprising a collection material and a noble metal in a cupel to a temperature sufficient to melt the fused sample so that at least a portion of the collection material is absorbed by the cupel;

the cupel automatically ceases to absorb the collection material after a predetermined time so that the remaining sample contains a portion of the collection material.

The step of stopping the absorption of the collecting material by the cupel may comprise lowering the temperature of the furnace after the predetermined time or removing the cupel from the furnace after the predetermined time.

Alternatively, the well may be a recess in the bottom of the cupel, not extending through the bottom. The diameter of the groove is smaller than that of the cupel. For example, the grooves may have a diameter of about 5 to 10mm, or about 5-10%, 10-20%, or 20-30% of the cupel. The internal volume of the recess may be 1%, 1-2%, 2-5%, 5% -10% or 10-20% less than the internal volume of the cupel. When the sample in the cupel is absorbed, the amount of sample decreases until the sample is only in the groove. Since the surface area of the grooves is significantly smaller than the total area of the interior of the cupel, the blowing (absorption) is slowed down, making it easier to control the sample residual volume and the time the sample is cast.

In a fourth aspect of the invention, there is provided a system for automatically preparing an analytical sample, the system comprising:

a furnace having at least one receiving station located inside the furnace and an entrance facilitating access to the receiving station;

a container as described above arranged to be received by the or a respective receiving station;

a loading mechanism for moving the container relative to the furnace;

and a controller for controlling the loading mechanism.

The controller is further configured to change the start-up operating parameters of the furnace after a predetermined time. The furnace operating parameters can be changed by lowering the temperature inside the furnace or by opening or closing the inlet.

The controller is arranged such that the container is automatically loaded or unloaded after a predetermined time.

The system also includes another container, such as a chill, for pouring the contents of the container therein.

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 comprising a collection material and a precious metal, the cavity for melting the sample and oxidizing the collection material, the cavity comprising:

a second region defined by a material substantially incapable of absorbing the melted and oxidized collection material, the second region capable of containing a volume of the fused sample;

Optionally, the first and second regions of the container are arranged such that the collecting material is absorbed by the porous material of the first region, and the amount of sample is reduced during the ashing process until the sample remains substantially only in the second region, thereby avoiding further absorption of the collecting material.

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

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

Optionally, the container is a cupel.

According to another aspect of the present invention there is provided a method of preparing an assay sample, the method comprising:

providing a container according to any one of the preceding claims;

wherein the portion of the fused sample remaining in the cavity is retracted into the second region by arranging the container and performing the method, thereby preventing further absorption thereof by the porous material.

Optionally, by performing the method such that a collecting material is absorbed by the porous material of the first region, the amount of the sample is reduced until the sample substantially remains in the second region, thereby avoiding further auto-absorption thereof by the collecting material.

Optionally, the collecting material comprises silver as co-collecting material.

Optionally, the step of heating the sample within the container comprises oxidation of the collection material.

Optionally, the method further comprises increasing or decreasing the rate at which the receptacle absorbs the collection material during heating of the sample by changing a property of an environment surrounding the receptacle.

Optionally, the altering the environment comprises adding oxygen to increase the degree of oxidation of the collecting material.

Optionally, the method further comprises pouring the remaining sample into a mold after stopping the absorption of the collecting material.

heating a fused sample comprising a collection material and a noble metal in a cupel to a temperature sufficient to melt the fused sample and absorb at least a portion of the collection material by the cupel:

the cupel automatically ceases to absorb the collecting material after a predetermined time so that the remaining sample contains a portion of the collecting material.

Optionally, the step of stopping the cupel from absorbing the collection material comprises reducing the temperature of the furnace after the predetermined period of time, or removing the cupel from the furnace after a predetermined time.

Optionally, the bottom of the cupel has a groove.

Optionally, by performing the method, the collecting material is absorbed until the remaining sample is substantially located in the recess, thereby reducing the rate of progression of the cupellation process.

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

a container as described above configured to be received by the or a respective receiving station;

a loading mechanism for moving the container relative to the furnace;

and a controller for controlling the loading mechanism.

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

Optionally, the controller is arranged to reduce the temperature within the furnace after a predetermined period of time.

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

Optionally, the system is further configured to pour the contents of the container into a chill.

Hereinafter, specific embodiments of the present invention will be described in conjunction with the accompanying drawings in order to more fully understand the present invention.

Drawings

FIG. 1 is a flow chart illustrating a method of an embodiment of the present invention;

FIG. 2 is a flow chart illustrating a method of another embodiment of the present invention;

FIG. 3a is a plan view of a cupel according to an embodiment of the invention;

FIG. 3b is a cross-sectional view of the cupel of FIG. 3 a;

FIG. 3c is a perspective cross-sectional view of the cupel shown in FIGS. 3a and 3 b;

fig. 4a and 4b are perspective views of systems according to embodiments of the present invention.

Detailed Description

The present invention relates to a method and vessel for preparing an analytical mineral sample, for example for spectroscopic analysis, to determine the content of precious metals in the sample.

Mineral samples for spectroscopic analysis are typically fused with flux and collection material prior to analysis. Fluxing agents can be used to lower the melting point and to impart uniform fluidity to the sample. The flux may also contain a collection material such as a lithium battery and silver. The mixture of sample and flux is then placed in a furnace and heated to about 1000 c to form a melt. The slag floats on top of the melt and the collecting material sinks with the precious metal alloy in the sample to the bottom, forming a molten pool of molten collecting and precious metal, which is then separated from the slag and rapidly cooled until a homogeneous snap fastener is formed.

The spectral analysis is then usually performed directly on the button. Suitable spectroscopic analysis techniques include laser ablation, optical emission spectroscopy or X-ray fluorescence (XRF). However, a problem with this is that the non-uniformity of the snap fasteners may produce inaccurate analysis results, which may be problematic during spectroscopic analysis, which typically only measures a small area of the sample, for example, if the snap fasteners are not formed by rapid cooling. As a result, significant errors can occur if the precious metal is not evenly distributed within the snap fastener. Furthermore, impurities in the sample may also interfere with the results of the analysis.

Referring to FIG. 1, a method 100 of an embodiment of the present invention is now described. The method 100 includes heating a fused sample containing a collection material and a precious metal in a cupel to a temperature sufficient to melt the fused sample and oxidize the collection material such that at least a portion of the collection material is absorbed by the cupel (step 102).

In a particular embodiment of the invention, the sample is a fused sample containing lead and a noble metal. More specifically, the sample is from a fusion process in which a mineral sample is combined with a flux and a collection material (lead in this example) and heated in a crucible to melt the sample. During this process, the collecting material (lead) melts and oxidizes, collecting the precious metals and precipitating at the bottom of the crucible. Silver may also be used as a co-collecting material. The lead and precious metals may then be separated from the slag to form a fused sample or "lead button". Noble metals may include, but are not limited to, gold, silver, platinum, palladium, ruthenium, and rhodium.

The method 100 further includes automatically stopping the process of absorbing lead oxide in the cupel after a predetermined time so that the remaining sample contains a portion of the original lead (step 104).

The cupel comprises a porous material such as bone ash or magnesium oxide. In step 102, the cupel and snap fasteners are heated in a furnace to about 1000-. During this process, the lead is oxidized by reacting with the oxygen entering the furnace. The lead oxide then melts by capillary action and diffuses into the pores of the cupel, separating from the precious metal. The noble metal precipitates without being absorbed.

If the heating in step 102 is continued for a sufficient period of time, eventually all of the lead in the sample will be oxidized and absorbed by the cupel, thereby forming a precious metal "pearl" of extremely high purity. However, it is understood from the method 100 that the step 104 is performed before the above-described situation may occur, i.e., the oxidation of lead does not proceed. After a predetermined time, the process of the cupel absorbing the collecting material is stopped, so that a part of the collecting material remains in the cupel. In other words, the process 100 allows only partial cupellation processing.

Thus, the method 100 increases the concentration of noble metals, facilitating sample analysis. Furthermore, by performing a partial blowing process, impurities in the mixture of sample and flux (which may cause interference during the spectroscopic analysis) can also be absorbed by the cupel material in order to be removed.

The method of automatically stopping the process of absorbing the collecting material (lead oxide) by the cupel in step 104 may be a method of reducing the temperature of the furnace after a predetermined time or taking the cupel out of the furnace.

In another embodiment, step 102 of method 100 may include changing the environment surrounding the cupel during heating of the sample to increase or decrease the rate at which the cupel absorbs lead oxide. In one embodiment, changing the environment includes introducing oxygen into the interior of the furnace used to heat the cupel to increase the oxidation of the lead, and correspondingly increase 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 door for a predetermined time for air to flow outside the furnace.

In a particular embodiment of the invention, the cupel has a groove in the bottom of the cupel. The diameter of the groove is much smaller than that of the cupel. For example, the diameter of the groove may be about 5-10 mm. When the sample's collection material is absorbed by the cupel, the amount of sample decreases until the sample is fully seated in the recess. Since the surface area of the grooves is much smaller, the cupellation process (absorption) is significantly slower, making it easier to control the volume of sample remaining and the time it takes to cast the sample.

Referring to fig. 2, a method 200 of preparing a sample according to another embodiment of the present invention will now be described, particularly with reference to a fused sample in the form of a lead button.

The method 200 includes providing a container having a cavity with 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 incapable of absorbing the melted and oxidized collection material, the second region capable of holding a volume of a fused sample (step 202). The container will be described in more detail below with reference to fig. 3(a), (b) and (c). In an embodiment, the collection material is lead and the sample is a fusion sample or "lead button".

The method 200 also includes placing a fused sample or lead button containing a noble metal in the cavity (step 204).

Further, the method 200 includes heating the lead button in the cupel to a temperature sufficient to melt the lead button and allowing oxidized lead to be absorbed by the porous cupel material, thereby reducing the volume of the lead button, wherein the container is arranged in such a way that the remaining portion of the sample is completely withdrawn to the second region, preventing further absorption by the porous material (step 206).

The method 200 is similar to the method 100 in that both methods involve heating the sample in the container and stopping the absorption of the lead collection material as early as possible within a predetermined time. Thus, in both methods of the invention, the remaining sample to be analyzed still contains a portion of the lead collecting material, the precious metal is more refined and the sample contains fewer impurities than if no partial blowing step were used.

However, in the method 200, the container adopts a structure that prevents further absorption of the lead collecting material.

In the embodiments described above, silver may be added to the flux to act as a co-collecting material when the mineral sample is fused with the flux containing the primary collecting material (typically lead). The silver may be added in the form of a metal or silver salt. At the end of the melting process, the separated collection material, which typically consists mainly of lead, will contain all the silver as well as all other collected precious metals. For mineral samples that are melted with a flux that contains silver as a co-trap in addition to lead, the blowing process may be continued for a sufficient time so that all of the lead is oxidized and absorbed by the porous bodies of the cupel until only one silver bead containing the trapped precious metal remains in the cupel. The silver beads are then analyzed, for example by light emission spectroscopy. Further, when the collection material comprises lead and silver as a co-collection material, the

method

100 or 200 may further comprise allowing all of the lead to be oxidized so that only silver co-collects and collected precious metals remain in the cupel. The silver and other precious metals can then be analyzed using spectroscopy, such as laser ablation or optical emission spectroscopy.

Referring to fig. 3a to 3c, a cupel 300 that may be used in the method 200 is described in one embodiment. Figures 3b and 3c show cross-sectional views through section a-a shown in figure 3 a. The cupel 300 includes a cavity 302 for receiving material to be partially ash blown. The material to be received may be a lead button that includes precious metal that has been collected, as is the case with

methods

100 and 200. The cavity 302 includes a first region 304 and a second region 306.

The first region 304 is defined by a porous material capable of absorbing oxidized and molten lead. The porous material may be the same material as the cupel suitable for the method 100, such as ashes/magnesium oxide.

The second region 306 is defined by a largely impermeable material. In this embodiment, the second region includes the annular wall 308 and the bottom. The second region 306 is capable of holding a volume of the fused sample.

The first and

second regions

304 and 306 are arranged in such a way that, in use, when the mixture decreases in volume due to the porous material absorbing the collecting material, the remainder of the fused sample recedes completely 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.

In this particular embodiment, the second region 306 is located below the first region 304 and extends from the bottom of the first region 304 when the cupel 300 is upright. In other words, the open bottom 310 of the first region 304 is adjacent to and in communication with the open top 312 of the second region 306, thereby allowing fluid communication between the first and

second regions

304 and 306. In one embodiment, the first region 304 is configured with a concavely curved inner surface 314, and the second region 304 is cylindrical, as shown in fig. 3a-3 c. The second region 306 is smaller in volume than the first region 304.

Furthermore, the annular wall 308 of the second region 306 may be in the form of an insert 316, in particular a cylindrical insert, comprising a bottom 318 and a side wall 320 extending upwardly from the bottom. Thus, the insert 316 may be manufactured separately from the body of the cupel 300 and then assembled together.

When manufacturing the cupel 300, the body of the cupel 300, which is completely made of ashes or magnesium oxide, may be first formed with a cavity 302 for receiving the insert 316. The insert 316 is then placed in the corresponding portion of the cavity 302. The insert 316 may be made of any suitable material, such as a ceramic, that can withstand temperatures of about 1000-.

In an alternative embodiment, the container used in the method 200 may be a combination of a cupel and a crucible made of an impermeable material. For example, the cupel may have a longitudinal hole through the bottom end of the cupel to which the crucible is attached and seals the opening created by the hole. The crucible may be fitted within the hole such that the bottom end of the crucible is flush with the bottom end of the cupel. Alternatively, the crucible may be coupled to the outer surface of the cupel to form an attachment to the cupel. The advantages of using the above-described container assembly in the method 200 are: a consistent volume or desired amount of sample for subsequent analysis can be accurately obtained. In other words, the method 200 can produce multiple samples having the same predetermined volume, thereby enabling a more efficient precious metal assay.

In further embodiments,

methods

100 and 200 may include pouring the remaining sample into a chill after

steps

104 and 206, respectively. Thus, after the absorption of the collecting material has ceased, or in other words after the partial cupellation process has been completed, the remaining sample is allowed to cool and solidify in a chill before the precious metal content is analysed. In embodiments, the chill may also serve as a sample holder for subsequent spectroscopy or other analysis. The chill may take any suitable shape.

With reference to fig. 4a and 4b, a system 400 of an embodiment of the present invention will now be described. The system 400 enables automated preparation of mineral samples for analysis to determine precious metal content. The system 400 may 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.

The furnace 402 includes a receiving station located inside the furnace 402. The receiving station is capable of receiving a suitable container or cuvette containing the respective sample. For example, each container received by a respective receiving station may be in the form of a cupel 300 as described above, and further configured to be received by the receiving station. The furnace 400 also includes an entrance to facilitate access to the receiving station. For example, the entrance may be a door.

Multiple receiving stations 404 may be provided so that a sample or batch of samples may be prepared automatically. It should be noted that the number of receiving stations 404 is merely exemplary, and that the furnace 402 may accommodate any number of receiving stations.

The controller can control the various components in the system 400, at least the loading mechanism 404 to perform the corresponding processing tasks. Tasks include loading, unloading and dumping the contents of a container into another container. As shown in fig. 4a and 4b, the loading mechanism 404 may be fixed relative to the furnace or may be movable relative to the furnace to perform these tasks.

In one example, the controller is configured such that the container may be automatically loaded or unloaded after a predetermined time. In other words, the controller may be programmed and execute predetermined movements in connection with loading and unloading containers. For example, mechanism 404 may be programmed to remove the container from the oven 402 and pour the sample in the container into the mold when the container and corresponding sample have been heated in the oven 402 for a predetermined time. After the sample is cooled in the mold, the sample can be analyzed for precious metal content. The mechanism 404 can perform the above-described tasks for each container in the furnace in sequence, thereby automating the process.

In another embodiment, the controller is further configured to change an operating parameter of the furnace start-up after a predetermined time or other condition is met. The operating parameters of the furnace may include a decrease in temperature within the furnace, and the opening or closing of the inlet. The furnace 402 may include control electronics to communicate with the controller so that the controller may control these changes. For example, the furnace may include an electronic temperature sensor and/or a timer. Once the predetermined temperature and/or duration conditions are reached, the controller may cause the furnace to automatically reduce or stop heating of the container and sample. The controller may then control the loading mechanism to perform such tasks as unloading and dumping.

The oven 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 an aperture or recess in the platform sized to receive a corresponding container.

In another example, the furnace 402 includes a rotating platform or carousel on or within which the receiving stations are disposed. The carousel may be arranged to receive a plurality (e.g. six) of receiving stations, the plurality of receiving stations being arranged around its longitudinal central axis of the carousel.

The turntable facilitates moving the container relative to the receiving station, in particular placing and moving the container on the oven. Thus, when a container needs to be placed in or removed from a particular receiving station, the carousel rotates such that the receiving station moves to a loading/unloading position relative to the furnace 402. The oven 402 then allows the mechanism 404 to drop or remove the container at the corresponding receiving station through the entrance.

Obvious modifications and variations to the above would be 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 alternative shapes and configurations to the particular embodiment described above.

Claims

1. A container for preparing an analytical sample, the container comprising: a cavity for receiving a sample comprising a collection material and a precious metal, the cavity for melting the sample and oxidizing the collection material, the cavity comprising:

2. The container of claim 1, wherein the first and second regions of the container are configured such that the collection material is absorbed by the porous material of the first region, and the amount of sample is reduced during the ashing process until the sample remains substantially only in the second region, thereby substantially preventing further absorption of the collection material.

3. A method of preparing a sample for analysis, the method comprising:

4. The method of claim 3, wherein the step of stopping the cupel from absorbing the collection material comprises reducing the temperature of the furnace after the predetermined period of time or removing the cupel from the furnace after a predetermined time.

5. The method of claim 3 or 4, wherein the bottom of the cupel has a groove.

6. The method of claim 5, wherein the method is performed such that the collection material is absorbed until the remaining sample is substantially only located in the recess, thereby reducing the rate of progression of the cupola melt.

7. A method according to claim 5 or claim 6, wherein the grooves are 5-10mm in diameter.

8. The method according to any of claims 5-7, wherein the diameter of the groove is about 5-30% of the diameter of the cupel, more preferably 5-20% of the diameter of the cupel.

9. The method according to any one of claims 5-8, wherein the internal volume of the recess is 1-20% of the internal volume of the cupel.

10. A system for automatically preparing an analytical sample, the system comprising:

the container of any one of claims 1 to 2, configured to be received by the receiving station or a respective receiving station;

a loading mechanism for moving the container relative to the furnace;

and a controller for controlling the loading mechanism.