Patent Description:
The technical field generally relates to the field of analytical sample preparation and, more particularly, to the field of analytical sample preparation by flux fusion, such as borate fusion.

Preparing an analytical inorganic sample (or mineral sample) using a fusion fluxer (also referred to herein simply as a "fluxer") includes multiple steps, manipulations and technical "know how". Fluxers are configured to raise the temperature of crucibles placed within a furnace in order to fuse a flux material (e.g., a borate flux material) to obtain a fused flux. An inorganic sample is solubilized in the fused flux to obtain a fused mixture suitable to prepare analytical samples. For example, the analytical sample can be a glass disk for X-ray fluorescence (XRF) analysis, a solution for inductively coupled plasma (ICP) analysis or a solution for atomic absorption (AA) analysis. Since the process temperature can be quite high, various problems and challenges can arise, such as contamination of the inorganic sample, among others.

Document <CIT> discloses a fluxer including a single, wide furnace enclosure that is sufficiently large and prewired accommodate multiple fusion positions. The furnace includes at least one movable insulated partition that defines the actual insulated volume of the furnace.

Many challenges still exist in the field of analytical sample preparation by flux fusion.

The scope of the present invention is defined by independent claim <NUM>, and further embodiments of the invention are specified in dependent claims <NUM>-<NUM>.

As will be explained herein in relation to various embodiments, a fluxer for the preparation of inorganic analytical samples (or mineral analytical samples) is provided. The fluxer includes a furnace adapted to receive crucibles therein for heating the contents of the crucibles in order to prepare a fused mixture for analysis. An inorganic sample is solubilized in a fused flux to obtain a fused mixture suitable to prepare analytical samples. For example, the analytical sample can be a glass disk for X-ray fluorescence (XRF) analysis, a solution for inductively coupled plasma (ICP) analysis or a solution for atomic absorption (AA) analysis.

Broadly described, the fluxer includes a furnace assembly having a furnace chamber provided with heating elements, a sample support assembly adapted to support a plurality of crucibles in which the fused mixture can be generated, containers in which the fused mixture can be poured for cooling, and a motion system adapted to move the crucibles and/or containers within the furnace chamber for heating and fusing the contents of the crucibles. Once fused, the samples are transferred from the crucibles to the containers for cooling, and the analytical samples thereby obtained can be analyzed. For example, the containers can be molds in the case of XRF analysis to obtain glass disks, or beakers (or other types of containers) containing an acidic solution for ICP and/or AA analysis.

It should be understood that, as used herein, the expressions "fuse", "fusing", "fusion", or any other equivalent expression, refers to the process of melting one or more flux material in order to prepare a homogeneous, or near-homogeneous, mixture. It should also be understood that the material being fused generally includes a fusion flux compound or a mixture of several fusion flux compounds, such that the material to be analyzed can be solubilized upon fusion of the flux material.

In some embodiments, the flux material is a borate compound. In such case, the process can be referred to as a "borate fusion" process. Is should be understood that the borate fusion process can include various steps that can be implemented using a fluxer. In a non-limiting example, the borate fusion process can include the following steps:.

As mentioned above, the flux material can be a borate compound. The more commonly used borate flux materials are selected from the group consisting of lithium tetraborate (Li<NUM>B<NUM>O<NUM>), lithium metaborate (LiBO<NUM>), sodium tetraborate (Na<NUM>B<NUM>O<NUM>) and combinations thereof. The choice of flux material typically depends on the composition of the sample to be analyzed, as would be known to a person skilled in the art.

Additives can optionally be added to the flux material to modify their properties or to help oxidize partially oxidized elements that can be present in a sample to be analyzed. Non-limiting examples of additives that can be added include the following:.

When oxidizers are used, it may be desirable to pre-heat the flux material/oxidizer/sample mixture to an oxidizing temperature (also referred to herein as a "pre-heating temperature") that is lower than the fusion temperature and at which oxidizing of the non-oxidized and/or partially-oxidized inorganic elements can occur. For example, in the case of borate flux materials, the oxidizing temperature can be set between <NUM> and <NUM>.

For example, when ammonium nitrate is used, the pre-heating of the flux material/oxidizer/sample mixture can be performed at a temperature that decomposes the ammonium nitrate into NO<NUM> and HNO<NUM>. At least one of these gases can then oxidize the non-oxidized and/or partially-oxidized inorganic elements present in the mixture.

In some embodiments, it can be desirable that a slow decomposition of the oxidizer occurs, as a slow decomposition typically allows for a longer action on the non-oxidized and/or partially-oxidized inorganic elements present in the mixture. A "slow decomposition" can for example be triggered by first subjecting the flux material/oxidizer/sample mixture to a first temperature that is lower than the temperature of the main fusion step in the furnace chamber. The decomposition of the oxidizer can then occur slower at the first temperature than if it had occurred directly at the fusion temperature. Subsequent oxidizing action on the non-oxidized and/or partially-oxidized inorganic elements being prolonged when performed at the first temperature compared to instances where the flux material/oxidizer/sample mixture is directly subjected to the fusion temperature.

It should also be understood that other types of flux materials can be used, such as a peroxide flux material (for example, sodium peroxide Na<NUM>O<NUM>). In such case, the mixture in the crucible can be heated between <NUM> and <NUM> with agitation until the peroxide flux melts and the inorganic analytical sample dissolves homogeneously in the fused peroxide flux.

In some embodiments, the material to be analyzed can include various inorganic materials (also referred to as mineral materials). Non-limiting examples of inorganic materials that can be subjected to the borate fusion process include cement, lime, carbonate, ceramic, glass, slag, refractory material, mining and geological materials, silicate, clay, ores, sulfides, fluorides, bauxite, aluminum, metal-based catalysts, steel, metals, ferroalloys, non-ferrous alloys and mineral/inorganic impurities contained in organic compounds such as polymers or pharmaceutical products.

In the present description, it should be understood that the process of "preparing an analytical sample by flux fusion" refers to a process including the steps of mixing an inorganic sample with a flux material, heating the mixture until the flux material melts and the inorganic sample dissolves into the fused flux material to obtain a fused mixture, and pouring the fused flux mixture into a container to be cooled and to obtain the analytical sample. Non-limiting examples of "flux fusion" include the "borate fusion" and the "peroxide fusion".

Referring to <FIG>, a fusion fluxer <NUM> (or simply "fluxer") in accordance with a possible embodiment is shown. The fluxer <NUM> includes a furnace assembly <NUM> for generating heat, a sample support assembly <NUM> and a motion system <NUM> adapted to move the support assembly <NUM>. In this embodiment, the furnace assembly <NUM> includes a furnace chamber <NUM> provided with heating elements <NUM> (seen in <FIG>) configured to generate heat and raise the temperature of the interior volume of the furnace chamber <NUM>. In the context of the present disclosure, the fluxer <NUM> generally refers to an electric fluxer (i.e., the heating elements <NUM> are electrical heating elements), although it is appreciated that some components and configurations can be used in a gas fluxer.

Referring to <FIG>, in addition to <FIG>, the furnace chamber <NUM> illustratively has a generally rectangular shape, although it is appreciated that other configurations/shapes are possible. It is noted that the furnace chamber <NUM> has an interior volume defined by a front wall <NUM>, a rear wall <NUM> opposite the front wall <NUM>, side walls <NUM> extending between the front and rear walls <NUM>, <NUM>, and a top wall, or ceiling <NUM> opposite a bottom wall <NUM>. The furnace chamber <NUM> further includes an access opening <NUM> which includes a front opening <NUM> defined on the front wall <NUM> for allowing the support assembly <NUM> to at least partially enter the furnace chamber <NUM> for heating and fusing samples for analysis. In this embodiment, the heating elements <NUM> are mounted within the furnace chamber <NUM> proximate the rear wall <NUM> (i.e., opposite the front opening <NUM>), although other configurations are possible, such as providing heating elements on the side walls <NUM>, or on the top and bottom walls <NUM>, <NUM>, for example.

In some embodiments, the front opening <NUM> can have a substantially rectangular, or channel-like shape, having a greater width than height, and can span across an entire width of the front wall <NUM>. Furthermore, the access opening <NUM> can include lateral openings <NUM> extending on either side of the front opening <NUM>, i.e., along the side walls <NUM> of the furnace chamber <NUM>. As will be further described below, the lateral openings <NUM> can be shaped and configured to allow the support assembly <NUM> to move towards and within the furnace chamber <NUM>, while having a portion thereof remain outside. In other words, the support assembly <NUM> can include a portion moving along the side walls <NUM> outside the furnace chamber <NUM>, while having another portion within the interior volume of the furnace chamber <NUM>.

As seen in <FIG>, the lateral openings <NUM> can extend from the front wall <NUM> towards the rear wall <NUM> along a portion of the sidewalls <NUM>. It should be understood that the length of the lateral openings <NUM> can correspond to the distance that the support assembly can travel within the furnace chamber <NUM>. The support assembly can be adapted to abut against an end of the lateral openings <NUM>, thus preventing further movement thereof towards the rear wall <NUM>. It is appreciated that the access opening <NUM> can have any suitable shape and size to accommodate at least a portion of the support assembly for the preparation of fused samples for analysis.

In this embodiment, the furnace chamber <NUM> includes a door, or door mechanism <NUM>, configured to selectively block the access opening <NUM> and prevent components from entering (or exiting) the interior volume of the furnace chamber <NUM>. As seen in <FIG> and <FIG>, the door mechanism <NUM> can include a panel <NUM> operatively mounted on the furnace chamber <NUM> and being movable between an open position (<FIG>) and a closed position (<FIG>). It should be understood that closing the access opening <NUM> (i.e., by moving the panel <NUM> in the closed position) can promote raising the temperature of the furnace chamber <NUM> since heat loss is prevented, or at least reduced. The panel <NUM> can be mounted on rails configured to allow the panel <NUM> to slide up and down between the open and closed positions. However, it is appreciated that any suitable door mechanism can be used for blocking the access opening <NUM>, such as a pivoting or rotating door, or a panel sliding horizontally instead of vertically, for example.

As will be explained further below, the furnace chamber <NUM> can be removable from the furnace assembly <NUM> which can facilitate maintenance and/or replacement of the furnace chamber <NUM> without having to remove or replace the entire furnace assembly <NUM>, for example. Still with reference to <FIG>, in some embodiments, the furnace assembly <NUM> includes a furnace base <NUM> positioned below the furnace chamber <NUM> to support the furnace chamber <NUM> in a generally elevated state. In other words, the furnace base <NUM> can be adapted to raise the furnace chamber <NUM> by a predetermined height (i.e., the height of the furnace base <NUM>). It should be noted that the furnace base <NUM> can have any suitable shape, size and configuration adapted to support the furnace chamber <NUM> thereon. For example, in this embodiment, the furnace base <NUM> includes a foot member <NUM> adapted to extend below the furnace chamber <NUM>. The furnace base <NUM> can be positioned in a manner such that the back of the foot member <NUM> is substantially aligned and parallel with the rear wall <NUM> of the furnace chamber <NUM>.

Referring more specifically to <FIG>, <FIG> and <FIG>, the furnace base <NUM> further includes a plate member <NUM> connected at a top end of the foot member <NUM> and extending transversely therefrom for at least partially supporting the furnace chamber <NUM>. In this embodiment, the plate member <NUM> is substantially parallel to the bottom wall <NUM> and extends from the rear wall <NUM> towards the front wall <NUM>. It is noted that the plate member <NUM> can have any suitable thickness adapted to effectively support the furnace chamber <NUM> and maintain structural integrity (e.g., prevent bending).

In the present embodiment, the furnace chamber <NUM> is removably connected to the furnace base <NUM> to allow removal of the furnace chamber <NUM> from the furnace assembly <NUM>. More specifically, in this embodiment, the furnace chamber <NUM> is removably connected to the furnace base <NUM> via one or more connectors <NUM> adapted to hold the furnace chamber <NUM> in position relative to the furnace base <NUM> (e.g., on top of the furnace base <NUM>). In the present embodiment, the furnace assembly <NUM> includes a pair of connectors <NUM> positioned on either side of the furnace chamber <NUM> to fasten the furnace chamber <NUM> to the furnace base <NUM>. In some embodiments, the connectors <NUM> are secured to one of the furnace chamber <NUM> and furnace base <NUM>, and are removably connected to the other one to allow the furnace chamber <NUM> to be removed.

The connectors <NUM> can include a pair of brackets <NUM> secured to the furnace base <NUM> at a first end thereof, and removably connected to the furnace chamber <NUM> at a second end thereof. In this embodiment, the bracket <NUM> can be connected to the furnace chamber <NUM> and/or furnace base <NUM> at more than one location. For example, the bracket <NUM> can be shaped and sized such that it can be secured to both the foot member <NUM> and plate member <NUM>, therefore preventing rotation of the bracket <NUM>. As seen in <FIG> and <FIG>, the plate member <NUM> can have a bended forward section extending downwardly to facilitate connection of the bracket <NUM> to the plate member <NUM>. The bracket <NUM> can be secured to the furnace base <NUM> using any suitable method, such as mechanical fasteners (e.g., bolts, nails, screws) or via an adhesive, for example.

In this embodiment, the brackets <NUM> are removably connected to the furnace chamber <NUM> via removable mechanical fasteners, although other configurations are possible. More specifically, each bracket <NUM> is connected to the furnace chamber <NUM> at two separate locations via thumb screws <NUM>, therefore allowing manual fastening and removal of the fasteners. It should thus be noted that the furnace chamber <NUM> can be fully disconnected from the furnace base <NUM> and removed from the furnace assembly <NUM> manually. In some embodiments, the furnace base <NUM> includes a backplate <NUM> adapted to assist in positioning the furnace chamber <NUM> on the furnace base <NUM>. As seen in <FIG>, the backplate <NUM> can be secured to the back of the foot member <NUM> and extend upwardly such that a portion of the backplate <NUM> extends above the plate member <NUM>. The furnace chamber <NUM> can then be positioned on the furnace base <NUM>, with the rear wall <NUM> abutting against the back plate <NUM>. It should thus be noted that the backplate <NUM>, in combination with the brackets <NUM>, can be adapted to properly position the furnace chamber <NUM> on the furnace base <NUM> prior to fastening the brackets <NUM> to the furnace chamber <NUM>.

Now referring to <FIG>, in addition to <FIG>, the support assembly <NUM> will now be described. The support assembly <NUM> is preferably adapted to support a plurality of crucibles <NUM> and a corresponding number of molds <NUM>, although it is appreciated that the support assembly <NUM> can alternatively be configured to support a single crucible <NUM>, along with a single mold <NUM>. As will be described further below, the support assembly <NUM> can be operatively connected to the motion system <NUM> in a manner such that the plurality of crucibles can be moved within the furnace chamber <NUM> to prepare the samples (i.e., to fuse the mixture within the crucibles). In addition, the support assembly <NUM> can be adapted to transfer the fused samples from the crucibles <NUM> to the molds <NUM>, whereby the content of the molds <NUM> (i.e., the fused samples) can then be analyzed. In this embodiment, the support assembly <NUM> includes a support frame <NUM>, a crucible support <NUM> connected to the support frame <NUM>, and a mold support <NUM> also connected to the support frame <NUM> spaced from the crucible support <NUM>.

In some embodiments, the crucibles are divided into multiple zones, with each zone including its own thermocouple. This can be useful in instances where some of the zones require a different amount of energy compared to other zones, to maintain the same temperature. For example, referring to <FIG>, six crucibles are shown. The first two crucibles starting from one end of the support assembly <NUM> can be part of a first zone, the two middle crucibles can be part of a second zone, and the last two crucibles can be part of a third zone. Each zone can be provided with a thermocouple and temperature can be independently controlled in each zone. This can allow for a more homogeneous temperature within the fusion chamber and/or the pre-heating compartment, as the zones located on a side typically require less energy than a middle zone to maintain a target temperature.

As seen in <FIG>, among others, the support frame <NUM> can be shaped and configured to support the crucible support <NUM> and mold support <NUM> in an elevated manner, such that the crucibles <NUM> are substantially aligned with the access opening <NUM> of the furnace chamber <NUM>. Therefore, it is appreciated that displacing the support assembly <NUM> towards the furnace chamber <NUM> can move the crucibles support <NUM>, and thus the crucibles <NUM>, into the interior volume of the furnace chamber <NUM> (i.e., through the access opening <NUM>). In this embodiment, the support frame <NUM> can include an outer frame <NUM> for supporting the mold support <NUM>, and an inner frame <NUM> for supporting the crucible support <NUM>. As will be described further below, the inner frame <NUM> is mounted on the outer frame <NUM> and is movable relative thereto. However, it is appreciated that the components of the support assembly <NUM> (e.g., crucible support and mold support) can alternatively be connected to the same portion of the support frame <NUM>.

In some embodiments, the outer and/or inner frames <NUM>, <NUM> can be substantially U-shaped, with a support base and sidewalls extending at either end of the corresponding support base. More specifically, the outer frame <NUM> has an outer support base <NUM> and outer walls <NUM> extending upwardly from either end of the outer support base <NUM>. Similarly, the inner frame <NUM> has an inner support base <NUM> and inner walls <NUM> extending upwardly at either end of the inner support base <NUM>. In some embodiments, the outer and inner walls <NUM>, <NUM> are substantially parallel to each other, and the outer and inner support bases <NUM>, <NUM> are also generally parallel to each other. It should be understood that the outer support base <NUM> is longer than the inner support base <NUM>, and that the inner walls <NUM> are positioned between the outer walls <NUM>. In other words, the outer frame <NUM> is shaped and sized to contain the inner frame <NUM> within its U-shaped structure.

Now referring to <FIG>, in addition to <FIG>, the crucible support <NUM> can include a crucible holder <NUM> operatively connected to the support frame <NUM> at opposite ends thereof. The crucible holder <NUM> illustratively has an elongated shape provided with a plurality of crucible receiving apertures <NUM> (<FIG>) configured to receive and support the crucibles <NUM> in a side-by-side configuration. It should be understood that, as used herein, the expression "side-by-side configuration" generally refers to the crucibles being adjacent to other crucibles. For example, the crucibles can be axially aligned (as seen in <FIG>), offset with respect to one another, such as in a zig-zag pattern between the walls of the support frame <NUM>, in a square pattern or in any other suitable configuration. For this reason, the expression "side-by-side configuration", as used herein, should not be taken as to limit the scope of the present disclosure as limiting the position of the crucibles and/or molds to being aligned along a common axis, but should encompass any other suitable configuration of the crucibles and/or molds with which the described embodiments could be used and may be useful. It should also be understood that each crucible <NUM> is adapted to receive a mixture of a sample material and a flux material for fusing within the furnace chamber <NUM>.

In some embodiments, the crucible holder <NUM> can be removably connected to the support frame <NUM> such that the crucibles <NUM> can be removed from the support assembly <NUM>. As such, every crucible <NUM> can be manipulated together by installing and/or removing the crucible holder <NUM> from the support frame <NUM>, advantageously preventing having to manipulate each crucible <NUM> individually. In this embodiment, the crucible support <NUM> includes a pair of crucible anchors <NUM> attached to the support frame <NUM> and to which the crucible holder <NUM> can be removably connected. As seen in <FIG>, the crucible anchors <NUM> can be connected to and extend from the support frame <NUM> opposite one another such that each end of the crucible holder <NUM> is connected to a corresponding one of the crucible anchors <NUM>. More particularly, the crucible anchors <NUM> extend from the inner frame <NUM> opposite one another such that the crucible holder <NUM> is held in place between the inner walls <NUM>.

The crucible anchors <NUM> can be pivotally connected to a corresponding inner wall <NUM> to allow rotation of the crucible holder <NUM> for pouring the fused samples from the crucibles <NUM> to the molds <NUM>. In this embodiment, the crucible support <NUM> is provided with a motor <NUM> operatively connected to one of the crucible anchors <NUM> configured to engage the crucible anchor <NUM> in rotation. It is appreciated that the crucible support <NUM> can be provided with a pair of motors <NUM>, i.e., each motor being operatively connected to a respective one of the crucible anchors <NUM>, although a single motor <NUM> connected to a first crucible anchor <NUM> is possible, with the second crucible anchor <NUM> being pivotally connected to the corresponding inner wall <NUM>.

With reference to <FIG>, in some embodiments, the crucible anchors <NUM> can include a latching mechanism <NUM> adapted to selectively secure the crucible holder <NUM> to the crucible anchor <NUM>. In this embodiment, each crucible anchor <NUM> includes a latching mechanism <NUM> for securing each end of the crucible holder <NUM> thereto, although it is appreciated that other configurations are possible, such as providing a latching mechanism <NUM> to a single crucible anchor <NUM>, for example. In some embodiments, the latching mechanism <NUM> can be operable between a locked configuration (<FIG>) and an unlocked configuration (<FIG>). It should be understood that, when in the unlocked configuration, the crucible holder <NUM> can be coupled to and/or uncoupled from the crucible anchor <NUM>, and that when in the locked configuration, the crucible holder <NUM> is secured to the crucible anchor <NUM> (if previously coupled thereto).

The latching mechanism <NUM> can be manually operable to facilitate removal and installation of the crucible holder <NUM> in the support assembly <NUM>. In this embodiment, the latching mechanism <NUM> includes a latch body <NUM> having a recess <NUM> defined therein for receiving one end of the crucible holder <NUM>. The recess <NUM> can be complimentarily shaped with respect to the end of the crucible holder <NUM> to promote cooperation therebetween. Once the end of the crucible holder <NUM> is inserted in the recess <NUM> of the corresponding latch body <NUM>, the latching mechanism <NUM> can be moved to the locked configuration, thereby securing the end of the crucible holder <NUM> within the recess <NUM>. In some embodiments, the latching mechanism <NUM> includes a latch cover <NUM> operatively connected to the latch body <NUM> and being operable to selectively cover the recess <NUM> and enclose the end of the crucible holder <NUM> therein. More particularly, in this embodiment, the latch cover <NUM> is pivotally connected to the latch body <NUM> and is pivotable between an open position, where the recess <NUM> is generally uncovered, and a closed position, where the recess <NUM> is occluded. It is appreciated that the locked configuration of the latching mechanism <NUM> corresponds to positioning the latch cover <NUM> in the closed position, and that the unlocked configuration of the latching mechanism <NUM> corresponding to positioning the latch cover <NUM> in the open position.

As mentioned above, the latching mechanism <NUM> is preferably manually operable, although it is appreciated that other configurations are possible. In this embodiment, the latch cover <NUM> is provided with a grip <NUM> extending from the latch cover <NUM> and being shaped and sized to be gripped to allow manually moving the latch cover <NUM>. It is appreciated that the grip <NUM> can have any suitable shape, size or configuration to promote manually operating the latching mechanism <NUM>. In addition, the latch cover <NUM> can be provided with a catch <NUM> extending therefrom for abutting against the latch body <NUM> upon positioning the latch cover <NUM> in the closed position. Therefore, movement of the latch cover <NUM> is blocked in a first direction when in the closed position and is allowed in a second direction in order to move back to the open position. In this embodiment, the catch <NUM> has an abutment surface extending generally transversely therefrom and over the latch body <NUM>, although it is appreciated that other configurations are possible.

In some embodiments, the latching mechanism <NUM> can be provided with a retainment system configured to effectively retain the latch cover <NUM> in the closed position. For example, and as seen in <FIG>, the latch body <NUM> can include a groove <NUM> extending along an outer surface thereof proximate the recess <NUM>, and the latch cover <NUM> can include a ridge <NUM> shaped and sized to be positioned within the groove <NUM> upon moving the latch cover in the closed position. As such, the latch cover <NUM> can be at least partially retained in the closed position via the cooperation of the ridge <NUM> and the groove <NUM>. It is noted that the ridge <NUM> can be disengaged from the groove <NUM> upon the application of a rotational force on the latch cover <NUM> in order to move it to the open position. In this embodiment, the groove <NUM> is substantially parallel to the recess <NUM> of the latch body <NUM>, although it is appreciated that other positions and configurations are possible. Moreover, the groove <NUM> can be defined as a depression extending along the latch body <NUM>, or alternatively be defined between a pair of elongated protrusions extending upwardly from the outer surface of the latch body <NUM>.

Although the above-described latching mechanism <NUM> includes a recess <NUM> defined in a body <NUM>, with a pivotable latch cover <NUM> operable to block the recess <NUM>, it should be appreciated that other mechanisms or devices are possible for locking the crucible holder in place among the support assembly <NUM>. For example, the support frame <NUM> can be provided with snap-fit connectors or any other suitable quick-release mechanisms.

Now referring to <FIG>, in some embodiments, the crucible anchors <NUM> can include a latching mechanism <NUM> adapted to selectively secure the crucible holder <NUM> to the crucible anchor <NUM>. In this embodiment, each crucible anchor <NUM> includes a latching mechanism <NUM> for securing each end of the crucible holder <NUM> thereto, although it is appreciated that other configurations are possible, such as providing a latching mechanism <NUM> to a single crucible anchor <NUM>, for example. In some embodiments, the latching mechanism <NUM> can be operable between a locked configuration (<FIG>) and an unlocked configuration (<FIG>). It should be understood that, when in the unlocked configuration, the crucible holder <NUM> can be coupled to and/or uncoupled from the crucible anchor <NUM>, and that when in the locked configuration, the crucible holder <NUM> is secured to the crucible anchor <NUM> (if previously coupled thereto).

The latching mechanism <NUM> can be manually operable to facilitate removal and installation of the crucible holder <NUM> in the support assembly <NUM>. In this embodiment, the latching mechanism <NUM> includes a latch body <NUM> having a recess <NUM> defined therein for receiving one end of the crucible holder <NUM>. The recess <NUM> can be complimentarily shaped with respect to the end of the crucible holder <NUM> to promote cooperation therebetween. Once the end of the crucible holder <NUM> is inserted in the recess <NUM> of the corresponding latch body <NUM>, the latching mechanism <NUM> can be moved to the locked configuration, thereby securing the end of the crucible holder <NUM> within the recess <NUM>. In some embodiments, the latching mechanism <NUM> includes a latch cover <NUM> operatively connected to the latch body <NUM> and being operable to selectively cover the recess <NUM> and enclose the end of the crucible holder <NUM> therein. More particularly, in this embodiment, the latch cover <NUM> is pivotally connected to the latch body <NUM> and is pivotable between an open position, where the recess <NUM> is generally uncovered, and a closed position, where the recess <NUM> is occluded. It is appreciated that the locked configuration of the latching mechanism <NUM> corresponds to positioning the latch cover <NUM> in the closed position, and that the unlocked configuration of the latching mechanism <NUM> corresponding to positioning the latch cover <NUM> in the open position. As mentioned above, the latching mechanism <NUM> is preferably manually operable, although it is appreciated that other configurations are possible.

In some embodiments, the latch body <NUM> includes a first latch recess <NUM> provided in a top surface of the latch body <NUM>, proximate to the end of the crucible holder <NUM>, and the latch cover <NUM> includes a first cover recess <NUM>. When the latch cover <NUM> is in the closed configuration, the first cover recess <NUM> aligns with the first latch recess <NUM> and allows a user to insert a tool therein to conveniently open the latch cover <NUM>. In the embodiment shown, a second latch recess <NUM> and a second cover recess <NUM> can be provided.

In some embodiments, the latching mechanism <NUM> can be provided with a retainment system configured to effectively retain the latch cover <NUM> in the closed position. For example, and as seen in <FIG>, the latch body <NUM> can include a pair of grooves <NUM> extending along an inner surface thereof proximate the recess <NUM>, and the latch cover <NUM> can include a ridge <NUM> shaped and sized to be positioned within the groove <NUM> upon moving the latch cover in the closed position. As such, the latch cover <NUM> can be at least partially retained in the closed position via the cooperation of the ridge <NUM> and the groove <NUM>. It is noted that the ridge <NUM> can be disengaged from the groove <NUM> upon the application of a rotational force on the latch cover <NUM> in order to move it to the open position. In this embodiment, the groove <NUM> is substantially perpendicular to the recess <NUM> of the latch body <NUM>, although it is appreciated that other positions and configurations are possible.

Referring back to <FIG> and <FIG>, the mold support <NUM> can have a similar configuration as the crucible support <NUM> described hereinabove. For example, the mold support <NUM> can include a mold holder <NUM> operatively connected to the support frame <NUM> at opposite ends thereof. The mold holder <NUM> can have an elongated shape provided with a plurality of mold receiving apertures configured to receive and support the molds <NUM> in a side-by-side configuration. It should be understood that each mold <NUM> is adapted to receive a fused sample from a corresponding one of the crucibles <NUM>.

Furthermore, in some embodiments, the mold holder <NUM> can be removably connected to the support frame <NUM> such that the molds <NUM> can be removed from the support assembly <NUM>. Therefore, every mold <NUM> can be manipulated together by installing and/or removing the mold holder <NUM> from the support frame <NUM>, advantageously preventing having to manipulate each mold <NUM> individually. In this embodiment, the mold support <NUM> includes a pair of mold anchors <NUM> attached to the support frame <NUM> and to which the mold holder <NUM> can be removably connected. More specifically, each mold anchor <NUM> can be provided with a latching mechanism <NUM> similar to the one described above in relation with the crucible anchors <NUM>, such as a latching mechanism <NUM> identical to the one described above in relation to the crucible anchors <NUM>. As seen in <FIG> and <FIG>, the mold anchors <NUM> can be connected to and extend from the support frame <NUM> opposite one another such that each end of the mold holder <NUM> is connected to a corresponding one of the mold anchors <NUM>. More particularly, the mold anchors <NUM> extend from the outer frame <NUM> opposite one another such that the mold holder <NUM> is held in place between the outer walls <NUM>.

Now referring to <FIG>, in addition to <FIG>, the motion system <NUM> can include an axial displacement system configured to move the support frame <NUM>, and thus the crucibles <NUM>, towards the furnace chamber. It should be understood that the axial displacement system can be adapted to move the components connected thereto axially in any suitable direction. In this embodiment, the axial displacement system includes a pair of rails <NUM> extending on either side of the furnace assembly <NUM> and support assembly <NUM>. In this embodiment, the support frame <NUM> is operatively mounted on the pair of rails <NUM> for moving it towards and/or away from the furnace chamber <NUM>. More specifically, the outer frame <NUM> is slidably mounted to the pair of rails <NUM>, with the outer support base <NUM> extending transversely between the rails <NUM>. It is noted that the inner frame <NUM>, being mounted on the outer frame <NUM>, simultaneously moves along the rails <NUM> with the outer frame <NUM>. In this embodiment, the support frame <NUM> is moved axially towards and away from the furnace chamber <NUM>, although it is appreciated that other configurations are possible. As seen in <FIG>, the crucibles <NUM> can be inserted into the furnace chamber <NUM> through the access opening <NUM> by moving the support frame <NUM> along the rails <NUM>.

Referring to <FIG> and <FIG>, in addition to <FIG>, the crucibles <NUM> remain inside the furnace chamber <NUM> to allow the mixture contained within each crucible to fuse and form a fused sample for subsequent analysis. In order to facilitate fusing of the mixture, the motion system <NUM> can include a mixing mechanism <NUM> configured to move the crucibles <NUM> within the furnace chamber <NUM> in order to promote fusing of the mixture. In this embodiment, the mixing mechanism <NUM> includes one or more eccentrics <NUM> operatively connected to the support frame <NUM> and being operable to engage the crucibles <NUM> in a circular motion for mixing the mixture within the crucibles <NUM>, thus promoting fusing. It should be understood that, as used herein, the term "eccentric" refers to a device configured to transform rotational movement into a backward-and-forward motion. In this embodiment, and as seen in <FIG>, each eccentrics <NUM> can be embodied by a disc, a gear, or a wheel <NUM>, provided with an axle, or shaft <NUM>, extending therefrom at a location offset from a center axis (A) of the wheel <NUM> and being connectable to the support frame <NUM>.

The eccentrics <NUM> can be provided between the outer and inner support bases <NUM>, <NUM>, with the shafts <NUM> engaging the inner support base <NUM>. Therefore, it should be understood that rotation of the eccentrics <NUM> engages the inner frame <NUM> in the circular motion and can maintain the outer frame <NUM> substantially motionless. In other words, the eccentrics <NUM> can be adapted to engage the crucibles <NUM> in the circular motion, while having the molds <NUM> remain motionless. In this embodiment, the circular motion is accomplished in a plane substantially perpendicular to the axis of the shafts <NUM> and substantially parallel to the outer and inner support bases <NUM>, <NUM>. However, it is appreciated that other means for providing a mixing motion to the crucibles is possible. For example, it is known to provide a rocking motion to the crucibles <NUM> by engaging the ends of the crucible holder <NUM> in a back-and-forth pivoting motion. It should be noted that the rocking motion can be combined with the circular motion provided by the eccentrics to further promote fusing of the mixture. Additionally, in this embodiment, the eccentrics <NUM> are engaged in rotation via a motor <NUM> operatively connected to one or more of the eccentrics <NUM>, although other mechanisms for engaging the eccentrics in rotation are possible.

In some embodiments, the mixing mechanism <NUM> includes two pairs of eccentrics <NUM> disposed at opposite ends of the inner support base <NUM>. It should be understood that more than two pairs of eccentrics may be used, such as <NUM>, <NUM> or more pairs or eccentrics. Alternatively, the mixing mechanism can include a single pair of eccentrics. More specifically, each eccentric <NUM> can be provided proximate a respective corner of the inner support base <NUM> to ensure that the inner frame <NUM> is engaged in the circular motion along its entire width. In this embodiment, the eccentrics <NUM> can be adapted to rotate in a clockwise and/or a counterclockwise direction. It is appreciated that changing the direction of the circular motion when the crucibles <NUM> are inside the furnace chamber <NUM> can promote fusing the mixture, thus reducing the time required for preparing the fused samples. Additionally, rotating the eccentrics <NUM> (and thus the crucibles <NUM>) at certain speeds can further promote fusing the mixture and reduce preparation time of the samples. In this embodiment, the eccentrics <NUM> are adapted to rotate at speeds between about <NUM> rpms and about <NUM> rpms. However, it is appreciated that other speeds are possible. Each eccentric <NUM> can be adapted to rotate at generally the same speed as the other eccentrics <NUM>, and have their shaft <NUM> be synchronized with the other shafts <NUM> (i.e., each shaft <NUM> can be at the same relative position with respect to the center of the corresponding wheel <NUM>). Therefore, the inner frame <NUM> remains substantially stable and parallel to the outer frame <NUM>.

Referring back to <FIG>, it should be noted that the molds <NUM> are also moved with the support frame <NUM> and are similarly inserted into the furnace chamber <NUM> upon moving the support frame <NUM> towards the furnace chamber <NUM>. The outer and inner frames <NUM>, <NUM> are shaped and sized in a manner such that, when inserting the crucibles <NUM> and molds <NUM> into the furnace chamber <NUM>, the inner and outer walls <NUM>, <NUM> remain outside the furnace chamber <NUM>, on either side thereof, as illustrated in <FIG>. It is appreciated that the lateral openings <NUM> of the access opening <NUM> allow the crucible anchors <NUM> and mold anchors <NUM> to at least partially move into the furnace chamber <NUM>, while maintaining the inner and outer walls <NUM>, <NUM> outside.

With reference to <FIG>, in addition to <FIG>, the mold support <NUM> can be provided with an alignment mechanism <NUM> configured to move the mold holder <NUM> vertically relative to the crucible holder <NUM> in order to align the mold holder <NUM> and crucible holder <NUM> in a common horizontal plane. In some embodiments, the size of the access opening <NUM> can be generally based on the distance between a top of the crucible support <NUM> and a bottom of the mold support <NUM> for allowing both the crucibles <NUM> and the molds <NUM> to be inserted within the furnace chamber <NUM>. It should thus be noted that aligning the crucible and mold holders <NUM>, <NUM> together advantageously allows for the size of the access opening <NUM> to be reduced. In some embodiments, the alignment mechanism <NUM> can be adapted to rotate the mold holder <NUM> about an axis which is offset relative to the longitudinal axis of the mold holder <NUM> in order to adjust the vertical position of the mold holder <NUM>. However, it is appreciated that other configurations are possible for adjusting the position of the molds <NUM>. For example, the alignment mechanism <NUM> can be adapted to axially move the mold holder <NUM> up and down (e.g., along rails) in order to adjust the vertical position of the molds <NUM>.

In some embodiments, the alignment mechanism <NUM> can be operated to move the mold holder <NUM> between at least a first position, where the molds <NUM> are vertically lower than the crucibles <NUM> (<FIG> and <FIG>), and a second position, where the molds <NUM> are substantially aligned with the crucibles <NUM> in a horizontal plane (<FIG> and <FIG>). It should be noted that the alignment mechanism <NUM> can be adapted to position the molds at any suitable position between the first and second positions. Referring more specifically to <FIG>, in this embodiment, the alignment mechanism <NUM> includes pivoting arms <NUM> positioned at each end of the mold holder adapted to pivotally connect the mold holder to the support frame <NUM> (i.e., to the outer frame <NUM>). More specifically, the pivoting arms <NUM> are pivotally connected to the outer frame <NUM> at a first end thereof, and pivotally connected to the mold anchor <NUM> at a second end thereof. The pivoting arms <NUM> can be adapted to pivot about their first end, therefore rotating the mold holder <NUM> about an offset axis (i.e., the axis extending between the first ends at opposite ends of the mold anchor <NUM>).

In this embodiment, the alignment mechanism <NUM> incudes two pairs of pivoting arms <NUM> connected to either end of the mold holder <NUM> (i. e, two pivoting arms <NUM> per end). More particularly, each pair of pivoting arms <NUM> include a first pivoting arm <NUM> and a second pivoting arm <NUM>, both being pivotally connected to the mold holder <NUM> at respective second ends thereof 257b, 258b. In some embodiments, each pivoting arm <NUM> of a given pair can be mechanically linked to the other pivoting arm <NUM> of that same pair such that pivoting the first pivoting arm <NUM> engages the second pivoting arm <NUM> in rotation simultaneously. In this embodiment, the first pivoting arm <NUM> is operatively connected to a motor <NUM> at a first end 257a thereof and the second pivoting arm <NUM> is pivotally connected to the outer frame <NUM>. The motor <NUM> can be mounted on the support frame <NUM> and is configured to engage the first end 257a of the first pivoting arm <NUM> in rotation.

The pivoting arms <NUM> can be connected to the mold anchor <NUM> in a manner whereby the mold holder is maintained substantially leveled during rotation thereof about the offset axis. In this embodiment, the second end of the first pivoting arm 257b and the second end of the second pivoting arm 258b are connected to the mold anchor <NUM> adjacent one another. Therefore, with the first and second pivoting arms <NUM>, <NUM> being mechanically linked together to rotate substantially simultaneously, it should be understood that the second ends thereof remain aligned during rotation, thus maintaining the mold holder substantially leveled. It should however be appreciated that other mechanisms and/or configurations are possible for maintaining the mold holder <NUM> leveled during rotation thereof.

In the illustrated embodiment, the pivoting arms <NUM> are generally C-shaped although other shapes are possible. The first and second pivoting arms <NUM>, <NUM> can be disposed in a "face-to-face" manner at each end of the mold holder <NUM>. This configuration can allow the pivoting arms <NUM> of a given pair to interlock each other upon rotation of the first pivoting arm <NUM>. In other words, the second end of one of the pivoting arms <NUM> can be shaped and sized to engage the central recessed portion of the other one of the pair of pivoting arms (depending on the direction of rotation), as seen in <FIG>.

Referring to <FIG>, once the samples within the crucibles <NUM> have been fused, the support frame <NUM> is moved along the rails <NUM> away from the furnace assembly <NUM> to remove the crucibles <NUM> and molds <NUM> from the furnace chamber <NUM>. The crucibles <NUM> can then be pivoted (e.g., via the motor <NUM>) to pour the fused samples into the corresponding molds <NUM>, as illustrated in <FIG>. In this embodiment, the support assembly <NUM> can include a retaining rod <NUM> shaped, sized and configured to retain the crucibles <NUM> in the crucible receiving apertures during rotation of the crucible holder <NUM>. More specifically, in this embodiment, the retaining rod <NUM> is connected to the support frame <NUM> at opposite ends thereof and is positioned generally above the crucible holder <NUM>. Therefore, when the crucible holder <NUM> is pivoted in order to pour the fused sample into the molds <NUM>, the crucibles <NUM> abut against the retaining rod <NUM> to prevent the crucibles <NUM> from falling out of the crucible holder <NUM>.

In some embodiments, the retaining rod <NUM> can be pivotally connected to the support frame <NUM> such that the retaining rod <NUM> can follow the rotational movement of the crucible holder <NUM> upon contacting the crucibles <NUM>. In other words, the crucibles <NUM> can be adapted to push the retaining rod <NUM> during rotation of the crucible holder <NUM>. In addition, the retaining rod <NUM> can be spring-loaded (e.g., via a torsion spring) and adapted to revert back to an initial position upon rotating the crucible holder <NUM> back to a substantially horizontal position. It should thus be understood that the spring-loaded retaining rod <NUM> can be adapted to apply a force on the crucibles <NUM> towards the crucible holder <NUM> in order to retain the crucibles <NUM> in the crucible receiving apertures <NUM> during rotation. Referring more specifically to <FIG>, the retaining rod <NUM> can include rod abutments <NUM> proximate the ends of the rod being shaped and sized to contact a top surface of the crucible holder <NUM> during transfer of the fused sample from the crucibles to the molds.

In this embodiment, the retaining rod <NUM> is connected to an independent portion of the support frame, or a secondary frame <NUM>. More specifically, the secondary frame <NUM> is not connected to the outer and/or inner frames <NUM>, <NUM>, as described above. Therefore, it is understood that moving the outer frame <NUM> forward (i.e., towards the furnace chamber <NUM>) along the rails <NUM> does not move the secondary frame <NUM>, and therefore does not move the retaining rod <NUM>. This configuration allows the retaining rod <NUM> to remain outside the furnace chamber <NUM> during the fusion of the mixture contained in the crucibles. It is appreciated that the secondary frame <NUM> is shaped and configured to position the retaining rod <NUM> at a predetermined position, whereby the crucibles <NUM> engage the retaining rod <NUM> when the crucible holder is retracted from within the furnace chamber <NUM> and pivoted to pour the fused samples into the molds. It should be noted that the retaining rod <NUM> can be made of any suitable material, such as alumina, stainless steel or nickel-based alloys for example. It is appreciated that having the retaining rod <NUM> remain outside the furnace chamber <NUM> advantageously allows for a wider range of materials to be used to make the retaining rod <NUM>. Moreover, since the retaining rod <NUM> is not heated with the crucibles within the furnace chamber <NUM>, the possibility of cross contaminating the fused samples is reduced since the heated crucibles do not abut against a heated retaining rod <NUM>.

Now referring to <FIG>, the fluxer <NUM> can be provided with an enclosure <NUM>, or partially isolated section, configured to pre-heat the crucibles <NUM> prior to moving the crucibles into the furnace chamber <NUM> for preparing the fused samples. Pre-heating the mixture within the crucibles <NUM> can reduce the time required for the temperature to reach the desired level, and thus reduce the time required by the mixture to fuse, among others. In some embodiments, the heating elements can require some time before generating the desired amount of heat. While the heating elements effectively heat up, the crucibles <NUM> can be placed within the enclosure <NUM> to pre-heat the mixture.

In this embodiment, the fluxer <NUM> includes a pre-heating compartment <NUM> adapted to cooperate with the furnace assembly <NUM> and house the crucibles <NUM> for pre-heating the mixture within each crucible. The pre-heating compartment <NUM> can be operable in a first position, or pre-heating position, for pre-heating the crucibles <NUM>, as seen in <FIG> and <FIG> for example. More specifically, the pre-heating compartment <NUM> can include a compartment body <NUM> pivotally connected to the furnace chamber <NUM> and being adapted to cover the crucibles <NUM> when in the pre-heating position. In this embodiment, the compartment body <NUM> covers the crucibles <NUM> proximate the access opening <NUM> such that the heat being generated by the heating elements can be transferred out of the furnace chamber <NUM> and into the compartment body <NUM> where the crucibles <NUM> are housed. Alternatively, or additionally, the pre-heating compartment <NUM> can be provided with an independent source of heat configured to raise the temperature of the interior of the compartment body <NUM> for pre-heating the crucibles <NUM>.

When a crucible is placed in the pre-heating compartment, its distance from the furnace chamber can allow controlling the temperature and the heating rate. The heat transfer from the furnace chamber is reduced the further away the crucible is placed from it within the pre-heating compartment. Depending on the nature of the oxidizing agent, the positioning of the crucibles within the pre-heating compartment can therefore have an impact on the oxidizing rate of the non-oxidized and/or partially oxidized compounds. For example, in comparison to sodium nitrate, the ammonium nitrate requires a lower temperature to insure a slow and controlled decomposition. A crucible containing ammonium nitrate can therefore be placed further away from the furnace chamber, compared to a crucible containing sodium nitrate. It is understood that the optimal positioning of the crucibles containing any given oxidizing agent can be obtained by trial and error.

It should be understood that the expression "the pre-heating compartment being in heat-transfer communication with a furnace chamber" means that the pre-heating compartment and the furnace chamber are separate compartments, that can be separated by a furnace chamber door. When the crucibles are located in the pre-heating compartment, at least a portion of the heating that is received comes from heating elements located in the furnace chamber via heat transfer, through the furnace chamber door, or through air if the furnace chamber door is kept open.

The pre-heating compartment and the furnace chamber can be two separate enclosures, with the pre-heating compartment being located proximate an entrance of the furnace chamber.

However, in other embodiments, the pre-heating compartment and the furnace chamber may be a single enclosure. In such case, when a crucible is said to be positioned in the furnace chamber, it is meant that the crucible is positioned such as it is directly heated by the heating element (e.g., directly above an electric heating element or a gaz heating element). Similarly, when a crucible is said to be positioned in the pre-heating compartment, it is meant that the crucible is positioned away from the heating element(s), but such that the crucible still receives heat via heat transfer from the furnace chamber.

Once the mixture has been pre-heated, the compartment body <NUM> can be pivoted in a second position, or uncovered position, (seen in <FIG>), e.g., away from the access opening, to allow the support frame <NUM> to move forward along the rails and move the crucibles <NUM> into the furnace chamber <NUM>. In this embodiment, the compartment body <NUM> is pivoted upwardly in order to uncover the crucibles <NUM>, although other configurations are possible.

The compartment body <NUM> can have any suitable shape, size and/or configuration adapted to selectively house the crucibles <NUM> within an interior volume thereof. In this embodiment, the compartment body <NUM> has a substantially flat top surface <NUM> having a hinged edge <NUM> pivotally connected to the front wall of the furnace chamber <NUM>. It should thus be understood that the compartment body <NUM> is adapted to rotate about the hinged edge <NUM> between the pre-heating and uncovered positions. Furthermore, the compartment body <NUM> has a pair of lateral surfaces <NUM> extending transversely at opposite ends of the top surface <NUM>, and a curved outer surface <NUM> joining the lateral surfaces <NUM> with the top surface <NUM>. As will be further described below, the compartment body <NUM> has a relatively open side through which the crucibles <NUM> can enter upon lowering the compartment body <NUM> in the pre-heating position.

As seen in <FIG>, in addition to <FIG>, each lateral surface <NUM> can be provided with an arcuated slot <NUM> adapted to receive a corresponding portion of the crucible support <NUM> therein upon pivoting the compartment body <NUM> in the pre-heating position. The slots <NUM> can be shaped and configured to prevent axial movement of the crucible support <NUM> when the crucibles <NUM> are housed within the compartment body <NUM>. As such, the compartment body <NUM> can be adapted to effectively prevent the crucibles <NUM> from entering the furnace chamber <NUM> when in the pre-heating position. In this embodiment, the curved outer surface <NUM> extends between the lateral surfaces <NUM> and includes a leading edge <NUM> being substantially aligned with and spaced from the hinged edge <NUM> of the top surface <NUM>. The compartment body <NUM> has a compartment opening <NUM> defined between the leading edge <NUM>, the hinged edge <NUM> and both lateral surfaces <NUM>. It should be understood that the crucibles <NUM> enter the compartment body <NUM> through the compartment opening <NUM> upon moving the compartment body in the pre-heating position.

In some embodiments, the top surface <NUM> can be substantially perpendicular to the front wall <NUM> of the furnace chamber <NUM> when the compartment body <NUM> is in the pre-heating position (<FIG>). However, when in the uncovered position, the top surface <NUM> can be parallel to and abut against the front wall (<FIG>). Therefore, it should be understood that the compartment body <NUM> can be adapted to rotate about <NUM> degrees between the pre-heating and uncovered positions, although it is appreciated that other configurations are possible. In some embodiments, the compartment body <NUM> can include abutments <NUM> configured to contact and rest on the furnace chamber <NUM> when in the pre-heating and/or uncovered position. For example, the compartment body <NUM> can include abutments <NUM> extending transversely from the lateral surface <NUM> for abutting against the front wall <NUM>. The abutments <NUM> can reduce damage caused to the compartment body <NUM> due to repeated contact between the edges of the compartment body <NUM> and the furnace chamber <NUM>, for example.

It should be understood that, although the various exemplary embodiments and features described herein may be used in relation with an electric fluxer for the preparation of samples by fusion, it is understood that it may be used with other types of fluxers and/or for other purposes. For this reason, the term "fluxer" as used herein should not be taken as to limit the scope of the present disclosure as being used with electrical fluxers in particular. It should be understood that the term "fluxer" should, in the context of the present disclosure, encompass all other types of instruments or devices with which the described embodiments and features could be used and may be useful.

In addition, although the optional configurations as illustrated in the accompanying drawings comprise various components and although the optional configurations of the fluxer as shown may consist of certain configurations as explained and illustrated herein, not all of these components and configurations are essential and thus should not be taken in their restrictive sense, i.e. should not be taken as to limit the scope of the present disclosure. It is to be understood that other suitable components and cooperations thereinbetween, as well as other suitable configurations may be used for the fluxer, and corresponding parts, as briefly explained, and as can be easily inferred herefrom, without departing from the scope of the disclosure.

Furthermore, it should be noted that, in the preceding description, the same numerical references refer to similar elements. In addition, for the sake of simplicity and clarity, namely so as to not unduly burden the figures with several references numbers, not all figures contain references to all the components and features, and references to some components and features may be found in only one figure, and components and features of the present disclosure which are illustrated in other figures can be easily inferred therefrom. The embodiments, geometrical configurations, materials mentioned and/or dimensions shown in the figures are optional and are given for exemplification purposes only. It should also be understood that the elements of the drawings are not necessarily depicted to scale, since emphasis is placed upon clearly illustrating the elements and structures of the present embodiments, the drawings can be interpreted as being to scale but should not be limited as such.

Experiments were conducted as follows. Three samples each containing <NUM> grams of lithium tetraborate were placed in platinum-gold crucibles (<NUM>-<NUM>).

Using an R-type thermocouple fitted onto a data logging device, the temperature of the tetraborate or tetraborate-nitrate mixture was monitored by inserting the thermocouple directly in the mixture. Temperature measurements were recorded every second and for each experiment, with the temperature of the furnace chamber maintained at about <NUM>.

In addition to heating rates measurements, the duration of the nitrate decomposition was monitored, for crucibles nos. <NUM> and <NUM>, by visually observing decomposition gasses from the nitrate component. After the experiments, the crucibles containing the nitrate-tetraborate mixture were weighed to estimate the completeness of the nitrate decomposition reaction.

Crucible no. <NUM> was placed within the pre-heating compartment for <NUM> minutes, with the compartment body in the pre-heating position, and with the door of the furnace chamber kept open. Two separate experiments were conducted using the same conditions and the decomposition time of ammonium nitrate was respectively of <NUM> and <NUM> seconds. The temperature range where decomposition was observed was between <NUM> and <NUM>. The decomposition of ammonium nitrate was complete as we calculated a <NUM>% loss of the nitrate addition after the heating regime. The heating rate (°C. sec-<NUM>) was <NUM> and <NUM> for the respective trials.

Crucible no. <NUM> was placed within the pre-heating compartment for <NUM> minutes, with the compartment body in the pre-heating position, and with the door of the furnace chamber kept open. Two separate experiments were conducted using the same conditions and decomposition was observed from the time of reaching <NUM> until the end of the experiment (<NUM>). Decomposition was observed during more than <NUM> seconds in both experiments and sodium nitrate losses of <NUM> and <NUM>%, respectively, were observed. The heating rate (°C. sec-<NUM>) was <NUM> and <NUM> for the respective trials.

Crucible no. <NUM> was placed directly in the furnace chamber and the temperature was monitored over time. The heating rate (°C. sec-<NUM>) was much faster, and of about <NUM> and <NUM> for replicate experiments. As visual observation of decomposition gases was not possible when the crucibles were placed directly in the fusion chamber, estimating how long ammonium and sodium nitrate would have taken to decompose was performed by comparing temperature curves. The temperature curves were used to estimate how long ammonium and sodium nitrate would have taken to decompose at respectively <NUM>% and <NUM>%. By using the calculated losses in the nitrate-tetraborate mixture experiments and the temperature range where the nitrate decomposition was observed, it was estimated that ammonium nitrate would take only <NUM> seconds to fully decompose and sodium nitrate would take <NUM> seconds to pass the <NUM>-<NUM> range where an average <NUM>% loss has been measured in the previous experiments.

Claim 1:
A fluxer (<NUM>) for preparing analytical samples by flux fusion, comprising:
a furnace assembly (<NUM>) including a furnace chamber (<NUM>) provided with heating elements (<NUM>) positioned therein for heating an interior of the furnace chamber (<NUM>), the furnace chamber (<NUM>) having an access opening (<NUM>);
a sample support assembly (<NUM>) comprising:
a support frame (<NUM>);
a crucible support (<NUM>) having a crucible holder (<NUM>) operatively connected to the support frame (<NUM>) at opposite ends thereof, the crucible holder (<NUM>) having a plurality of crucible receiving openings (<NUM>) for receiving and supporting a plurality of crucibles (<NUM>), each crucible (<NUM>) being adapted to receive a mixture of a sample and a flux material;
a mold holder (<NUM>) operatively connected to the support frame (<NUM>) at opposite ends thereof, the mold holder (<NUM>) having a plurality of mold receiving openings for receiving and supporting a plurality of molds (<NUM>), each mold being adapted to receive a fused mixture from a corresponding one of the plurality of crucibles (<NUM>) upon rotation of the crucible holder (<NUM>);
a secondary frame (<NUM>); and
a retaining rod (<NUM>) pivotally connected to the secondary frame (<NUM>) configured to retain the crucibles (<NUM>) within the crucible holder (<NUM>) upon rotation of the crucible holder (<NUM>), wherein the secondary frame (<NUM>) is fixed relative to the furnace chamber (<NUM>), and wherein the retaining rod (<NUM>) extends above the crucible holder (<NUM>).