JPH0446903B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an apparatus for efficiently preparing glass bead samples for fluorescent X-ray analysis and a method of using the same to obtain highly accurate samples.

[Conventional technology] Fluorescence of inorganic materials such as ores, refractories, cement, etc.
In line analysis, the powder of these test substances is heated and melted in a furnace together with a melting agent, etc. to form a molten metal, which is then cooled and solidified to form a glass-like disk (glass bead), which is used as a sample for analysis. The law is widely used.

First, to give a general explanation of the glass bead method, a predetermined amount of powdered material (sample) and a melting agent to be tested are each accurately weighed onto a paper bag or the like.

Next, use a medicine spoon to thoroughly mix the mixture on the paper and transfer it into a melting crucible (hereinafter simply referred to as "crucible"). This is to prevent the crucible from being damaged by mixing with a spoon.

After the crucible is ignited in a furnace to melt the above-mentioned mixture to form a molten metal, a shaking motion is applied to the crucible to mix the molten material and to degas it.

The crucible is taken out of the furnace, and the melt is cooled and solidified with cold air, etc., to form a glass-like disk.

The glassy disk is taken out, and the melting surface, generally on the inner bottom side of the crucible, is used as the measurement surface for X-ray fluorescence analysis.

This type of glass bead method eliminates differences in mineral phase and particle size distribution between sample powders, which are major error factors in fluorescent X-ray analysis, by using a homogenization method called vitrification. This generally improves the accuracy of analysis compared to measuring as is.

FIG. 5 is a sectional view showing a conventional glass bead sample preparation device (hereinafter simply referred to as "adjustment device") disclosed in, for example, Japanese Utility Model Publication No. 62-34294. In the figure, 1 is a crucible for melting the sample. The shape is an open top type, and the material is platinum alloy. Reference numeral 2 denotes a spiral high-frequency heating coil which heats and melts the sample and melting agent in the crucible 1 by using the crucible 1 as a heating element through high-frequency induction.

Reference numeral 3 denotes a furnace body surrounding the heating coil 2, which is made of a refractory material, and 4 is a support arm that supports the crucible 1, the heating coil 2, and the furnace body 3, as well as a drive arm for stirring motion. 5 is a shaft fulcrum; 6 is a transmission arm connected to the eccentric rotary disk 7 and the shaft fulcrum 5, and is driven by a drive motor 8 to convert the movement into left and right movement, thereby giving a left and right tilting movement to the crucible 1; It's summery.

FIG. 6 is a sectional view showing another conventional manufacturing apparatus disclosed in Japanese Utility Model Publication No. 19302/1983, in which the support arm 4 rotates by the rotation of the drive motor 8 to rotate the furnace body 3. This gives the crucible 1 a rotational motion in the horizontal circumferential direction. Note that 9 is the inner bottom surface of the crucible, and the glass bead surface formed on this surface is the surface to be measured.

[Problems to be Solved by the Invention] In the conventional adjustment device as described above, the shape of the crucible is an open top type, so when the crucible is rocked to homogenize the glass beads, it is difficult to prevent the molten metal from spilling. In order to do this, the limit for both the left and right front and rear tilt angles is about 45 degrees, and the limit for both the number of tilts and the number of plane rotations is about 5 times per minute.

This type of movement does not allow sufficient stirring of the molten metal, resulting in a problem that the glass bead sample lacks homogeneity and analysis errors are large.

Further, in the conventional adjusting device as described above, since the crucible itself is used as a heating element, a large temperature difference occurs between the crucible and the molten metal, and the molten metal volatilizes at the interface with the molten metal. According to experiments, the amount of volatilization is several times that of an electric resistance furnace. Furthermore, since it is difficult to maintain a constant catalytic state, the variation in the amount of volatilization is several times greater.

Such volatilization of the molten metal has the problem of causing errors other than the homogeneity of the glass beads and reducing analysis accuracy. Furthermore, the viscosity of the molten metal is greatly influenced by its temperature, and if the difference in viscosity caused by this temperature difference is effectively utilized in the rocking process of the sample, a great stirring effect can be expected.

That is, the molten metal flowing on the crucible wall due to the rocking has a low viscosity, so it flows quickly in the direction of the streamline at high temperatures in the furnace, and the vertical cross section of the streamline becomes narrow. On the other hand, when the molten metal is taken out of the furnace and subjected to similar shaking, the viscosity of the molten metal increases as it cools, and the flow gradually becomes slower and thicker.

The stirring effect exerted by such a change in fluid flow due to viscosity can be understood by considering the flow velocity distribution at the contact surface of the molten metal with the crucible wall, and at the contact surface between the interior of the molten metal and the outside air.

However, in the conventional adjusting device as described above, there is no rocking mechanism that takes advantage of this difference in viscosity, so the flow of the molten metal as a fluid becomes monotonous, resulting in insufficient agitation of the sample and, therefore, a lack of homogeneity. Another problem was that it was difficult to obtain highly accurate glass bead samples with little variation between samples.

The present invention was made to solve these problems, and includes a conditioning device and a conditioning device that can efficiently prepare a homogeneous and highly accurate glass bead sample by sufficiently stirring and defoaming the molten metal in the crucible. The purpose is to obtain usage.

[Means for Solving the Problems] The adjustment device according to the present invention includes a crucible chamber and a heat generating section, the crucible chamber is equipped with a closed crucible, and there is a heat generating section separated by a partition wall, and this partition wall is arranged between the heat generating section and the crucible chamber. It is attached to the side.

The crucible chamber and the heat generating section can be separated, and the crucible chamber alone and the crucible chamber and the heat generating section can be moved vertically and rotationally, respectively.

Furthermore, the ``method for using the preparation device'' according to the present invention is such that the test sample powder is melted in the crucible chamber by vertically swinging the crucible chamber and rotating the crucible upside down, either alone or in combination. The molten metal is thoroughly stirred and degassed, and then only the crucible chamber is moved in the atmosphere as described above, and the molten metal is sufficiently mixed by the flow change of the molten metal that occurs during the cooling process of the crucible and the molten metal.

Next, the heating part is connected and the crucible is reheated,
The glass-like material uniformly dispersed by the above cooling and shaking stirring is collected again as a molten metal at the bottom of the crucible, and then the crucible is taken out and cooled to obtain a glass bead sample for fluorescent X-ray analysis.

In another invention, by inverting the crucible of the apparatus of this invention vertically, melting, mixing, defoaming, and casting and cooling of the sample are performed on separate inner surfaces of the crucible.

[Operation] In this invention, the crucible is a closed type,
Since the crucible chamber housing the crucible can freely move up and down and rotate, the material to be melted in the crucible can be sufficiently mixed and stirred without leaking to the outside. Further, the partition wall separating the crucible chamber and the heating section protects the heating element of the heating section from alkali vapor generated from the material to be melted, and also prevents the heating section from being rapidly cooled.

Further, since the crucible chamber and the heat generating part can be separated and combined as desired, various rocking motions can be performed on the crucible during heating and cooling, and the molten metal is subjected to a wide variety of fluid agitation.

In the method of use of this invention, various vigorous movements are applied to the molten sample in a closed crucible to produce sufficient stirring and defoaming effects, and then the viscosity decreases as the sample is cooled by shaking in the atmosphere. When the crucible is heated again, the molten metal gathers at the bottom of the crucible and finally becomes cooled glass beads that are nearly perfect circles. In another invention of this invention, the crucible chamber is
Since the crucible is inverted, it has the function of melting, mixing, defoaming, and cooling and casting the test sample on separate inner surfaces within the crucible.

[Embodiment] FIG. 1 is a sectional view of a furnace body showing an embodiment of the apparatus of the present invention, and 11 is a crucible chamber, in which a closed crucible is placed in a space surrounded by a lower support part 12 and an upper support part 13. 14 is installed, and this crucible 14 has several crucible fixing seats 15 provided on the lower support part 12 and crucible fixing hooks 16 provided on the upper support part 13.
It is stably fixed by a crucible fixing part 17.

The lower support part 12 and the upper support part 13 are each made of a fireproof material and can be moved downward and upward independently of other members by means of a lower support part operating rod 18 and an upper support part operating rod 19, respectively. 20 and 21 are the lower support part 12 and the upper support part 13
This is an atmospheric gas supply/discharge port installed in the

Reference numeral 22 denotes a heat generating section, which is composed of an electric resistance type heat generating element 23 provided inside, a refractory furnace body 24 on its outer periphery, and a partition wall 25 attached on its inner periphery. The upper part of the partition wall 25 extends outward and is attached to the refractory furnace body 24, and the heating element 23 is attached to the refractory furnace body 24.
is enclosed inside the heat generating part.

The partition wall 25 is made of platinum or a platinum alloy, and has a thickness of 0.1 to 1.5 mm, with the thickness of the example being 0.3 mm.In order to protect the heating element 23 from vapors such as alkali generated when the glass beads are melted, the partition wall 25 is made of platinum or a platinum alloy. This is to suppress rapid cooling of the heat generating section 22. Therefore, various fireproof materials can be used as the material, but in this case, the appropriate thickness is 0.5 to 5 mm.

In addition, the furnace body part consisting of the crucible chamber 11 and the heat generating part 22 has a flat cylindrical shape as a whole,
In the case of the example, the height is 90 mm, the circumference is 150 mm, and the support rod is 18.
The weight excluding 19 is 4.5Kg.

Next, we will explain the drive mechanism that provides the various necessary movements to the furnace body. Figure 2 is a side view of the entire device for explanation, Figure 3 is a front view for explanation of the vertical shaking mechanism, FIG. 4 is a front view for explaining rotational movement. Base 26 in the figure
An inversion frame 28 rotatably supported by a support shaft 27 on the side of the
The rack 33 is connected to the furnace body part 31 through the forward or reverse rotation of the drive motor 32, and the rack 33 is moved to the right or in the opposite direction, and the reversing frame 28 and the furnace body part 31 are connected to the furnace body part 31 through the pinion 34. Rotate in any direction and speed.

On the other hand, by detecting the rotational position of the furnace body 31, it is possible to rotate the furnace body 31 at any angle, and when melting, mixing, defoaming, and casting of the sample are performed on separate inner surfaces of the crucible in a closed crucible, the furnace body 31 can be rotated at any angle. It can be stopped with .

Further, the furnace body 31 is supported vertically by an eccentric rotary disk 29 in the reversing frame 28 via a crankshaft 30, and the vertical movement of the furnace body is controlled by the rotation of the eccentric rotary disk 29. The furnace body 31 moves up and down at an arbitrary speed. The stroke of vertical movement is 10 to 70mm, and the number of vertical movements is 3.
~10 times/sec is preferred.

In addition, the lower support portion operating rod 18 is connected to the lower shaft 35.
It is further connected to the lower elevator 36.

By simultaneously operating the lower elevator 36 and the upper elevator 38 in the upward direction, the crucible chamber 11 (Fig. 1) located at the center of the furnace body 31 is raised, and the closed crucible 14 is moved out of the furnace. can be made,
Note that 39 is a furnace body frame provided with a mechanism for raising and lowering the furnace body.

In the adjustment device configured as described above, the closed crucible 14 containing the test sample and flux is placed on the crucible fixing seat 15 and fixed to the crucible fixing part 17 with the upper support part 13 lowered, and the heating element 23 is fixed to the crucible fixing part 17. When electricity is applied and the crucible chamber is heated at a predetermined temperature within the range of 900°C to 1300°C for about 5 minutes, the inside of the crucible becomes molten metal.

At this time, during heating, the lower support part operating rod 18 is slightly lowered to create a gap between the crucible body and the upper lid by the fixing hook 16, and the atmospheric gas from the atmospheric gas supply port 20 is used. Preferably, the atmosphere within the crucible is created by melting the sample.

After the melting is completed, the lower support operating rod 18 is raised to seal the crucible, and the driving device moves the entire device for a predetermined period of time to sufficiently stir and mix the molten metal in the crucible. During this rocking motion, it is preferable to keep the inside of the crucible chamber heated at 900°C to 1300°C.

Next, the upper and lower elevators 38 and 36 are operated to swing the crucible chamber 11 in the atmosphere in the same manner as described above, thereby mixing and agitating the molten metal by utilizing changes in the viscosity of the molten metal. By connecting the heat generating part 22 to the crucible chamber 11 and heating the crucible chamber, molten metal is cast within the crucible.

If necessary, repeat the above operation two or several times.

After completing the required operations, the crucible 14 is removed from the apparatus and allowed to cool, resulting in a homogeneous glass bead sample.

The analysis precision of the sample obtained in this way was improved by 1.52 to 5.05 times compared to the sample prepared using the conventional apparatus using the JISR2216-1987 assay method.

Next, in the method of using this adjustment device, a clay refractory as a test material sample is heated at 1150°C for 5 minutes with the upper lid of the crucible slightly raised to form a molten metal.

While the crucible is sealed and the inside of the crucible chamber is maintained at 1150° C., the drive motor 39 provided in the reversing frame 28 is activated to perform vertical swinging motion for 1 minute, and then the drive motor 32 is used to perform rotational motion for 1 minute. .

The upper and lower elevators 38 and 36 are operated to raise the furnace body 31, and the crucible chamber is rotated for 1 minute while the crucible is exposed to the atmosphere.

Connect the heat generating part to the crucible chamber again and heat the crucible chamber to 1150°C for 1 minute.

Repeat the above operations twice.

Remove the crucible and cool to room temperature.

By the above operations, the sample can be sufficiently melted and vitrified, stirred and mixed, defoamed, and cast, so that a glass bead sample that is homogeneous and has little variation between samples can be obtained.

In another method of using this device, the sample is melted at the bottom of the crucible, mixed and degassed by shaking the crucible left and right, and then the crucible chamber is rotated 180 degrees up and down. If casting and cooling are performed on the lid surface, there will be less roughness of the casting surface on the lid side of the glass bead sample, so performing fluorescent X-ray analysis using this surface will increase analysis accuracy and suppress roughness on the casting surface. This will improve the durability of the crucible.

[Effects of the Invention] As explained above, the present invention makes it possible to separate the crucible chamber in which the closed crucible is provided and the heat generating part to which the partition is attached, and sufficiently applies various types of rocking motion to the crucible. Since the required number of homogeneous and highly accurate glass bead samples can be prepared with high efficiency, the accuracy of fluorescent x-ray analysis can be significantly improved.

Another invention of the present invention is to perform various types of crucible rocking movements in combination in each sample preparation process, and to separate and connect the crucible chamber and the heat generating part as appropriate to handle various test samples. Since this apparatus is used, it is possible to obtain a glass bead sample that allows a wide range of samples to be analyzed with high precision in X-ray fluorescence analysis.

In another invention, the closed crucible is turned half way and casting is performed on the inner surface of the unused crucible, so a surface with less surface roughness is obtained, and this surface is used for analysis, making it possible to obtain highly accurate analytical results. It also improves the service life of the crucible.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a furnace body showing an embodiment of the apparatus of the present invention, FIG. 2 is a side view of the entire apparatus, and FIG. 3 is an explanatory diagram of the vertical shaking mechanism of the furnace body.
Figure 4 is also an explanatory diagram of the rotation mechanism of the furnace body, Figure 5
6 are cross-sectional views showing a conventional glass bead sample preparation device. 11 ... Crucible chamber, 14... Closed crucible, 18...
Lower support operation rod, 19... Upper support operation rod, 2
2... Heat generating part, 23... Heat generating element, 24... Refractory furnace body, 2
5... Partition wall, 28... Reversing frame, 29... Eccentric rotary disk, 30... Crankshaft, 31... Furnace body section, 33... Rack, 34... Pinion, 36... Lower elevator, 38
...upper lift.

Claims (1)

[Scope of Claims] 1. A crucible chamber equipped with a closed-type melting crucible and a heat generating part for heating the crucible are provided separated by a partition wall, and the partition wall can be separated from the crucible chamber when attached to the heat generating part side, and A glass bead sample preparation device characterized in that the crucible chamber is structured to be able to move up and down and rotate independently and together with a heat generating section. 2. In the apparatus according to claim 1, after the sample is melted, the crucible chamber is subjected to either an up-and-down rocking motion, an up-and-down rotational motion, or a combination thereof, and then the crucible chamber is opened in a state where the crucible chamber and the heat generating part are separated. A method of using a glass bead sample preparation device, which comprises carrying out the above-mentioned movement in the atmosphere, further heating a melting crucible by connecting a heat generating part, and then taking it out of the device and cooling it to obtain a sample. 3. A method of using the glass bead sample preparation device according to claim 1, characterized in that the crucible chamber is turned upside down to perform melting, mixing, defoaming, and casting of the sample on separate inner surfaces of the melting crucible.