JPH0234524A - Crucible for melting glass bead - Google Patents

Abstract

PURPOSE:To uniformly mix powder, to sufficiently shake the molten material, and to prepare a sufficient amt. of a homogenous glass bead sample by providing a lid fitted to a crucible main body, and placing the lid on the main body to obtain a closed vessel, and using the vessel. CONSTITUTION:The powder of firebrick and the powder of lithium tetrahydroborate as the flux are accurately weighed in advance, and transferred into the crucible main body 3. The crucible lid 6 is pressed on the main body from the upper and lower parts, and closely attached to the main body at the fitting surfaces 7 and 8. The crucible is then shaked in all directions to sufficiently mix both powders. A sodium iodide soln. and an org. release agent are added to the mixed powder, and the mixture is allowed to stand in an electric- resistance furnace held at about 1150 deg.C for 4min. The crucible lid is then closely attached to the crucible by a jig and fixed, and the crucible is violently shaked in all directions to homogenize the molten material. The shaking is repeated about twice, the crucible is then cooled, and a discoid glass bead sample is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a melting crucible that can efficiently prepare glass bead samples for fluorescent X-ray analysis.

[Prior art] In fluorescent X-ray analysis of inorganic materials such as ores, refractories, and cement, the powder of these specimens is heated and melted in a furnace together with a melting agent to form a molten metal, which is then cooled to form a glass-like material. The glass-to-one method is widely used, in which a circular plate (glass bead) is used as a sample for analysis.

Figure 5 is a cross section I'A of a conventional melting crucible (hereinafter referred to as "crucible") used for heating and melting a specimen, where l is the flange at the top of the crucible, and 2 is the internal bottom surface of the crucible. The material used is generally a platinum alloy. First, the glass beat method will be briefly explained.

■ Accurately weigh the specified amounts of the test substance powder and melting agent. At this time, instead of putting it directly into the crucible, it is scooped out into a medicine wrapper or the like.

(g) Next, use a drug holder or the like to thoroughly mix the mixture on paper and transfer it into the crucible.This is to prevent the mixing crucible from being damaged by the holder mentioned above.

(2) After igniting the crucible in a furnace to melt the above-mentioned mixture to form a molten metal, the melt is stirred by shaking the crucible either manually or by a mechanical device to mix and then defoamer.

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

(Q: The glass bead method, in which a glass-like disk is taken out and the molten surface on the inner bottom side of the crucible is generally used as the bottom surface for fluorescent By eliminating differences in mineral phases and particle size distributions between powders using a homogenizing means called vitrification, it is possible to generally improve analytical accuracy compared to measuring the powder as it is.

[Problems to be Solved by the Invention] In the conventional crucible of the northern open type as shown in FIG. 5, there were the following problems in the sample preparation process by the glass bead method described above.

■ Accurate and uniform mixing of test substance powder and melting agent is difficult. That is, as mentioned above, in order to prevent damage to the crucible 11=, the mixture is mixed on the drug wrapper paper, and the resulting static electricity causes the test substance powder to remain on the drug wrapper paper, resulting in a lack of accuracy in quantitative determination. Furthermore, if the ingredients are mixed in a crucible, as mentioned above, there is a risk that the crucible may be damaged by the medicine holder, so the mixing may be insufficient and it is difficult to achieve uniform mixing. Inaccurate mixing of the former causes analytical errors, while non-uniform mixing of the latter significantly lengthens the time required for melting.

) Shaking of the molten metal in the furnace tends to be insufficient,
It is difficult to obtain homogeneous glass beet samples. That is.

In order to prevent the melted material from spilling in the top-open crucible, there is a natural limit to the amount of shaking motion and movement that can be applied to the crucible, and sufficient stirring and homogenization cannot be achieved. Therefore, the analysis error also increases.

(■ It is not possible to increase the amount of molten glass.

That is, in order to increase the mixing effect, if the inclination angle of the crucible is increased and the rotation speed is increased, the amount of melt that can be mixed without spilling must be reduced. For this reason, the molten material with strong surface tension does not completely cover the inner bottom of the crucible and cools and solidifies in a lopsided state, resulting in the glass bead sample, which should be a single circular plate, becoming distorted and making measurements difficult. It's hard to predict.

This invention was made to solve these problems, and it is possible to prepare a homogeneous and sufficient amount of glass bead sample by uniformly mixing the powder and thoroughly shaking the melt. The purpose is to obtain a melting pot.

[Means for Solving the Problems] The crucible according to the present invention has a main body with a sliding fit on the upper part and a sliding lid on the top, so that the entire crucible is an integrated sealed container.

[Function] In this invention, since the lid is in close contact with the crucible body,
Since the contents do not leak even when the crucible is tilted at any angle or subjected to vigorous motion, a large amount of powder sample can be thoroughly mixed and the melt can be vigorously shaken.

[Embodiment] FIG. 1 is a cross section showing an embodiment of the present invention, in which 3 is a crucible body, 4 is an external bottom surface of the crucible body, 5 is an internal bottom surface of the crucible body, and 6 is a crucible lid.

7 forms a smoothly polished concave shape with a sliding surface on the crucible body side provided on the flange l on the upper part of the crucible body.

Reference numeral 8 denotes a convex sliding surface on the crucible lid side provided in M6, which is smoothly polished so as to come into close contact with the sliding surface 7 on the main body side.

In this example, the crucible body has an outer edge diameter of φ65 mm at the upper flange l, and an outer edge diameter of φ55 mm at the sliding surface 7.
mm, the inner edge diameter was 44 mm, the diameter of the inner bottom surface 5 was 34 mm, the radius R of the sliding surface 7.8 was 60 mm, and the height was 21 mm, and the outer diameter of the crucible 46 was 70 mm.

The material of the crucible is platinum mold body 124gr and aE73gr containing 5% gold for both the main body 1M, and the sliding surface 7.8 and the inner bottom surface 5 of the main body are flat. The n degree is 6.3S.

An example in which a glass bead sample was prepared using such a crucible will be described below.

Powder of refractory bricks that have been precisely soaked in the city.
50110gr, melting agent 4 lithium oxalate, ooo
.

Transfer gj to the crucible body 3 and slide the crucible lid 6 together.
, 8, the powders were manually pressed from the top so that they were in close contact, and then they were shaken down and left and right to ensure that both powders were sufficiently mixed, and the powder content did not escape at all.

Next, 50 w/v% solution of sodium iodide and an organic stripping agent were added to this mixed powder, and after leaving it in an electric resistance furnace at 1150°C for 4 minutes, the crucible lid was attached to the main body 3 using a jig. No leakage of the melt was observed, probably because the melt was fixed tightly and vigorously shaken up and down and left and right for 1 minute to homogenize the melt.

After repeating this shaking and mixing operation twice, the crucible was cooled to obtain a glass bead sample in the form of a perfect circular plate. The homogeneity test results of six samples obtained by repeating this experiment are shown in Experimental Example 1 in Table 1, in comparison with samples prepared using a conventional crucible.

This test was conducted in accordance with JISR2216 (1987), and the test materials were Si0□53%, Al2O, 343
% clay refractory brick powder.

Part 1 table In total, each of the above numerical values shows the results of six repeated experiments.

FIG. 2 is a sectional view showing another modified example in which the co-sliding surfaces 7.8 of the crucible body and the crucible lid are flat instead of uneven. It has the same purpose and effect as the pot shown in the figure.

FIG. 3 is a cross-sectional view of another embodiment showing a modification of the crucible lid. The crucible body 3 and the crucible lid 6a have the same shape so that both grooves can be shared, and the amount of glass melted can be increased. Ru. In this example, the outer edge diameter of the flange l is 55 mm, the inner edge diameter is 45 mm, the inner bottom diameter is 34 mm, and the height is 21 m.
It was set as m.

The material of the crucible is a platinum alloy containing 57% gold for both the main body and the lid, and the mass of both is 85 gr. The smoothness of the co-sliding portion 7.8 was set to 6.35.

Using this crucible, the preparation of the glass heat sample was repeated in the same manner as in Experimental Example 1, and no dissipation of the powder during mixing or leakage of the melt during melting was observed. In addition, glass bead samples in the shape of a perfect disk were always obtained. The homogeneity test results of these samples are shown in Experimental Example 2 in Table 1.

As shown in Table 1, in both Experiments 1 and 2, the homogeneity of the glass-vitreous samples was significantly improved compared to when a conventional open crucible was used, and the accuracy and precision of the fluorescent X-ray analysis was greatly improved. did it.

FIG. 4 is a sectional view showing a modification of the embodiment shown in FIG. 3, in which the crucible body 3 and the crucible M6b are slid together at 7°8 as a tab-shaped adhesive surface, which is the same as that shown in FIG. 3. First, it is possible to achieve the effect.

Next, the material of the crucible according to the present invention is stable at high temperatures and does not adhere more strongly than necessary to the co-sliding surfaces even when a load is applied at high temperatures, and is non-wetting with the melt. The disk sample can be easily separated from the crucible due to the difference in shrinkage rate during holding and cooling, and furthermore, it can be easily polished to correct the low F of smoothness of the sliding joint due to repeated use of the crucible. Due to these needs, pure platinum is an inappropriate material, and a platinum alloy containing 4 to 5% gold, or a platinum alloy containing 1 to 5% gold and 1 to 10% rhodium, should be used. It turned out to be desirable.

By the way, in the above description, the present invention has been described for the case where it is used for fluorescent X-ray analysis of refractory bricks, but it goes without saying that it can also be used for preparing test samples of other materials.

[Effects of the Invention] As explained in [2] above, the present invention is capable of preparing a glass bead sample for fluorescent X-ray analysis by using a detailed structure in which a crucible is provided with a lid co-printed with the main body and bonded to form a sealed container. In this method, necessary and sufficient powder mixing MUM and stirring of the melt can be added inside the crucible without any leakage of official substances to the outside, and a large amount of sample can be processed, and a homogeneous sample can be obtained. can be easily obtained.

Therefore, it has the effect of enabling highly accurate and precise fluorescent X-ray analysis.

[Brief explanation of the drawing]

1'fA is a sectional view showing one embodiment of the present invention, FIG. 2 is a sectional view showing another embodiment showing a modification of the article shown in FIG. 1,
FIG. 3 is a cross-sectional view showing still another embodiment of the present invention, FIG. 4 is another embodiment showing a modification of the one in FIG. 3, and FIG. 5 is a PR side view showing a conventional crucible for melting glass beads. It is. In each figure. 3... Crucible body, 6... Crucible lid, 7... Crucible body side sliding surface, 8-... Crucible lid side sliding surface. Representative Patent Attorney Kubo 1) Law Akira +-2 Diagram D +2 Diagram E +-2 Diagram F Diagram

Claims (1)

[Claims] A crucible for melting glass beads, characterized in that the crucible body is provided with a lid that slides together with the crucible body, and the crucible body is overlapped with the crucible body to form a sealed container.