JPH0765950B2 - Fluorescent X-ray analysis method and apparatus - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for direct X-ray fluorescence analysis of a slurry-like sample, and more particularly to a rotary blade rotated by the sample flowing into a sample holder. Is provided to homogenize the slurry-like sample.

Conventional method Fluorescent X-ray analysis is a composition analysis method widely used in powder metallurgy and other fields. A predetermined sample is wet pulverized with a suitable solvent by a ball mill or the like, and then the solvent is removed to obtain a powder. It is generally applied to an analyzer in a state, or in a state of being mixed and fused with a vitrifying agent and fixed, but it is possible to analyze in a powder state by removing the above solvent,
Since it takes a long time to remove the solvent and dry it, and it is inconvenient that the sample is fixed and analyzed by vitrification, the sample preparation in recent years is analyzed as it is. The method is being tried. However, this method is good when the specific gravities of the components contained in the sample are similar, but when components with different specific gravities are contained, the distribution of the components in the upper and lower phases in the slurry changes over time due to the difference in specific gravities. In other words, when heavy objects descend to the bottom with time, and X-rays are applied from above, the X-ray intensity of the heavy objects decreases, so it seems that the proportion of heavy objects is small. Will inevitably result in inaccurate measurement results. In consideration of this point, the inventor previously developed a method of preventing the sedimentation of a high specific gravity component by continuously circulating a slurry sample in a sample holder with a pump over a separately provided stirring chamber. No. 61-69486), this is not always satisfactory because the slurry is not sufficiently homogenized as compared with the original powder method and vitrification method.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention As described above, in the above method of forcibly circulating the sample through the pump, the sample holder is made thin so that X-rays do not pass therethrough, and the sample flow is made thin. Even if they come close
In portions other than the straight line distance connecting the inlet and outlet in the sample holder, it is inevitable that the flow velocity will decrease and it is difficult to keep the slurry sufficiently uniform.
It turns out that more accurate measurements are not made. An object of the present invention is to provide a method and a device for realizing the homogenization of the slurry in such a sample holder and improving the accuracy of measurement values.

Means for Solving the Problems The inventors have conducted various studies on means for homogenizing the slurry in the sample holder and increasing the measurement accuracy, and as a result, arranged a rotating blade that is self-propelled by the supply flow in the sample holder. Then
It was found that the object can be achieved by conducting analysis while stirring the slurry, and the present invention has been completed based on this finding.

That is, according to the present invention, when a predetermined sample is irradiated with X-rays and the intensity of fluorescent X-rays generated from each element in the sample is measured to analyze the substance, it is constructed in a liquid-tight manner and supplied. Using a sample holder with a cylindrical inner surface containing a self-propelled rotating blade, the slurry sample is continuously supplied and circulated at a flow velocity sufficient to rotate the rotating blade. In the fluorescent X-ray analysis method and the fluorescent X-ray analysis apparatus using the slurry-like sample, which is characterized by forcibly stirring the sample in the sample holder and performing measurement while homogenizing the sample, A sample holder having a sample inflow pipe and a sample outflow pipe is connected to a stirring tank via a pump and a circulation line,
The sample holder is provided with one rotary vane having a cylindrical inner peripheral surface and having a plurality of blades inside thereof, each blade rotating in proximity to the inner peripheral surface, and the sample inflow pipe and the sample outflow pipe are Opened in separate spaces in the sample holder, separated by the plurality of blades, in a direction in which the center line of each tube is deviated from the center of rotation of the rotor and the extension of each center line intersects with each other. The present invention provides a fluorescent X-ray analysis device characterized by the above.

As described above, in the present invention, in order to make the flow of the sample not only the free flow that flows in a fixed direction but also the pushing flow that is always performed in the entire area of the sample holder, the sample holder has a flat circular shallow box shape, that is, a flat box shape. Formed in a box-cylindrical shape, and provided in the vicinity of the inner peripheral surface thereof, a rotary blade composed of a plurality of blades for dividing and partitioning the cylindrical inner space, and
This rotary blade is not driven by the power from the outside, but is a structure in which the fluid flowing from the inlet to the outlet moves the enclosed space, that is, it is self-propelled by the same principle as the internal movable member in the positive displacement motor. The sample flowing from the inflow port into the closed space is agitated by the flow energy in the space and is further homogenized.

Next, an embodiment of the apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a side sectional view of a sample holder which is an essential part of the present invention, and this is shown in FIG. An O-ring 4 and a mylar 5 made of polypropylene film on the upper surface of a flat box cylindrical holder main body 3 having a sample inflow pipe 1 and a sample outflow pipe 2 at approximately the diameter position of the surface,
After the rubber packing 6 and the net 7 are placed and the frame lid 8 is screwed, the lower part of the holder main body 3 is fitted into the base body 9 to be integrally formed. As shown in FIG. The sample in the tank 10 is introduced into the sample inflow pipe 1 of the holder main body 3 through the stirring tank 12 by the pump 11 and the sample outflow pipe 2
It is designed to flow back to the sample storage tank 10 through. The holder main body 3 is formed in the shape of a circular shallow container as described above, and extends substantially tangentially to the inner peripheral surface through the peripheral wall as shown in FIGS. 4 and 5, and the respective center lines extend. A sample inflow pipe 1 and a sample outflow pipe 2 are arranged in a direction intersecting with each other. Inside, each blade tip is close to the inner peripheral surface, and one rotary blade 13 is axially supported on the bottom surface of the center. And is rotatably provided. The rotary blade 13 is composed of 6 blades, and each blade tip is bent at one side at an angle of about 40 to form a receiving surface 14, and the center portion is supported by a needle bearing or the like to be rotated very lightly. It is like this. The internal space of the flat box cylindrical holder is divided into six spaces by the six blades, but the sample inflow pipe 1 and the sample outflow pipe 2 are each divided into separate spaces. Must be opened in. It should be noted that the material of the rotary blade is preferably a material that does not affect the measurement elements and can be used for analysis of many kinds of substances. In this case, it is made of copper.

The present invention improves only the sample holder in the conventional X-ray fluorescence analyzer to a special structure so that a slurry sample can be homogenized and can be measured without causing an error due to uneven distribution of components. The other parts can have the same structure as the conventional one.

Further, in the apparatus of the present invention, the measured value may fluctuate slightly depending on the diameter of the sample inflow pipe, the diameter of the sample outflow pipe, the volume of the sample holder, the viscosity of the sample slurry supplied, etc. Under self-propelled conditions, sufficiently reliable measurements can be obtained.

EFFECTS OF THE INVENTION The present invention continuously feeds and circulates a slurry-like sample into a liquid-tight sample holder as described above, and tangentially connects the inflow sample from the sample inflow pipe 1 to the sample holder in advance. A rotary blade 13 is provided which receives in the direction, and each blade tip is positioned close to the inner peripheral surface of the holder, and this inflowing sample rotates the rotating blade 13, and this rotation causes the sample existing between the adjacent blades to rotate. The structure is such that it is pushed out toward the sample outflow pipe 2 and discharged. Since the closed space is moved as in the positive displacement pump as described above, there is no unevenness in the movement of the sample in the sample holder and it is extremely efficient. Analysis can be performed.

As a result of conducting an experiment with the above-mentioned apparatus, the results similar to those of the powder method and the vitrification method can be obtained as compared with the above-mentioned one in which the rotary blade is not provided in the sample holder and only the inflow / outflow tube is provided.

EXAMPLES Next, the present invention will be described in more detail by way of examples.

Example In the apparatus shown in FIG. 1, the holder mainly has an inner diameter of 43 mm, a depth of 12.5 mm, an inflow pipe and an outflow pipe diameter of 5 mm, and a rotary blade diameter of 40.5 m.
The sample powder containing iron and strontium was analyzed using m and height 10 mm.

The results are shown in the table below.

For comparison, the results obtained by using a sample holder having no rotary blade and the results obtained by the conventional powder method and vitrification method are also shown.

As is clear from this table, the measurement error (σ) according to the method of the present invention is remarkably improved as compared with the case where the rotor is not used, and shows the accuracy comparable to the powder method and the vitrification method.

[Brief description of drawings]

The drawings show the essential parts of the apparatus according to the present invention. Fig. 1 is a side sectional view of a sample holder, Fig. 2 is a side view showing each part of Fig. 1 in an exploded manner, and Fig. 3 is a sample circulation system. 4 is a partial sectional side view of the holder main body, and FIG. 5 is a plan sectional view of the same. In the figure, reference numeral 1 is a sample inflow pipe, 2 is a sample outflow pipe, 3 is a holder main body, 10 is a sample storage tank, 11 is a pump, 12 is a stirring tank, and 13 is a rotary blade.

Claims (2)

[Claims] 1. When a predetermined sample is irradiated with X-rays and the intensity of fluorescent X-rays generated from each element in the sample is measured to analyze a substance, it is constructed in a liquid-tight manner and supplied. Using a sample holder with a cylindrical inner peripheral surface that has a self-propelled rotor impinging on the flow of the sample, a slurry sample is continuously supplied and circulated into the holder at a flow velocity sufficient to rotate the rotor. Fluorescence X characterized in that the sample in the sample holder is forcibly stirred by this and the measurement is performed while homogenizing
Line analysis method. 2. A fluorescent X-ray analyzer using a slurry sample, wherein a sample holder which is liquid-tight and has a sample inflow pipe and a sample outflow pipe is connected to a stirring tank via a pump and a circulation pipe line. In addition, the sample holder is provided with one rotary blade having a cylindrical inner peripheral surface and having a plurality of blades for rotating each blade in proximity to the inner peripheral surface, and the sample inflow tube and the sample outflow tube. Is a separate space defined by the plurality of blades in the sample holder,
An X-ray fluorescence analyzer, characterized in that the center lines of the respective tubes are opened in a direction deviating from the center of rotation of the rotary blades and in a direction in which the extensions of the respective center lines intersect with each other.