JP7018805B2 - Method for preparing a sample-embedded resin for analysis - Google Patents

Description

The present invention relates to a method for preparing a sample-embedded resin for analysis by embedding and fixing a minute granular sample to be analyzed in a resin material prior to analysis, and in particular, in a resin material. It proposes a technique for improving the dispersibility of a granular sample.

For example, the element content, particle size distribution, unit separation degree, etc. of a granular sample consisting of ore, slag, sludge, dust, recycled raw materials such as electrical and electronic equipment, and other particles with non-uniform composition and particle size are measured and analyzed. Since the particles constituting the granular sample are very small, it is generally practiced to embed the granular sample in a resin material and fix it to obtain a sample-embedded resin before setting it in an analyzer. ing. As an example of such an analyzer, a mineral analysis system (Minal Liberation Analyzer, MLA) analyzes ore particles based on SEM-EDS, and is particularly used in the field of mineral resources.

In such a sample-embedded resin, in order to improve the analysis accuracy, it is required that the granular sample is sufficiently dispersed in the resin material and has a representative composition without separation and segregation.
Therefore, conventionally, when preparing a sample-embedded resin, a granular sample is first mixed with a liquid resin material, and the resulting mixture is manually stirred or in a container with an ultrasonic stirrer. After sufficient stirring and the like, the mixture was heated in the air to cure the liquid resin material contained therein.

Here, when the granular sample is particularly composed of ore particles, the particle size of the particles is non-uniform and contains various metals and compounds thereof. Therefore, when such a granular sample is to be analyzed. When the liquid resin material is used in the above, there is a difference in the settling rate of each particle of the granular sample that settles in the liquid resin material until the curing of the liquid resin material is completed. This has the problem that after the liquid resin material is cured, the dispersibility of the granular sample in the resin material is lowered, and the separation and segregation of the granular sample in the sample-embedded resin is caused.

To solve this problem, Patent Document 1 describes, "A method for producing a resin-embedded sample in which a granular sample is embedded in a resin, wherein a mixture of the granular sample and a granular resin for pellets is solidified. A method for producing a resin-embedded sample, which comprises a solidification step of obtaining a pellet molded body and a melt-solidification step of melting and solidifying the pellet resin contained in the pellet molded body to obtain a solidified pellet. Is proposed. According to this, "during sample preparation, it is possible to reduce the burden of analysis such as an increase in the number of analysis samples without causing a bias in the existence state of minerals due to the difference in specific gravity of the ore particles contained in the sample. It is possible to provide a resin-embedded sample and a method for producing the same. "

Japanese Unexamined Patent Publication No. 2016-50918

By the way, another factor that lowers the dispersibility of the granular sample in the resin material is the aggregation of particles that can occur in the fine particles of the granular sample. If the granular sample is fixed in the resin material without sufficiently removing the agglomeration of the particles, the analysis accuracy is caused by the analyzer misidentifying the agglomerated particles as a single particle when the granular sample is analyzed by the analyzer. The decline is undeniable.
The method described in Patent Document 1 can prevent a decrease in dispersibility due to a difference in the sedimentation rate of each particle when a liquid resin material is used, but cannot suppress such aggregation of particles. Therefore, it can be said that there is room for further improvement from the viewpoint of improving dispersibility.

An object of the present invention is to deal with such a problem of the prior art, and an object of the present invention is to prepare a sample-embedded resin from a granular sample and a granular resin material, and the purpose thereof is to form granules in the resin material. It is an object of the present invention to provide a method for producing a sample-embedded resin for analysis, which can sufficiently suppress the aggregation of sample particles and improve the dispersibility of the granular sample.

As a result of diligent studies, the inventor decided to use a rotating revolution stirrer for stirring the granular sample and the granular resin material, and by pressurizing and heating the granular sample and the granular resin material after the stirring, the aggregation of the particles is effective. It was found that the dispersibility of the granular sample in the resin material can be effectively improved and a representative composition without separation and segregation can be obtained. This is because the particles of the granular sample and the granular resin material are kneaded with each other by the rotation and revolution stirrer by rotating the container containing the granular sample and the granular resin material while rotating, and adhere to the particle surface of the granular sample. It is considered that the particles of the above are stripped off, but the present invention is not limited to such a theory.

Based on this finding, in the method for producing a sample-embedded resin for analysis of the present invention, a granular sample to be analyzed, which is composed of particles having a non-uniform particle size and contains a plurality of types of simple substances and / or compounds, is embedded in the resin material. A method for producing a sample-embedded resin in which the granular sample is fixed in the resin material. The granular sample is put into a container together with the granular resin material, and the granular sample and the container containing the granular resin material are placed in the container. The granular sample and the granular resin material in the container are stirred by rotating in the rotation direction opposite to the rotation while rotating with the rotation and rotation stirrer, and then the granular sample and the granular resin material in the container are pressurized. The granular resin material is melted and then cured, and the initial stage of stirring by the rotation / revolution stirrer is performed in an air atmosphere, and at least the final stage thereafter is performed in a vacuum atmosphere .

Further, in the method for producing a sample-embedded resin for analysis of the present invention, a granular sample to be analyzed, which is composed of particles having a non-uniform particle size and contains a plurality of types of simple substances and / or compounds, is embedded in a resin material and the resin is prepared. This is a method for producing a sample-embedded resin in which the granular sample is fixed in a material. The granular sample is put into a container together with the granular resin material, and the granular sample and the container containing the granular resin material are rotated and revolved. The granular sample and the granular resin material in the container are stirred by rotating the sample and the granular resin material in the same rotation direction while rotating with a stirrer, and then the granular sample and the granular resin material in the container are pressurized and heated. The granular resin material is melted and then cured, and the initial stage of stirring by the rotation / revolution stirrer is performed in an air atmosphere, and at least the final stage thereafter is performed in a vacuum atmosphere .

The revolution speed during stirring by the rotation / revolution stirrer is preferably 400 rpm to 2000 rpm.

It is effective that the stirring time by the rotation / revolution stirrer is 1 minute to 30 minutes.

In the method for producing the sample-embedded resin for analysis of the present invention, the granular sample and the granular resin material can be pressurized and heated at the same time.
In this case, the pressurization / heating time of the granular sample and the granular resin material is preferably 10 to 20 minutes.

In the method for producing a sample-embedded resin for analysis of the present invention, the pressure applied to the granular sample and the granular resin material when the granular sample and the granular resin material are pressed is preferably 7 MPa to 35 MPa, particularly 20 MPa to 30 MPa. ..
Further, in the method for producing a sample-embedded resin for analysis of the present invention, when the granular sample and the granular resin material are heated, the temperature of the granular sample and the granular resin material is set to 50 ° C to 220 ° C, particularly 100 ° C to 200 ° C. It is preferable to raise it to.

In the method for producing a sample-embedded resin for analysis of the present invention, the particles constituting the granular sample can be used as ore particles.

In the method for producing a sample-embedded resin for analysis of the present invention, a container in which a plurality of containers containing a granular sample and a granular resin material are arranged can be used as the container to be rotated by a rotating revolution stirrer.

According to the method for producing a sample-embedded resin for analysis of the present invention, a container containing a granular sample and a granular resin material is rotated and stirred while rotating with a rotating and revolving stirrer, and then the granular sample and granules in the container are stirred. By pressurizing and heating the resin material to melt and cure the granular resin material, the aggregation of the particles of the granular sample in the resin material is sufficiently suppressed, whereby the dispersibility of the granular sample in the resin material is sufficiently suppressed. Can be improved.

It is a perspective view which shows the state when the container containing the granular sample and the granular resin material is revolved while rotating in one embodiment of the present invention. It is a perspective view which shows the state when the container containing the granular sample and the granular resin material is revolved while rotating in another embodiment. It is a perspective view schematically showing the state of revolving while rotating a container in which a plurality of containers containing a granular sample and a granular resin material are arranged in still another embodiment.

Hereinafter, embodiments of the present invention will be described in detail.
In the method for producing a sample-embedded resin for analysis according to an embodiment of the present invention, a granular sample to be analyzed, which is composed of particles having a non-uniform particle size and contains a plurality of types of simple substances and / or compounds, is embedded in the resin material. In order to prepare a sample-embedded resin in which the granular sample is fixed in the resin material, the granular sample is put into a container together with the granular resin material, and then the granular sample and the container containing the granular resin material are contained. The granular sample and the granular resin material in the container are stirred by rotating the sample in the rotation direction opposite to the rotation or in the same rotation direction as the rotation while rotating with the rotation / rotation stirrer, and then in the container. The granular sample and the granular resin material are pressurized and heated to melt the granular resin material and then cure.

(Granular sample)
The granular sample to be analyzed shall be made into relatively small particles by subjecting ore, slag, sludge, dust, or its recycled raw materials including electrical and electronic equipment to a predetermined treatment. Can be done. Since such a granular sample is usually not intentionally homogenized in composition and particle size, it is composed of many kinds of non-uniform particles having different compositions and different particle sizes.

In particular, when targeting granular samples consisting of ore particles, such ore particles may contain copper ore, which may include, for example, chalcocite, covellite, chalcopyrite, copper ore, enargite, etc. Brochan copper ore and the like may be included. In addition to copper ore, pyrite, magnetite, silicate minerals, molybdenite, gold particles and the like can also be contained. The silicate minerals include orthoclase, albite, plagioclase, muscovite, biotite, quartz and the like.

When targeting a granular sample consisting of slag, the slag itself has a complex composition containing SiO ₂ , CaO, Al ₂ O ₃ , FeO, Fe ₃ O ₄ , etc., and the slag further contains matte particles and metal particles. In some cases.
In the case of a granular sample made of an electric / electronic device, there are particles having various compositions such as a resin part contained in the substrate, a metal part constituting a circuit, and a flame retardant part.
Sludge and dust are unlikely to have a single composition.

The particle size of the particles constituting the granular sample is, for example, in the range of 1 μm to 700 μm, typically 20 μm to 200 μm, and is relatively generally distributed and non-uniform. The particle size that can be measured by the particle size distribution meter may be, for example, 0.243 μm to 2000 μm, but the particle size of the granular sample as described above is unevenly distributed in this range.

(Resin material)
As the resin material for embedding and fixing the above-mentioned granular sample, there are various as long as it can be maintained in the form of granules when it is put into a container and when it is stirred, which will be described later, and can be subsequently cured by pressurization and heating. Those can be used, and examples thereof include phenol resin, epoxy resin, acrylic resin and the like. Of these, phenolic resin is preferable because it does not have a filler.
The particle size of the particles of the granular resin material is, for example, several μm to several hundred μm.

(Method for preparing a resin for implanting a sample for analysis)
In order to prepare a sample-embedded resin for analysis from the above-mentioned granular sample and resin material, first, the granular sample 2 is granulated in a predetermined container 1 such as a bottomed cylinder as illustrated in FIGS. 1 and 2. It is charged together with the resin material 3. In this embodiment, only the granular sample 2 and the granular resin material 3 can be charged into the container 1, and it is not necessary to further charge graphite or the like. This is because, as will be described later, the agglomeration of the particles of the granular sample 2 can be sufficiently effectively removed from the granular resin material 3 by the rotation / revolution stirrer. However, in other embodiments, materials such as graphite other than the granular sample 2 and the granular resin material 3 may be added.

Next, the container 4 containing the granular sample and the granular resin material is set in a predetermined rotation / revolution agitator, and based on the function of the rotation / revolution agitator, the granular sample and the granular sample and as shown by arrows in FIGS. 1 and 2 respectively. The container 4 containing the granular resin material is rotated and revolved at the same time to stir the granular sample 2 and the granular resin material 3 in the container 1. More specifically, the bottom of the bottomed cylindrical container 1 is arranged so as to incline its central axis toward the diagonally downward side, and the container 4 containing the granular sample and the granular resin material is rotated around the central axis as the rotation axis. At the same time, the revolution axis is set so that the rotation axis tilts at a predetermined angle θ at a distance from the container 1, and the container 4 containing the granular sample and the granular resin material is revolved around the revolution axis.

As a result, the particles of the granular sample 2 and the granular resin material 3 are kneaded with each other, and other particles adhering to the surface of the aggregated particles of the granular sample 2 are stripped off. It can be effectively removed. Further, at this time, since the granular sample 2 and the granular resin material 3 are sufficiently mixed, the bias of the granular sample 2 in the container 1 is eliminated. As a result, the dispersibility of the granular sample 2 in the granular resin material 3 in the produced sample-embedded resin can be greatly improved.

In addition to stirring by the planetary rotation mixer, it is possible to perform stirring before or after that, for example, by manual work, but from the viewpoint of reducing work man-hours and work time, it is possible. It is preferable not to perform stirring other than the rotation / revolution stirrer. In many cases, stirring with a rotation / revolution stirrer can sufficiently improve the dispersibility.

The rotation / revolution agitator is not particularly limited as long as it can perform such rotation and revolution of the container 4 containing the granular sample and the granular resin material, and for example, a known one can be used. The rotation and rotation of the rotation / revolution stirrer can be opposite to each other as shown in FIG. 1, or can be in the same rotation direction as shown in FIG. That is, the relative rotation direction of the revolution and the rotation is not particularly limited, and can be appropriately set according to the rotation / revolution agitator to be used, the state of the granular sample 2 or the granular resin material 3, and the like.

Further, as shown in FIG. 3, a container 4a in which a plurality of containers 4 containing a granular sample and a granular resin material are arranged can be rotated and revolved. This container 4a, which may also be called a table depending on the rotation / revolution stirrer, can also be regarded as a container containing a granular sample and a granular resin material. In this case, the container 4a is rotated around the central axis of the container 4a as a rotation axis, the revolution axis is set so that the rotation axis is tilted at a predetermined angle θ, and the container 4a is rotated around the revolution axis. In FIG. 3, four containers 4 containing a granular sample and a granular resin material are arranged around the central axis of the container 4a at equal intervals, but the granular sample and the granular resin material in the container 4a are arranged. The arrangement mode and number of the containers 4 are not limited to this. By rotating and revolving the container 4a in which a plurality of containers 4 containing the granular sample and the granular resin material are arranged in this way, the plurality of granular samples and the granular sample 2 of the container 4 containing the granular resin material are dispersed at one time. Therefore, the work efficiency can be greatly improved.

Here, the revolution speed at the time of stirring by the rotation / revolution stirrer is preferably 400 rpm to 2000 rpm. If the revolution speed is too slow, there is a concern that aggregated grains will be formed, while if the revolution speed is too fast, the grains may wear due to friction. Although it depends on the particle size of the granular sample 2 and the granular resin material 3, the revolution speed is set to be relatively slow under the initial atmospheric atmosphere as described later, and after the granular sample 2 and the granular resin material 3 are mixed to some extent, the subsequent revolution speed is set. In a vacuum atmosphere, it is preferable to set the revolution speed faster than that. From this point of view, it is effective to initially set the revolution speed within the range of 400 rpm to 2000 rpm, and then set the revolution speed within the range of 1000 rpm to 2000 rpm on the premise that the revolution speed is higher than the initial revolution speed.
Further, here, it is preferable that the rotation speed at the time of stirring by the rotation / revolution stirrer is 0.4 to 0.6 times the revolution speed. If the rotation rate is too slow, it is possible that agglutinated particles are present. On the other hand, if the rotation speed is too fast, there is a concern that the particles will wear out and differ from the original particle size.
The above-mentioned revolution speed and rotation speed can be set by the rotation revolution agitator.

The angle θ of the rotation axis during stirring by the rotation / revolution stirrer is preferably 30 ° to 60 °, more preferably 40 ° to 50 °, and the rotation axis is tilted from the revolution axis for stirring. Can be done. If the tilt angle θ of the rotation axis is small, the one with a large specific gravity tends to settle at the bottom of the container, and if the tilt angle θ is large, resin may spill from the container and the required amount of resin may not be filled in the container. There is sex. The inclination angle θ can be appropriately set according to the properties of the material.

By the way, in the stirring by the rotation / revolution stirrer as described above, it is preferable to use the atmosphere around the container 4 containing the granular sample and the granular resin material as a vacuum atmosphere in that the gap between the particles can be reduced.

However, if the vacuum atmosphere is created around the granular sample in the rotating and revolving stirrer and the container 4 containing the granular resin material from the initial stage of stirring, the granular sample 2 existing near the surface of the opening of the container 1 may be scattered. I am concerned. In order to prevent this, it is preferable to perform stirring under the action of gravity as an atmospheric atmosphere in the initial stage of stirring, and then switch to a vacuum atmosphere for further stirring. That is, it is preferable that the initial stage of stirring is an atmospheric atmosphere, and at least the final stage thereafter is a vacuum atmosphere.
Here, the initial stage of stirring can be from the start time of stirring by the rotation / revolution stirrer to the time when 30 seconds to 60 seconds have elapsed. After that, the time for creating a vacuum atmosphere can be 60 seconds to 30 minutes.

The stirring time by the rotation / revolution stirrer is preferably 1 minute to 30 minutes, more preferably 5 minutes to 15 minutes, as the total time when switching from the atmospheric atmosphere to the vacuum atmosphere on the way as described above. Can be done. If the stirring time is short, there is a concern that the dispersion of the granular sample 2 in the granular resin material 3 will be insufficient. On the other hand, if the stirring time is too long, the granular sample 2 in the granular resin material 3 may be insufficiently dispersed. There is a risk of particle destruction due to the collision of the particles with each other.

Then, the granular sample 2 and the granular resin material 3 in the container 1 are pressurized and heated to melt the granular resin material while forming it, and then cure it. At this time, it is necessary to take out the granular sample 2 and the granular resin material 3 from the container 1 in order to pressurize and heat, but it is desirable to introduce the granular sample 2 and the granular resin material 3 into the pressurizing apparatus while maintaining the mixed state as much as possible. Before putting the granular sample 2 and the granular resin material 3 in the container 1 set in the stirrer, a sheet such as polyvinylidene chloride is laid in advance, and the granular sample 2 and the granular resin material 3 are put on the sheet. It may be mixed with a rotation / revolution stirrer. Then, after mixing, it can be wrapped in a sheet of polyvinylidene chloride or the like, taken out, and set in the pressure heating device as it is.

Here, for example, a known hot embedding device can be used. In this case, in general, the pressure and heating of the granular sample 2 and the granular resin material 3 are performed at the same time, and the time from the start to the end of the heating and pressurization is preferably 1 minute to 30 minutes. It is preferably 10 to 20 minutes. If the pressurization / heating time is too long, there is a concern that the particles of the granular sample 2 may settle at different velocities when the granular resin material 3 is melted before it is cured. On the other hand, the pressurization / heating time may occur. If it is too short, the sample may come off during surface polishing.
However, for example, cold forming and heating may be performed in this order or vice versa, and pressurization and heating may be performed separately.

When the granular sample 2 and the granular resin material 3 are pressurized, the pressure applied to the granular sample 2 and the granular resin material 3 is preferably 7 MPa to 35 MPa, and even more preferably 20 MPa to 30 MPa. If the pressing force at this time is too small, the resin material is not sufficiently molded, and there is a concern that the sample-embedded resin cannot be produced or that the sample-embedded resin is destroyed during subsequent handling or analysis. On the other hand, if the pressing force is too large, there is a risk of damaging the particles of the granular sample 2.

When the granular sample 2 and the granular resin material 3 are heated, the temperature of the granular sample 2 and the granular resin material 3 is preferably 50 ° C. to 220 ° C., more preferably 100 ° C. to 200 ° C. If the maximum temperature reached is too low, the granular resin material 3 may not be effectively melted and cured, and if it is too high, the properties of the sample may change.
When raising the temperature of the granular sample 2 and the granular resin material 3, it is desirable to make fine adjustments such as adjusting each time the temperature is raised by 1 ° C. Generally, the temperature rising rate and the cooling rate are changed depending on the type and volume of the granular sample 2 and the granular resin material 3.

In the sample-embedded resin prepared as described above, the particle size distribution of the particles of the granular sample dispersed in the resin material in the sample-embedded resin is almost the same as, that is, almost the same as the particle size distribution of the granular sample before embedding. It is preferable that the same tendency is obtained from the viewpoint of suppressing aggregation of particles.
Then, such a sample-embedded resin can be used for analysis of the element content, particle size distribution, elemental separation degree, etc. of the granular sample using various analyzers. In particular, when the particles constituting the granular sample are ore particles, the sample-embedded resin can be effectively used for analysis by a mineral analysis system (Mineral Liberation Analyzer, MLA).

1 Container 2 Granular sample 3 Granular resin material 4, 4a Container containing granular sample and granular resin material θ Tilt angle of rotation axis with respect to revolution axis

Claims (10)

A granular sample to be analyzed, which is composed of particles having a non-uniform particle size and contains a plurality of types of simple substances and / or compounds, is embedded in a resin material to prepare a sample-embedded resin in which the granular sample is fixed in the resin material. It ’s a method,
The granular sample is put into the container together with the granular resin material, and the container containing the granular sample and the granular resin material is rotated in the direction opposite to the rotation while rotating with a rotation / revolution stirrer. The granular sample and the granular resin material in the container are stirred, and then the granular sample and the granular resin material in the container are pressurized and heated to melt and then cure the granular resin material.
A method for producing a sample-embedded resin for analysis , wherein the initial stage of stirring by the rotation / revolution stirrer is performed in an atmospheric atmosphere, and then at least the final stage is performed in a vacuum atmosphere . A granular sample to be analyzed, which is composed of particles having a non-uniform particle size and contains a plurality of types of simple substances and / or compounds, is embedded in a resin material to prepare a sample-embedded resin in which the granular sample is fixed in the resin material. It ’s a method,
The granular sample is put into the container together with the granular resin material, and the container containing the granular sample and the granular resin material is rotated in the same rotation direction as the rotation while rotating with a rotation / revolution stirrer. The granular sample and the granular resin material are stirred, and then the granular sample and the granular resin material in the container are pressurized and heated to melt and then cure the granular resin material.
A method for producing a sample-embedded resin for analysis , wherein the initial stage of stirring by the rotation / revolution stirrer is performed in an atmospheric atmosphere, and then at least the final stage is performed in a vacuum atmosphere . The method for producing a sample-embedded resin for analysis according to claim 1 or 2, wherein the revolution speed at the time of stirring by a rotation / revolution stirrer is 400 rpm to 2000 rpm. The method for producing a sample-embedded resin for analysis according to any one of claims 1 to 3 , wherein the stirring time by the rotation / revolution stirrer is 1 minute to 30 minutes. The method for producing a sample-embedded resin for analysis according to any one of claims 1 to 4 , wherein the granular sample and the granular resin material are simultaneously pressurized and heated. The method for producing a sample-embedded resin for analysis according to claim 5 , wherein the pressurization / heating time of the granular sample and the granular resin material is 10 to 20 minutes. The preparation of the sample-embedded resin for analysis according to any one of claims 1 to 6 , wherein the pressure applied to the granular sample and the granular resin material when pressurizing the granular sample and the granular resin material is 20 MPa to 30 MPa. Method. The analytical sample-embedded resin according to any one of claims 1 to 7 , wherein the temperature of the granular sample and the granular resin material is raised from 100 ° C. to 200 ° C. when the granular sample and the granular resin material are heated. How to make. The method for producing a sample-embedded resin for analysis according to any one of claims 1 to 8 , wherein the particles constituting the granular sample are ore particles. The analytical sample-embedded resin according to any one of claims 1 to 9 , wherein a container in which a plurality of containers containing a granular sample and a granular resin material are arranged is used as the container to be rotated by a rotation / revolution stirrer. Manufacturing method.

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