JP7298326B2 - Method for preparing samples for mineral analysis - Google Patents

Description

The present invention relates to a method for preparing a sample for mineral analysis, which is a sample used in an automatic analyzer such as an MLA (Mineral Liberation Analyzer), for analyzing granular ore by irradiating it with an electron beam.

Non-ferrous metals such as copper, lead, zinc and nickel and precious metals such as gold and silver are industrially extremely important materials. These metals usually exist as compounds (minerals) such as oxides and sulfides containing the metal elements in nature. Then, such minerals are mined as ores, and through each treatment process such as crushing, beneficiation, smelting, etc., the purity of the metal is increased step by step, and finally, for example, a purity of 99.99 wt% or more is obtained. It can be obtained as a metal (bare metal) having

The ore to be mined is crushed into ore particles having a certain degree of particle size (also referred to as "granular ore"). Ore particles can be divided into ore particles (single ore) composed of one type of mineral and ore particles (bound ore) composed of multiple types of minerals.

Usually, the ratio of the target metal contained in the ore (ore grade) is very small, for example, several percent or less. Therefore, in the ore beneficiation process, minerals containing target metals (useful minerals) and minerals not containing desired metals (unnecessary minerals) are separated from ore particles (single ores and combined ores) under predetermined processing conditions. are separated and selected, and as many useful minerals as possible are recovered, ores with a grade of several percent or less are turned into concentrates with a grade of several tens of percent. This reduces the cost of obtaining the bare metal of the target metal.

In the beneficiation process, if the ore containing the target metal exists as "elementary ore", good separation and recovery efficiency can be expected. Therefore, when determining and verifying processing conditions in the ore dressing process, for example, it is necessary to grasp the weight ratio of single ore to the total weight of single ore and binder ore in granular ore (also referred to as "single separation degree"). is important. Therefore, by analyzing the granular ore sampled as a sample from the ore before and after the beneficiation process, the degree of isolation of each mineral contained in the granular ore is evaluated, and the information is fed back to the beneficiation process to improve the treatment conditions. Determined and verified.

Specifically, as a method of evaluating the degree of isolation of minerals, conventionally, a method of acquiring and analyzing optical information of minerals by visual observation using an optical microscope has been used. However, since the evaluation of the degree of separation of minerals by such a method takes time and depends on the experience and skill of the observer, accurate evaluation is difficult unless the observer is skilled. .

On the other hand, a method has also been developed that enables even an unskilled observer to make an accurate evaluation at a certain level. Specifically, in the analysis method using an optical microscope, MLA (Mineral Liberation Analyzer) and QEMSCAN (Quantitative Evaluation of Minerals), which evaluate the degree of liberation by distinguishing whether it is a single ore or a combined ore by image analysis (by SCANning) or the like is known.

In such a method, a quantitative analysis of the existing state of minerals is performed using an analyzer specialized for mineral analysis. The apparatus is an automatic analyzer capable of automatically measuring and analyzing samples and outputting information about minerals such as degree of liberation.

JP 2016-050919 A

However, even in the evaluation method using such an analyzer, there is a problem that the evaluation accuracy is lowered when the granular ore is in a poor state, that is, when the granular ore is in an agglomerated state. This is because, in an agglomerated state of granular ores, if particles are agglomeration of single ore and binder ore, in image analysis, the aggregated particles as a whole are regarded as one binder ore.

Therefore, it is important to suppress the agglomeration of granular ores. For example, Patent Document 1 discloses that when a sample for mineral analysis is prepared, wet granular ores are dried to cause the granular ores to adhere to each other. A technique characterized by having a binder removing step for removing the binder that is attached to the substrate is disclosed. This method can be said to be an effective technique for suppressing strong agglomeration caused by the binder.

However, if the binder is simply removed, weak agglomeration may remain in the granular ore after drying, and a separate operation is required, for example, using a spatula-shaped jig to apply a fairly strong force to crush the ore. . The crushing operation requires a working time of about 2 to 3 minutes, for example, when crushing about 10 g of granular ore.

The present invention has been proposed in view of such circumstances, and a sample for mineral analysis in which agglomeration of granular ore is efficiently suppressed without necessarily performing an operation of crushing the granular ore after drying. The object is to provide a method that can be produced.

The inventor of the present invention has made intensive studies to solve the above-described problems. As a result, it was found that agglomeration of the granular ore can be suppressed by mixing and agitating the granular ore with a specific particulate material prior to drying the granular ore to be analyzed to form a powder mixture. was completed.

(1) A first aspect of the present invention is a method for preparing a sample for mineral analysis for analyzing a granular ore by irradiating it with an electron beam, comprising: the granular ore in a wet state; A step of mixing and stirring a particle material having a small particle size and capable of obtaining a backscattered electron image different from that of the granular ore to obtain a powder-grain mixture, a step of drying the powder-grain mixture, and a step of drying the powder-grain. A sample for mineral analysis, comprising the steps of mixing a mixture and a thermosetting resin, embedding the powder mixture with the thermosetting resin, and curing the thermosetting resin by heat treatment. It is a manufacturing method of.

(2) A second aspect of the present invention is the method for preparing a sample for mineral analysis according to the first aspect, wherein the particulate material is graphite powder.

(3) A third aspect of the present invention is the method for preparing a sample for mineral analysis according to the first or second aspect, wherein the particle size of the particle material is 1 μm to 40 μm in P80 particle size.

(4) A fourth aspect of the present invention is the method according to any one of the first to third aspects, wherein the binder adhering to the granular ore can be dissolved prior to mixing the granular ore and the particulate material. A method for preparing a sample for mineral analysis, comprising the step of adding an organic solvent and washing.

(5) A fifth aspect of the present invention is that in any one of the first to fourth aspects, when the particle size of the particulate material is in the range of 10 μm to 33 μm, the volume of the granular ore is 7 times A method of making a sample for mineral analysis by mixing a volume of said particulate material from 1 to 22 volumes.

(6) A sixth aspect of the present invention is any one of the first to fourth aspects, when the particle size of the particulate material is in the range of 3 μm to 10 μm, the volume of the granular ore is 12 times A method of making a sample for mineral analysis by mixing a volume of said particulate material from a volume to 17 volumes.

(7) A seventh aspect of the present invention is the preparation of a mineral analysis sample according to any one of the first to sixth aspects, wherein the mineral analysis sample is used for analysis by an automatic ore analyzer (MLA). The method.

According to the present invention, it is possible to efficiently prepare a mineral analysis sample in which aggregation of granular ore is suppressed.

FIG. 4 is a process chart showing the flow of the method for producing a sample for mineral analysis.

Specific embodiments of the present invention will be described in detail below. In addition, the present invention is not limited to the following embodiments, and various modifications are possible without changing the gist of the present invention. In this specification, the notation "X to Y" (X and Y are arbitrary numerical values) means "X or more and Y or less".

≪1. Outline of the present invention>>
A method for preparing a sample for mineral analysis according to the present invention (hereinafter also simply referred to as a “method for preparing a sample”) is a method for preparing a sample for mineral analysis for analyzing granular ores by irradiating electron beams. Specifically, the mineral analysis sample is a sample for analysis by an automatic analyzer such as MLA or QEMSCAN.

Here, automatic analyzers such as MLA, QEMSCAN, etc. are analyzers specialized for mineral analysis, and scanning electron microscopes (EDS: Energy Dispersive X-ray Spectroscopy) attached SEM) incorporates analysis software dedicated to mineral analysis. According to these devices, samples are automatically measured and analyzed, and information on minerals contained in the samples (type, content, particle size, bonding state, degree of separation, etc.) is output in a predetermined format as analysis results. be able to.

Specifically, as the analysis operation, first, a backscattered electron image of the polished surface of the sample is acquired by SEM, and each granular ore is identified by image analysis of the backscattered electron image thus obtained. Subsequently, an EDS spectrum is obtained for each granular ore using an EDS device. The acquired backscattered electron image and EDS spectrum are analyzed, the database of the automatic analyzer is compared with the EDS spectrum to identify the mineral, and quantitative information on the mineral (content, grain size, bonding state, single degree of separation, etc.) can be obtained, and this information can be output as tables, graphs, mapping images of minerals, and the like.

Identification of granular ore by image analysis is performed as follows. First, in the acquired backscattered electron image, the portion other than the granular ore, that is, the background is removed by image processing. As a method for removing only the background, a known method may be used. For example, it is possible to remove only the background by judging whether it is the background or granular ore based on the magnitude of the brightness of the pixels forming the image. When the background is removed in this way, the image becomes recognizable as aggregates of granular ore. Subsequently, the image of the aggregate of granular ores is processed (image processing) to identify individual granular ores.

At this time, if aggregates are present in the granular ore, a plurality of granular ores forming the aggregate may be erroneously recognized as one particle (bound ore) in which minerals are combined. If the granular ore cannot be correctly identified, the ore particles that should be identified as single ore (granular ore composed of one mineral) may It is erroneously identified as a single particle, ie, ore (an ore particle composed of multiple minerals). Such erroneous identification greatly affects the degree of singular separation that is measured. As mentioned above, the degree of liberation indicates the ratio of single ore that can be easily separated and sorted, and should serve as an indicator of whether or not useful minerals can be recovered efficiently. have a direct impact. Therefore, it is necessary to correctly grasp the degree of unit separation.

Therefore, in the sample preparation method according to the present invention, in preparation of a mineral analysis sample used for analysis by the automatic analyzer, prior to drying the wet granular ore, the granular ore and the grain size of the granular ore A particulate material that has a small particle diameter and that gives a backscattered electron image different from that of the granular ore is mixed and stirred.

According to such a method, it is possible to prepare a mineral analysis sample in which agglomeration of ore particles is suppressed. This is because by mixing and agitating the granular ore with the specific particulate material described above, the particulate material intervenes between the individual granular ores to reduce the contact between the granular ores, and thus the wetting of the granular ores. It is considered that even if the granular ore in the state is dried, the aggregation of the granular ore due to drying can be suppressed. Moreover, even if aggregates are partially formed, it is considered that the strong cohesive force can prevent aggregation.

Therefore, according to such a method, erroneous identification can be prevented in image processing, and the accuracy of identification evaluation can be improved. In addition, it does not necessarily require processing such as crushing the granular ore after drying as in the past, and even if crushing is performed separately, it is possible to work with a relatively weak force and a short required time, making it efficient. A sample for mineral analysis can be prepared in

≪2. Each step of the method for preparing samples for mineral analysis>>
FIG. 1 is a process chart showing the flow of the method for preparing a sample for mineral analysis. Specifically, this sample preparation method includes a step S1 of mixing and stirring a wet granular ore and a specific particle material to obtain a powder-grain mixture, a step S2 of drying the obtained powder-grain mixture, and a step S2 of drying the obtained powder-grain mixture. A step S3 of mixing the powder-grain mixture and a thermosetting resin and embedding in the resin, and a step S4 of curing the thermosetting resin by heat treatment to obtain a mineral analysis sample.

[Step of mixing with particulate material]
In step S1, wet granular ore and specific particulate material are mixed and agitated to obtain a powder mixture. Specifically, as the specific particle material, a material having a particle size smaller than that of the granular ore and capable of obtaining a backscattered electron image different from that of the granular ore is used.

Here, wet granular ore means granular ore before being subjected to drying treatment, and examples thereof include wet ore products obtained through flotation treatment. Ores in a wet state after washing and removing binders adhering to granular ores with an organic solvent such as ethanol can also be used.

The granular ore is an aggregate of ore particles composed of single ore or combined ore. In addition, ore particles include various minerals. For example, copper concentrates include chalcopyrite (CuFeS ₂ ), chalcocite (Cu ₂ S), bornite (Cu ₅ FeS ₄ ), pyrite (FeS ₂ ), gangue (silicate minerals, oxide minerals, etc.) and other minerals. Further, the particle size of the granular ore varies depending on the type of minerals contained, etc., but has a particle size distribution of, for example, about 10 μm to 200 μm.

In this sample preparation method, prior to subjecting the granular ore to a drying treatment, the granular ore and the above-described particulate material are mixed and stirred to obtain a powder-grain mixture, thereby performing a subsequent drying treatment. It is possible to suppress the formation of aggregates of granular ores. In addition, even if some aggregates are formed due to the drying treatment in the post-process, it is possible to prevent aggregation with a strong cohesive force, and if necessary, perform a weak crushing treatment to easily remove the aggregates. Able to disaggregate.

Regarding the particulate material, the particle size is smaller than the granular ore. Specifically, the size of the particulate material is preferably about 1/100 to 1/10 of the particle size of the granular ore. Since the particulate material is smaller than the particle size of the granular ore, an excess amount of the particulate material can be added to and mixed with the granular ore, and the particulate mixture can be configured to include the granular ore. As a result, contact between granular ores can be effectively suppressed. Thereby, the formation of aggregates can be effectively suppressed.

Also, the particulate material provides a backscattered electron image different from that of the granular ore. This is because when granular ore is analyzed using an automatic ore analyzer such as MLA, a backscattered electron image of the polished surface of the sample is obtained by SEM and the backscattered electron image is image-analyzed. It means that it cannot be recognized as granular ore. In other words, if the particle material gives a backscattered electron image different from the backscattered electron image of the granular ore, it should be possible to accurately distinguish between the particulate material and the granular ore by image analysis even in a mixed state (state of powder-granule mixture). Therefore, it is possible to prevent the accuracy of identification evaluation from deteriorating due to the particulate material.

In this way, even if the particulate material is mixed with the granular ore, a backscattered electron image of the particulate material different from that of the granular ore is obtained, so image analysis by the automatic ore analyzer is not affected. Also, the density at which the granular ore appears in the image does not affect the results of the analysis, even if an excess amount of particulate material is incorporated as described above.

As the particulate material, an appropriate material combined with the granular ore may be selected while satisfying the above conditions. Examples include particulate materials such as graphite powder, polyethylene, and PTFE (polytetrafluoroethylene). Among them, graphite powder is preferable.

Graphite powder has an appropriate particle size in relation to the granular structure of the object to be analyzed, does not affect the analysis results by image analysis, and is a material that can be obtained relatively easily. Further, by using graphite powder, even when the crushing operation is performed as necessary, sufficient crushing can be performed with a relatively weak force, and the required time is only about several tens of seconds.

Further, since the graphite powder is conductive, it can impart conductivity to the resin when it is embedded in a thermosetting resin, which will be described later. As a result, in the analysis by an automatic ore analyzer such as MLA, charge-up can be prevented without vapor deposition, and appropriate image analysis can be performed.

The particle size of the particulate material should be an appropriate size (particle size smaller than the particle size of the granular ore) in relation to the particle size of the granular ore. It is preferably in the range of about 40 μm, more preferably in the range of about 2 μm to 25 μm, and particularly preferably in the range of about 3 μm to 15 μm.

The mixing and stirring of the granular ore and the particulate material is not particularly limited as long as the particulate mixture is obtained in such a manner that the granular ore is included by the particulate material, and can be carried out by known methods.

Regarding the amount of the particulate material mixed with the granular ore, it is preferable to make it an excess amount (volume) with respect to the amount (volume) of the granular ore as described above, but the particle size of the granular ore, the type and particle size of the particle material can be set as appropriate.

For example, when the particle size of the particulate material used is in the range of 10 μm to 33 μm, it is preferable to mix the particulate material in a volume that is 7 to 22 times the volume of the granular ore. Further, when the particle size of the particulate material used is in the range of 3 μm to 10 μm, it is preferable to mix the particulate material in a volume that is 12 to 17 times the volume of the granular ore. Aggregation can be suppressed more effectively by mixing the particle materials preferably in such a mixing amount.

[Drying process]
In step S2, the powder-grain mixture obtained through step S1 is dried. As mentioned above, the granular ore to be analyzed, which constitutes the grain mixture, is in the wet state. The wet powder mixture is dried prior to being embedded in resin as an ore analysis sample by an automatic ore analyzer.

In this sample preparation method, as described above, the granular ore and the particulate material are mixed and agitated to obtain the powder-grain mixture. It's becoming By subjecting the powder-grain mixture in such a state to a drying treatment, it is possible to effectively suppress the occurrence of agglomeration of the granular ores due to drying. In addition, even if agglomerates are partially formed, agglomeration can be prevented with a strong cohesive force, so that the agglomeration can be easily broken by performing a weak pulverizing treatment as necessary. Furthermore, even if agglomerates are partially formed, the particle material contained in the powder mixture collides with the agglomerates during the drying process, causing a crushing action to break the agglomerated state. .

The drying method is not particularly limited as long as it can remove moisture (liquid component) adhering to the granular ore. For example, it may be allowed to stand in the air for natural drying, or it may be air-dried by positively blowing air of a predetermined amount.

[Step of embedding with thermosetting resin]
In step S3, the powder-grain mixture after drying is mixed with a thermosetting resin, and the powder-grain mixture is embedded in the thermosetting resin. A sample of the powder-grain mixture after drying is subjected to mineral analysis, but since it is in the form of powder, it is difficult to analyze its cross section as it is. Therefore, by embedding the dried powder-grain mixture sample in resin, the powder-grain sample is fixed in the resin. This makes it easier to expose the cross-section of the sample by subsequent polishing.

A thermosetting resin (hot resin) is preferably used as the resin for embedding the sample of the powder-grain mixture. By embedding and fixing the powder-grain mixture with a thermosetting resin, cutting processing becomes unnecessary when the mixture is used for analysis, and good analysis can be performed only by polishing the cross section to expose it. In addition, in the case of a room-temperature-curing resin (cold resin), there is a possibility that the mixture cannot be properly mixed due to insufficient permeation between the powder and grain mixtures.

Specifically, known resins can be used as thermosetting resins, and examples thereof include epoxy resins, phenol resins, acrylic resins, and diallyl resins.

The amount of the thermosetting resin to be mixed is not particularly limited, but the resin can be mixed in an amount of about 10 to 20 times the volume of the granular ore.

The powder mixture and the thermosetting resin are mixed by placing the powder mixture in a container such as a vial bottle, adding the thermosetting resin thereto, and mixing for a predetermined time with a mixer such as a rocking mill. be able to.

[Curing process]
In step S4, the resin is hardened by heat-treating the powder-grain mixture embedded in the resin. A sample for mineral analysis is thus obtained. As described above, since the thermosetting resin is used as the embedding resin, the resin can be cured by heat treatment under predetermined conditions.

The heat treatment conditions (curing conditions) are preferably appropriately set according to the type of thermosetting resin used, and the treatment is performed at a heating temperature equal to or higher than the curing temperature of the thermosetting resin. Moreover, the heating time may be set to such a time as to obtain strength capable of withstanding mechanical processing such as polishing of the mineral analysis sample, and about one hour is sufficient at the longest.

When performing the heat treatment, the thermoplastic resin is heated to a temperature below the curing temperature, preferably a lower temperature (for example, a temperature of about 75% of the curing temperature, preferably a temperature of about 70%), and is kept constant at that temperature. It may be held for a period of time and then heated to a heating temperature (set heating temperature) equal to or higher than the curing temperature. In this way, by performing the treatment of holding at a temperature lower than the curing temperature for a certain period of time, the resin can be reliably permeated into the voids of the powder-grain mixture, and a better mineral analysis sample can be obtained.

[Process of polishing]
Although not shown in the process chart of FIG. 1, as a sample for analysis by an automatic analyzer such as MLA, a predetermined surface of the produced mineral analysis sample is polished to expose a cross section of the granular ore. form a smooth surface (polished surface). This polished surface is subjected to analysis by mineral image analysis.

Although the polishing method is not particularly limited, it can be performed by mechanical polishing such as buffing or polishing using abrasive paper.

[Other processes]
Although not shown in the process diagram of FIG. 1, the following processes may be included.

(Step of dissolving and removing binder)
Prior to the step of mixing and agitating the granular ore and the particulate material (step S1), a step of dissolving and removing the binder adhering to the granular ore to be analyzed may be included.

Granular ore is a wet ore product obtained through, for example, a flotation process as described above, and aggregates in which a plurality of ore particles are aggregated may be present in the concentrate. Such a plurality of ore particles adhere to each other through binders present between the ore particles to form an aggregate. The binder is derived from, for example, a reagent used in ore flotation, and examples of the reagent include a collector containing a surfactant and the like, a foaming agent, and the like.

Therefore, from the viewpoint of more effectively suppressing aggregation of the granular ore, an organic solvent capable of dissolving the binder is added and washed prior to mixing and stirring the granular ore and the particulate material. This removes the binder that adheres the ore particles together.

The step of dissolving and removing the binder may be performed at the same time as step S1. That is, when mixing the granular ore weighed in a predetermined amount and the particulate material in a container, an organic solvent such as ethanol is added together and stirred to obtain a mixture (granule mixture) and to combine The material removal operation may also be performed at the same time.

Examples of the organic solvent capable of dissolving the binder include alcohols, and specifically, ethanol can be particularly used.

(Process of crushing)
Moreover, after drying the powder-grain mixture in step S2, a step of pulverizing the dried powder-grain mixture may be provided. By having such a crushing process, it is possible to more effectively prepare a sample for mineral analysis without aggregates.

As described above, in step S1, the granular ore and the particulate material are mixed and agitated to obtain a powder mixture. can prevent the formation of Alternatively, even when aggregates are formed, aggregation via strong cohesive force can be suppressed.

Therefore, by drying the powder-grain mixture in step S2 and then crushing the dried powder-grain mixture, aggregates formed with relatively weak cohesive force can be crushed, A sample for mineral analysis without aggregates can be produced more effectively.

The crushing method is not particularly limited, but crushing with a relatively weak force is sufficient, and the required time is from several tens of seconds to several minutes. For example, it can be carried out by a method using a spatula-shaped jig. When graphite powder is used as the particle material and the binder removal step is performed with ethanol or the like prior to step S1, such crushing operation is almost unnecessary.

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[Regarding sample constituent materials]
Granular ore: flotation product of copper ore (P80 particle size: 170 μm)
Embedding resin: Phenolic thermosetting resin (Bakelite PR50252, manufactured by Sumitomo Bakelite Co., Ltd.)
Particle material: graphite powder (average particle size A: 3 μm, B: 10 μm, C: 33 μm)

[Preparation of sample for mineral analysis]
First, 0.25 cc of granular ore was weighed out with a light spoon, added to 50 cc of ethanol solution, and treated with a commercially available ultrasonic cleaner. Next, graphite powder having a volume shown in Tables 1 to 3 below was prepared, and 0.25 cc of the washed granular ore and the graphite powder were charged into a mixing and stirring device and mixed and stirred. After that, a solid-liquid separation treatment was performed with a membrane filter (for 0.1 μm) to obtain a powder-grain mixture as a solid content.

Next, the obtained powder-grain mixture was dried by natural drying.

Next, the powder-grain mixture after drying was pulverized by lightly tapping with a spatula for about 30 seconds.

Next, the crushed powder mixture is placed in a polypropylene vial, a phenolic thermosetting resin is added, and mixed for 10 minutes with a rocking mill (model number RM-05, manufactured by Seiwa Giken Co., Ltd.). , the powder-grain mixture was embedded in resin.

Next, the resin-embedded powder-grain mixture was heat-treated to harden the resin to obtain a sample for mineral analysis. The heat treatment was performed using a pressurized heating device (model number CitoPress-20, manufactured by Marumoto Struers Co., Ltd.). It was done by holding for 1 minute.

After that, a predetermined surface of the mineral analysis sample was buffed to a mirror finish and subjected to SEM observation.

[evaluation]
Tables 1 to 3 below show the presence or absence of aggregation of granular ore and the presence or absence of aggregation of graphite powder in the sample for mineral analysis prepared as described above, and the analysis when MLA analysis was performed using this sample. It shows the evaluation result of judgment.

Regarding the presence or absence of agglomeration of granular ore, if ore agglomeration (aggregate) is confirmed by SEM observation, it is indicated as "aggregated (x)", and if no ore agglomeration is confirmed, it is indicated as "no agglomeration ( ○)”.

Regarding the presence or absence of agglomeration of the graphite powder, when the SEM observation confirmed that the graphite powders agglomerated each other, “aggregation was observed (yes)”. When slight aggregation was confirmed, it was evaluated as "slight occurrence".

Regarding the determination of MLA analysis, "○" indicates that MLA analysis could be performed properly without vapor deposition without charge-up, and charge-up occurred without vapor deposition and MLA analysis could not be performed. The case was evaluated as "×", and the case where MLA analysis was possible but charge-up occurred in part was evaluated as "Δ". Table 4 is a chart showing the relationship between the particle size of graphite powder and the amount of mixture, based on the determination result of MLA analysis.

As shown in Table 1, in Comparative Example 1 in which the granular ore to be analyzed was not mixed with the graphite powder as the particulate material, aggregation occurred in the granular ore after the drying treatment. An analysis sample in which such agglomeration occurred could reduce the accuracy of identifying whether it is a single ore or a binder ore in image analysis by MLA analysis. In addition, in order to crush the formed aggregates, crushing using a jig such as a spatula is not sufficient, and it is necessary to perform the crushing treatment with a stronger crushing force for a required time of 5 minutes or more. rice field.

On the other hand, in Examples 1 to 15 in which the granular ore to be analyzed was added and mixed with the graphite powder as the particulate material, the granular ore did not agglomerate even after the drying treatment.

Here, since the graphite powder used as the particle material is a conductive material, it can impart conductivity to the resin. For this reason, even when performing MLA analysis, it is possible to perform analysis while preventing charge-up without performing a vapor deposition operation. As can be seen from the results in Tables 1 to 3, although there are dependencies on the particle size and the amount of graphite powder mixed, in the examples in which the granular ore and the graphite powder were mixed to prepare the sample, the vapor deposition operation was not performed. I was able to prevent charge-up and perform an appropriate and clear analysis even if I didn't do it.

Claims (5)

A method for preparing a sample for mineral analysis for analyzing granular ore by irradiating it with an electron beam, comprising:
a step of mixing and stirring the wet granular ore and a particulate material having a smaller particle size than the granular ore and obtaining a backscattered electron image different from that of the granular ore to obtain a powder-grain mixture;
a step of drying the powder-granule mixture;
a step of mixing the dried powder-grain mixture with a thermosetting resin and embedding the powder-grain mixture with the thermosetting resin;
A step of curing the thermosetting resin by heat treatment;
has
the particulate material is graphite powder;
In the step of obtaining the powder-grain mixture,
The granular ore and the particulate material are mixed and stirred so that the particle size of the particulate material is 1/100 to 1/10 of the particle size of the granular ore,
Mixing a volume of the particulate material that is 7 to 22 times the volume of the granular ore
A method for preparing a sample for mineral analysis. 2. The method of preparing a sample for mineral analysis according to claim 1 , wherein the particle size of the particle material is 1 μm to 40 μm in terms of P80 particle size. 3. The mineral analysis sample according to claim 1 or 2, further comprising a step of washing by adding an organic solvent capable of dissolving the binder adhering to the granular ore prior to mixing the granular ore and the particulate material. How to make. When the particle size of the particulate material is in the range of 3 μm to 10 μm,
4. The method of preparing a sample for mineral analysis according to any one of claims 1 to 3 , wherein the particulate material is mixed in a volume that is 12 to 17 times the volume of the granular ore. 5. The method of preparing a mineral analysis sample according to any one of claims 1 to 4, wherein the mineral analysis sample is used for analysis by an automatic ore analyzer (MLA).

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