JP2018031779A - Sample preparation method and sample analysis method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method that can correctly identify ore particles even when the ore particles aggregate in powdery ore after floatation, and hence can prepare a sample reflecting a single body separation degree in an actual floatation process.SOLUTION: A method of preparing a sample for mineral analysis including a powdery ore to be analyzed includes: a drying process of drying a powdery ore including a plurality of ore particles obtained by floatation; a cracking process of mixing a resin granular matter into the powdery ore after the drying that contains an aggregate obtained by aggregation of ore particles due to the drying, and stirring the mixture with a mill to crack the aggregate; and a resin embedding process of embedding, into a thermosetting resin, the powdery ore whose ore particles are dispersed by the cracking of the aggregate.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sample preparation method and a sample analysis method.

  Non-ferrous metals such as copper and nickel and noble metals such as gold are industrially extremely important materials. In nature, these metals exist as compounds (hereinafter also referred to as “minerals”) such as oxides and sulfides containing the metal elements. By mining these minerals as ores and through each processing step such as crushing, beneficiation, refining, etc., the quality of the metal element is increased stepwise, for example, a metal having a purity of 99.99% or more can be obtained.

  When the ore to be mined is crushed, it is composed of a plurality of ore particles and becomes a powdered ore having a certain degree of particle size. The ore particles can be divided into ore particles (single ore) composed of one mineral and ore particles (bonded ore) composed of a plurality of minerals. Usually, the ratio (quality) in which the desired metal is contained in the ore is very small, for example, several percent or less. Therefore, in the ore beneficiation treatment, minerals containing the desired metal (useful minerals) and minerals not containing the desired metal (unnecessary minerals) from the ore particles (single ore and combined ore) under the prescribed treatment conditions. And ore and recovering as many useful minerals as possible, ores with a grade of several percent or less need to be made into concentrates with a grade of several tens of percent.

  In the beneficiation process, if the mineral containing the desired metal is present as a single ore, it is easy to separate and recover. Therefore, it is preferable that the ratio of the single ore is large. Therefore, in order to determine and verify the processing conditions in the beneficiation process, for example, it is important to grasp the weight ratio (unit separation degree) of the single ore to the total weight of the single ore and combined ore for each mineral. . Therefore, the ore sampled from the ore before and after the beneficiation process is analyzed, the degree of single segregation of each mineral is evaluated, and this information is fed back to the beneficiation process to determine and verify the treatment projects in the beneficiation process. It has been broken.

  As a method for evaluating the degree of single unit separation of minerals, conventionally, a method has been used in which optical information or the like of minerals is acquired and analyzed by visual observation using an optical microscope. However, since the evaluation of the degree of separation of minerals by the above method takes time and depends on the experience and skill of the observer, accurate evaluation is difficult unless it is an expert observer. was there.

  Therefore, as an analysis method using an optical microscope, a method is known in which an image analysis apparatus is used to identify whether a single ore or a combined ore and to evaluate a single unit separation degree. In recent years, a method of quantitatively analyzing the presence state of minerals using an analyzer specialized in mineral analysis such as MLA (Mineral Liberation Analyzer) has been performed (see, for example, Patent Document 1). . Such an apparatus is an automatic analyzer that can automatically measure and analyze a sample and output information on minerals such as the degree of separation of a single substance.

  In such an analysis, a powdered ore as a sample is embedded in a resin to prepare a resin-embedded sample, and this is polished to form a smooth cross section (polished surface) with exposed ore particles. The polished surface is analyzed.

JP, 2006-050918, A

  By the way, as a typical flotation process, a flotation process is known in which separation and recovery are performed using the wettability of minerals. In this flotation process, powdered ore obtained by pulverizing ore is put into water to form a slurry, and a reagent such as a collecting agent or a foaming agent is added to the slurry. The ore particles (hydrophobic ore) adsorbed in the bubbles generated in the slurry are separated and recovered as concentrate. The obtained concentrate is sent to the next step (for example, smelting).

  The concentrate after flotation is dried to remove moisture before being sent to the next process. However, a plurality of ore particles gather and aggregate during drying. Therefore, in the concentrate after drying, there may be an aggregate in which a plurality of ore particles are aggregated. And when this inventor analyzes the sample sampled from the concentrate after drying with an automatic analyzer, the said apparatus is the aggregate which each ore particle which should be originally identified as one ore particle aggregated one I found the problem of misidentification as particles. In the first place, automatic analyzers and analysis software have been developed and used for the purpose of automatic analysis of pulverized powdered ores, and are intended to expand the range of measurement to aggregates generated by flotation ore as described above. As a result, current devices and software cannot keep up.

  When such misidentification occurs, if there are a plurality of types of minerals contained in the ore particles constituting the aggregate, the aggregate is identified as a particle (bond ore) containing a plurality of minerals. This will greatly affect the beneficiation process. That is, when the ore particle to be identified as one particle is a simple ore, when the corresponding ore particle is part of the aggregate and the corresponding aggregate is identified as one ore particle (bond ore), As the particle size distribution of the ore particles changes, the ore particles, which are simple ores, are identified as minerals constituting the combined ore. If it does so, the particle size distribution of the sample obtained as an analysis result will shift to the coarse grain side, and the unit separation degree in a sample will be calculated lower than the unit separation degree in an actual mineral processing process. That is, the analysis result obtained by the automatic analyzer does not correctly reflect the presence of minerals (especially, the particle size, the degree of simple separation) in the actual beneficiation process. As a result, the corresponding analysis results have low value as information for determining the beneficiation processing conditions or information for verifying the beneficiation processing conditions, and as a result, the beneficiation processing conditions cannot be optimized, and the beneficiation processing conditions cannot be optimized. This greatly affects the recovery rate.

  Note that this problem does not occur if the mineral analysis is performed by an observer using an optical microscope. Even if ore particle aggregates exist in the concentrate after flotation, the observer formed the aggregates by gathering multiple ore particles instead of one ore particle by visual observation. It is because it can be judged that it is a thing.

  On the other hand, quantitative analysis by an automatic analyzer is more accurate than quantitative analysis using an optical microscope, does not require a skilled observation technique, and can obtain analysis results in a short time. Therefore, it is desired to take measures so that the above-described erroneous identification of ore particles does not occur even in the analysis by the automatic analyzer.

  The present invention has been made in view of the above situation, and even when agglomeration occurs in the ore particles after the beneficiation treatment, the ore particles can be correctly identified, and as a result, simple substance separation in the actual beneficiation process It is an object of the present invention to provide a method for producing a sample in which the degree is reflected.

  The present inventor does not divide the aggregates into individual ore particles depending on the image processing capability of the analysis software, but physically breaks up the aggregates of the aggregates to perform individual image processing. The cause of the agglomeration was investigated aiming at making it possible to divide into ore particles. As a result, the reagent added to the slurry adheres around the ore particles during the flotation, and when drying, the corresponding sample functions as a binder, and the concentrate is dried while the particles adhere to each other. As a result, it was found that the ore particles after drying are aggregated.

  It is conceivable to break up the agglomeration of ore particles by applying physical force to the ore particles to break up the agglomeration, but if excessive force is applied to the ore particles, the ore particles are broken up. Then, the particle size distribution / bonding state of the ore particles collapses, and the unit separation degree cannot be evaluated correctly. Therefore, it is necessary to satisfy the following two requirements in the aggregate crushing step. That is, one is to break up the aggregates and disperse the ore particles adhering to each other, and the other is to change the particle size and bonding state of the ore particles without crushing the ore particles during crushing. Do not let it.

  In order to make these requirements compatible in the crushing process, moderate force adjustment is required. Therefore, as a result of intensive studies, the present inventors have found a method for crushing a sample that satisfies these requirements, and have completed the present invention. The present invention for solving the above problems is as follows.

That is, the first aspect of the present invention is:
A method for producing a mineral analysis sample having a powdered ore to be analyzed,
A drying step of drying powdered ore containing a plurality of ore particles obtained by flotation; and
A crushing step of crushing the agglomerates by mixing resin granules into the powdered ore after drying containing agglomerates in which the ore particles are agglomerated by drying, and stirring the mixture in a mill;
There is provided a sample preparation method including a resin embedding step of embedding the powdered ore in which the ore particles are dispersed by pulverization of the aggregate with a thermosetting resin.

According to a second aspect of the present invention, in the sample preparation method of the first aspect,
The resin granules include at least resin beads.

According to a third aspect of the present invention, in the sample preparation method of the second aspect,
In the crushing step, the thermosetting resin powder is added and stirred together with the resin beads.

According to a fourth aspect of the present invention, in the sample preparation method of the second or third aspect,
The resin beads have a specific gravity of 0.5 g / cm ³ or more and 2.2 g / cm ³ or less.

According to a fifth aspect of the present invention, in the sample preparation method according to any one of the second to fourth aspects,
The average particle diameter of the resin beads is 2 mm or more and 8 mm or less.

According to a sixth aspect of the present invention, in the sample preparation method according to any one of the second to fifth aspects,
The resin beads are formed of at least one resin selected from polyethylene resin, polystyrene resin, acrylic resin, vinyl resin, polypropylene resin, polyacetal resin, and polyamide resin.

According to a seventh aspect of the present invention, in the sample preparation method according to any one of the second to sixth aspects,
In the crushing step, the resin beads are added in a range of 0.01 g to 0.4 g with respect to 1 cm ^{3 of the} powdered ore.

According to an eighth aspect of the present invention, in the sample preparation method according to any one of the first to seventh aspects,
The mill is a rocking mill.

According to a ninth aspect of the present invention, in the sample preparation method of the eighth aspect,
In the crushing step, the rocking mill is stirred at a frequency of 30 Hz to 60 Hz and a stirring time of 2 minutes to 30 minutes.

According to a tenth aspect of the present invention, in the sample preparation method according to any one of the first to ninth aspects,
In the crushing step, the mixture is placed in a resin container and stirred.

The eleventh aspect of the present invention is
There is provided a sample analysis method including an analysis step of analyzing a sample obtained by the sample preparation method according to any one of the first to tenth aspects using an automatic analyzer.

The twelfth aspect of the present invention provides
A method for preparing a sample is provided, which includes a crushing step of crushing the agglomerate by adding a non-metallic granular material to a metal powder containing the agglomerate and stirring the mixture with a mill.

According to the present invention, even if agglomeration occurs in the ore particles after the beneficiation treatment, the ore particles can be correctly identified, and as a result, the sample in which the degree of simple substance separation in the actual beneficiation process is reflected. Can be provided.
Moreover, according to this invention, it also becomes possible to disintegrate the aggregate resulting from metal powder other than the ore particle after a beneficiation process.

FIG. 1 is a process diagram for explaining a sample preparation method according to an embodiment of the present invention. FIG. 2 is a schematic perspective view of a sample manufactured by the method according to one embodiment of the present invention. FIG. 3 is an image showing a reflected electron image of the polished surface of the resin-embedded sample according to Example 1. Figure 4 is a diagram showing the values of D ₈₀ at after solution砕前powdery ore. FIG. 5 is an image showing a backscattered electron image of the polished surface of the resin-embedded sample according to Comparative Example 1. FIG. 6 is a photograph showing a state in which the sample in Example 2 was observed with an optical microscope.

Hereinafter, the present invention will be described in detail in the following order based on embodiments shown in the drawings.
1. Sample Preparation Method 1-1 Preparatory Step 1-2 Drying Step 1-3 Crushing Step 1-4 Resin Embedding Step 1-5 Polishing Step 2. Sample analysis method Effects of the present embodiment 4. Modified example

<1. Sample preparation method>
Hereinafter, a sample preparation method according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a process diagram for explaining a sample preparation method according to an embodiment of the present invention. FIG. 2 is a schematic perspective view of a sample manufactured by the method according to one embodiment of the present invention. The sample preparation method of the present embodiment is a method of preparing a resin-embedded sample (hereinafter also simply referred to as a sample) formed by embedding a powdered ore to be analyzed with a resin, and includes a preparation step S10 and drying. It has process S20, crushing process S30, resin embedding process S40, and polishing process S50. Hereinafter, each process is explained in full detail.

(1-1 Preparation Step S10)
First, in preparation process S10, the powdered ore sampled from the concentrate collect | recovered by the flotation process (henceforth the powdered ore after a flotation process) is prepared as an object of mineral analysis. The powdered ore is an aggregate including a plurality of ore particles made of simple or combined ore. Ore particles include various minerals, for example, copper concentrates include chalcopyrite (CuFeS ₂ ), chalcocite (Chalcocite: Cu ₂ S), chalcopyrite (Bornite: Cu ₅ FeS ₄ ), pyrite. It contains minerals such as (Pyrite: FeS ₂ ), gangue (Gangue: silicate mineral, oxide mineral, etc.).

(1-2 Drying step S20)
Since the powdered ore after flotation is attached with water used during flotation, it is necessary to dry them. Therefore, in the drying step S20, the powdered ore after the flotation is dried to remove water adhering to the ore particles. As described above, when the powdered ore after the flotation is dried, a plurality of ore particles gather and aggregate at the time of drying. Therefore, the dried powdered ore (hereinafter also referred to as powdered ore after drying) has an aggregate in which a plurality of ore particles are aggregated. In the present specification, “aggregated” indicates a state in which a plurality of ore particles are attached to each other to form an aggregate.

  The average particle size of the ore particles contained in the powdered ore varies depending on the degree of crushing, the type of mineral, and the like, but has a particle size distribution of, for example, about 10 μm to 200 μm.

  In addition, as a drying method, it can carry out by a well-known method, for example, heat drying and reduced pressure drying are mentioned.

(1-3 Crushing step S30)
The powdered ore after drying contains aggregates. Therefore, when mineral analysis is performed by an automatic analyzer, the aggregate is misidentified as one ore particle and analyzed. (Separation level etc.) may not be reflected correctly. Therefore, in the present embodiment, as the crushing step S30, the dried powdered ore containing aggregates is made of resin, and resin granules having a relatively small specific gravity than the ore particles (for example, resin beads and resin powder, hereinafter And resin beads are exemplified.) And the mixture is stirred with a rocking mill.

  A rocking mill is generally a pulverizer that agitates and pulverizes a substance in a mill container by vibrating the mill container in three dimensions while rotating. However, according to the study by the present inventors, even in a rocking mill that is a pulverizer, the resin beads are added together with the powdered ore into the mill container and agitated, so that the ore particles are not pulverized and crushed. It was found that the aggregate could be crushed. When the resin beads collide with the aggregates during stirring, the aggregates having a weak binding force can be crushed and the ore particles can be dispersed. In addition, since the specific gravity of resin beads is small compared to particles made of zirconia, for example, zirconia particles or the like crush ore particles when colliding with ore particles, whereas resin beads reduce collision energy. Thus, pulverization of the ore particles can be suppressed. Thus, in the rocking mill, the powdered ore after drying in the presence of the predetermined resin beads is agitated, so that the collision energy of the resin beads is moderated, the aggregates are crushed and the ore particles are dispersed. However, the pulverization of the ore particles can be suppressed. That is, the ore particles can be dispersed without greatly changing the particle size of the powdered ore.

  Further, in the present embodiment, in the crushing step S30, the thermosetting used for embedding the powdered ore after pulverization in the resin embedding step described later together with the resin beads in the powdered ore after drying. It is preferable to add and stir the resin powder. This is because the thermosetting resin powder has a smaller specific gravity than the ore particles, and thus functions as a cushioning material when the powdered ore is agitated, and can further suppress the pulverization of the ore particles. That is, when ore powder containing aggregates is crushed with a rocking mill and resin beads, by adding an appropriate amount of a thermosetting resin in powder form to the ore powder, Plays the role of dispersing collision energy (so-called cushion). By doing so, the ore particles are not destroyed by the impact of the resin beads and only the aggregates are crushed.

  Agitation in the rocking mill breaks up the agglomerates and provides a mixture in which the ore particles, resin beads, and thermosetting resin powder are dispersed. Then, by removing the resin beads from this mixture, a mixture of powdered ore without aggregation (hereinafter also referred to as powdered ore after pulverization) and thermosetting resin powder is obtained.

The resin beads preferably have a specific gravity smaller than that of the ore particles from the viewpoint of reducing collision energy and suppressing pulverization of the ore particles. Specifically, it is preferable specific gravity of the resin beads is ^{0.5g / cm 3 ~2.2g / cm 3} . The average particle size of the resin beads is not particularly limited, but is preferably 2 mm to 8 mm.

  As the resin beads, it is preferable to use spherical particles made of a resin having a specific gravity smaller than that of the ore particles, and from at least one resin of polyethylene resin, polystyrene resin, acrylic resin, vinyl resin, polypropylene resin, polyacetal resin and polyamide resin. More preferably it is formed. According to such a resin bead, an appropriate collision energy is obtained at the time of stirring, and the aggregate can be crushed without crushing the ore particles. In addition, as a spherical particle, the particle | grains which consist of glass, a zirconia, etc. can be considered, but since the specific gravity is small and the grinding | pulverization of an ore particle can be suppressed, it is preferable.

The amount of resin beads added is not particularly limited as long as the aggregate can be crushed, but it is 0 with respect to 1 cm ³ of powdered ore from the viewpoint of pulverizing the aggregate while suppressing the pulverization of the ore particles. It is preferable to set it as 0.01 g-0.4 g.

  The frequency and stirring time of the rocking mill are not particularly limited, but for example, the frequency is preferably 30 Hz to 60 Hz, and the stirring time is preferably 2 minutes to 30 minutes. Moreover, from the viewpoint of further suppressing the pulverization of the ore particles, it is preferable to use a resin container formed of a resin having a specific gravity smaller than that of the ore particles as the mill container for stirring the powdered ore.

(1-4 resin embedding process S40)
Although the pulverized powdered ore is subjected to mineral analysis, it is in the form of powder, so it is difficult to analyze the cross section of each ore particle as it is. Therefore, in this embodiment, in the resin embedding step S40, the pulverized powder ore is embedded with a thermosetting resin to form a resin-embedded sample as shown in FIG. In the resin-embedded sample 10, since the powdered ore 1 can be fixed with a thermosetting resin, the resin-embedded sample 10 is polished in a polishing step S50 described later, and the powdered particles 1 are exposed on the cross section (polished surface 10a). It becomes easy to make.

  Specifically, first, a mixture of the pulverized powdered ore 10 obtained in the pulverizing step S30 and the thermosetting resin powder is filled in a molding die, and a known pressurizing device (press device, Pressure forming using a vise etc. to obtain a pellet molded body in which the powdery mixture is solidified.

  In the obtained pellet molded body, the presence state of the mineral in the actual beneficiation process is fixed, but the strength and the like are insufficient for performing the polishing process S50 described later. Therefore, the pellet molded body is placed in a hot embedding apparatus and heated, for example, so that the thermosetting resin is melted and solidified to form the solidified pellet 2. At this time, only the pellet molded body may be melted and solidified, but the outer layer material containing a thermosetting resin may be filled around the pellet molded body and heated while pressing the outer layer material together with the pellet molded body. Thereby, the thermosetting resin contained in each of the pellet molded body and the outer layer material is melted and solidified, and the solidified pellet 2 and the outer layer 3 provided around the solidified pellet 2 are integrally formed. Thereafter, by cooling, a resin-embedded sample 10 having a two-layer structure in which the solidified pellet 2 and the outer layer 3 are formed around it is obtained.

  In the resin-embedded sample 10, the powdered ore 1 is formed into a pellet molded body together with a thermosetting resin, and melted and solidified to cause sedimentation due to the difference in specific gravity of the plurality of ore particles 1 a included in the powdered ore 1. Can be suppressed. Moreover, since the powdered ore 1 is contained only in the solidified pellet 2, the usage-amount of the powdered ore 1 can be reduced.

  In addition, as a thermosetting resin which embeds the powdered ore 1, a phenol resin etc. can be used, for example. A known device may be used as the hot embedding device.

(1-5 Polishing step S50)
The resin-embedded sample 10 after the resin embedding step S40 has a smooth surface (polished surface) in which the surface of the resin-embedded sample 10 is polished by a known grinder in the polishing step S50 and the cross section of the powdered ore 1 to be analyzed is exposed. 10a) is formed.

(Other)
When the obtained resin-embedded sample 10 is analyzed by a scanning electron microscope (SEM) or the like, since the powdered ore 1 is a non-conductor, electrons accumulate in the powdered ore 1 and charge during the analysis. There is a possibility of up. When charge-up occurs, normal SEM observation cannot be performed. Therefore, a conductive material such as carbon may be deposited on the polished surface 10a of the resin-embedded sample 10.

  By passing through the above process, the resin embedding sample 10 with which the mineral presence state in the actual beneficiation process was maintained can be obtained.

<2. Sample analysis method>
Subsequently, mineral analysis is performed using the obtained resin-embedded sample 10. In the present embodiment, the type of mineral contained in the ore is identified (qualitative analysis), and further, the size of the mineral, the content of the desired metal element in the mineral, the bonding state, etc. are quantitatively analyzed. As the analyzer, an automatic analyzer such as MLA (Mineral Liberation Analyzer) or QEMSCAN (Quantitative Evaluation of Minerals by Scanning) is used. This is because an accurate mineral analysis can be performed in a short time.

  Automatic analyzers such as MLA, QEMSCAN, etc. are analyzers specialized in mineral analysis, such as a scanning electron microscope (SEM) with an energy dispersive X-ray spectroscopy (EDS) device. Analysis software dedicated to mineral analysis is built in. According to these devices, measurement and analysis of a sample are automatically performed, and information (type, content, particle size, bonding state, degree of unit separation, etc.) regarding minerals contained in the sample is output in a predetermined format as an analysis result. be able to.

  Specifically, in MLA, first, a reflected electron image of a polished surface of a resin-embedded sample is obtained by SEM, and each of the plurality of ore particles is identified by image analysis of the obtained reflected electron image. Subsequently, an EDS spectrum is acquired for each ore particle by an EDS apparatus. Analyzes the acquired backscattered electron image and EDS spectrum, compares the MLA database with the EDS spectrum, identifies minerals, and obtains quantitative information (content, particle size, bonding state, etc.) regarding minerals Such information can be output as a table, a graph, a mineral mapping image, or the like.

  Specifically, ore particles are identified as follows. First, in the acquired reflected electron image, a portion other than the ore particles, that is, the background is removed by image processing. As a method of removing only the background, a known method may be used. For example, it may be determined whether the background or the ore particle is based on the brightness of the pixels constituting the image.

  The image after the background is removed is recognized as an aggregate of ore particles. Subsequently, an image of the aggregate of ore particles is processed to identify each ore particle. For example, in an aggregate of ore particles, paying attention to differences in brightness, contrast, etc. between the ore particles and the space (gap) between the ore particles, whether or not these satisfy a predetermined judgment criterion (for example, a threshold) To determine whether it can be divided into individual ore particles. By changing this determination criterion, it is also possible to change the determination of whether or not division is possible.

  However, when a resin-embedded sample containing aggregates of ore particles is subjected to image processing, even if the above-described determination standard is changed, the determination standard does not function because the ore particles are attached to each other. As a result, it may not be possible to divide each ore particle unit well, and ore particles may not be correctly identified.

  On the other hand, when the observer identifies the ore particles, the skilled observer determines whether the ore particles are agglomerated aggregates or one ore particle (bonded ore) according to the observation result. And the aggregate is not misidentified as a single particle.

  If the ore particles cannot be correctly identified, the ore particles that should be identified as simple ores (ore particles composed of one mineral), together with ore particles having minerals different from the minerals constituting the simple ores, It is mistakenly identified as one particle, that is, a bond ore (ore particle composed of a plurality of minerals).

  Such misidentification greatly affects the degree of single unit separation to be measured. As described above, the degree of simple substance separation indicates the ratio of simple ore that can be easily separated and selected in the process, and should be an indicator of whether or not useful minerals can be recovered efficiently. It directly affects the recovery rate. Therefore, although it is necessary to correctly grasp the single unit separation degree, in the automatic analyzer, as described above, the image processing capability is not to divide the aggregates of ore particles after flotation into individual ore particle units. Since it does not correspond, the identification of the ore particle contained in the aggregate may not be performed correctly.

  Therefore, by crushing the aggregate of the ore particles generated in the drying step S20 in the crushing step S30, a resin-embedded sample in which the ore particles are not aggregated is obtained, and this sample is subjected to mineral analysis by an automatic analyzer. If used, the ore particles can be correctly identified by normal image processing. Therefore, even if the aggregate of ore particles is contained in the powdered ore dried after flotation, it is possible to correctly grasp the degree of separation of minerals in the beneficiation process.

  The results obtained by the above analysis are fed back to the beneficiation process and used to determine the processing conditions or to verify the selected processing conditions.

<3. Effects of the embodiment>
In the beneficiation process, the unit separation degree for each mineral contained in the ore particles is grasped, and the processing conditions in the beneficiation process are determined or verified. Therefore, it is necessary to evaluate the unit degree of separation for the powdered ore obtained by sampling the ore during the beneficiation process. However, when powdered ore after flotation, which is a typical beneficiation process, is dried, ore particles may aggregate to form aggregates. Such an aggregate should be identified not as a single particle, but as a collection of particles constituting the aggregate. When an automatic analyzer is used, such an aggregate is separated by image processing. Even if an attempt is made to divide into ore particle units, the image processing is not compatible, and thus the aggregate may be erroneously identified as one particle. When such misidentification occurs, the degree of single unit separation of the mineral obtained by analyzing the sample changes. Therefore, in order to maintain the presence state of the mineral at the time of sampling, it is necessary to use the image processing as described above or physically dissolve the aggregation.

  Therefore, in this embodiment, instead of increasing the image processing capability and dividing the aggregate into units of each ore particle, the aggregate is physically solved so that individual ore particles can be recognized by normal image processing. ing. In other words, the dried powdered ore is agitated in the presence of resin beads with a rocking mill so that the resin beads collide with the ore particles, flocculation of the ore particles is avoided as much as possible, and the ore particles are dispersed. I am letting. As a result, even if the dispersed ore particles are resin-embedded and a resin-embedded sample is prepared and subjected to mineral analysis by an automatic analyzer, the ore particles are sufficiently dispersed and disperse on the polished surface. The ore particles can be correctly identified. Therefore, even when powdered ore dried after flotation is analyzed by an automatic analyzer, ore particles can be correctly identified by normal image processing. As a result, it is possible to correctly grasp the degree of separation of minerals when the sample is sampled.

  In addition, although the method of using an ultrasonic wave is also considered as a crushing method of an aggregate, there exists a possibility that an aggregate may remain | survive by this method. In the case of using ultrasonic waves, for example, the powdered ore containing aggregates can be added to a liquid such as ethanol, and the aggregates can be crushed by stirring using an ultrasonic homogenizer. However, in this case, it is necessary to dry the liquid adhering to the powdered ore, and the ore particles may aggregate again during drying. That is, in the method using ultrasonic waves, the aggregates are formed again because they are dried again after crushing, and may remain in the powdered ore. In contrast, in this embodiment, since the rocking mill is used only in the presence of the resin beads, the ore particles are not re-agglomerated as in the method using ultrasonic waves, and the remaining aggregates are suppressed. can do.

  Moreover, in this embodiment, it is preferable to add the powder of a thermosetting resin with predetermined resin beads to the powdered ore after drying, and to stir with a rocking mill. The thermosetting resin powder has a relatively small specific gravity and functions as a cushioning material during stirring. By reducing the collision energy applied to the powdered ore by stirring, the ore particles are crushed while crushing the aggregates. Can be further suppressed.

Further, the resin beads, a specific gravity of ^{0.5g / cm 3 ~2.2g / cm 3} , an average particle diameter of at 2mm or 8mm or less, polyethylene resins, polystyrene resins, acrylic resins, vinyl resins, polypropylene resins, polyacetal resins And a resin bead formed from at least one resin of polyamide resin. According to such resin beads, when agitated with ore particles, it is possible to obtain an appropriate collision energy that prevents the ore particles from being pulverized as much as possible while crushing the aggregates.

<4. Modification>
In the above embodiment, the mineral analysis is performed using an automatic analyzer such as MLA or QEMSCAN. However, the mineral analysis may be performed using an optical microscope. When an optical microscope is used, the polished surface 10a of the resin-embedded sample 10 is observed at a predetermined magnification, and the mineral is visually identified based on optical information (color, gloss, etc.) of the observed mineral. Get quantitative information about minerals. Even in this case, it is not necessary for the observer to determine whether the ore particle is a single ore particle (bond ore) or an aggregate in which a plurality of ore particles are agglomerated, so that the efficiency of analysis can be improved. it can.

  Moreover, in said embodiment, although the resin embedding sample 10 was produced so that the outer layer 3 might be formed in the circumference | surroundings of the solidification pellet 2, without forming the outer layer 3, with the powdered ore 1 (ore particle 1a) You may comprise the resin embedding sample 10 only with the solidification pellet 2 which consists of a material containing a thermosetting resin. Even in this case, the resin-embedded sample 10 reflecting the presence state of the mineral during the actual beneficiation process can be produced.

  In the above embodiment, a rocking mill is used. However, the present invention is not limited to this, and the present invention is applicable as long as it is generally called a mill, that is, a grinder and has a stirring function. One of the major features of the present invention is that the aggregate is crushed while the pulverization is suppressed by what is called a pulverizer.

  Moreover, in said embodiment, the resin bead was used as a resin granular material with relatively small specific gravity rather than an ore particle. On the other hand, instead of or together with the resin beads, the thermosetting resin powder described in the above embodiment may be used. That is, the “resin granular material” in this specification is an expression including resin beads and resin powder.

  Further, non-metallic powder other than the thermosetting resin powder may be used. Non-metallic powder (particularly resin powder) acts as a cushion to suppress crushing of the ore powder particles, while the aggregate can be crushed. As a further effect, when the measurement related to the mineral described above is performed later, the influence on the measurement result is insignificant even if the nonmetallic powder is contained in the sample. That is, it is not necessary to remove the non-metallic powder after the non-metallic powder is added and then stirred to break up the aggregates, thereby significantly improving the work efficiency.

The nonmetallic powder is not particularly limited as long as it is a nonmetallic powder. The particle size and shape of each particle constituting the nonmetallic powder is not particularly limited, but in the present embodiment, for example, the average particle size is preferably 50 to 1000 μm (preferably 50 to 100 μm). Note the average particle size of the non-metallic powder is D ₅₀ of the particle size distribution obtained from laser diffraction scattering method, the average particle diameter of the resin beads millimeter size mentioned above is based on a value measured visually on a scale Is.

  Further, the composition of the non-metallic powder may be, for example, a silicone powder, but considering the balance of “suppressing ore powder particle crushing” and “aggregation of agglomerates”, it is a resin powder. Is preferred. Furthermore, considering the hardness that can improve this balance and the ease of becoming a cushion when used as a powder, it is more preferable to use the thermosetting resin powder mentioned above.

  In the above embodiment, resin beads are used when a rocking mill is used, but other non-metallic beads may be used. This is because non-metallic beads, compared to metallic beads, make it easier to suppress pulverization of the ore powder particles. However, it is preferable that the non-metallic beads are resin beads in terms of balance of “suppressing the crushing of the ore powder particles” and “crushing the aggregate”. More specifically, it is preferable to use resin beads that are softer or equivalent in hardness to the mineral contained in the ore powder (more specifically, the metal constituting the aggregate).

  In the above embodiment, ore particles obtained by flotation are handled. On the other hand, what is not an ore particle but a general metal particle and contains an aggregate may be made into a processing target. In that case, crushing is performed by crushing the agglomerate by adding a non-metallic granular material (for example, glass or silicone), which is broader than the resin granular material, to the metal powder containing the agglomerate and stirring with a mill. You may produce a crushing body by performing a process. In that case, what is necessary is just to select the kind of the said nonmetallic granular material according to the kind of metal in metal powder.

  As mentioned above, although embodiment of this invention has been described, this invention is not limited to the embodiment mentioned above at all, and can be variously modified within the range which does not deviate from the summary of this invention.

  Hereinafter, the present invention will be described based on further detailed examples, but the present invention is not limited to these examples.

Example 1
In this example, as a powdered ore to be analyzed, a powdered copper concentrate obtained by beneficiation treatment of copper ore was prepared and dried. Then, 0.5 cc of the dried powdered copper concentrate was added to the plastic container together with 10 cc of the powdered phenol resin and 8 polyethylene resin beads having a diameter of 2 mm and a weight of 0.01 g as resin beads, The mixture was stirred for 5 minutes at a frequency of 50 Hz using a rocking mill. Subsequently, the polyethylene resin beads were taken out, the obtained mixture was filled in a compression molding metal fitting, and compression molded into a cylindrical shape having a diameter of about 20 mm and a height of about 3 mm using a vise to obtain a pellet molded body. The obtained pellet molded body was placed in a hot embedding apparatus (manufactured by Marumoto Struers) and filled with about 2 g of phenol resin so as to cover the periphery of the pellet molded body, and then the conditions of 180 ° C. and 75 bar And heated for 5 minutes to obtain a cylindrical resin-embedded sample having a diameter of about 25 mm and a height of about 6 mm. The obtained resin-embedded sample was subjected to cross-section polishing with a buffing machine to expose the cross-section of the ore particles, thereby producing a polished surface. Thereafter, carbon deposition was performed on the polished surface.

The prepared resin-embedded sample was placed in an MLA apparatus (manufactured by Japan FEI Co., Ltd.) and subjected to mineral analysis to obtain a backscattered electron (BSE) image on the polished surface. FIG. 3 is an image showing a reflected electron image of the polished surface of the resin-embedded sample according to Example 1. According to FIG. 3, it was confirmed that the ore particles of powdered copper concentrate are uniformly dispersed without agglomeration.
Also, in order to grasp the pulverization of ore particles by crushing when adding resin beads and stirring with a rocking mill, the difference in particle size before and after crushing the dried powdered copper concentrate was evaluated. did. Specifically, the particle size after solution砕前for powdered copper concentrate drying was measured with a particle size distribution meter MLA device, comparing the value of each D _80. As a result, as shown in FIG. 4, no significant change in the value of D ₈₀ after solution砕前was confirmed. That is, it was confirmed that when the powdered copper concentrate was crushed, ore particles were not crushed and the particle size did not change.

(Comparative Example 1)
In Comparative Example 1, the resin-embedded sample was prepared in the same manner as in Example 1 except that the powdered copper concentrate was directly mixed with the powdered phenol resin without being crushed by a rocking mill and then embedded in the resin. Produced. This resin-embedded sample was subjected to mineral analysis using an MLA apparatus in the same manner as in Example 1. FIG. 5 is an image showing a backscattered electron image of the polished surface of the resin-embedded sample according to Comparative Example 1. According to FIG. 5, it was confirmed that an aggregate of ore particles was present.

  As explained above, by stirring the powdered ore after flotation with a rocking mill together with resin beads, the aggregate can be disintegrated and the ore particles can be finely dispersed while minimizing ore particle crushing. Was confirmed.

(Example 2)
First, bakelite powder was added to ore powder A. Thereafter, a mixer (model RM-05, manufactured by Seiwa Giken Co., Ltd.) was used, and the mixture was stirred to break up the aggregates. The container was made of resin and the beads were resin beads. The conditions at that time are shown in the following Table 1 (the same applies to each of Examples and Comparative Examples described later).

Next, what was obtained after stirring (pulverized product) was packed in a metal fitting for compression molding, and compression molded into a cylindrical shape having a diameter of about 20 mm and a height of about 3 mm using a vise, to produce a pellet.
Then, after placing this pellet in a hot embedding apparatus, about 2 g of phenol resin was further added and sealed, heated and pressurized for 5 minutes under the conditions of 180 ° C. and 75 bar, and a cylindrical shape having a diameter of 25 mm and a height of about 6 mm. A thermosetting resin cured product (consolidated piece) was obtained.
Thereafter, the produced consolidated pieces were polished in the order of rough polishing, intermediate polishing, and final polishing to produce a smooth polished surface, thereby producing a 25 mmφ polished piece.

And the polishing piece produced in this way was observed with the optical microscope, and the number of aggregates was measured. FIG. 6 is a photograph showing a state in which the sample in Example 2 was observed with an optical microscope. In this example, the number of aggregates confirmed by observation was evaluated as representing the degree of crushing of the aggregates.
As the evaluation method of the average particle diameter of ore powder agglomerates disintegrated here, was adopted D ₅₀ of the particle size distribution obtained using a MLA previously mentioned average particle size. As a result, the average particle diameter of the ore powder A was found to be 27 μm.
The number and average particle size of the above-mentioned aggregates are shown in Table 2 below (the same applies to Examples and Comparative Examples described later).

(Examples 3 to 4)
In Examples 3-4, the crushing process was performed on the conditions described in Table 1. Other than that was the same as Example 1. As a result, the results shown in Table 2 were obtained. As long as the results are seen, the average particle size is almost the same in each example. That is, in each Example, it turns out that the grinding | pulverization of each particle | grains which comprise the ore powder A has hardly arisen. And it turns out that the number of aggregates can be made into a remarkably low value in that state.

  As a result, in Examples 2 to 4, it was found that the aggregates can be crushed while suppressing the pulverization of the ore particles. Furthermore, it was also found that by pulverizing the aggregates, it is possible to more accurately grasp the particle size distribution and the degree of separation of the ore powder.

DESCRIPTION OF SYMBOLS 1 Powdered ore 1a Ore particle 2 Solidified pellet 3 Outer layer 10 Resin embedding sample 10a Polishing surface

Claims (12)

A method for producing a mineral analysis sample having a powdered ore to be analyzed,
A drying step of drying powdered ore containing a plurality of ore particles obtained by flotation; and
A crushing step of crushing the agglomerates by mixing resin granules into the powdered ore after drying containing agglomerates in which the ore particles are agglomerated by drying, and stirring the mixture in a mill;
A resin embedding step of embedding the powdered ore in which the ore particles are dispersed by pulverization of the aggregate with a thermosetting resin.   The sample preparation method according to claim 1, wherein the resin granular material includes at least resin beads.   The sample preparation method according to claim 2, wherein in the crushing step, the thermosetting resin powder is added and stirred together with the resin beads. The sample preparation method according to claim 2 or 3, wherein the specific gravity of the resin beads is 0.5 g / cm ³ or more and 2.2 g / cm ³ or less.   The sample preparation method of any one of Claims 2-4 whose average particle diameter of the said resin bead is 2 mm or more and 8 mm or less.   The sample preparation according to any one of claims 2 to 5, wherein the resin beads are formed of at least one of a polyethylene resin, a polystyrene resin, an acrylic resin, a vinyl resin, a polypropylene resin, a polyacetal resin, and a polyamide resin. Method. The sample preparation method according to any one of claims 2 to 6, wherein in the crushing step, the resin beads are added in a range of 0.01 g to 0.4 g with respect to 1 cm ^{3 of the} powdered ore. .   The sample preparation method according to claim 1, wherein the mill is a rocking mill.   The sample preparation method according to claim 8, wherein in the crushing step, the rocking mill is stirred with a frequency of 30 Hz to 60 Hz and a stirring time of 2 minutes to 30 minutes.   The sample preparation method according to claim 1, wherein in the crushing step, the mixture is accommodated in a resin container and stirred.   The sample analysis method which has an analysis process which analyzes the sample obtained with the preparation method of any one of Claims 1-10 with an automatic analyzer. The sample preparation method which has the crushing process which stirs with the mill what added the nonmetallic granular material with respect to the metal powder containing an aggregate, and crushes this aggregate.