JP2000074814A - Particle shape determination method for minute mineral and its particle size measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten extremely the time required for a shape determination of one sample, thereby obtains particle shape determinations of many samples easily in a short time, and to execute easily the operation of a crusher or a grinder in optimum operation conditions. SOLUTION: This particle shape determination method for a minute mineral (sample) and its particle size measuring apparatus are used for quality determination of particle shapes of minute particles produced in a stone-crushing work or the like, and have a vessel 1 in which the sample is charged as much as a prescribed quantity and a small-sized hole 11 on the lower end part, from which the sample will flow out therefrom smoothly and easily, and a time required for outflow of the sample from the hole 11 is measured and the quality of the particle shapes of the sample is determined by the time. Measurement of the outflow time from the point of time when the outflow of the full sample of the prescribed quantity in the vessel 1 starts to the end of the outflow is executed by a stopwatch or a detector 3 automatically.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for judging the quality of fine granules (crushed sand) produced in the crushed stone industry and the like, and to a granule measuring instrument therefor.

[0002]

2. Description of the Related Art Fine aggregate (sand) used in the production of concrete and the like has recently shifted to mountain sand and sea sand due to the problem of depletion of natural sand. ,
Sea sand has quality problems such as the danger of rusting of steel due to salt content. On the other hand, crushed sand produced by crushing rock is square and has a poor grain shape as compared with natural sand.
The grain shape depends on the type of rock and the operating conditions of the crusher or crusher used in the crushing process.

[0003] The grain shape of the crushed sand used for concrete is an important factor that greatly affects the fluidity of the concrete and the unit water amount. Therefore, Japanese Industrial Standard JIS A50
A standard for crushed sand for concrete is set forth as 04-1980, and a test method for the actual rate of grain shape determination is specified therein. According to this regulation, (1) the sample is sieved while washing thoroughly with water.
A sample that passes through a 5 mm sieve and remains on a 1.2 mm sieve is taken to be in a completely dry state. (2) Calculate the unit volume mass T (kg / l) of the sample by the method specified in JIS A 1104 (test method for unit weight and actual rate of aggregate). (3) Determine the absolute dry specific gravity DD of the sample by the method specified in JIS A 1109 (Test method for specific gravity and water absorption of fine aggregate). (4) The actual rate of the determination of the grain shape of the crushed sand is calculated by the following formula. Grain shape determination actual rate (%) = T / DD × 100 In order to judge the quality of the crushed sand, the above-mentioned grain shape determination actual rate is obtained in accordance with this regulation. It has not become.

[0004]

In order to find the optimum operating conditions of a crusher or a crusher in order to improve the performance ratio of crushed sand for determining the grain shape, a sample for determining the grain shape is prepared under a number of operating conditions, and the grain size is determined. It is necessary to conduct a test of the actual shape determination rate. This requires a great deal of time and manpower, and it is difficult to obtain optimum operating conditions of the crusher or crusher in a short time. The present invention, in order to solve the above problems, in a very short time and easily from samples prepared under a number of operating conditions,
It is an object of the present invention to provide a method for determining the particle shape of fine minerals for finding the optimal operating conditions of a crusher or a crusher, and a particle size measuring device therefor.

[0005]

Means for Solving the Problems The method for judging the grain shape of fine minerals and the grain size measuring instrument according to the present invention are used for judging the quality of the grain shape of fine grains produced in the crushed stone industry and the like. A container 1 in which a predetermined amount is charged, and a small-diameter hole 11 at the lower end of the container 1 so that the sample can flow out easily and smoothly.
1 is characterized in that the time when the sample flows out is measured and the quality of the fine mineral is determined based on the measured time. The measurement of the outflow time from the time when a predetermined amount of all the samples in the container 1 starts flowing out to the time when the outflow ends is measured by a stopwatch or automatically by the detector 3.

[0006] With this configuration, the time required for determining the grain shape of one sample is extremely short, and therefore the determination of the grain shape of many samples can be easily obtained in a short time. Therefore, the operation of the crusher or the crusher under the optimum operating conditions can be easily performed.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a flow sheet diagram showing an embodiment of the present invention, FIG. 2 shows a container for a sample for measuring a particle size of the present invention, (A) is a cross-sectional view thereof, and (B) is a sectional view. FIGS. 3A and 3B are plan views and FIGS. 3A and 3B show an embodiment of the present invention. FIG. 3A shows a sample measuring device, and FIG. 3B shows a particle size measuring device. Referring to FIG. 1, the method for determining a grain shape according to the present invention will be described.
Then, the sample is put into the container 1, the cock 2 is opened from the hole 11 and the sample is allowed to flow down. The flow-down state of the sample is detected by the detector 3, and the flow time is measured. The sample that has passed through the detector 3 is stored in the collection box 5. Container 1 has a truncated inverted conical shape (funnel shape) as shown in FIG.
At the lower part of the main body 11, a hole 11 having a predetermined diameter (a range of a diameter of 10 mm to 15 mm) for discharging a fixed amount of the sample is formed, and a (glass) cock 2 for closing down the flow of the sample is provided. As shown in FIG. 3B, the detector 3 is provided immediately below the cock 2 to detect the presence or absence of the sample flowing down. The detector 3 also has a function of measuring the outflow time of the sample. ing. As shown in FIG. 3A, the weighing device 4 puts a sample in a weighing dish 41 and weighs the mass. The weighed sample is placed in the container 1, and then the determination of the particle shape is performed. The form of the figure is merely an example,
In practice, it is necessary to adjust the shape, material, dimensions, measuring elements, and the like to an optimum mode by appropriately changing them. For example, in this example, the horizontal cross-sectional shape of the container 1 is based on a circle, but may be oval, and the container 1 and the cock 2 are made of glass, but may be made of metal.

[0008]

EXAMPLE First, a sample of granite having a particle size passing through a crushed sand, that is, a 2.5 mm sieve and remaining in a 1.2 mm sieve was measured by a measuring device 4 and then 750 g was transferred to a container 1 having an internal volume of about 1000 CC. Start measurement. The measurement of the outflow time from the container 1 is as follows. When the cock 2 is set to the open position, the sample starts flowing out through the small hole 11 having a predetermined diameter (set to 13 mm in diameter), and at the same time, the detector 3 starts operating and measures time. . The detector 3 uses a transmission type light amount discrimination sensor, and has a timing accuracy of 1/100 second. In this example, a roller mill type pulverizer (manufactured by our company) was operated under eight operating conditions (see Table 1 below), and the outflow time was measured five times for each of the eight samples obtained. This average outflow time was calculated. In addition, apart from this test, the same sample was used and the Japanese Industrial Standard JIS
The actual particle size determination rate is determined in accordance with the rules of A5004,
The correlation with the outflow time according to the present example was examined. The results of these measurements are shown in Table 2 below.

[0009]

[Table 1]

[0010]

[Table 2]

From the results in Table 2 above, it was confirmed that the shorter the outflow time, the higher the JIS-stipulated actual rate and the better the particle size, and only by measuring the outflow time, the optimum operation of the crusher or the crusher was completed in a short time. It turned out that conditions could be found. In this embodiment, the required measurement time (all samples) is about 2 hours and the number of required personnel is one, whereas the required measurement time (all samples) of the performance rate according to JIS is about 26 hours, and the required personnel is Is three people, and the present embodiment can greatly reduce the time.

[0012]

As described above, the present invention is based on the method specified by the JIS standard as a means for finding the operating conditions of a crusher or a crusher such that the actual record rate of the determination of the particle shape of the fine mineral is maximized. If not, it is possible to easily find the optimum operating conditions in a very short time.

In addition, since the determination measuring device according to the present invention has an extremely low manufacturing cost, the utility obtained with its implementation is incalculable.

[Brief description of the drawings]

FIG. 1 is a flow sheet diagram showing an embodiment of the present invention.

FIG. 2 shows a container for a sample for determining a particle shape according to the present invention, and (A)
Is a sectional view, and (B) is a plan view.

FIG. 3 shows an embodiment of the present invention, wherein (A) is a scale,
(B) is a particle size measuring device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container 2 Cock 3 Detector 4 Meter 5 Collection box 11 holes

Claims (4)

[Claims] 1. A method for determining the particle shape of a fine mineral, comprising measuring a time required for a predetermined amount of the fine mineral to flow out of a hole at a lower end of a container, and judging the quality of the particle shape of the fine mineral from the measured time. . 2. The method according to claim 1, wherein the time required for the fine mineral to flow out of the hole at the lower end of the container is automatically measured by a detector. 3. A container 1 for accommodating a fine mineral having a predetermined shape and capacity having a hole 11 having a predetermined diameter at a lower end thereof, and a cock 2 provided immediately below the hole 11 for closing the passage of the fine mineral. And a detector 3 for detecting the presence or absence of the fine mineral. 4. The fine mineral particle shape measuring device according to claim 3, wherein the detector 3 is a transmission type light amount discriminating sensor.