JPS60241943A - Manufacture of metallic grain piece - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to the granulation of copper cathodes and other metals received in plate form.

[Conventional technology]

The most efficient known manufacturing process, at least for copper cathodes (UK patent no. 2021974B owned by the applicant), is such that the size of the resulting granules is such that they can pass through the screens separating the processing areas of the machine. A metal sheet is processed by a graining machine of the type that includes a rotor with at least one force-bearing blade working in conjunction with at least one stationary plate l° to repeatedly chop the material until it becomes finely grained. Including chopping. This manufacturing process is as follows:
It will be noticed that it involves two separate operations called ``11th cut'' and ``river light''. Here, the primary cutting is
Cutting off a cut piece (usually a narrow band) from the leading edge of the board material, and cutting the cut pieces (usually a narrow band) at 1 to allow the resulting granules to pass through the holes of the screen. It involves cutting pieces repeatedly and randomly.

[Problem to be solved by the invention]

We believe that substantial improvements in energy efficiency can be obtained by performing this primary cutting and mastication operations separately;
and found that the harmful heating of the metal being granulated is significantly reduced.

[Failure to solve the problem]

According to the invention, the manufacturing process for granulating metal received in the form of a plate comprises at least one step in which the metal plate is advanced, working in cooperation with a stationary blade over which the metal plate is fed. A first cutting section is cut from its leading edge by a shearing machine comprising a rotor with one blade.
At least one step is carried out in order to carry out the following operations, namely the primary cutting operation and the repeated chopping of the material until the resulting granules are thin enough to pass through the screens separating the processing area.
a second granulator supplying the cut pieces formed in the first operation to at least one granulator of the type comprising a rotor comprising at least one blade working in cooperation with a second granulator; The work consists of the work of kawamei.

Although the basic design of a shearing machine (without a screen) and a granulating machine (with a screen) may be the same, the details of their structure and processing conditions should be optimized for each task. are selected as such. In particular, 1. Blades of shearing machines and granulators are divided along the direction of the rotation axis into divided pieces arranged at different levels around the outer peripheral surface of the rotor in order to reduce the impact load. To further reduce the load, the blade segments of the shearer may be shorter than those of the granulator.

2. The number of cuts per unit time at any point along the axial length of the shear and granulator (this depends on the rotational speed, the number of rotating blades, and although this usually applies only to the granulator) , which is proportional to the number of fixed blades) may be higher in the granulator than in the shearer.

Therefore, under the conditions that the material is not fed at a rate faster than the granulator can process, or the boarding material is fed too slowly, creating metal dust, - The subsequent cutting can be a continuous operation at bt from the beginning to the end of each plate being granulated.

The blade angle and machining interval for the filter grade can be separated into two operations and the optimal values can be selected independently for each.

4. If desired, one shearer can feed a relatively small granulator.

(Also, if it is absolutely necessary, two or more shears can be fed into one relatively large granulator.) 5. If desired, the unproductive longitudinal direction In order to reduce the frequency at which cuts occur, the relatively long pieces formed by the primary cutting are fed to the granulator with their generally aligned directions perpendicular to the granulator blades. The feeding device can be designed to do so.

However, it is possible to feed the material into the granulator directly above it, and since the freely rotating pieces of material tend to be oriented perpendicular to the grade by the action of the blades themselves, this is not usually the case. That is not needed.

Due to these factors, the energy efficiency of this manufacturing process is
Can be meaningfully improved. Furthermore, according to the production method of the present invention, the grain pieces produced from at least the copper cathode are substantially different from the grain pieces produced by a single granulator that supplies plates and processes them into grain pieces. was found to have a high volume density. Although this has not been proven, it is assumed that the high content of relatively uniform fine particles probably contributes to this. The high bulk density provides further energy savings when the pellets are later used as feed to an extrusion process.

The size of the rotary shear can vary depending on the dimensions of the plates to be granulated and the strength of the parts. However, the diameter of the rotor may always be considered to be in the range 0.25 m to 0.5 m. At least for shears in this range, the blade arrangement is such that one cut is made per rotation at any point along the length of the shear (i.e., along the width of the plate). we particularly like.

To facilitate this, when it is necessary or desirable to use very short blade segments, we
at least one of the outer circumferences of at least one of the plurality of plates;
At this point, there is a recess in the blade holder extending over the entire thickness of this plate, into which a blade can be attached with a single screw so that both sides of the blade coincide with both main surfaces of this plate. Furthermore, the adjacent plate that nestles on the main surface of this plate is constructed by stacking multiple plates in the axial direction, which also fit on both sides of the blade, in order to increase the rigidity of the blade installation. We suggest using a rotor.

Adjacent plates may be matched with the blades at other points around the rotor, unless they are the terminal plates, and the adjacent plates may be matched with the blades at other points around the rotor (
If the metal to be cut is sufficiently brittle, a spacer plate may be incompatible with the blade. To maximize the rate of inertia, these plates are preferably solid and substantially circular except for the recess for the blade.

Equivalent monolithic rotors can be used equally effectively, but are somewhat difficult to fabricate.

A similar rotor design may be used in the granulator, but in this case the outer circumference of each plate may be padded to balance it and/or to increase the effective volume between the rotor and... It is desirable to do so.

Depending on the operating speed of the shear, it may be desirable to cool the cutting blade to slow down the cutting edge of the blade. Because the blade is in contact with copper or other metal for a short time during the primary cutting operation, the risk of overheating this metal is relatively small, but not always negligible.

On the other hand, in the granulators used in the Kawamei process, due to the long residence time of the metal, a considerable temperature rise of the metal occurs and cooling is almost always required.

Convection cooling by directing airflow from the soil into the granulator and out through screens and/or by pumping water into channels in the rotor and machine casing avoids overheating of the grain pieces. otherwise, we prefer to use evaporative cooling. This requires introducing into the granulator a suitable amount of at least 1 quart of non-flammable volatile material. The amount should be such that the heat generated during the granulation process plus any heat flowing in from the surroundings is sufficient to evaporate (and sublimate) substantially all volatile substances. In addition, in the case of copper granulation, this amount is such that the evaporation (or sublimation) of the volatiles will cause the temperature of a substantial portion of the copper to be 80°C (desirably) for a significant period of time. The amount must be sufficient to prevent the temperature from rising above 70°C.

There are many volatile substances that are technically satisfactory, but due to soil and economic constraints, the preferred substances are water (free of harmful contaminants), liquid nitrogen, solid 2
carbon oxide, and unseparated liquid air.

Of these, water is readily available, inexpensive, does not require insulated containers for storage, and has a boiling point higher than the working temperature.
This is considered best because it preferentially evaporates when and where the surface temperature of the copper is highest (we will soon see that much, or in some cases all, evaporation occurs individually on the surface of the copper). ).

Supplying deionized or otherwise purified water, e.g. while the pickled cathode is wet with rinsing water, and/or flushing the copper near where the first cut is to be made. It may be fed to the granulator in the form of a liquid (or frozen) film on the surface of the copper, such as by coating.

Alternatively, or if a large amount of volatile material is required, one of the alternatives already mentioned is 1) directly in the granulator and/or in the air stream blown into the granulator. Alternatively, it may be sprayed as a fine mist.

It may be desirable to monitor the copper feed rate and/or the resulting increase in power consumption to the granulator and adjust the water or other volatile material feed rate accordingly.

〔Example〕

Hereinafter, the present invention will be explained in detail by way of examples and with reference to the accompanying drawings.

The manufacturing apparatus shown in FIG. 1 produces bulk copper granules for use after appropriate heat treatment as feed to a continuous extrusion process (conform process) in the friction application of copper wire production. The material itself to be supplied to the manufacturing equipment shown in Figure 1 is as follows:
A copper cathode typically 1 square meter in area and approximately 20 or 22 mm thick (14 day cathode, i.e., under the current density and other conditions for normal copper smelting, a continuous Murayama of 140 mm) The thickness of the cathode grown by

12- After the cathode has been pickled, washed with water and other necessary treatments, it is placed as a stack 1 on the support pedestal 2. At appropriate time intervals, the individual cathodes are removed from the pile by a machine 4% 6 and moved (in a direction perpendicular to the plane of the figure) on a feeding table 50 1 . Rano 4 then moves forward to force the cathode under a gripper which is biased by spring force or otherwise (so that the cathode does not tip or roll back); It is passed through a simple gap and pushed at 1 into a rotary shearing machine 5 which performs the primary cutting. The shearing machine consists of one continuous fixed blade on which the cathode rests at the inlet gap, and one blade divided into short segments distributed around the rotor. It is equipped with This results in a length approximately equal to the length of the splitting blade, a width equal to the thickness of the cathode (which varies considerably from cathode to cathode and even locally), and one revolution of the shearer. (this dimension also varies considerably, especially at the beginning and end of the cathode cut) with a thickness equal to the width of the cathode (if the cathode is thin) .

Once the cathode has been cut off, the ram 4 is retracted to repeat the feed cycle and the shearer 5 is idle until the ram advances again to force the copper fully into it.

On the other hand, the primary cut pieces formed in the shearing machine 5 are processed by at least one granulator 8 of a very conventional design (a Cumberland 67 type granulator with a standard hollow-hole feeder). A packet conveyor 7 (
It immediately falls into a hollow grate 6 which discharges the cut pieces (shown schematically).

The granulator 8 is cooled by blowing through it air at 1 m/s into which deionized water is injected at a rate of 1 liter per kg of copper. This is sufficient to drop the average temperature of the grain particles by about 40°C and keep virtually all the grain fragments below 70°C, where discoloration is virtually prevented, while reducing the heat generated. is sufficient to evaporate all the water and dry the grain pieces.

As usual, the grain pieces are transferred to a hora-ya 9 and a second packet conveyor 10, and the sieved portion is transferred to a container 51 (too-large pieces are returned to the granulator, and fine powder is sorted to be disposed of). ) and the magnetic separation device 11 and are discharged to the receiving tank 12.

The preferred type of shearing machine 5 is a Cumberland 43 granulator with only one fixed blade (which is located directly below the receiving gap of the copper cathode) and distributed in short segments around the rotor. It is manufactured by modifying it so that it has one rotating blade.

Two suitable rotor designs are illustrated.

The relatively common rotor shown in Figures 2-6 is of monolithic construction and forms ten sections, 13 to 22, of the same shape, but each oriented in a unique direction. It is easy to understand that it is a cylinder with most of its surface machined away. Figure 5 is the best one 15 = It looks good, but the five large planes of this section 2 to 27, the section 28 that forms part of the cylindrical surface, and the blade dividing section 2 that are at right angles to each other. a small flat surface 30.5 forming a recess into which is fixed by a pair of screws 66;
limited by 1. Surfaces 25 to 27 are five of the six sides of a symmetrical hexagonal prism (but not a regular hexagonal prism) with two corners (at 64 and 35) at 72° and the other four at 54°. Form.

Sections 16 and 14 are offset from each other by 180° and, when taken together, form a hexagonal prism with two protrusions 36,57 forming a rest for each blade segment 32°6. Rotor sections 15 and 16 are 72 from the first pair
They form a similar pair offset by 6 degrees, and the other 6 pairs are 17 and 18 (144 degrees offset from the first pair), 19 and 20 (216
The same applies to 21 and 22 (288°).

By doing this, cuts are made every 36° (1/10 of a revolution) somewhere along the length of the rotor, but
Adjacent cuts will always be made at times sufficiently far apart.

In FIG. 4, only the section numbers are marked to clarify the order in which the blades make the cuts.

FIG. 7 shows an alternative design in which the rotor is made of multiple axially stacked discs. In the figure, only the three plates are shown, one with a solid line and the two adjacent plates with broken lines.

Apart from the plates at both ends, which are simply circular plates, all the other plates have the same shape, but are all oriented differently.

The plate 68 shown by the solid line is basically a disk, but
Although the center of rotation of the rotor is at 40, it is mounted eccentrically with the center of the disc at position 69. The concavity of the blade 41 is shaped so that the face of the blade 9 is at its maximum radius and has a machining gap in front of the blade. The axial length of each blade segment is substantially the same as the thickness of the plate. The thickness X of the blade is related to the eccentricity of the adjacent plates 43 and 45 (their centers are at 45 and 46, respectively) so that they press down on both end faces of the blade segment.

Therefore, the blade can be firmly attached with only one screw 47. This allows the use of blade segments that are only half the minimum length required for the designs of FIGS. 2-6.

FIG. 7 also shows the stationary blade 48 of the shear and the copper cathode or other plate 49 about to be advanced to the cutting position.

〔Effect of the invention〕

No quantitative results have yet been obtained from the preferred form of production apparatus described so far. The following example, based on preliminary experiments with existing equipment, is given to demonstrate the retrospective nature of the present invention.

Assembled as described and illustrated in the examples of the applicant's European Patent Application Publication No. 94258 (Cumberland Type 37 Granulator with Feed Device Modified to Accept Plate Materials) The granulator has a nominal width of 50
It was used to granulate copper half-cathode plates with a length of 1 m and a thickness varying between 5 and 12 nm. Two fixed blades and six rotor blades were installed, each divided into five 180 mm length staggered segments.

The nominal rotational speed of the rotor was 600 revolutions per minute. The half cathode, with the short side at the beginning, moves at a speed of 100 ryu/s.
It was supplied in such a way that it was sent for 1 second every 20 seconds.

Nominally 6 pieces of grain are 50 pieces using a 65 piece screen.
produced at the rate of kg/hr. Its average effective energy consumption rate was 66 kWh/ton, and the average temperature of the produced grain pieces was 175 °C when working without cooling. A significant portion of this heat is generated in the copper piece that is trapped (more than once) between the rotating blade and the leading edge of the copper cathode that rests on the stationary blade that makes the primary cut. As a result, this heat is considered to reduce the effectiveness of the blade to a greater or lesser extent in the subsequent granulation process. The volume density of this particle is 66 to 3.6 +on/
It was found that the range of m is 19-.

Next, in order to carry out the manufacturing process of the present invention, the screen is removed from the granulator (thereby converting it into a shearer) and by attaching essentially only one blade to the rotor. This granulator was modified. This blade consists of 15 blades installed at different levels around the entire outer circumference of the rotor (with an overlap of about 2 blades in the axial direction).
It was divided into pieces 65 mm long.

This time, the half-cathode was fed continuously at a rate of 3511/'sec, except when needed to introduce the next half-cathode. This primary cutting work averages a length of 65m x
Cut pieces 5 to 12 mm wide x 6 mm thick are produced at an average energy consumption rate of approximately 20 kWh/ton, with a moderate temperature rise, and at a production efficiency of approximately 800 to 9/hr. did.

Half of this cutting section (400 in 9/hr) has the same blade arrangement as in the applicant's European patent application, cited at the beginning of the Effects of the Invention section, without modifications. was fed into a Cumberland Model 67 granulator equipped with a conventional 20-inch granulator. All copper has a nominal grain size of 6Il1m with an energy consumption rate of approximately 30 kWh/ton.
granulated into. (The shearing and granulation operations add up to 50 kWh/ton, which is a 24% reduction). Substantially all of the pellets produced without cooling have a temperature below 90°C, so relatively little cooling is required to prevent surface oxidation. The bulk density of the particles was approximately 43 to 4.5 jan/m2.

In this graining operation, both stationary blades function with comparable efficiency. Furthermore, since the feed point is directly above the rotor, the risk of large pieces of copper getting caught in the gap between the screen and the rotor is greatly reduced.

[Brief explanation of drawings]

1 is a schematic diagram of an apparatus for carrying out the invention; FIG. 2 is a perspective view of a rotor for a shearing machine suitable for use in carrying out the invention; FIG. 6 is a side view of the four rotors; Figure 4 is a front view of the same rotor, Figures 5 and 6 are cross-sectional views taken along lines ■-■ and IV-IV in Figure 6, with some details omitted for clarity, and Figure 7. also shows generally rigid cooperating stationary blades of other designs of shear rotors suitable for use in practicing the present invention. 5...Shearing machine 11 Granulating machine 32.38.41...Blade dividing piece 48...Fixed blade 49...Copper cathode Patent applicant BIC Nozo Brick Limited Konno Yanie Agent Tadashi Wakabayashi

Claims (1)

Claims: 1. A metal plate is advanced, the metal plate further comprising a rotor having at least one blade working in cooperation with a stationary blade across which the metal plate is fed. a first primary cutting operation in which a cut piece is cut from its leading edge by a shear, and the cut pieces formed in the first operation are so small that the pieces can pass through a screen separating the processing area; a second masticating machine chopped by a granulator of the type comprising a rotor having at least one blade working in cooperation with at least one stationary blade for repeatedly chopping the material until it is fine; a manufacturing process for granulating metal received in the form of plates, characterized in that said shearing machine and said granulation machine are separate and distinct machines; Method for manufacturing chemical fragments. 2. A manufacturing method according to claim 1, characterized in that it comprises using a shearing machine with blade segments shorter than those of the granulator. 6. The manufacturing method according to claim 1 or 2, wherein the number of cuts per unit time in the step is greater when using a granulator than when using a shearing machine. 4. The manufacturing method according to claim 3, wherein the primary cutting operation is continuous. 5. The manufacturing method according to any one of claims 1 to 4, which is distinguished from others by cooling the granulator by evaporation. 6. A shearing machine according to any one of claims 1 to 5, characterized in that the shearing machine has a rotor having substantially one blade made of divided pieces distributed around the outer periphery of the rotor. Production method. Z At least one of the plurality of plates has around its periphery at least one of the blade reservoirs extending over the entire thickness of this plate.
This blade has only one recess in the recess.
An adjacent plate attached by screws and having an end surface substantially flush with the major surface of this plate and also nestled against the major surface of this plate adds further rigidity to the attachment of the blade. According to claims 1 to 5, a shearing machine and a granulating machine are used which have a rotor configured by stacking a plurality of plates in the axial direction, which are also close to the end faces of the blades. The manufacturing method according to any one of the items. 8. The manufacturing method according to any one of claims 1 to 7, characterized in that the copper cathode is granulated. 9. Copper granules, characterized in that they are actually made by the manufacturing process according to any one of the preceding claims and are a direct product of this manufacturing process.