JP2024005708A - Oil-removing method of metal cut waste, oil-removing system, and producing method of metal scrap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce oil attached to metal cut waste, and improve uniformity of sizes of metal cut waste.

SOLUTION: An oil-removing method M1 of metal cut waste Mt1 to which oil is attached comprises: a first crushing process S1-1 of roughly crushing metal cut waste Mt1 into a crushed product Mt2; an oil-removing process S1-2 of removing the metal cut waste Mt1 or the oil in crushed product Mt2; a second crushing process S1-3 of further crushing an obtained crushed product Mt2 after the first crushing process S1-1 and the oil-removing process S1-2; a cleaning process S1-4 of cleaning and degreasing a crushed product Mt3 obtained in the second crushing process S1-3 by using superheated steam; and a selecting process S1-5 of selecting the cleaned crushed product Mt3 obtained in the cleaning process S1-4 corresponding to grain size and magnetism.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

Application for application of Article 30, Paragraph 2 of the Patent Act was filed.On May 12, 2020, we were interviewed by the Nikkan Sangyo Shimbun. [Publications, etc.] We applied for the second business restructuring subsidy on July 1, 2021. [Publications, etc.] On August 17, 2021, we applied for the 7th Manufacturing, Commerce, and Service Productivity Improvement Promotion Subsidy (General Type).

The present invention relates to a method for removing oil from metal cutting waste, an oil removal system, and a method for producing metal scrap.

BACKGROUND ART Conventionally, there has been known a method of recycling waste materials such as composite materials and iron-based waste materials by crushing and classifying them (see, for example, Patent Documents 1 and 2).

Patent No. 3369234 Patent No. 4907284

By the way, when recycling metal waste, the waste is first cut into cutting waste. Depending on the recycling application, the cutting waste is required to be of high quality. Specifically, cutting waste is often coated with oil due to oil originating from cutting machines used to cut waste, and there is a desire to reduce the amount of oil attached as much as possible. Furthermore, there is a demand for making the size of cutting chips uniform.

Therefore, an object of the present invention is to reduce the amount of oil adhering to the metal cutting chips and to improve the uniformity of the size of the metal cutting chips.

The first technique disclosed herein is a method for removing oil from metal cutting chips to which oil has adhered, and includes a first crushing step of roughly crushing the metal cutting chips to obtain a crushed product; an oil removal step of removing the oil from the crushed material; a second crushing step of further crushing the obtained crushed material after the first crushing step and the oil removal step; and a second crushing step of further crushing the resulting crushed material. A cleaning step of cleaning the crushed material using superheated steam to degrease it, and a sorting step of sorting the washed crushed material obtained in the cleaning step according to particle size and magnetism. .

In addition, in this specification, "crushed material" refers to crushed metal cutting waste. "Metal cutting waste" is sometimes simply referred to as "cutting waste." "Removing oil" does not only mean completely removing oil, but also includes reducing the amount of oil. "Degreasing" means to completely remove oil or to extremely reduce the amount of oil.

According to the first technique, crushing is performed in two stages: a first crushing step in which the cutting waste is roughly crushed, and a second crushing step in which the crushed material is further crushed, so that the size of the resulting crushed materials is uniform. It gets expensive. Furthermore, since the crushed material is washed in the washing step, the amount of oil adhering to the crushed material can be extremely reduced.

By the way, in order to perform the cleaning process efficiently, it is necessary to optimize the implementation conditions such as the steam temperature and rotation rate (the amount of crushed items that can be washed in a certain amount of time) in the cleaning process, depending on the amount of oil in the crushed items that you want to reduce. I want to become However, the greater the amount of oil adhering to the crushed material supplied to the cleaning process, and the less uniform the size of the crushed materials supplied to the cleaning process, the more difficult it is to optimize the operating conditions. Do you get it.

Here, according to the first technique, the crushed material supplied to the cleaning process through the oil removal process, the first crushing process, and the second crushing process, which are performed before the cleaning process, has an oil adhesion amount. The size is less and the uniformity of the size is high. Therefore, the conditions for implementing the cleaning process can be optimized, the cleaning process can be performed efficiently, and the effectiveness of the cleaning process S can be enhanced. In this way, by performing the oil removal process, first crushing process, and second crushing process before the cleaning process, it is possible to not only simply remove the oil from the cutting chips and improve the size uniformity, but also to improve the cleaning process. It also has a synergistic effect of increasing the effectiveness of the process. As a result, with the first technique, the amount of oil adhering to cutting waste can be extremely reduced.

A second technique is that in the first technique, in the cleaning step, the amount of crushed material supplied to the cleaning step per unit time is controlled to be a constant amount.

According to the second technique, the amount of the crushed material supplied to the cleaning process per unit time is a constant amount, so the optimal implementation conditions according to the supply amount remain unchanged while the cleaning process is executed. It is. Therefore, once the optimal operating conditions according to the supply amount are determined, the cleaning process can be automatically and efficiently executed without changing the operating conditions during the execution of the cleaning process.

A third technique is a manufacturing method for manufacturing metal scrap from metal cutting waste to which oil is attached, which includes a first crushing step of roughly crushing the metal cutting waste to obtain a crushed product; an oil removal step of removing the oil from the crushed material; a second crushing step of further crushing the obtained crushed material after the first crushing step and the oil removal step; and a second crushing step of further crushing the resulting crushed material. A cleaning step in which the crushed material is cleaned and degreased using superheated steam, and the cleaned crushed material obtained in the cleaning step is sorted according to particle size and magnetism to obtain the metal scrap. and a sorting step.

In addition, in this specification, "metal scrap" means the same thing as the said "crushed material" which crushed "metal cutting waste."

According to the third technique, the same effects as the first technique can be achieved, and metal scrap with extremely reduced amount of oil adhesion can be newly produced.

A fourth technique is an oil removal system for carrying out the method for removing oil from metal cutting waste according to the first technique or the method for manufacturing metal scrap according to the third technique, and the system performs the oil removal step. a centrifugal separator that removes the oil from the metal cuttings by centrifugal force; a first crusher that roughly crushes the metal cuttings in the first crushing step; A second crusher that further crushes the , a superheated steam machine that performs the cleaning process, and a sorting system that performs the sorting process.

Note that in this specification, a configuration in which a plurality of devices are combined is referred to as a "system," but a single device having multiple functions may also be referred to as a "system."

The oil removal system according to the fourth technique can perform the method for removing oil from cutting waste according to the second technique. In general, the type of crusher suitable for use differs depending on the size of the object to be crushed, but in the fourth technique, large cutting waste is coarsely crushed by a first crusher, and then crushed by a second crusher. Make it even finer with a machine. Thereby, it is possible to obtain a large amount of crushed materials having a uniform size with a high yield, and damage to the crusher can be suppressed.

A fifth technique is, in the fourth technique, a first tank for storing the crushed material obtained in the second crushing step, and a supply supply for supplying the crushed material from the first tank to the superheated steam machine. means, a control means for controlling the supply amount of the crushed material to be supplied to the superheated steam machine per unit time by the supplying means to a constant amount, and the crushed material obtained in the washing step, or The apparatus further includes a second tank for storing the crushed material sorted in the sorting step.

According to the fifth technique, the crushed material obtained in the second crushing step is stored in the first tank, and a certain amount of crushed material is heated per unit time from the first tank by the control means and the supply means. Since it can be supplied to a steam machine, a system with the same effects as the third technique can be specifically obtained.

By the way, for the superheated steam machine used in the cleaning process, it is better to start it once and then run it non-stop rather than repeatedly starting and stopping it, which reduces damage to the equipment and the time required to start the equipment. Preferable from this point of view.

Here, according to the fifth technique, since a fixed amount of crushed material can be supplied from the first tank to the superheated steam machine per unit time, the superheated steam machine can be operated non-stop for a long time after being operated once. Cheap. As a result, damage to the superheated steam machine can be suppressed, the time required to start up the device can be reduced, and the oil removal method can be carried out efficiently.

As explained above, according to the present invention, it is possible to reduce the amount of oil adhering to metal cutting chips and improve the uniformity of the size of the metal cutting chips.

It is a flowchart which shows the oil removal method of the cutting waste based on 1st Embodiment. FIG. 1 is a schematic diagram showing a portion of an oil removal system. It is a figure corresponding to FIG. 1 of a 2nd embodiment. 3 is a photograph showing the crushed material used in Reference Example 1. It is a photograph showing the crushed material used in Reference Example 2. 3 is a photograph showing the crushed material used in Reference Example 3. It is a photograph showing the crushed material used in Reference Example 4. 5 is a photograph showing the crushed material used in Reference Example 5.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings. The following description of preferred embodiments is merely exemplary in nature and is not intended to limit the invention, its applications or its uses.

(First embodiment)
FIG. 1 shows a method M1 for removing oil from cutting waste Mt1 according to a first embodiment of the present invention. The cutting waste Mt1 is obtained by cutting waste with a cutting machine. The cutting waste Mt1 is a metal member that constitutes waste, and includes, for example, a plate material, a tube material, a side trimming material, a punched material, a punched material, a coil material, a bolt, and the like. Although the metal constituting the cutting waste Mt1 is not limited, examples thereof include nickel, cobalt, titanium, aluminum, iron, and mixtures thereof.

For example, oil originating from a cutting machine or oil originally attached to waste is attached to the cutting waste Mt1. The oil removal method M1 is a method of completely removing the oil from the cutting waste Mt1 to which such oil is attached or extremely reducing the amount of oil attached. The oil removal method M1 includes a first crushing step S1-1, an oil removing step S1-2, a second crushing step S1-3, a cleaning step S1-4, and a sorting step S1-5.

FIG. 2 schematically shows part of an oil removal system for carrying out the oil removal method M1. Note that FIG. 2 is only a conceptual diagram and does not accurately show the configuration, shape, etc. of each device, cutting waste Mt1, etc.

The oil removal system includes a first crusher 1 for performing a first crushing process S1-1, a centrifugal separator 2 for performing an oil removal process S1-2, and a second crushing process S1-3. A superheated steam machine (not shown) for carrying out the cleaning process S1-4, and a sorting system (not shown) for carrying out the sorting process S1-5 are provided.

Hereinafter, each process will be explained, and the apparatus or system used in each process will also be explained.

-First crushing process-
The first crushing step S1-1 is a step of roughly crushing the cutting waste Mt1 into crushed material Mt2. The cutting waste Mt1 that is roughly crushed in this process often retains the shape of the metal member that constituted the waste (hereinafter referred to as "tangible material"). "Roughly crushing" means, for example, breaking the shape of these tangible objects.

The first crushing step S1-1 is performed using the first crusher 1. The first crusher 1 is not limited as long as it roughly crushes the cutting waste Mt1, but a specific example is a coarse powder crusher. For example, as schematically shown in FIG. 2, the first crusher 1 includes a substantially inverted conical storage section 1a into which cutting waste Mt1 is input, and a storage section 1a provided at the bottom of the storage section 1a for storing cutting waste Mt1. It has an arm 1b to be rotated. A plurality of protrusions or blades (not shown) are provided on the inner surface of the housing portion 1a. Due to the rotation of the arm 1b, the cutting waste Mt1 rotating along the inner surface of the housing portion 1a is roughly crushed by hitting the protrusion or the blade, and is made into crushed material Mt2.

-Oil removal process-
The oil removal step S1-2 is a step executed after the first crushing step S1-1 to remove oil from the crushed material Mt2 obtained in the first crushing step S1-1. In the oil removal step S1-2, it is sufficient to reduce the amount of oil in the crushed material Mt2, but from the viewpoint of efficiently executing the cleaning step S1-4, the amount of oil attached should be 2% or less of the total weight of the crushed material Mt2. It is preferable to do so.

The oil removal step S1-2 is performed using a centrifuge 2. The centrifugal separator 2 applies centrifugal force to the crushed material Mt2 obtained in the first crushing step S1-1, and removes attached oil by the centrifugal force. A specific example of the centrifugal separator 2 is an air deoiling machine.

-Second crushing process-
The second crushing step S1-3 is performed after the oil removing step S1-2, and is a step of crushing the crushed material Mt2 obtained in the oil removing step S1-2 even more finely.

The second crushing step S1-3 is performed using the second crusher 3. The second crusher 3 is not limited as long as it can further finely crush the coarsely crushed crushed material Mt2, and a specific example thereof includes a uniaxial crusher. In addition, in FIG. 2, the code|symbol Mt3 refers to the crushed material finely crushed by the 2nd crusher 3.

The oil removal system further includes a first tank (not shown). The crushed material Mt3 obtained in the second crushing step S1-3 is stored in the first tank.

-Cleaning process-
The cleaning step S1-4 is a step of cleaning and degreasing the crushed material Mt3 further crushed in the second crushing step S1-3 using superheated (heated) steam. Cleaning with superheated steam takes place in a high temperature furnace. The temperature of the steam used in the cleaning step S1-4 and the temperature in the high-temperature furnace are preferably determined depending on the type of metal constituting the crushed material Mt3. For example, if the crushed material Mt3 is a superalloy made of nickel or the like, the temperature of the high-temperature furnace should be set at 300°C or higher to 450°C in order to efficiently consume time and energy for cleaning. It is preferable that the temperature of the steam be 350°C or more and 500°C or less. In this case, the amount of oil attached to the crushed material Mt3 obtained in the cleaning step S1-4 is, for example, 0.1% by weight or less with respect to the entire weight of the crushed material Mt3, and the amount of oil attached is extremely small.

The cleaning step S1-4 is performed using a superheated steam machine. The superheated steam machine generates steam superheated to 100°C or higher, applies the steam to the crushed material Mt3, and further dries the crushed material Mt3, thereby removing the remaining oil attached to the crushed material Mt3 along with moisture. do. The superheated steam machine is not limited as long as it is such a machine, but a specific example is a superheated steam type continuous rotary kiln. A superheated steam continuous rotary kiln can generate steam at a high temperature of 900° C. or lower.

Furthermore, in the cleaning step S1-4, the amount of crushed material Mt3 supplied per unit time is controlled to be a constant amount. For this reason, the oil removal system includes a supply means (not shown) for supplying the crushed material Mt3 from the first tank to the superheated steam machine. The supply means is, for example, a screw conveyor. The oil removal system further comprises control means (not shown). The control means is a supply means, and controls the supply amount of the crushed material Mt3 to be supplied to the superheated steam machine per unit time to be a constant amount.

-Sorting process-
The sorting step S1-5 is a step of sorting the washed crushed material Mt3 obtained in the washing step S1-4 according to particle size and magnetism. In detail, the sorting process S1-5 includes a magnetic selection process S1-5-1, a classification process S1-5-2 that follows this, a sampling process S1-5-3 that follows this, and an analysis process S1 that follows this. -5-4.

In the magnetic separation step S1-5-1, a magnetic separator is used to remove magnetic materials such as iron from the crushed material Mt3. The magnetic separator is not particularly limited, and general magnetic separators such as a drum type, counter-electrode drum type, hanging type, and conveyor type can be employed.

In the classification step S1-5-2, a sieve is used to divide the crushed material Mt3 into at least two sizes, and those that do not meet the standard size are removed. The sieving machine is not particularly limited, and examples include a single-stage vibrating sieve machine equipped with mesh materials of one type of pore size, a two-stage vibratory sieve machine equipped with two types of mesh materials of different pore diameters in upper and lower stages, etc. , a general sieving machine can be adopted.

In the sampling step S1-5-3, a certain amount of the crushed material Mt3 is automatically collected at certain time intervals using an automatic sampling machine. The collected crushed material Mt3 is melted using an arc button melter and processed into a button-shaped sample of a certain size. In the analysis step S1-5-4, the components of this sample are analyzed, and the quality of the crushed material Mt3 obtained through the first crushing step S1-1 to the classification step S1-5-2 is evaluated. The analysis in the analysis step S1-5-4 uses, but is not limited to, a fluorescence X-ray analyzer, a plasma emission analyzer, an inductively coupled plasma (ICP) emission spectrometer, etc., for example.

The oil removal system further includes a second tank (not shown) that stores the crushed material Mt3 sorted in the sorting step S1-5.

-Metal scrap manufacturing method-
Although the method M1 for removing oil from cutting waste Mt1 has been described above, metal scraps may be manufactured by a similar process. The metal scrap manufacturing method according to the present embodiment is a manufacturing method for manufacturing metal scrap from oil-adhered cutting waste Mt1, in which the first crushing step S1- 1, an oil removal step S1-2 for removing oil from the metal cutting waste Mt1 or the crushed material Mt2, and after the first crushing step S1-1 and the oil removal step S1-2, the obtained crushed material Mt2 is further crushed. a second crushing step S1-3, a cleaning step S1-4 in which the crushed material Mt3 obtained in the second crushing step S1-3 is cleaned and degreased using superheated steam, and a cleaning step S1- The method includes a sorting step S1-5 in which the washed crushed material Mt3 obtained in step 4 is sorted according to particle size and magnetism to obtain metal scrap.

The oil removal system described above can be used to carry out this method of manufacturing scrap metal.

-Actions and effects of the first embodiment-
According to the present embodiment, the crushed material obtained is crushed in two stages: a first crushing step S1-1 in which the cutting waste Mt1 is roughly crushed, and a second crushing step S1-3 in which the crushed material Mt2 is further crushed. The uniformity of the size of Mt3 becomes high. Furthermore, since the crushed material Mt3 is washed in the cleaning step S1-4, the amount of oil adhering to the crushed material Mt3 can be extremely reduced.

By the way, in order to efficiently perform the cleaning process S1-4, the temperature, steam temperature, and rotation rate of the high-temperature furnace in the cleaning process S1-4 (cleaning is performed at a certain time We would like to optimize the implementation conditions such as the amount of crushed material Mt3 that can be produced. However, the larger the amount of oil attached to the crushed material Mt3 supplied to the cleaning step S1-4, and the lower the uniformity of the size of the crushed material Mt3 supplied to the cleaning step S1-4, the more the implementation conditions are changed. It turned out to be difficult to optimize.

Here, according to the present embodiment, after the oil removal process S1-2, the first crushing process S1-1, and the second crushing process S1-3, which are executed before the cleaning process S1-4, the cleaning process S1 -4, the crushed material Mt3 has a reduced amount of oil adhesion and is highly uniform in size. Therefore, the conditions for implementing the cleaning step S1-4 can be optimized, the cleaning step S1-4 can be performed efficiently, and the effectiveness of the cleaning step S1-4 can be enhanced. In this way, by performing the oil removal step S1-2, the first crushing step S1-1, and the second crushing step S1-3 before the cleaning step S1-4, it is possible to simply remove the oil from the cutting waste Mt1 to Mt3. This not only removes particles and improves size uniformity, but also has a synergistic effect of enhancing the effect of the cleaning step S1-4. As a result, according to this embodiment, the amount of oil adhering to the cutting waste Mt1 can be extremely reduced.

For example, in the oil removal step S1-2, by reducing the amount of oil adhesion to 2% by weight or less based on the total weight of the crushed material Mt2, the oil adhesion on the cleaned crushed material Mt3 obtained after the cleaning step S1-4 is reduced. It has been found that the amount can be reduced to 0.1% by weight or less.

Furthermore, according to the present embodiment, the amount of crushed material Mt3 supplied to the cleaning step S1-4 per unit time is a constant amount, so the optimal implementation conditions according to the amount of supply are the cleaning step S1-4. 4 remains unchanged during execution. Therefore, once the optimum execution conditions according to the supply amount are determined, the cleaning process S1-4 can be automatically and efficiently executed without changing the execution conditions during the execution of the cleaning process S1-4.

Further, according to the oil removal system of this embodiment, the crushed material Mt3 obtained in the second crushing step S1-3 is stored in the first tank, and the control means and the supply means control the crushed material Mt3 from the first tank for a unit time. A certain amount of crushed material Mt3 can be supplied to the superheated steam machine per unit.

By the way, it is better to start the superheated steam machine used in the cleaning step S1-4 non-stop than to repeatedly start and stop it, to prevent damage to the superheated steam machine (for example, heat of the equipment components). This is preferable from the viewpoint of suppressing shrinkage, deterioration, etc.) and reducing the time required to start up the superheated steam machine (for example, 2 to 3 hours). Additionally, running a superheated steam machine non-stop means that energy can be used efficiently to maintain the temperature inside the high-temperature furnace through the combined heat transfer of convection, radiation, and condensation of superheated steam. preferable.

Here, according to the oil removal system of this embodiment, since a certain amount of crushed material Mt3 can be supplied from the first tank to the superheated steam machine per unit time, once the superheated steam machine is operated, it can be operated non-stop. Easy to operate for long periods of time. As a result, damage to the superheated steam machine can be suppressed, the time required for startup is reduced, energy is also saved, and the oil removal method M1 can be executed efficiently.

Moreover, non-stop operation of the superheated steam machine is preferable from the viewpoint of preventing oxidation of the crushed metal Mt3 and from the viewpoint of fire prevention, since the inside of the high-temperature furnace can be maintained in a low oxygen state.

As a specific method of using the oil removal system of this embodiment, for example, a user may start the superheated steam machine, operate it for a long time (for example, 24 hours), and then stop the superheated steam machine. . According to this method, the user does not need to change the setting conditions of the superheated steam machine for a long time when the superheated steam machine is in operation, so there is no need to be particularly concerned about the operating status of the superheated steam machine. It is extremely convenient.

Moreover, according to the method for producing metal scrap of this embodiment, it is possible to newly produce metal scrap with a reduced amount of oil attached. Since such metal scrap has an extremely small amount of oil adhesion, it is very useful as a raw material for producing superalloy ingots by vacuum melting, for example. Generally, in vacuum melting, it is impossible or extremely difficult to adjust the constituent components or remove impurities after melting the raw materials. Since oil generally contains impurities such as carbon and sulfur, if metal scrap with a lot of oil attached is used as a raw material for vacuum melting, the ingot produced by vacuum melting will also contain a lot of impurities. In this regard, since the metal scrap produced by the production method of this embodiment has an extremely small amount of oil, it is suitable for the production of precision instruments, parts, etc., which are produced using high-quality ingots with extremely few impurities as raw materials. Very useful. Examples of such equipment, parts, etc. include medical equipment, mining equipment, automobile engine parts, power generation turbines, aircraft, and the like.

Note that the metal scrap manufactured by the metal scrap manufacturing method of the present embodiment may be other than the raw material for superalloy ingots, and may be, for example, a stainless steel alloy.

Furthermore, the oil removal system of this embodiment allows the oil removal method M1 or the metal scrap manufacturing method to be performed. In general, the type of crusher suitable for use differs depending on the size of the object to be crushed, but in the oil removal system of this embodiment, large cutting waste Mt1 is coarsely crushed by the first crusher 1 and then Then, the second crusher 3 crushes it further. Thereby, a large amount of crushed material Mt3 having a uniform size can be obtained with a high yield, and damage to the second crusher 3 can be suppressed.

(Modified example of the first embodiment)
In the first embodiment, the oil removal step S1-2 is performed after the first crushing step S1-1, but instead of this, the oil removal step S1-2 is performed before the first crushing step S1-1. You can. Further, the first crushing step S1-1 and the oil removal step S1-2 may be performed simultaneously.

In the first embodiment, the crushed material Mt3 sorted in the sorting step S1-5 is stored in the second tank, but instead of this, the crushed material Mt3 obtained in the cleaning step S1-4 is stored in the second tank. May be stored.

(Second embodiment)
FIG. 3 shows an oil removal method M2 according to a second embodiment. This oil removal method M2 includes a first crushing process S2-1 (S1-1), an oil removal process S2-2 (S1-2), a small tangible object removal process S2-3, and a first magnetic separation process S2- 4, the first sampling step S2-5, the second crushing step S2-6 (S1-3), the washing step S2-7 (S1-4), and the second sorting step S2-8 (S1-5) and in the order listed. Note that the same steps as in the first embodiment are given the same reference numerals in parentheses as in the first embodiment, and the description thereof will be omitted below.

The small tangible object removal step S2-3 is a step for removing small tangible objects that could not be sufficiently destroyed in the first crushing step S2-1 (S1-1). The specific method of the small tangible object removal process S2-3 is not limited, but for example, the user of the oil removal system visually observes the tangible objects that were not sufficiently destroyed in the first crushing process S2-1 (S1-1). The user may manually remove the tangible objects by checking the oil removal system using a small tangible object sorter (not shown) as described below to perform the small tangible object removal step S2-3. ).

For example, similar to the first crusher 1 shown in FIG. It has an arm. A plurality of small diameter holes and one large diameter hole are formed at the bottom of the housing portion. Due to gravity, the crushed objects Mt2 rotated on the bottom by the arm are small in size and fall into a plurality of small-diameter holes, and large-sized small tangible objects fall into one large-diameter hole. The small-sized crushed materials Mt2 that have fallen into the plurality of small diameter holes are supplied to the subsequent first magnetic separation step S2-4. The small tangible object that has fallen into one large diameter hole may be removed as is, or may be supplied to the first crushing step S2-1 (S1-1) again.

The first magnetic separation step S2-4 is a step of removing magnetic substances such as iron from the crushed material Mt2 using, for example, a drum type magnetic separator. In the first sampling step S2-5, a fixed amount of crushed material Mt2 is automatically collected at fixed time intervals using an automatic sampling machine. The collected crushed material Mt2 is melted using an arc button melter and processed into a button-shaped sample of a certain size. This sample is analyzed, for example, for its components, and based on the analysis results, it is determined whether to proceed to the subsequent second crushing step S2-6 (S1-3).

-Actions and effects of the second embodiment-
This embodiment can also provide the same effects as the first embodiment.

By the way, in the first crushing step S2-1 (S1-1), the supplied cutting waste Mt1 is roughly crushed, but there are cases where the tangible objects are not sufficiently destroyed in this step and remain as small tangible objects. be. In the second crushing step S2-6 (S1-3), the crushed material Mt2 roughly crushed in the first crushing step S2-1 (S1-1) is further finely crushed. -3) If such small tangible objects remain in the supplied crushed material Mt2, the equipment used in (3) (for example, a uniaxial crusher) may damage the blades, screens, shafts, etc. installed in the equipment. Cheap.

Here, in this embodiment, since the small tangible object removal step S2-3 is provided to remove the small tangible objects that could not be destroyed in the first crushing step S2-1 (S1-1), the second crushing step S2-6 This makes it difficult to damage the equipment used in (S1-3).

Furthermore, in this embodiment, since the first magnetic separation step S2-4 is executed before proceeding to the cleaning step S2-7 (S1-4), magnetic materials such as iron contained in the crushed material Mt3 are It has been removed beforehand. In the subsequent steps S2-5 to S2-7, even if magnetic substances are mixed in, they will be removed in the second magnetic separation step S2-8-1 (S1-5-1). , magnetic objects can be reliably removed.

(Modified example of second embodiment)
In the second embodiment, the first crushing step S2-1 (S1-1), the oil removal step S2-2 (S1-2), and the small tangible object removal step S2-3 are performed in this order. However, the order is not limited to this. The first crushing step S2-1 (S1-1), the oil removal step S2-2 (S1-2), and the small tangible object removal step S2-3 may be performed simultaneously.

Furthermore, in the second embodiment, the small tangible object removal process S2-3, the first magnetic separation process S2-4, and the first sampling process S2-5 are processes that are not present in the first embodiment, but these three It is not necessary to perform one or two of the steps S2-3 to S2-5.

(Other embodiments)
Examples of the second crusher 3 include a single-shaft crusher, a twin-shaft crusher, a four-shaft crusher, and the like.

Reference Examples 1 to 5 in which the results of the oil removal process were confirmed using a centrifuge are shown below. In Reference Examples 1 to 5, the oil removal process was performed using a centrifuge on the Inconel materials shown in FIGS. 4 to 8, respectively.

Oil was attached to each Inconel material before the oil removal process, and the total weight of each Inconel material and the weight % of the attached oil are as shown in Table 1.

That is, each Inconel material contains 3.54% by weight (Reference Example 1), 4.03% by weight (Reference Example 2), 5.11% by weight (Reference Example 3), and 8.14% by weight based on the total weight. % by weight (Reference Example 4) and 10.08% by weight (Reference Example 5) of oil were attached.

The total weight of each Inconel material after the oil removal process and the weight percent of the attached oil are shown in Table 1. That is, the amount of oil attached to each Inconel material after the oil removal process was 1.48% by weight (Reference Example 1), 1.52% by weight (Reference Example 2), and 1.27% by weight based on the total weight. (Reference Example 3), 1.19% by weight (Reference Example 4), and 1.36% by weight (Reference Example 5).

From the above, it was shown that in the oil removal process, the amount of oil adhering to each Inconel material was 2% by weight or less.

INDUSTRIAL APPLICATION This invention is useful for the oil removal method of cutting waste, an oil removal system, and the manufacturing method of metal scrap.

M1 Oil removal method S1-1 First crushing process S1-2 Oil removal process S1-3 Second crushing process S1-4 Washing process S1-5 Sorting process Mt1 Cutting waste Mt2, Mt3 Crushed material 1 First crusher 2 Centrifugation Machine 3 2nd crusher

The present invention relates to a method for removing oil from metal cutting waste, an oil removal system, and a method for producing metal scrap.

BACKGROUND ART Conventionally, there has been known a method of recycling waste materials such as composite materials and iron-based waste materials by crushing and classifying them (see, for example, Patent Documents 1 and 2).

Patent No. 3369234 Patent No. 4907284

By the way, when recycling metal waste, the waste is first cut into cutting waste. Depending on the recycling application, the cutting waste is required to be of high quality. Specifically, cutting waste is often coated with oil due to oil originating from cutting machines used to cut waste, and there is a desire to reduce the amount of oil attached as much as possible. Furthermore, there is a demand for making the size of cutting chips uniform.

Therefore, an object of the present invention is to reduce the amount of oil adhering to the metal cutting chips and to improve the uniformity of the size of the metal cutting chips.

The first technique disclosed herein is a method for removing oil from metal cutting chips to which oil has adhered, and includes a first crushing step of roughly crushing the metal cutting chips to obtain a crushed product; an oil removal step (first degreasing step) for removing the oil from the crushed material; a second crushing step for further crushing the obtained crushed material after the first crushing step and the oil removal step; A cleaning step (second degreasing step) in which the crushed material obtained in the crushing step is washed and degreased using superheated steam, and the washed crushed material obtained in the cleaning step is and a sorting step of sorting according to magnetism.

In addition, in this specification, "crushed material" refers to crushed metal cutting waste. "Metal cutting waste" is sometimes simply referred to as "cutting waste." "Removing oil" does not only mean completely removing oil, but also includes reducing the amount of oil. "Degreasing" means to completely remove oil or to extremely reduce the amount of oil.

According to the first technique, crushing is performed in two stages: a first crushing step in which the cutting waste is roughly crushed, and a second crushing step in which the crushed material is further crushed, so that the size of the resulting crushed materials is uniform. It gets expensive. Furthermore, since the crushed material is washed in the washing step, the amount of oil adhering to the crushed material can be extremely reduced.

By the way, in order to perform the cleaning process efficiently, it is necessary to optimize the implementation conditions such as the steam temperature and rotation rate (the amount of crushed items that can be washed in a certain amount of time) in the cleaning process, depending on the amount of oil in the crushed items that you want to reduce. I want to become However, the greater the amount of oil adhering to the crushed material supplied to the cleaning process, and the less uniform the size of the crushed materials supplied to the cleaning process, the more difficult it is to optimize the operating conditions. Do you get it.

Here, according to the first technique, the crushed material supplied to the cleaning process through the oil removal process, the first crushing process, and the second crushing process, which are performed before the cleaning process, has an oil adhesion amount. The size is less and the uniformity of the size is high. Therefore, the conditions for implementing the cleaning process can be optimized, the cleaning process can be performed efficiently, and the effectiveness of the cleaning process S can be enhanced. In this way, by performing the oil removal process, first crushing process, and second crushing process before the cleaning process, it is possible to not only simply remove the oil from the cutting chips and improve the size uniformity, but also to improve the cleaning process. It also has a synergistic effect of increasing the effectiveness of the process. As a result, with the first technique, the amount of oil adhering to cutting waste can be extremely reduced.

A second technique is that in the first technique, in the cleaning step, the amount of crushed material supplied to the cleaning step per unit time is controlled to be a constant amount.

According to the second technique, the amount of the crushed material supplied to the cleaning process per unit time is a constant amount, so the optimal implementation conditions according to the supply amount remain unchanged while the cleaning process is executed. It is. Therefore, once the optimal operating conditions according to the supply amount are determined, the cleaning process can be automatically and efficiently executed without changing the operating conditions during the execution of the cleaning process.

A third technique is a manufacturing method for manufacturing metal scrap from metal cutting waste to which oil is attached, which includes a first crushing step of roughly crushing the metal cutting waste to obtain a crushed product; an oil removal step (first degreasing step) for removing the oil from the crushed material; a second crushing step for further crushing the obtained crushed material after the first crushing step and the oil removal step; A cleaning step (second degreasing step) in which the crushed material obtained in the crushing step is washed and degreased using superheated steam, and the washed crushed material obtained in the cleaning step is and a sorting step of sorting according to magnetism to obtain the metal scrap.

In addition, in this specification, "metal scrap" means the same thing as the said "crushed material" which crushed "metal cutting waste."

According to the third technique, the same effects as the first technique can be achieved, and metal scrap with extremely reduced amount of oil adhesion can be newly produced.

A fourth technique is an oil removal system for carrying out the method for removing oil from metal cutting waste according to the first technique or the method for manufacturing metal scrap according to the third technique, and the system performs the oil removal step. a centrifugal separator that removes the oil from the metal cuttings by centrifugal force; a first crusher that roughly crushes the metal cuttings in the first crushing step; A second crusher that further crushes the , a superheated steam machine that performs the cleaning process, and a sorting system that performs the sorting process.

Note that in this specification, a configuration in which a plurality of devices are combined is referred to as a "system," but a single device having multiple functions may also be referred to as a "system."

The oil removal system according to the fourth technique can perform the method for removing oil from cutting waste according to the second technique. In general, the type of crusher suitable for use differs depending on the size of the object to be crushed, but in the fourth technique, large cutting waste is coarsely crushed by a first crusher, and then crushed by a second crusher. Make it even finer with a machine. Thereby, it is possible to obtain a large amount of crushed materials having a uniform size with a high yield, and damage to the crusher can be suppressed.

A fifth technique is, in the fourth technique, a first tank for storing the crushed material obtained in the second crushing step, and a supply supply for supplying the crushed material from the first tank to the superheated steam machine. means, a control means for controlling the supply amount of the crushed material to be supplied to the superheated steam machine per unit time by the supplying means to a constant amount, and the crushed material obtained in the washing step, or The apparatus further includes a second tank for storing the crushed material sorted in the sorting step.

According to the fifth technique, the crushed material obtained in the second crushing step is stored in the first tank, and a certain amount of crushed material is heated per unit time from the first tank by the control means and the supply means. Since it can be supplied to a steam machine, a system with the same effects as the third technique can be specifically obtained.

By the way, for the superheated steam machine used in the cleaning process, it is better to start it once and then run it non-stop rather than repeatedly starting and stopping it, which reduces damage to the equipment and the time required to start the equipment. Preferable from this point of view.

Here, according to the fifth technique, since a fixed amount of crushed material can be supplied from the first tank to the superheated steam machine per unit time, the superheated steam machine can be operated non-stop for a long time after being operated once. Cheap. As a result, damage to the superheated steam machine can be suppressed, the time required to start up the device can be reduced, and the oil removal method can be carried out efficiently.

As explained above, according to the present invention, it is possible to reduce the amount of oil adhering to metal cutting chips and improve the uniformity of the size of the metal cutting chips.

It is a flowchart which shows the oil removal method of the cutting waste based on 1st Embodiment. FIG. 2 is a schematic diagram showing a portion of an oil removal system. It is a figure corresponding to FIG. 1 of a 2nd embodiment. 3 is a photograph showing the crushed material used in Reference Example 1. It is a photograph showing the crushed material used in Reference Example 2. 3 is a photograph showing the crushed material used in Reference Example 3. It is a photograph showing the crushed material used in Reference Example 4. 5 is a photograph showing the crushed material used in Reference Example 5.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings. The following description of preferred embodiments is merely exemplary in nature and is not intended to limit the invention, its applications or its uses.

(First embodiment)
FIG. 1 shows a method M1 for removing oil from cutting waste Mt1 according to a first embodiment of the present invention. The cutting waste Mt1 is obtained by cutting waste with a cutting machine. The cutting waste Mt1 is a metal member that constitutes waste, and includes, for example, a plate material, a tube material, a side trimming material, a punched material, a punched material, a coil material, a bolt, and the like. Although the metal constituting the cutting waste Mt1 is not limited, examples thereof include nickel, cobalt, titanium, aluminum, iron, and mixtures thereof.

For example, oil originating from a cutting machine or oil originally attached to the waste is attached to the cutting waste Mt1. The oil removal method M1 is a method of completely removing the oil from the cutting waste Mt1 to which such oil has adhered or extremely reducing the amount of oil adhering. The oil removal method M1 includes a first crushing process S1-1, an oil removing process S1-2 (first degreasing process) , a second crushing process S1-3, and a cleaning process S1-4 (second degreasing process). , and a sorting step S1-5.

FIG. 2 schematically shows part of an oil removal system for carrying out the oil removal method M1. Note that FIG. 2 is only a conceptual diagram and does not accurately show the configuration, shape, etc. of each device, cutting waste Mt1, etc.

The oil removal system includes a first crusher 1 for performing a first crushing process S1-1, a centrifugal separator 2 for performing an oil removal process S1-2, and a second crushing process S1-3. A superheated steam machine (not shown) for carrying out the cleaning process S1-4, and a sorting system (not shown) for carrying out the sorting process S1-5 are provided.

Hereinafter, each process will be explained, and the apparatus or system used in each process will also be explained.

-First crushing process-
The first crushing step S1-1 is a step of roughly crushing the cutting waste Mt1 into crushed material Mt2. The cutting waste Mt1 that is roughly crushed in this process often retains the shape of the metal member that constituted the waste (hereinafter referred to as "tangible material"). "Roughly crushing" means, for example, breaking the shape of these tangible objects.

The first crushing step S1-1 is performed using the first crusher 1. The first crusher 1 is not limited as long as it roughly crushes the cutting waste Mt1, but a concrete example includes a coarse powder crusher. For example, as schematically shown in FIG. 2, the first crusher 1 includes a substantially inverted cone-shaped storage section 1a into which cutting waste Mt1 is input, and a storage section 1a provided at the bottom of the storage section 1a for storing cutting waste Mt1. It has an arm 1b to be rotated. A plurality of protrusions or blades (not shown) are provided on the inner surface of the housing portion 1a. Due to the rotation of the arm 1b, the cutting waste Mt1 rotating along the inner surface of the housing portion 1a is roughly crushed by hitting the protrusion or blade, and is made into crushed material Mt2.

-Oil removal process-
The oil removal step S1-2 is a step executed after the first crushing step S1-1 to remove oil from the crushed material Mt2 obtained in the first crushing step S1-1. In the oil removal step S1-2, it is sufficient to reduce the amount of oil in the crushed material Mt2, but from the viewpoint of efficiently executing the cleaning step S1-4, the amount of oil attached should be 2% or less of the total weight of the crushed material Mt2. It is preferable to do so.

The oil removal step S1-2 is performed using a centrifuge 2. The centrifugal separator 2 applies centrifugal force to the crushed material Mt2 obtained in the first crushing step S1-1, and removes attached oil by the centrifugal force. A specific example of the centrifugal separator 2 is an air deoiling machine.

-Second crushing process-
The second crushing step S1-3 is performed after the oil removing step S1-2, and is a step of crushing the crushed material Mt2 obtained in the oil removing step S1-2 even more finely.

The second crushing step S1-3 is performed using the second crusher 3. The second crusher 3 is not limited as long as it can further finely crush the coarsely crushed crushed material Mt2, and a specific example thereof includes a uniaxial crusher. In addition, in FIG. 2, the code|symbol Mt3 refers to the crushed material finely crushed by the 2nd crusher 3.

The oil removal system further includes a first tank (not shown). The crushed material Mt3 obtained in the second crushing step S1-3 is stored in the first tank.

-Cleaning process-
The cleaning step S1-4 is a step of cleaning and degreasing the crushed material Mt3 further crushed in the second crushing step S1-3 using superheated (heated) steam. Cleaning with superheated steam takes place in a high temperature furnace. The temperature of the steam used in the cleaning step S1-4 and the temperature in the high-temperature furnace are preferably determined depending on the type of metal constituting the crushed material Mt3. For example, if the crushed material Mt3 is a superalloy made of nickel or the like, the temperature of the high-temperature furnace should be set at 300°C or higher to 450°C in order to efficiently consume time and energy for cleaning. It is preferable that the temperature of the steam be 350°C or more and 500°C or less. In this case, the amount of oil attached to the crushed material Mt3 obtained in the cleaning step S1-4 is, for example, 0.1% by weight or less with respect to the entire weight of the crushed material Mt3, and the amount of oil attached is extremely small.

The cleaning step S1-4 is performed using a superheated steam machine. The superheated steam machine generates steam superheated to 100°C or higher, applies the steam to the crushed material Mt3, and further dries the crushed material Mt3, thereby removing the remaining oil attached to the crushed material Mt3 along with moisture. do. The superheated steam machine is not limited as long as it is such a machine, but a specific example is a superheated steam type continuous rotary kiln. A superheated steam continuous rotary kiln can generate steam at a high temperature of 900° C. or lower.

Furthermore, in the cleaning step S1-4, the amount of crushed material Mt3 supplied per unit time is controlled to be a constant amount. For this reason, the oil removal system includes a supply means (not shown) for supplying the crushed material Mt3 from the first tank to the superheated steam machine. The supply means is, for example, a screw conveyor. The oil removal system further comprises control means (not shown). The control means is a supply means, and controls the supply amount of the crushed material Mt3 to be supplied to the superheated steam machine per unit time to be a constant amount.

-Sorting process-
The sorting step S1-5 is a step of sorting the washed crushed material Mt3 obtained in the washing step S1-4 according to particle size and magnetism. In detail, the sorting process S1-5 includes a magnetic selection process S1-5-1, a classification process S1-5-2 that follows this, a sampling process S1-5-3 that follows this, and an analysis process S1 that follows this. -5-4.

In the magnetic separation step S1-5-1, a magnetic separator is used to remove magnetic materials such as iron from the crushed material Mt3. The magnetic separator is not particularly limited, and general magnetic separators such as a drum type, counter-electrode drum type, hanging type, and conveyor type can be employed.

In the classification step S1-5-2, a sieve is used to divide the crushed material Mt3 into at least two sizes, and those that do not meet the standard size are removed. The sieving machine is not particularly limited, and examples include a single-stage vibrating sieve machine equipped with mesh materials of one type of pore size, a two-stage vibratory sieve machine equipped with two types of mesh materials of different pore diameters in upper and lower stages, etc. , a general sieving machine can be adopted.

In the sampling step S1-5-3, a certain amount of the crushed material Mt3 is automatically collected at certain time intervals using an automatic sampling machine. The collected crushed material Mt3 is melted using an arc button melter and processed into a button-shaped sample of a certain size. In the analysis step S1-5-4, the components of this sample are analyzed, and the quality of the crushed material Mt3 obtained through the first crushing step S1-1 to the classification step S1-5-2 is evaluated. The analysis in the analysis step S1-5-4 uses, but is not limited to, a fluorescence X-ray analyzer, a plasma emission analyzer, an inductively coupled plasma (ICP) emission spectrometer, etc., for example.

The oil removal system further includes a second tank (not shown) that stores the crushed material Mt3 sorted in the sorting step S1-5.

-Metal scrap manufacturing method-
Although the method M1 for removing oil from cutting waste Mt1 has been described above, metal scraps may be manufactured by a similar process. The metal scrap manufacturing method according to the present embodiment is a manufacturing method for manufacturing metal scrap from oil-adhered cutting waste Mt1, in which the first crushing step S1- 1, an oil removal step S1-2 for removing oil from the metal cutting waste Mt1 or the crushed material Mt2, and after the first crushing step S1-1 and the oil removal step S1-2, the obtained crushed material Mt2 is further crushed. a second crushing step S1-3, a cleaning step S1-4 in which the crushed material Mt3 obtained in the second crushing step S1-3 is cleaned and degreased using superheated steam, and a cleaning step S1- The method includes a sorting step S1-5 in which the washed crushed material Mt3 obtained in step 4 is sorted according to particle size and magnetism to obtain metal scrap.

The oil removal system described above can be used to carry out this method of manufacturing scrap metal.

-Actions and effects of the first embodiment-
According to the present embodiment, the crushed material obtained is crushed in two stages: a first crushing step S1-1 in which the cutting waste Mt1 is roughly crushed, and a second crushing step S1-3 in which the crushed material Mt2 is further crushed. The uniformity of the size of Mt3 becomes high. Furthermore, since the crushed material Mt3 is washed in the cleaning step S1-4, the amount of oil adhering to the crushed material Mt3 can be extremely reduced.

By the way, in order to efficiently perform the cleaning process S1-4, the temperature, steam temperature, and rotation rate of the high-temperature furnace in the cleaning process S1-4 (cleaning is performed at a certain time We would like to optimize the implementation conditions such as the amount of crushed material Mt3 that can be produced. However, the larger the amount of oil attached to the crushed material Mt3 supplied to the cleaning step S1-4, and the lower the uniformity of the size of the crushed material Mt3 supplied to the cleaning step S1-4, the more the implementation conditions are changed. It turned out to be difficult to optimize.

Here, according to the present embodiment, after the oil removal process S1-2, the first crushing process S1-1, and the second crushing process S1-3, which are executed before the cleaning process S1-4, the cleaning process S1 -4, the crushed material Mt3 has a reduced amount of oil adhesion and is highly uniform in size. Therefore, the conditions for implementing the cleaning step S1-4 can be optimized, the cleaning step S1-4 can be performed efficiently, and the effectiveness of the cleaning step S1-4 can be enhanced. In this way, by performing the oil removal step S1-2, the first crushing step S1-1, and the second crushing step S1-3 before the cleaning step S1-4, it is possible to simply remove the oil from the cutting waste Mt1 to Mt3. This not only removes particles and improves size uniformity, but also has a synergistic effect of enhancing the effect of the cleaning step S1-4. As a result, according to this embodiment, the amount of oil adhering to the cutting waste Mt1 can be extremely reduced.

For example, in the oil removal step S1-2, by reducing the amount of oil adhesion to 2% by weight or less based on the total weight of the crushed material Mt2, the oil adhesion on the cleaned crushed material Mt3 obtained after the cleaning step S1-4 is reduced. It has been found that the amount can be reduced to 0.1% by weight or less.

Furthermore, according to the present embodiment, the amount of crushed material Mt3 supplied to the cleaning step S1-4 per unit time is a constant amount, so the optimal implementation conditions according to the amount of supply are the cleaning step S1-4. 4 remains unchanged during execution. Therefore, once the optimum execution conditions according to the supply amount are determined, the cleaning process S1-4 can be automatically and efficiently executed without changing the execution conditions during the execution of the cleaning process S1-4.

Further, according to the oil removal system of this embodiment, the crushed material Mt3 obtained in the second crushing step S1-3 is stored in the first tank, and the control means and the supply means control the crushed material Mt3 from the first tank for a unit time. A certain amount of crushed material Mt3 can be supplied to the superheated steam machine per unit.

By the way, it is better to start the superheated steam machine used in the cleaning step S1-4 non-stop than to repeatedly start and stop it, to prevent damage to the superheated steam machine (for example, heat of the equipment components). This is preferable from the viewpoint of suppressing shrinkage, deterioration, etc.) and reducing the time required to start up the superheated steam machine (for example, 2 to 3 hours). Additionally, running a superheated steam machine non-stop means that energy can be used efficiently to maintain the temperature inside the high-temperature furnace through the combined heat transfer of convection, radiation, and condensation of superheated steam. preferable.

Here, according to the oil removal system of this embodiment, since a certain amount of crushed material Mt3 can be supplied from the first tank to the superheated steam machine per unit time, once the superheated steam machine is operated, it can be operated non-stop. Easy to operate for long periods of time. As a result, damage to the superheated steam machine can be suppressed, the time required for startup is reduced, energy is also saved, and the oil removal method M1 can be executed efficiently.

Moreover, non-stop operation of the superheated steam machine is preferable from the viewpoint of preventing oxidation of the crushed metal Mt3 and from the viewpoint of fire prevention, since the inside of the high-temperature furnace can be maintained in a low oxygen state.

As a specific method of using the oil removal system of this embodiment, for example, a user may start the superheated steam machine, operate it for a long time (for example, 24 hours), and then stop the superheated steam machine. . According to this method, the user does not need to change the setting conditions of the superheated steam machine for a long time when the superheated steam machine is in operation, so there is no need to be particularly concerned about the operating status of the superheated steam machine. It is extremely convenient.

Moreover, according to the method for producing metal scrap of this embodiment, it is possible to newly produce metal scrap with a reduced amount of oil attached. Since such metal scrap has an extremely small amount of oil adhesion, it is very useful as a raw material for producing superalloy ingots by vacuum melting, for example. Generally, in vacuum melting, it is impossible or extremely difficult to adjust the constituent components or remove impurities after melting the raw materials. Since oil generally contains impurities such as carbon and sulfur, if metal scrap with a lot of oil attached is used as a raw material for vacuum melting, the ingot produced by vacuum melting will also contain a lot of impurities. In this regard, since the metal scrap produced by the production method of this embodiment has an extremely small amount of oil, it is suitable for the production of precision instruments, parts, etc., which are produced using high-quality ingots with extremely few impurities as raw materials. Very useful. Examples of such equipment, parts, etc. include medical equipment, mining equipment, automobile engine parts, power generation turbines, aircraft, and the like.

Note that the metal scrap manufactured by the metal scrap manufacturing method of the present embodiment may be other than the raw material for superalloy ingots, and may be, for example, a stainless steel alloy.

Furthermore, the oil removal system of this embodiment allows the oil removal method M1 or the metal scrap manufacturing method to be executed. In general, the type of crusher suitable for use differs depending on the size of the object to be crushed, but in the oil removal system of this embodiment, large cutting waste Mt1 is coarsely crushed by the first crusher 1 and then Then, the second crusher 3 crushes it further. Thereby, a large amount of crushed material Mt3 having a uniform size can be obtained with a high yield, and damage to the second crusher 3 can be suppressed.

(Modified example of the first embodiment)
In the first embodiment, the oil removal step S1-2 is performed after the first crushing step S1-1, but instead of this, the oil removal step S1-2 is performed before the first crushing step S1-1. You can. Further, the first crushing step S1-1 and the oil removal step S1-2 may be performed simultaneously.

In the first embodiment, the crushed material Mt3 sorted in the sorting step S1-5 is stored in the second tank, but instead of this, the crushed material Mt3 obtained in the cleaning step S1-4 is stored in the second tank. May be stored.

(Second embodiment)
FIG. 3 shows an oil removal method M2 according to a second embodiment. This oil removal method M2 includes a first crushing process S2-1 (S1-1), an oil removal process S2-2 (S1-2), a small tangible object removal process S2-3, and a first magnetic separation process S2- 4, the first sampling step S2-5, the second crushing step S2-6 (S1-3), the washing step S2-7 (S1-4), and the second sorting step S2-8 (S1-5) and in the order listed. Note that the same steps as in the first embodiment are given the same reference numerals in parentheses as in the first embodiment, and the description thereof will be omitted below.

The small tangible object removal step S2-3 is a step for removing small tangible objects that could not be sufficiently destroyed in the first crushing step S2-1 (S1-1). The specific method of the small tangible object removal process S2-3 is not limited, but for example, the user of the oil removal system visually observes the tangible objects that were not sufficiently destroyed in the first crushing process S2-1 (S1-1). The user may manually remove the tangible objects by checking the oil removal system using a small tangible object sorter (not shown) as described below to perform the small tangible object removal step S2-3. ).

For example, similar to the first crusher 1 shown in FIG. It has an arm. A plurality of small diameter holes and one large diameter hole are formed at the bottom of the housing portion. Due to gravity, the crushed objects Mt2 rotated on the bottom by the arm are small in size and fall into a plurality of small-diameter holes, and large-sized small tangible objects fall into one large-diameter hole. The small-sized crushed materials Mt2 that have fallen into the plurality of small diameter holes are supplied to the subsequent first magnetic separation step S2-4. The small tangible object that has fallen into one large diameter hole may be removed as is, or may be supplied to the first crushing step S2-1 (S1-1) again.

The first magnetic separation step S2-4 is a step of removing magnetic substances such as iron from the crushed material Mt2 using, for example, a drum type magnetic separator. In the first sampling step S2-5, a fixed amount of crushed material Mt2 is automatically collected at fixed time intervals using an automatic sampling machine. The collected crushed material Mt2 is melted using an arc button melter and processed into a button-shaped sample of a certain size. This sample is analyzed, for example, for its components, and based on the analysis results, it is determined whether to proceed to the subsequent second crushing step S2-6 (S1-3).

-Actions and effects of the second embodiment-
This embodiment can also provide the same effects as the first embodiment.

By the way, in the first crushing step S2-1 (S1-1), the supplied cutting waste Mt1 is roughly crushed, but there are cases where the tangible objects are not sufficiently destroyed in this step and remain as small tangible objects. be. In the second crushing step S2-6 (S1-3), the crushed material Mt2 roughly crushed in the first crushing step S2-1 (S1-1) is further finely crushed. -3) If such small tangible objects remain in the supplied crushed material Mt2, the equipment used in (3) (for example, a uniaxial crusher) may damage the blades, screens, shafts, etc. installed in the equipment. Cheap.

Here, in this embodiment, since the small tangible object removal step S2-3 is provided to remove the small tangible objects that could not be destroyed in the first crushing step S2-1 (S1-1), the second crushing step S2-6 This makes it difficult to damage the equipment used in (S1-3).

Furthermore, in this embodiment, since the first magnetic separation step S2-4 is executed before proceeding to the cleaning step S2-7 (S1-4), magnetic materials such as iron contained in the crushed material Mt3 are It has been removed beforehand. In the subsequent steps S2-5 to S2-7, even if magnetic substances are mixed in, they will be removed in the second magnetic separation step S2-8-1 (S1-5-1). , magnetic objects can be reliably removed.

(Modified example of second embodiment)
In the second embodiment, the first crushing step S2-1 (S1-1), the oil removal step S2-2 (S1-2), and the small tangible object removal step S2-3 are performed in this order. However, the order is not limited to this. The first crushing step S2-1 (S1-1), the oil removal step S2-2 (S1-2), and the small tangible object removal step S2-3 may be performed simultaneously.

Furthermore, in the second embodiment, the small tangible object removal process S2-3, the first magnetic separation process S2-4, and the first sampling process S2-5 are processes that are not present in the first embodiment, but these three It is not necessary to perform one or two of the steps S2-3 to S2-5.

(Other embodiments)
Examples of the second crusher 3 include a single-shaft crusher, a twin-shaft crusher, a four-shaft crusher, and the like.

Reference Examples 1 to 5 in which the results of the oil removal process were confirmed using a centrifuge are shown below. In Reference Examples 1 to 5, the oil removal process was performed using a centrifuge on the Inconel materials shown in FIGS. 4 to 8, respectively.

Oil was attached to each Inconel material before the oil removal process, and the total weight of each Inconel material and the weight % of the attached oil are as shown in Table 1.

That is, each Inconel material contains 3.54% by weight (Reference Example 1), 4.03% by weight (Reference Example 2), 5.11% by weight (Reference Example 3), and 8.14% by weight based on the total weight. % by weight (Reference Example 4) and 10.08% by weight (Reference Example 5) of oil were attached.

The total weight of each Inconel material after the oil removal process and the weight percent of the attached oil are shown in Table 1. That is, the amount of oil attached to each Inconel material after the oil removal process was 1.48% by weight (Reference Example 1), 1.52% by weight (Reference Example 2), and 1.27% by weight based on the total weight. (Reference Example 3), 1.19% by weight (Reference Example 4), and 1.36% by weight (Reference Example 5).

From the above, it was shown that in the oil removal process, the amount of oil adhering to each Inconel material was 2% by weight or less.

INDUSTRIAL APPLICATION This invention is useful for the oil removal method of cutting waste, an oil removal system, and the manufacturing method of metal scrap.

M1 Oil removal method S1-1 First crushing process S1-2 Oil removal process (first degreasing process)
S1-3 Second crushing process S1-4 Cleaning process (second degreasing process)
S1-5 Sorting process Mt1 Cutting waste Mt2, Mt3 Crushed material 1 First crusher 2 Centrifugal separator 3 Second crusher

Claims (5)

A method for removing oil from metal cutting chips coated with oil, the method comprising:
a first crushing step of roughly crushing the metal cutting waste to obtain a crushed product;
an oil removal step of removing the oil from the metal cutting waste or the crushed material;
a second crushing step of further crushing the obtained crushed material after the first crushing step and the oil removal step;
a cleaning step of cleaning and degreasing the crushed material obtained in the second crushing step using superheated steam;
A method for removing oil from metal cutting waste, comprising a sorting step of sorting the washed crushed material obtained in the washing step according to particle size and magnetism. The method for removing oil from metal cuttings according to claim 1,
In the washing step, the amount of crushed material supplied to the washing step per unit time is controlled to be a constant amount;
Method for removing oil from metal cutting chips. A manufacturing method for manufacturing metal scrap from metal cuttings coated with oil, the method comprising:
a first crushing step of roughly crushing the metal cutting waste to obtain a crushed product;
an oil removal step of removing the oil from the metal cutting waste or the crushed material;
a second crushing step of further crushing the obtained crushed material after the first crushing step and the oil removal step;
a cleaning step of cleaning and degreasing the crushed material obtained in the second crushing step using superheated steam;
A method for producing metal scrap, comprising a sorting step of sorting the washed crushed material obtained in the washing step according to particle size and magnetism to obtain the metal scrap. An oil removal system for carrying out the method for removing oil from metal cutting waste according to claim 1 or the method for manufacturing metal scrap according to claim 3, comprising:
a centrifugal separator that removes the oil from the metal cuttings by centrifugal force in order to perform the oil removal step;
a first crusher that roughly crushes the metal cutting waste in the first crushing step;
a second crusher that further crushes the crushed material in the second crushing step;
a superheated steam machine that performs the cleaning process;
and a sorting system that performs the sorting step. The oil removal system according to claim 4,
a first tank that stores the crushed material obtained in the second crushing step;
Supply means for supplying the crushed material from the first tank to the superheated steam machine;
Control means for controlling the supply amount of the crushed material to be supplied to the superheated steam machine per unit time by the supply means to a constant amount;
An oil removal system further comprising a second tank for storing the crushed material obtained in the washing step or the crushed material sorted in the sorting step.