KR101125359B1 - Method for purificating abrasive cutting sludge - Google Patents

Abstract

PURPOSE: A method for regenerating a waste mixed solution for cutting and polishing is provided to prevent environmental pollution and to improve the quality and the productivity of wafers by using regenerated mixed solution for cutting and polishing. CONSTITUTION: A method for regenerating a waste mixed solution for cutting and polishing includes the following: a first cutting and polishing material is eliminated from a waste mixed solution for cutting and polishing based on the application of ultrasound wave(S10). The waste mixed solution is separated into a second cutting and polishing material and a waste mixed solution without the second cutting and polishing material(S20). A filtering membrane is formed on the external side of a rotary drum. The inside of rotary drum becomes a vacuum state which is lower than atmospheric pressure. The waste mixed solution without the second cutting and polishing material passes through the filtering membrane. A third cutting and polishing material is eliminated from the waste mixed solution and coolant is collected from the waste mixed solution(S30). The collected coolant is mixed with the separated second cutting and polishing material to generate a mixed solution for cutting and polishing(S50). Iron components are eliminated from the mixed solution(S60).

Description

Method for Purifying Abrasive Cutting Mixture

The present invention relates to a method for regenerating waste cutting polishing mixture, and more particularly, cutting polishing material and cooling oil in a high-concentration, high-viscosity waste cutting polishing mixture containing cutting abrasives, cooling oils and cutting powders generated during the cutting polishing process of wafers. The present invention relates to a method for regenerating waste cutting abrasive mixture, which recovers and produces a new cutting abrasive mixture.

Recently, with the development of the telecommunications, semiconductor and solar cell industries, the demand for silicon single crystal wafers is increasing rapidly. In general, a silicon wafer is manufactured by cutting with a wire saw while supplying a cooling oil and a cutting abrasive to a silicon ingot, and then grinding the wafer using a grinding machine. In this process, about 20-30% of the silicon ingot initially supplied is generated as saw dust.

In the manufacture of silicon wafers, by-products such as cutting powder, abrasives (silicon carbide, aluminum oxide, silicon dioxide, diamond, boron carbide, etc.) and cooling oils are removed from the wafer through a cleaning process. Therefore, the cutting abrasive, which is a grinding component and a silicon (Si) component, is present in the form of being dispersed in a cooling oil in the waste cutting polishing mixture generally generated by wafer manufacture.

Waste cutting and polishing mixtures generated during wafer manufacturing are classified as special industrial wastes. Since the generated waste cutting mixture contains cutting powder and cooling oil, it cannot be simply incinerated, and in the case of simple landfill, serious soil contamination by the cooling oil may be concerned. Therefore, the generated waste cutting mixture is solidified and landfilled. Special treatment methods are applied. However, the landfill treatment method is a very special treatment method, which is very unsuitable in terms of environmental, economic and time.

Therefore, research on the method of regenerating the waste cutting polishing mixture is actively progressing. Recently, instead of solidifying the waste cutting polishing mixture and embedding it, a method of recovering and reusing the cutting abrasive, cutting powder or cooling oil contained in the waste cutting polishing mixture has been proposed.

Recycling of the waste cutting polishing mixture is typical of solvent and centrifugation. However, in the method using a solvent, the waste cutting polishing mixture is easily dissolved by water or solvent to separate the cooling oil.However, during the drying or distillation process, the emulsifier added in the cooling oil is changed so that the cutting abrasive is not dispersed during reuse. There is a problem that does not settle.

On the other hand, the centrifugal separation method has a problem in that the recovery rate of the cutting abrasive is not only low, but the purity of the recovered cutting abrasive is also poor. As the cutting abrasive, which has reached the end of its life as a cutting abrasive, is continuously recovered and reused, it causes a decrease in polishing quality and polishing rate. In addition, because the particle size is very small, the cutting powder or cutting abrasive material which is no longer capable of cutting is not properly removed and remains in the recovered cooling oil, so that a wire mark remains on the cutting polishing surface of the wafer and the cutting polishing speed is lowered. There is a problem that the quality and productivity of the wafer is lowered. At the same time, the iron component not removed from the recovered coolant provides a cause of increased metal contamination on the wafer surface.

Accordingly, an object of the present invention is to solve such a conventional problem, and provides a cutting and polishing function in a high-concentration, high-viscosity, waste-cutting polishing mixture containing cutting abrasives, cooling emulsions and cutting powders generated during the cutting polishing process of the wafer. By sorting and removing the lost cutting abrasive and recovering high-purity cooling oil, it is possible to minimize the amount of waste generated in the cutting and polishing process of the wafer, and to improve the quality and productivity of the wafer by using a high quality recycled cutting mixture. The present invention provides a method for regenerating waste cutting polishing mixture which can be improved.

In order to achieve the above object, the method for regenerating the waste cutting abrasive mixture of the present invention comprises purifying the waste cutting abrasive mixture containing the cutting abrasive, the cooling oil and the cutting powder generated in the cutting polishing process of the wafer, thereby cutting the cutting abrasive and the cooling oil. A waste cutting polishing mixture regeneration method for recovering a cutting abrasive mixture by recovering the same, the method comprising: a first separation step of removing a first cutting abrasive having a first granularity by applying ultrasonic vibration to the waste cutting polishing mixture; Centrifuging the waste cutting polishing mixture from which the first cutting abrasive is removed, and separating the second cutting abrasive having a second particle size smaller than the first particle size, and the waste cutting polishing mixture from which the second cutting abrasive is removed. A second separation step; Forming a filtration membrane outside the rotating drum, forming the inside of the rotating drum in a vacuum lower than atmospheric pressure, and filtering the waste cutting polishing mixture from which the second cutting abrasive is removed through the filtration membrane in an inward direction from the outside of the rotating drum. A third separation step of removing the cutting powder and the third cutting abrasive material having a third particle size smaller than the second particle size from the waste cutting abrasive mixture and recovering a cooling oil from the waste cutting abrasive mixture; A mixing step of mixing the cooling oil recovered in the third separation step with the second cutting abrasive separated in the second separation step to generate a cutting abrasive mixture; And an iron removing step of removing iron from the cutting polishing mixture generated in the mixing step.

In the method for regenerating the waste cutting polishing mixture according to the present invention, preferably, in the third separating step, the cutting powder and the third cutting abrasive are filtered by the filtration membrane, and the cooling oil is sucked into the rotating drum. It is recovered.

In the method for regenerating the waste cutting polishing mixture according to the present invention, preferably, in the third separating step, the second cutting abrasive is removed by adjusting the rotation speed of the rotating drum or the thickness of the filtration membrane. The filtration rate of the mixed liquid or the quality of the cooling oil recovered is controlled.

In the method for regenerating the waste-cutting abrasive mixture according to the present invention, preferably, after the third separation step, by supplying heat to the recovered cooling oil, the moisture contained in the cooling oil is evaporated and discharged to the outside. It further comprises a; water removal step of removing water from the cooling emulsion.

In the waste cutting polishing mixture regeneration method according to the present invention, Preferably, after the third separation step, further comprising a cooling oil purification step of refining the recovered cooling oil using a hollow fiber membrane.

In the method for regenerating the waste cutting polishing mixture according to the present invention, preferably, a part of the cooling oil recovered through the third separation step is mixed with silica powder or diatomaceous earth powder used for the filtration membrane to form the filtration membrane.

In the method for regenerating the waste cutting polishing mixture according to the present invention, preferably, the mixing step includes generating the cutting polishing mixture by mixing the recovered cooling oil with the second cutting polishing material to reach a predetermined first density, A new cutting abrasive material not used in the cutting polishing process is added so that the cutting polishing mixture reaches a second density higher than the first density.

In the method for regenerating the waste cutting polishing mixture according to the present invention, preferably, after the third separation step, the new cutting abrasive material of the mixing step is purified using a part of the cooling oil recovered through the third separation step. It further comprises a; cutting polishing material purification step.

In the method for regenerating the waste cutting polishing mixture according to the present invention, Preferably, the iron removing step includes: a first removing step of removing iron molecules from the cutting polishing mixture generated in the mixing step by using a magnetic separator; And a second removing step of removing iron ions from the cutting polishing mixture to which new cutting polishing materials have been added using the electrodeionization.

In the method for regenerating the waste cutting polishing mixture according to the present invention, preferably, in order to separate the cutting abrasive and the cutting powder from the waste cutting polishing mixture from which the first cutting polishing material has been removed, the cooling recovered through the third separation step is performed. A part of the emulsion is mixed with the waste cutting polishing mixture from which the first cutting abrasive is removed to dilute the waste cutting polishing mixture passed through the first separation step.

According to the recycling method of the waste cutting polishing mixture of the present invention, it is possible to contribute to the prevention of environmental pollution by reducing the amount of waste generated in the cutting polishing process of the wafer, and to improve the quality and productivity of the wafer by using a high quality recycling cutting polishing mixture. Can be.

In addition, according to the waste cutting polishing mixture regeneration method of the present invention, it is possible to provide a large amount of filtration and a fast filtration rate compared to the general filtration method, and can actively cope with the change in the allowed conditions.

In addition, according to the method for regenerating the waste cutting polishing mixture of the present invention, it is possible to improve the viscosity of the cutting polishing mixture, prevent the formation of bubbles by frictional heat, and evenly disperse the cutting abrasive mixture in the cutting polishing process to improve the cutting polishing quality. Can be.

Further, according to the waste cutting polishing mixture regeneration method of the present invention, metal contamination on the wafer surface can be prevented.

In addition, according to the method for regenerating the waste cutting abrasive mixture, the quality of the reclaimed cutting abrasive can be improved by easily separating the cutting abrasive material and the cutting powder which are stuck together in the waste cutting abrasive mixture.

1 is a view sequentially showing a method for regenerating waste cutting polishing mixture according to an embodiment of the present invention,
2 is a view showing an example of a system for implementing the waste cutting polishing mixture regeneration method of FIG.
3 is a view schematically showing an example of a rotating drum for implementing a third separation step of the waste cutting polishing mixture regeneration method of FIG.
Figure 4 is a view showing an example of a system for implementing a cooling oil purification step that can be added to the waste cutting polishing mixture regeneration method of Figure 1,
5 is a diagram illustrating an example of a system for implementing a cutting abrasive purification step that may be added to the method for regenerating the waste cutting abrasive mixture of FIG. 1.

Hereinafter, with reference to the accompanying drawings embodiments of the waste cutting polishing mixture mixture regeneration method according to the present invention will be described in detail.

1 is a view showing the waste cutting polishing mixture regeneration method in order according to an embodiment of the present invention, Figure 2 is a view showing an example of a system for implementing the waste cutting polishing mixture regeneration method of Figure 1, FIG. 3 is a view schematically showing an example of a rotating drum implementing the third separation step of the waste cutting polishing mixture regeneration method of FIG. 1.

1 to 3, the method for regenerating the waste cutting abrasive mixture according to the present invention is a cutting abrasive in a high concentration, high viscosity waste cutting abrasive mixture containing a cutting abrasive, a cooling oil and a cutting powder generated during the cutting polishing process of the wafer. And recovering the cooling oil to generate a new cutting polishing mixture, the first separation step S10, the second separation step S20, the third separation step S30, the water removal step S40, Mixing step (S50), and iron removal step (S60).

The first separation step (S10), by applying ultrasonic vibration to the waste cutting polishing mixture to remove the first cutting abrasive having a first particle size. The first cutting abrasive material of the present embodiment loses the cutting polishing function due to the abrasion of the edges in the cutting polishing process, and has a relatively large first particle size disposed at 90% or more when arranged in order based on the size in the particle size distribution diagram. Refers to cutting abrasive having a particle size.

In this embodiment, the ultrasonic vibrator 110 is used to remove the first cutting abrasive from the waste cutting abrasive mixture. First, the waste cutting polishing mixture is supplied to the ultrasonic vibrator 110. The ultrasonic vibrator S110 generates a three-dimensional vibration by applying ultrasonic waves having a high frequency and low amplitude of 30 to 38 kHz, and selects the first cutting abrasive material that is worn in the cutting polishing process and loses the cutting polishing function, and discharges it as waste.

The waste cutting abrasive mixture, in which the first cutting abrasive is removed, is received and stored in the first tank 120, and is then transferred to the centrifuge 130 used in the second separation step S20.

Meanwhile, a part of the cooling oil recovered through the third separation step S30 to be described later may be transferred to the first tank 120. In the waste cutting polishing mixture in which the first cutting abrasive is removed, the cutting abrasive and the cutting powder are agglomerated, so it is not easy to separate them in a subsequent separation process. Therefore, in order to easily separate the cutting abrasive and the cutting powder, a part of the recovered cooling oil is mixed and diluted with the waste cutting abrasive mixture from which the first cutting abrasive is removed, thereby separating the cutting abrasive and the cutting powder from the waste cutting abrasive mixture. Can be.

The second separation step (S20), by using a centrifuge 130 centrifuged to remove the first cutting abrasive waste cutting mixture, the second cutting abrasive having a second particle size smaller than the first particle size Then, the second cutting abrasive is separated into the waste cutting abrasive mixture removed.

The second cutting abrasive material of the present embodiment is a cutting abrasive material which is regenerated without losing the cutting polishing function and can sufficiently perform the cutting polishing function even when used in the cutting polishing process, when arranged in order based on the size in the particle size distribution diagram. It refers to the cutting abrasive material disposed at a position of 10% to 90%. The second cutting abrasive material has a second particle size with a relatively small particle size compared to the first cutting abrasive material.

The waste cutting polishing mixture from which the second cutting abrasive separated through the second separation step is removed, and the second cutting abrasive are separately accommodated in the tank. The waste cutting abrasive mixture is accommodated in the second tank 140 and then transferred to the rotating drum 160 used in the third separation step S30, and the second cutting abrasive is accommodated in the third tank 150 and subsequently It is mixed with the cooling oil recovered in the three separation step (S30).

The third separation step (S30), by using the filtration membrane 161 containing silica or diatomaceous earth to filter the waste cutting polishing mixture 10 from which the second cutting abrasive is removed to recover the cooling oil.

In the third separating step (S30), the waste cutting abrasive mixture 10 from which the second cutting abrasive is removed is passed through the filtration membrane 161 to remove the cutting powder and the third cutting abrasive from the waste cutting abrasive mixture 10, and the waste The cooling oil is recovered from the cutting polishing mixture 10.

The third cutting abrasive material of the present embodiment has a very small particle size that is disposed at a position less than 10% when arranged in order based on the size in the particle size distribution diagram in the cutting polishing process, and the particle size is so small that the cutting polishing function is completely performed. Refers to lost cutting abrasives. The third cutting abrasive has a third particle size with a relatively small particle size compared to the second cutting abrasive.

The cutting powder removed in the third separation step S30 refers to a very small particle size powder discharged from the wafer ingot in the cutting polishing process.

Referring to FIG. 3, in the third separation step S30, the filtration membrane 161 is formed on the outside, and the cooling oil is recovered using the rotating drum 160 formed in a vacuum state lower than atmospheric pressure. The waste cutting polishing mixture 10 in which the second cutting abrasive is removed by the vacuum inside the rotating drum 160 passes through the filtration membrane 161 in the inward direction from the outside of the rotating drum 160, and the waste cutting polishing mixture 10 The cutting powder and the third cutting abrasive contained in the filter are filtered by the filtration membrane 161, and the coolant is sucked into the rotating drum 160 and recovered.

Rotating drum 160 is a receiving portion 162 for receiving the waste cutting polishing mixture 10 to be filtered in the third separation step (S30), and maintains a vacuum of about 400 ~ 700 mmHg inside the rotating drum 160 Vacuum pump 164, a drive unit (not shown) for rotating the rotating drum 160, and the filtration membrane 161, the cutting portion and the third cutting abrasive material is scraped off and discharged as waste to the new filter membrane 161 Is connected to devices such as a knife 163 to form a.

A filter membrane 161 including silica or diatomaceous earth is formed on the outside of the rotating drum 160, and a surface of the cutting powder and the third cutting abrasive accumulated in the filter membrane 161 using the knife 163 during the regeneration process is formed. By slicing and continuously supplying a new filtration membrane 161, it is possible to provide a larger amount of filtration and a faster filtration rate than a general filtration method.

In the third separation step (S30), by adjusting the rotational speed of the rotating drum 160, it is possible to adjust the filtration rate of the waste cutting polishing mixture 10, the second cutting abrasive is removed. Rotating drum 160 is rotated about the axis of rotation while being partially locked in the waste cutting polishing mixture 10 accommodated in the receiving portion 162 and the remaining portion is exposed to the air, waste cutting polishing mixture to be filtered to increase the rotational speed (10) ), The filtration speed of the waste cutting polishing mixture 10 can be increased.

In addition, by cutting the filtration membrane 161 by using the knife 163 to adjust the thickness of the filtration membrane 161, to control the filtration rate of the waste cutting polishing mixture 10 from which the second cutting abrasive is removed or the quality of the cooling oil recovered. It may be. The thicker the filtration membrane 161 is, the longer it takes for the waste cutting polishing mixture 10 to pass through the filtration membrane 161, so that the filtration speed of the waste cutting polishing mixture 10 is lowered, but more cutting powder and third cutting are required. The quality of the coolant recovered by filtering the abrasive is improved. Therefore, when the conditions allowed in the regeneration process are changed, the filtration rate and the quality of the cooling oil may be controlled by adjusting the thickness of the filtration membrane 161 using the knife 163.

The water removal step (S40) removes water from the cooling oil recovered through the third separation step (S30).

The cooling oil recovered in the rotating drum 160 in the third separation step S30 is transferred to the fourth tank 171, and the heat exchanger (not shown) supplies heat to the recovered cooling oil in the fourth tank 171. Is mounted). Water evaporated by the heat supplied from the heat exchanger is discharged to the outside together with air by the vacuum pump 172 connected to the fourth tank 171. The cooling oil from which water is removed is transferred to and stored in the fifth tank 176.

Meanwhile, a part of the cooling oil recovered through the third separation step S30 and the water removal step S40 is transferred to the sixth tank 180 in which silica powder or diatomaceous earth powder used for the filtration membrane 161 is stored. It may be mixed with silica powder or diatomaceous earth powder and used to form the filtration membrane 161.

The mixing step (S50), the third tank for storing the second cutting abrasive material recovered in the third separation step (S30) and stored in the fifth tank 176 separated in the second separation step (S20) ( 150) to form a cutting abrasive mixture by mixing the coolant and the second cutting abrasive.

In the mixing step (S50), first, the coolant and the second cutting abrasive are first mixed to generate a cutting polishing mixture to reach a first predetermined density (1.30 to 1.50 g / cc). In the process of mixing the coolant and the second cutting abrasive, the density of the cutting polishing mixture is continuously measured using a density meter (not shown).

Thereafter, a new cutting abrasive material which is not used in the cutting polishing process is added to reach the second density higher than the first density. The second density is the use density that the cutting polishing mixture used in the actual cutting polishing process should have and has a density of about 1.50 to 1.70 g / cc. The cutting abrasive mixture, in which the new cutting abrasive is added to reach the second density, is transferred to and stored in the seventh tank 190 in which the final product used in the actual cutting polishing process is stored.

In the iron removing step (S60), the iron powder is removed from the cutting polishing mixture generated in the mixing step (S50). In the cutting polishing process, the wire saw may be worn and iron may be mixed into the waste cutting polishing mixture. Iron remaining in the regeneration cutting grinding mixture may cause metal contamination on the wafer surface. Iron removal step S60 includes a first removal step and a second removal step.

In the first removing step, the magnetic separator 151 is mounted on the third tank 150 to remove iron molecules from the cutting polishing mixture generated in the mixing step S50. The cutting polishing mixture may be circulated between the third tank 150 and the magnetic separator 151 to remove iron molecules remaining in the cutting polishing mixture.

In the second removing step, an electrodeionizer 191 is mounted to the seventh tank 190 to remove iron ions from the cutting polishing mixture in which a new cutting abrasive is added using the electrical deionization. The cutting polishing mixture may be circulated between the seventh tank 190 and the electric deionizer 191 to remove iron ions remaining in the cutting polishing mixture.

In the waste cutting polishing mixture regeneration method according to the present embodiment configured as described above, the cutting abrasive having lost cutting function is removed from the high concentration and high viscosity waste cutting polishing mixture and the wafer is recovered by recovering a high-purity cooling oil. It can contribute to the prevention of environmental pollution by reducing the amount of wastes generated in the cutting and polishing process of the cutting process, and it is possible to obtain the effect of improving the quality and productivity of the wafer by using a high quality recycled cutting mixture.

In addition, the waste cutting polishing mixture regeneration method according to the present embodiment configured as described above, by forming a filtration membrane containing silica or diatomaceous earth and scraping off the surface unnecessarily accumulated during the regeneration process to continuously supply a new filtration membrane and rotating drum By adjusting the rotational speed of, it is possible to provide a larger amount of filtration and a faster filtration rate than the general filtration method, and to obtain an effect that can actively cope with the change in the allowable conditions.

In addition, the waste cutting polishing mixture regeneration method according to the present embodiment configured as described above removes moisture from the recovered cooling oil, thereby improving the viscosity of the cutting polishing mixture, preventing formation of bubbles due to frictional heat, and cutting In the polishing process, the cutting abrasive mixture may be evenly dispersed, thereby improving cutting polishing quality.

In addition, the waste cutting polishing mixture regeneration method according to the present embodiment configured as described above can obtain the effect of preventing metal contamination on the wafer surface by removing the iron powder remaining in the cutting polishing mixture.

In addition, the waste cutting polishing mixture regeneration method according to the present embodiment configured as described above, by mixing and diluting the recovered cooling oil to the waste cutting polishing mixture from which the first cutting abrasive is removed, the cutting agglomerated in the waste cutting polishing mixture The abrasive and the cutting powder can be easily separated to obtain an effect of improving the quality of the reclaimed cutting abrasive.

On the other hand, as a modification of the embodiment shown in Figure 1, the cooling oil purification step may be added. 4 is a view showing an example of a system for implementing a cooling oil purification step that can be added to the waste cutting polishing mixture regeneration method of FIG.

In the cooling oil purification step, the cooling oil recovered through the third separation step S30 may be purified by using the hollow fiber membrane 211 before mixing with the second cutting abrasive separated in the second separation step S20. . The cooling oil refined through the hollow fiber membrane 211 using compressed air is accommodated in the cooling oil purification tank 212 and then transferred to the third tank 150.

On the other hand, as a modification of the embodiment shown in Figure 1, cutting abrasive material purification step may be added. 5 is a diagram illustrating an example of a system for implementing a cutting abrasive purification step that may be added to the method for regenerating the waste cutting abrasive mixture of FIG. 1.

In the cutting abrasive refining step, a new cutting abrasive added to the cutting abrasive mixture in the mixing step S50 may be preliminarily purified using a part of the cooling oil recovered through the third separation step S30. In the cutting polishing material refining step, the coolant and the new cutting abrasive are mixed and stored in the mixing tank 221, and then the mixed liquid is transferred to the ultrasonic vibrator 222.

The cutting abrasive having a large particle size is removed through the ultrasonic vibrator 222 and the mixed liquid is stored in the first auxiliary tank 223. Thereafter, the new cutting abrasive is separated using a centrifugal separator 224, and the purified new cutting abrasive is transferred to the third tank 150, and the coolant is stored in the second auxiliary tank 225.

The scope of the present invention is not limited to the above-described embodiments and modifications, but may be embodied in various forms of embodiments within the scope of the appended claims. Without departing from the gist of the invention claimed in the claims, it is intended that any person skilled in the art to which the present invention pertains falls within the scope of the claims described in the present invention to various extents which can be modified.

110: ultrasonic vibrator
120: first tank
130: centrifuge
140: second tank
150: third tank
160: rotating drum
171: fourth tank
176: fifth tank
180: 6th tank
190: 7th tank

Claims (10)

In the waste grinding polishing mixture regeneration method of reclaiming a cutting abrasive material and a cooling oil by refining a waste abrasive polishing mixture containing a cutting abrasive, a cooling oil and a cutting powder generated in a wafer polishing process, recovering the cutting abrasive mixture.
A first separation step of removing the first cutting abrasive having a first particle size by applying ultrasonic vibration to the waste cutting polishing mixture;
Centrifuging the waste cutting polishing mixture from which the first cutting abrasive is removed, and separating the second cutting abrasive having a second particle size smaller than the first particle size, and the waste cutting polishing mixture from which the second cutting abrasive is removed. A second separation step;
Forming a filtration membrane outside the rotating drum, forming the inside of the rotating drum in a vacuum lower than atmospheric pressure, and filtering the waste cutting polishing mixture from which the second cutting abrasive is removed through the filtration membrane in an inward direction from the outside of the rotating drum. A third separation step of removing the cutting powder and the third cutting abrasive material having a third particle size smaller than the second particle size from the waste cutting abrasive mixture and recovering a cooling oil from the waste cutting abrasive mixture;
A mixing step of mixing the cooling oil recovered in the third separation step with the second cutting abrasive separated in the second separation step to generate a cutting abrasive mixture; And
And a iron removal step of removing iron from the cutting polishing mixture generated in the mixing step. The method of claim 1,
In the third separation step,
And the cutting powder and the third cutting abrasive are filtered by the filtration membrane, and the cooling oil is sucked into the rotating drum and recovered. The method of claim 2,
In the third separation step,
By adjusting the rotational speed of the rotating drum or the thickness of the filtration membrane, the pulverization of the waste cutting polishing mixture, characterized in that to control the filtration rate of the waste cutting polishing mixture from which the second cutting abrasive is removed or the quality of the recovered cooling oil. . The method of claim 1,
After the third separation step,
Recycling the waste cutting polishing mixture, further comprising: a water removal step of supplying heat to the recovered cooling oil to remove moisture from the recovered cooling oil by evaporating the moisture contained in the cooling oil to the outside. Way. The method of claim 1,
After the third separation step,
And a cooling oil refining step of refining the recovered cooling oil using a hollow fiber membrane. The method of claim 1,
A part of the cooling oil recovered through the third separation step is mixed with the silica powder or diatomaceous earth powder used for the filtration membrane to form the filtration membrane. The method of claim 1,
The mixing step,
The recovered grinding fluid is mixed with the second cutting abrasive to generate a cutting abrasive mixture to reach a predetermined first density,
A method for regenerating waste cutting mixture, characterized in that for adding a new cutting abrasive material not used in the cutting polishing process to reach the second density higher than the first density. The method of claim 7, wherein
After the third separation step,
And a cutting abrasive material refining step of refining the new cutting abrasive material of the mixing step by using a part of the cooling oil recovered through the third separation step. The method of claim 7, wherein
The iron removal step,
A first removal step of removing iron molecules from the cutting polishing mixture generated in the mixing step by using a magnetic separator;
And a second removing step of removing iron ions from the cutting polishing mixture to which new cutting polishing materials have been added by using the electrodeionization. The method of claim 1,
In order to separate the cutting abrasive and the cutting powder from the waste cutting abrasive mixture from which the first cutting abrasive is removed, a part of the cooling oil recovered through the third separation step is added to the waste cutting abrasive mixture from which the first cutting abrasive is removed. The method for regenerating the waste cutting polishing mixture, characterized in that to dilute the waste cutting polishing mixture passed through the first separation step.

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