JPH085008Y2 - Polishing waste liquid treatment device - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing waste liquid treatment device.

[0002]

2. Description of the Related Art Conventionally, the recycling of polishing waste liquid has been widely practiced. For example, as disclosed in Japanese Examined Patent Publication No. 58-30112, the polishing waste liquid is generally subjected to solid-liquid separation treatment and then The processing liquid is regenerated by replenishing and mixing the required amount of coolant.

[0003]

However, such a regeneration treatment involves solid-liquid separation because it regenerates by replenishing the required amount of coolant directly to the treatment liquid that has been solid-liquid separated by a screen or a centrifuge. The composition of the regenerating liquid is not constant due to the performance, and while the coolant is replenished and mixed with the treatment liquid that has been solid-liquid separated, the PH of the mixed liquid is measured to control the replenishment amount of the coolant in a predetermined manner. It has various drawbacks such as difficulty in quick adjustment.

The present invention pays attention to such a situation, and as a result of intensive studies from various directions to solve this, as a result, the primary treatment liquid obtained by solid-liquid separation of the polishing waste liquid with a centrifugal separator is further electrostatically filtered. It has been found that the above-mentioned drawbacks can be solved at once by controlling the replenishment amount of the coolant based on the flow rate and the concentration of the secondary treatment liquid while filtering to obtain the secondary treatment liquid. is there.

[0005]

[Means for Solving the Problems] That is, a polishing waste liquid treatment apparatus according to the present invention comprises a centrifuge for solid-liquid separating the polishing waste liquid, and a primary separator supplied directly from the centrifuge or through an intermediate storage tank. An electrostatic filter for filtering the processing liquid, a regenerating liquid storage tank for storing a regenerating liquid in which a secondary processing liquid supplied from the electrostatic filter and a coolant supplied from a coolant replenishing device are stored, and the secondary processing A coolant replenishment amount control device for controlling the replenishment amount of the coolant based on the flow rate and the concentration of the liquid.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, this polishing waste liquid treatment device includes a centrifugal separator 1, an electrostatic filter 2, a coolant replenishing device 3, Coolant replenishment amount control device 4, stock solution storage tank 5, intermediate storage tank 6, regenerated liquid storage tank 7
And so on.

The separator 1 solid-liquid separates the polishing waste liquid supplied from the stock solution storage tank 5 through the pipe line 8. As a result, most of the solid particles in the polishing waste liquid are removed, and the primary treatment liquid is sent to the intermediate storage tank 6 via the pipe 9. Then, from here, it is supplied to the electrostatic filter 2 through the pipe line 10 and filtered, and the residual solid particles in the primary treatment liquid (solid particles leaked during solid-liquid separation by the centrifuge 1) are filtered by this filtration. To be removed. At that time, since the solid-liquid separation of the pretreatment is performed by the centrifugal separator 1, the clogging of the electrostatic filter 2 can be prevented for a long period of time.

The centrifuge 1 is used to prevent the removal of the valuable coolant component suspended in the emulsion state, and other solid-liquid separation means
This is because even if the removal of the dissolved coolant component can be prevented, it is difficult for the coolant component suspended in the emulsion state.

That is, most of the solid particles are removed by centrifugal force by utilizing the difference in specific gravity between the coolant having a specific gravity of about 1 and the solid fine particles having a specific gravity of about 2, and the leaked solid particles are removed. Is removed by the electrostatic filter 2 having a larger opening than the coolant.

Thereafter, the secondary treatment liquid discharged from the electrostatic filter 2 is sent to the regeneration liquid storage tank 7 through the pipe line 11, and at the same time, the coolant is replenished by the coolant replenishing device 3 to perform the secondary treatment. It is replenished with liquid. In this replenishing device 3, the coolant stored in the tank 15 can be circulated by the pump 16 with the valve 13 closed and the valve 14 opened, that is, the coolant can be circulated through the pipelines 17 and 18. , And open the valves 13 and 14 as desired,
It is possible to circulate a part of the coolant extracted from the tank 15 and replenish the rest with the secondary treatment liquid.

The coolant replenished with the secondary treatment liquid is mixed with the secondary treatment liquid by the static mixer 19 mounted on the pipe 11, and the mixed liquid (hereinafter,
This is called a regenerant. ) Is sent to the regenerant storage tank 7. In such coolant replenishment, the coolant replenishment amount control device 4 controls the replenishment amount to a predetermined level.

The replenishment amount control device 4 measures the flow rate and concentration of the secondary treatment liquid discharged from the electrostatic filter 2 by means of the measuring device 20 mounted on the pipe line 11, and outputs the measured signals as those measurement signals. A motor 21 that drives the pump 16 based on
Is controlled in a predetermined manner to control the amount of coolant replenishment.

Since the measuring device 20 uses the ultraviolet ray absorptiometer as the concentration measuring means, it is possible to quickly and accurately measure even the secondary treatment liquid which is flowing down. Therefore, the motor 21 is highly accurate. Can be controlled to a constant value, and a regenerated liquid having a constant composition can be always maintained, and a polishing liquid suitable for reuse can be obtained.

The regenerant storage tank 7 is provided with a circulation line 22 for circulating the regenerant, and the regenerant (polishing liquid) is pumped to a polishing work site via a line 23. . In the figure, 24 to 26 indicate pumps attached to the respective pipelines, and 27 to 29 indicate circulation pipelines.

Although one embodiment according to the present invention has been described above, in the present invention, the intermediate treatment tank 6 is not installed and the primary treatment liquid is directly supplied from the centrifuge 1 to the electrostatic filter 2. Good. Further, the coolant may have any composition, such as one containing a polishing powder dispersant such as a surfactant, an agglomeration inhibitor or a rust preventive agent, and other liquid additive for polishing liquid.

[0016]

As described above, according to the present invention, since the centrifugal separator and the electrostatic filter are used, the solid particles are satisfactorily removed while preventing the removal of the valuable coolant component in the polishing waste liquid. Since it is equipped with a coolant replenishment amount control device that replenishes a predetermined amount of coolant based on the flow rate and concentration of the secondary treatment liquid from the electrostatic filter, it is always suitable for reusing a constant composition. A polishing liquid can be obtained.

[Brief description of drawings]

FIG. 1 is a flow sheet diagram of a polishing waste liquid processing apparatus.

[Explanation of symbols]

 1 Centrifuge 2 Electrostatic Filter 3 Coolant Replenishing Device 4 Coolant Replenishing Volume Control Device 5 Stock Solution Storage Tank 6 Intermediate Storage Tank 7 Regeneration Liquid Storage Tank

Claims (1)

[Scope of utility model registration request] 1. A centrifuge for solid-liquid separating the polishing waste liquid, and an electrostatic filter for filtering the primary treatment liquid supplied from the centrifuge directly or through an intermediate storage tank.
A regeneration liquid storage tank that stores a regeneration liquid in which a secondary treatment liquid supplied from the electrostatic filter and a coolant supplied from a coolant replenishing device are stored, and the coolant based on the flow rate and concentration of the secondary treatment liquid. And a coolant replenishment amount control device for controlling the replenishment amount of the polishing waste liquid treatment device.