JPH0636762U - Polishing waste liquid treatment device - Google Patents

Abstract

(57) [Summary] [Purpose] A reclaimed liquid (polishing liquid) suitable for re-use that can replenish a predetermined amount of coolant with high precision according to the flow rate and concentration of the secondary treatment liquid that has separated impurities from the polishing waste liquid. ) Quickly adjust. [Structure] After solid-liquid separation of the polishing waste liquid with a centrifuge, it is filtered with an electrostatic filter so that a predetermined amount of coolant can be replenished and mixed with the filtered liquid based on the flow rate and concentration of the filtered liquid so as to be adjusted. Constitution.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a polishing waste liquid treatment device.

[0002]

[Prior art]

 Conventionally, the recycling of polishing waste liquid has been widely practiced. For example, as disclosed in Japanese Patent Publication No. 58-30112, etc., generally, the polishing waste liquid is subjected to a solid-liquid separation treatment, and then treated. It regenerates by replenishing and mixing the required amount of coolant.

[0003]

[Problems to be solved by the device]

 However, this regeneration treatment is affected by the solid-liquid separation ability because the regeneration amount is replenished by directly supplying the required amount of coolant to the treatment liquid that has been solid-liquid separated by a screen or a centrifuge. Since the composition is not constant and the coolant is replenished and mixed into the solid-liquid separated processing liquid, the PH of the mixed liquid is measured to control the replenishment amount of the coolant in a predetermined manner, which makes rapid adjustment difficult. It had various drawbacks.

The present invention pays attention to such a situation, and as a result of diligent investigations from various aspects to solve the problem, 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 was found that the above-mentioned drawbacks can be solved all at once by controlling the replenishment amount of the coolant based on the flow rate and concentration of the secondary treatment liquid while filtering with a filter to obtain the secondary treatment liquid. Of.

[0005]

[Means for Solving the Problems]

 That is, the polishing waste liquid treatment apparatus according to the present invention comprises a centrifugal separator for solid-liquid separation of polishing waste liquid and an electrostatic filter for filtering the primary treatment liquid supplied directly from the centrifuge or through an intermediate storage tank. Based on the flow rate and concentration of the secondary treatment liquid, and a regenerant storage tank that stores a regenerant liquid in which a secondary treatment liquid supplied from the electrostatic filter and a coolant supplied from a coolant replenishing device are mixed. In addition, a coolant replenishment amount control device for controlling the replenishment amount of the coolant is provided.

[0006]

【Example】

 An embodiment according to the present invention will be described below with reference to the drawings. In FIG. 1, this polishing waste liquid treatment device includes a centrifuge 1, an electrostatic filter 2, a coolant replenishing device 3, and a coolant replenishment amount control. It is equipped with a device 4, a stock solution storage tank 5, an intermediate storage tank 6, a reclaimed solution storage tank 7, and the like.

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 due to this filtration (solid particles leaked during solid-liquid separation by the centrifuge 1) Are removed. At that time, the solid-liquid separation of the pretreatment is performed by the centrifuge 1, so that 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 coolant component, which is a valent substance, suspended in the emulsion state, and is dissolved in other solid-liquid separation means. This is because even if it is possible to prevent the removal of the existing coolant components, it is difficult for the coolant components 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 is then removed. The particles are 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 regenerant storage tank 7 via the pipe 11, and at the same time, the coolant is supplied by the coolant replenishing device 3 to the secondary treatment liquid. It is replenished with the next processing 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. Further, the valves 13 and 14 can be opened in a predetermined manner so that a part of the coolant extracted from the tank 15 can be circulated and the rest can be replenished to the secondary treatment liquid.

The coolant replenished with the secondary treatment liquid is mixed with the secondary treatment liquid by the static mixer 19 attached to the pipe 11, and the mixed liquid (hereinafter, this is regenerated). Liquid) is sent to the regeneration liquid storage tank 7. In such coolant replenishment, the coolant replenishment amount control device 4 controls the replenishment amount to a predetermined amount.

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

Since the measuring device 20 uses the ultraviolet absorptiometer as the concentration measuring means, it is possible to quickly and accurately measure even the secondary treatment liquid which is flowing down. It can be controlled with high precision and can be always maintained in a regenerant liquid having a constant composition, and a polishing liquid suitable for reuse can be obtained.

The regenerant storage tank 7 is equipped 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, reference numerals 24 to 26 denote pumps attached to the respective pipelines, and 27 to 29 denote circulation pipelines.

Although one embodiment according to the present invention has been described above, in the present invention, the primary treatment liquid is directly supplied from the centrifuge 1 to the electrostatic filter 2 without installing the intermediate storage tank 6. Good. Further, the coolant may be of any composition, such as one containing a polishing powder dispersant such as a surfactant, an anti-aggregation agent or an anticorrosive agent, and other liquid additive for polishing liquid. Good.

[0016]

[Effect of device]

 As described above, according to the present invention, since the centrifugal separator and the electrostatic filter are used, it is possible to satisfactorily remove the solid particles while preventing the removal of the coolant component which is the valuable material in the polishing waste liquid, and Since 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 is installed, a polishing liquid suitable for reuse with a constant composition is always obtained. be able to.

[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.