JP2002292566A - Recovering method for non-oxide based ceramic grinding powder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recovering method for non-oxide based ceramic grinding powder in which non-oxide based ceramic grinding powder contained in an abrasive liquid exhausted in grinding work of non-oxide based ceramic can be excellently and easily recovered. SOLUTION: In a recovering method for non-oxide based ceramic grinding powder in which non-oxide based ceramic grinding powder contained in the abrasive liquid exhausted in grinding work of non-oxide based ceramic is recovered, after adding oil to a grinding liquid and scattering the oil evenly in the grinding liquid, the non-oxide based ceramic grinding powder is deposited onto the oil. Then, phase separation is carried out, whereby the non-oxide based ceramic grinding powder is recovered in the oil phase.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for effectively separating and recovering non-oxide ceramic grinding powder from a grinding fluid discharged in the grinding of non-oxide ceramic.

[0002]

2. Description of the Related Art Various ceramic products made of non-oxide ceramics have been proposed. As a ceramic product made of such a non-oxide-based ceramic, for example, by passing exhaust gas discharged from an internal combustion engine of a vehicle such as a bus or a truck or a construction machine through a porous ceramic, A ceramic filter that collects contained particulates and purifies exhaust gas may be used.

As such a ceramic filter, for example, a plurality of porous ceramic members 40 as shown in FIG. 3 are bound via an adhesive layer 34 to form a cylindrical ceramic block 35, and a seal is provided on the outer periphery thereof. The honeycomb filter 30 on which the material layer 33 is formed is used. As shown in FIG. 4, the porous ceramic member 40 has a large number of through holes 41 arranged in the longitudinal direction, and a partition 43 separating the through holes 41 functions as a filter.

That is, as shown in FIG. 4B, the through hole 41 formed in the porous ceramic member 40 has a filler 42 at one of the inlet and outlet ends of the exhaust gas.
The exhaust gas that has been plugged in and has flowed into one through hole 41 always passes through a partition 43 separating the through hole 41 and then flows out from another through hole 41. When passing through, the particulates are trapped in the partition 43 and the exhaust gas is purified.

As a non-oxide ceramic material constituting such a porous ceramic member 40, silicon carbide is
Since it has extremely excellent heat resistance and is easy to regenerate, it is used for various large vehicles and vehicles equipped with a diesel engine.

Conventionally, such a porous ceramic member is prepared by first mixing a ceramic powder, a binder and a dispersion medium to prepare a mixed composition for producing a molded body, and then extruding the mixed composition. Is performed to produce a ceramic molded body, and further, the ceramic molded body is degreased and fired to produce the ceramic molded body.

Further, a plurality of the obtained porous ceramic members are bound via an adhesive layer to produce a prismatic ceramic structure, and the outer periphery of the ceramic structure is shown in FIG. 3 using a grinding member. After performing a grinding process for grinding into a cylindrical shape like the ceramic block 35 to produce a ceramic block, a sealing material layer is formed on the outer periphery of the ceramic block to produce a honeycomb filter as shown in FIG. I was

Here, it is necessary to perform the grinding while supplying a grinding liquid between the ceramic structure and the grinding member. This is because of the cooling of the frictional heat generated between the ceramic structure and the grinding member, the high accuracy and high quality of the ceramic block to be produced, the prevention of the deterioration of the grinding member, the reduction of the amount of wear, and the ceramic grinding powder. However, the grinding fluid discharged through such a grinding process contains ceramic grinding powder for the reason of preventing scattering of the powder.

[0009]

Most of the particle size of the ceramic grinding powder contained in such a grinding fluid is 1%.
Since it is a very small fine powder of about μm, it is generally difficult to collect only the above-mentioned ceramic grinding powder with a paper filter type filtration device used for filtering non-ferrous materials. Therefore, in order to recover the ceramic grinding powder from the above-mentioned grinding fluid, it was necessary to use a special filtering device such as a centridge separator (a centrifugal filter) or a silicon earth filter.

[0010] However, the introduction of such a special filtration device causes an increase in processing cost, and its structure is complicated and proper maintenance is complicated, so that it is economically disadvantageous. The above-mentioned ceramic grinding powder had to be discarded together with the grinding fluid.

[0011]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a non-oxide ceramic grinding powder contained in a grinding fluid discharged in the grinding of a non-oxide ceramic. And a method for recovering non-oxide-based ceramic grinding powder that can be suitably and easily recovered.

That is, the present invention relates to a method for recovering non-oxide ceramic grinding powder for recovering non-oxide ceramic grinding powder contained in a grinding fluid discharged in grinding of non-oxide ceramic, Add oil to the above grinding fluid,
In the above-mentioned grinding fluid, after uniformly dispersing the above-mentioned oil, the above-mentioned non-oxide ceramic grinding powder is made to adhere to the above-mentioned oil, and then, by performing phase separation, the above-mentioned non-oxide ceramics A method for recovering non-oxide ceramic grinding powder, comprising recovering grinding powder. Hereinafter, the present invention will be described specifically with reference to embodiments.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a method for recovering non-oxide ceramic grinding powder for recovering non-oxide ceramic grinding powder contained in a grinding fluid discharged in the grinding of non-oxide ceramic. Then, after adding an oil component to the grinding fluid and dispersing the oil component uniformly in the grinding fluid,
Non-oxide ceramic grinding powder characterized in that the non-oxide ceramic grinding powder is adhered to the oil component, and thereafter, phase separation is performed to collect the non-oxide ceramic grinding powder in the oil phase. This is a method for collecting powder.

In the method for recovering non-oxide ceramic grinding powder of the present invention (hereinafter also referred to as the recovery method of the present invention), the object to be recovered is non-oxide ceramic grinding powder and exhibits hydrophobic properties. Ceramic powder. In general, many non-oxide ceramics exhibit hydrophobic properties, and such non-oxide ceramics exhibiting such hydrophobic properties are preferably prepared by the recovery method of the present invention in which an oil component is added to a grinding fluid. This is because it can be collected. The reason will be described later in detail. In addition, examples of such a non-oxide ceramic include silicon carbide, silicon nitride, and the like.

The grinding fluid is not particularly limited, and any of a straight type, a solution type, a soluble type and an emulsion type can be used.

Further, the recovery method of the present invention mainly comprises a grinding fluid storage step, a grinding fluid separation step, and a recovery step.

Hereinafter, the recovery method of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view for explaining the recovery method of the present invention, and FIG. 2 is a partially enlarged sectional view schematically showing a nozzle used in the recovery method of the present invention.

In the recovery method of the present invention, first, a grinding fluid storing step is performed. In the above-mentioned grinding fluid storage step, the processing machine 1
The grinding fluid containing the non-oxide ceramic grinding powder discharged from 1 is stored in the grinding fluid tank 10 via the storage pipe 150.

The processing machine 11 is not particularly limited as long as it can grind a non-oxide ceramic.
For example, by grinding a non-oxide ceramic while rotating a cylindrical grinding member provided with a diamond grindstone at its tip, a cylindrical grinding device or an endless tape-shaped flat blade is rotated. For grinding non-oxide ceramics.

Next, a grinding fluid separation step is performed. In this grinding fluid separation step, after a certain amount of grinding fluid containing non-oxide ceramic is stored in the grinding fluid tank 10, the high pressure pump 18
The grinding fluid containing the non-oxide ceramic grinding powder is sent to the two-fluid nozzle 13 through the suction pipe 130. At the same time, a predetermined amount of oil is supplied from the oil tank 12 to the two-fluid nozzle 13 to add the oil to the grinding fluid.

The oil content is not particularly limited, and, for example, commercially available processing machine oil or the like can be used.
It is desirably 0 to 20 L. If the amount added to 1000 L of the grinding fluid is less than 10 L, the amount of oil in the grinding fluid is small, and the non-oxide ceramic grinding powder cannot be sufficiently collected. On the other hand, the addition amount to 1000 L of the grinding liquid is 20 L, which is an amount that can sufficiently collect the non-oxide-based ceramic grinding powder. Therefore, the addition of an oil content exceeding 20 L only causes an increase in the processing cost.

Next, the grinding fluid to which the oil has been added is stored again in the grinding fluid tank 10, and the oil is uniformly dispersed in the grinding fluid. The material-based ceramic grinding powder is adhered to the oil, and then the grinding fluid containing the oil is allowed to stand, so that the oil phase 16
And the grinding liquid phase 17 to separate the non-oxide ceramic grinding powder into the oil phase 16. Here, it is considered that the non-oxide-based ceramic grinding powder can be recovered in the oil phase for the following reasons.

As described above, the object to be recovered in the recovery method of the present invention is a ground powder made of a non-oxide ceramic having hydrophobic properties, and the non-oxide ceramic having such hydrophobic properties is ground. Grinding powder has a low affinity for water. Therefore, in the above-mentioned grinding fluid, it is considered that the non-oxide ceramic grinding powder easily adheres to the oil uniformly dispersed in the above-mentioned grinding fluid. That is, the non-oxide ceramic grinding powder is selectively supplied to the grinding fluid tank 1.
The non-oxide-based ceramic grinding powder, together with the oil component, adheres to the oil component uniformly dispersed in the oil and then separates the oil phase 16 and the grinding liquid phase 17 by allowing the grinding liquid to stand still. It is believed that they migrate and are recovered in the oil phase 16.

It is desirable to stir the grinding fluid after adding oil to the grinding fluid. This is because the oil can be more uniformly dispersed in the grinding fluid. In particular,
The two-fluid nozzle 13 is provided with a stirrer for stirring the grinding fluid and the oil, or the grinding fluid tank 10 is provided with a stirring means such as a stirring rod or a stirring blade, so that the grinding fluid and the oil can be mixed. Can be stirred.

It is desirable that after the oil is added to the grinding fluid, high-pressure air is further blown into the grinding fluid to cause foaming. By foaming the grinding fluid, the oil can be more uniformly dispersed in the grinding fluid, and the phase separation between the grinding fluid and the oil can be promoted. Further, in the recovery method of the present invention, the grinding fluid may be foamed and the grinding fluid may be stirred. This is because the oil can be more quickly and uniformly dispersed in the grinding fluid, and phase separation can be promoted.

The pressure of the air at this time is 5 to 10
It is desirable to be MPa. This is because the grinding fluid can be suitably foamed.

When blowing high-pressure air into such a grinding fluid for foaming, it is desirable to use a nozzle as shown in FIG. The nozzle 23 shown in FIG.
Three flow paths through which the grinding fluid, oil and air flow are formed, and these substances are mixed in the middle of the nozzle 23 and pass through the stirrer 21. That is, by using the nozzle 23, the grinding fluid, oil, and air mixed in the nozzle 23 are stored in the grinding fluid tank 10 shown in FIG. Accordingly, when the grinding fluid is stored in the grinding fluid tank 10, the oil and air are considerably dispersed in the grinding fluid.

Next, a recovery step is performed. In this recovery step, in the grinding fluid tank 10, the grinding fluid containing the oil is
After completely separating the oil phase 16 and the grinding liquid phase 17, the oil phase 16 is discharged from the discharge pipe 14 to the outside.

The oil phase 16 thus discharged to the outside contains diamond powder and the like together with the above oil and non-oxide ceramic grinding powder. In the grinding process of the non-oxide ceramic, usually, the non-oxide ceramic is ground using a grinding member provided with a diamond grindstone. This is because they gradually wear and are discharged into the grinding fluid.

The oil phase 16 containing such oil, non-oxide ceramic grinding powder and diamond powder is then carried into an oxidation furnace and heated to 400 to 700 ° C. to burn off the oil and diamond powder. As a result, only the non-oxide ceramic grinding powder remains, and a reusable non-oxide ceramic powder can be obtained.

The oxidizing furnace is not particularly limited as long as it can heat the oil phase 16 to the above-mentioned temperature. For example, a degreasing furnace used when manufacturing non-oxide ceramic products is used. be able to.

The grinding liquid phase 1 after removing the oil phase 16
Since the non-oxide-based ceramic grinding powder is hardly contained in the grinding fluid in 7, it can be reused as the grinding fluid. When the grinding fluid is thus reused, the high-pressure pump 1
By operating 80, the grinding fluid may be sent from the grinding fluid tank 10 to the processing machine 11 via the circulation pipe 15.

As explained above, the recovery method of the present invention
Utilizing the hydrophobicity of non-oxide ceramics,
This is to separate and collect non-oxide ceramic grinding powder contained in the grinding fluid discharged in the grinding process. Therefore, according to the recovery method of the present invention, the non-oxide-based ceramic grinding powder contained in the above-mentioned grinding fluid can be satisfactorily and easily recovered without newly providing a special filtering device. Further, according to the recovery method of the present invention, the processing cost for recovering the non-oxide ceramic grinding powder can be kept low, and the recovered non-oxide ceramic grinding powder and non-oxide ceramic powder can be removed. Since the recovered grinding fluid can be reused, its economic effect is also large.

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Example 1 In this example, the non-oxide ceramic grinding powder contained in the grinding fluid discharged in the grinding process for manufacturing a honeycomb filter, which was described in the prior art, was collected.

In this embodiment, the non-oxide ceramic grinding powder is a silicon carbide powder having an average particle size of 1 μm.
Met. The grinding fluid used in the above-mentioned grinding was N-150 (Noritake Cool) of Chemical Solution, and the grinding member used was a diamond grinding stone having diamond powder bonded with a resin bond.

First, as a grinding fluid storage step, 1000 L of the above-described grinding fluid was stored in a grinding fluid tank 10 as shown in FIG. In addition, this grinding fluid contained, along with the silicon carbide powder, a small amount of diamond powder that had fallen off due to wear of the diamond grindstone of the grinding member.

Next, as a grinding fluid separation step, the high-pressure pump 18 is operated to suck the grinding fluid from the suction pipe 130, and at the same time, from the oil content tank 12 to the processing machine oil (Uniway SF # 68 manufactured by Nisseki Mitsubishi Corp.). Slowly add
It was mixed with the grinding fluid in the two-fluid nozzle 13 and stored in the grinding fluid tank 10 again. The total amount of the processing machine oil was 20 L.

Next, the high-pressure pump 18 is continuously operated to circulate the grinding fluid containing the processing machine oil for a while to uniformly disperse the processing machine oil in the grinding fluid, and then the high-pressure pump 18 is stopped. The above-mentioned grinding fluid was allowed to stand and phase-separated into a grinding fluid phase and a processing machine oil phase.

Then, as a recovery step, the grinding fluid tank 1
The oil phase of the processing machine separated into the upper layer
And the oil phase of the processing machine was carried into the oxidation furnace. Thereafter, the oil phase of the processing machine was set to 70
By heating to 0 ° C. and burning off the processing machine oil, diamond powder and the like, 700 g of silicon carbide powder could be recovered per 1 L of processing machine oil.

Example 2 The same as Example 1, except that the total addition amount of the processing machine oil added to the grinding fluid was 15 L, and a stirring blade was provided in the grinding fluid tank 10 so that the processing machine oil was removed. The grinding fluid was stirred. Thereafter, a phase is separated into a grinding liquid phase and a processing machine oil phase in the same manner as in Example 1. After the processing machine oil phase is discharged, the processing machine oil phase is heated to 700 ° C. in an oxidation furnace.
Heated. As a result, 1000 g of silicon carbide powder could be recovered per 1 L of processing machine oil.

Example 3 The same as Example 1, except that the total amount of processing machine oil added to the grinding fluid was 10 L, and the pressure of 8 MPa was applied using a nozzle as shown in FIG. Air was blown in to cause the grinding fluid to foam. Thereafter, a phase was separated into a grinding liquid phase and a processing machine oil phase in the same manner as in Example 1. After the processing machine oil phase was discharged, the processing machine oil phase was heated to 700 ° C. in an oxidation furnace. As a result, processing machine oil 1
1500 g of silicon carbide powder per L could be recovered.

Further, in the grinding fluid phase after the oil phase of the working machine according to Examples 1 to 3 was discharged, almost no silicon carbide powder was present, and the grinding fluid phase could be reused as the grinding fluid. Was something.

[0043]

As is clear from the above description, according to the method for recovering non-oxide ceramic grinding powder of the present invention, non-oxide ceramic grinding powder can be preferably used without using a special filtering device. And it can be easily collected.
In addition, the processing cost for collecting the non-oxide ceramic grinding powder can be kept low, and the recovered non-oxide ceramic grinding powder, and the grinding fluid after the collection of the non-oxide ceramic grinding powder, Since it can be reused, the economic effect is great.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a method for collecting non-oxide ceramic grinding powder according to the present invention.

FIG. 2 is a partially enlarged cross-sectional view schematically showing a nozzle used in the method for collecting non-oxide ceramic grinding powder of the present invention.

FIG. 3 is a perspective view schematically showing a honeycomb filter which is an example of a non-oxide ceramic product.

4 (a) is a perspective view schematically showing a porous ceramic member constituting the honeycomb filter shown in FIG. 3, and FIG. 4 (b) is a cross-sectional view taken along the line AA.

[Explanation of symbols]

 Reference Signs List 10 grinding fluid tank 11 processing machine 12 oil tank 13 two-fluid nozzle 14 discharge pipe 15 circulation pipe 16 oil phase 17 grinding fluid phase 18,180 high-pressure pump 130 storage pipe 150 suction pipe 21 stirrer 23 nozzle

Claims (3)

[Claims] 1. A non-oxide ceramic grinding powder recovery method for recovering non-oxide ceramic grinding powder contained in a grinding fluid discharged in a grinding process of a non-oxide ceramic, comprising: After adding an oil component and uniformly dispersing the oil component in the grinding fluid, the non-oxide-based ceramic grinding powder is adhered to the oil component, and thereafter, a phase separation is performed, whereby the oil phase is separated into an oil phase. A method for collecting non-oxide ceramic grinding powder, comprising collecting non-oxide ceramic grinding powder. 2. The method according to claim 1, wherein the oil is dispersed by stirring the grinding fluid after adding the oil to the grinding fluid.
The method for collecting non-oxide ceramic grinding powder according to the above. 3. The grinding fluid is further foamed by adding high-pressure air to the grinding fluid after adding oil to the grinding fluid.
Or the method for collecting non-oxide ceramic grinding powder according to item 2.