JP2001310259A - Briquette of polishing sludge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily squeeze out coolant from polishing sludge containing oil coolant, to easily solidify polishing sludge, and t form strong briquette hardly collapsing. SOLUTION: This briquette B is solidified by squeezing the polishing sludge containing oil coolant generated in a polishing line for sintering parts, and formed into a cylindrical shape with a hollow part (a) in the center thereof. The hollow part (a) is formed, for example, as a through-hole penetrating both end surfaces of the briquette B, and the briquette B is formed to be a thick cylindrical shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for solidifying grinding sludge generated in a grinding line for hardened parts, for example, iron-based components such as inner and outer rings of rolling bearings and rolling elements, and grinding sludge of other steel materials for bearings. The present invention relates to a solidified grinding sludge (hereinafter referred to as "briquette").

[0002]

2. Description of the Related Art Iron-based components such as inner and outer races and rolling elements of a rolling bearing are hardened after quenching.
The rolling surface and the like are ground. The powdery grinding waste generated by the grinding is discharged as sludge together with the coolant outside the machine, and after filtration, the coolant is reused for grinding. Grinding sludge remaining by filtration is landfilled as sludge. FIG. 8 is a block diagram showing the flow of the processing. Grinding debris generated by the grinding machine 101 is conveyed through a pipe together with a coolant, filtered by a filtering means 102 such as a filter or a sedimentation facility, and the purified coolant is filtered by a coolant tank 103 for supply to the grinding machine 101. And return via pump. Since the grinding sludge remaining after filtration contains a large amount of coolant, it cannot be reused, and a disposal company of industrial waste performs disposal processing such as landfill. The amount of grinding waste generated by grinding is small compared to cutting, etc., but in mass production lines such as bearings, the amount generated is large, and landfilling of grinding sludge is not only unfavorable from the environmental point of view, but also It is clear that landfills will no longer be possible due to dead ends in the treatment plant.

[0003] For this reason, it has been studied to solidify the grinding sludge by squeezing and reuse the squeezed coolant and to reuse the solidified briquette as a steelmaking material. Grinding sludge using an aqueous coolant can be easily solidified, and solidifying machines have already been sold. However, oil-based coolant has a higher viscosity than aqueous coolant, and grinding sludge using oil-based coolant has various problems in solidification. For example, when squeezed, the oil-based coolant is difficult to discharge, and cannot be solidified to a required strength simply by increasing the pressure during squeezing. Therefore, solidification of grinding sludge containing oil-based coolant has not yet been put to practical use.

[0004] In a grinding line for polishing and removing surface flaws of a metal strip in the process of manufacturing a rolled steel strip, grinding sludge is filtered, solidified by pressing and collected as briquettes, and is used for steelmaking. It has been proposed to use it again. In the grinding sludge generated by grinding the rolled steel strip, grinding chips in the grinding sludge are relatively soft and easily solidified. In addition, this grinding sludge has a low proportion of coolant, which also facilitates solidification. However, in the case of hardened part grinding sludge, grinding debris is hard and hard to harden. Therefore, it is necessary to squeeze strongly, but in the grinding sludge of oil-based coolant as described above,
Since it is difficult to discharge the coolant during squeezing, it is more difficult to solidify the coolant. Also, in the case of grinding sludge for hardened parts,
For example, for grinding 1 to 2 g of steel, several liters of coolant /
Since min is used, the ratio of coolant in the grinding sludge is large, and solidification is difficult because most of the coolant is coolant.

Conventionally, briquettes obtained by solidifying cutting powder,
As shown in FIG. 7, the briquette obtained by solidifying the grinding sludge of the aqueous coolant has a cylindrical shape. However, in order to efficiently squeeze the highly viscous oil-based coolant, it is considered advantageous to increase the inner and outer peripheral lengths of the briquette B ″ without reducing the surface pressure at the time of pressing. It has been proposed to provide a passage for discharging the oil component in the punch, or to provide a pressure valve. However, there is a possibility that a problem such as clogging of sludge may occur, which is not practical.

An object of the present invention is to provide a solidified solidified grinding sludge which is easy to squeeze and solidify a coolant and is hard to collapse.

[0007]

The solidified grinding sludge of the present invention is a solidified material obtained by solidifying grinding sludge containing oil-based coolant generated in a grinding line of a quenched part by pressing, and has a hollow portion in the center. Characterized by being formed in a columnar shape having According to the solidified material of this configuration, since it has a shape having a hollow portion in the center, the inner and outer peripheral lengths can be increased without increasing the cross-sectional area affecting the surface pressure at the time of squeezing compared to a solid cylindrical shape. This makes it easier for the coolant to be squeezed out during squeezing. That is, the coolant oozes out from the inner surface of the cavity, and the coolant is easily squeezed out. Therefore, even with grinding sludge containing oil-based coolant, it is easy to solidify by pressing, and the coolant can be efficiently discharged without providing a separate discharge passage. Further, even if the grinding waste is hard and fine grinding sludge of a hardened part, the coolant can be easily squeezed out, so that the solidification can be quickly performed. For this reason, it becomes a hard solidified material that is difficult to collapse. Note that the shape of the hollow portion is preferably cylindrical.

[0008] The cavity may be a through-hole penetrating both end surfaces of the solidified material. In the case of a cylindrical shape having a through hole at the center, that is, a cylindrical shape, the inner and outer peripheral lengths, which are the coolant discharge areas, can be increased over the entire length. Therefore, the coolant outflow gap can be increased without lowering the surface pressure with the same amount of sludge as compared with the case of the cylindrical shape, and solidification becomes easy.

When the solidified product is formed into a cylindrical shape as described above, the ratio of the inner diameter D2 of the hollow portion to the outer diameter D1 of the solidified product is preferably D2 / D1 = 0.40 to 0.60. The larger the ratio, the larger the surface area can be obtained. However, if the outer diameter of the solidified product is increased, there is a problem that the solidified product manufacturing apparatus becomes large. Further, when the outer diameter of the solidified material increases, the wall thickness between the inner and outer peripheral surfaces of the solidified material decreases, and when the ratio exceeds 0.60, there is a problem that the wall thickness is easily collapsed due to the small thickness. If the above ratio is small, the effect of increasing the surface area is not sufficient, and if this ratio is less than 0.4, it is difficult to obtain the effect of the ease of squeezing out the coolant due to the formation of the cavity.

In the solidified product of the present invention, the coolant in the solidified product is oily, and the amount thereof is 5 to 10 wt.
% May be used. When the solidified material is reused as a steelmaking material, it is preferable that the amount of coolant as an impurity is small. Coolant amount is 10wt%
If it exceeds 300, it is difficult to reuse it as a steelmaking material, and the strength tends to be insufficient.

In the solidified product of the present invention, the hardened part of the grinding sludge may be an iron-based component of a rolling bearing. The iron-based component is, for example, an inner ring, an outer ring, or a rolling element. In the process of grinding rolling bearing components, oil-based coolant is often used,
In addition, grinding sludge is hard and fine, and grinding sludge which is difficult to solidify is generated. However, the grinding waste is grinding waste such as high-quality bearing steel and is generally mass-produced, so that it becomes grinding sludge having a constant component. Therefore, when it is solidified, a high-quality solidified material is obtained as a steelmaking material. In addition, the conditions for pressing for solidification are easily set, and solidification can be stably performed by setting appropriate conditions.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. The briquette B is a briquette obtained by solidifying grinding sludge containing oil-based coolant generated in a grinding line of a quenched part by squeezing, and is formed in a column shape having a hollow portion a in the center. Cavity a
Is a through-hole having a circular cross section penetrating both end surfaces of the briquette B, and the briquette B has a thick cylindrical shape. Inner diameter D of cavity a with respect to outer diameter D1 of briquette B
The ratio of 2 is D2 / D1 = 0.40 to 0.60. The ratio of the height H to the outer diameter D1 is H / D1 = 0.
The range is 5 to 1.0.

The component of the briquette B is a steel material mainly composed of grinding chips, the amount of the coolant is 5 to 10 wt%, and a very small amount of grinding abrasive remaining after the most is discharged together with the coolant during the solidification treatment. including. The coolant is
A paraffinic coolant of oiliness may be used. The grinding debris has a curled short linear shape and is entangled with each other in the briquette B. The hardened component for obtaining cutting chips is preferably a steel component for a bearing, for example, an iron-based component of a rolling bearing. Specifically, the quenched component is an inner ring, an outer ring, or a rolling element of a rolling bearing, and is preferably made of bearing steel. As bearing steel materials, high-hardened chromium steel (such as SUJ2), medium carbon steel (S
53C), induction hardened steel, case hardened steel (SCR415
Etc.). It should be noted that no binder (cutting chips, etc.) for hardening grinding chips is mixed into the briquette B at all. Briquette B has a predetermined strength,
For example, even if it is dropped from a height of 1 m, it has a strength such that the number of fragments does not become three or more. The briquette B having such a strength can be realized by adopting a manufacturing method described later.

According to the briquette B having this configuration, since it has a shape having the hollow portion a in the center, the inner and outer peripheries can be formed without increasing the cross-sectional area affecting the surface pressure at the time of squeezing as compared with the solid cylindrical shape. A large length is obtained, and the coolant is easily squeezed out during production by pressing. That is, the coolant oozes out from the inner surface of the cavity a, and the coolant is easily squeezed out. In particular, since the hollow portion a is formed as a through hole, the inner and outer peripheral lengths can be increased even if the cross-sectional area is the same over the entire length. Therefore, even with grinding sludge containing oil-based coolant, it is easy to solidify by pressing, and the coolant can be efficiently discharged without providing a separate discharge passage. Also, even if the grinding waste is hard and fine grinding sludge of a hardened part, the coolant can be easily squeezed out, so that it can be solidified. Therefore, the briquette is hard to collapse.

When the briquette B has a thick cylindrical shape, the inner and outer perimeters have the same sectional area (therefore, the same surface pressure at the time of pressing) and the oil discharge area as compared with the case where the briquette B is cylindrical as described above. The length can be increased. Briquette B
2B and FIG. 3B, a cylindrical briquette B ″ having the same volume (FIG. 2A, FIG.
3A, the inner and outer lengths are scaled as shown in Table 1 below according to the dimensions of the outer diameter D1 and the inner diameter D2.
The following numerical example shows the diameter D of a solid cylindrical briquette B "
3 is 80 mm, and is a calculation example when the outer diameter D1 of the cylindrical briquette B is variously changed. The height is 5
0 mm. Here, the relationship between the cross-sectional areas is (π × D3 × D
3) / 4 = (π × D1 × D1−π × D2 × D2) / 4 The ratio of the inner and outer lengths is (π × (D1 + D2))
/ (Π × D3).

(Table 1) Outer diameter D1 Inner diameter D2 D2 / D1 Inner / outer peripheral length 80 0.00 0.00 1.00 82 18.00 0.21 1.25 84 25.61 0.30 1.37 86 31.56 0.37 1.47 88 36.66 0.42 1.56 90 41.23 0.46 1.64 92 45.43 0.49 1.72 94 49.36 0.53 1.79 96 53.07 0.55 1.86 98 56.60 0.58 1.93 100 60.00 0.60 2.00

As can be seen from Table 1, the ratio of the inner diameter D2 of the hollow portion to the outer diameter D1 of the briquette increases as the inner and outer circumference lengths increase.
When 1 is large, there is a problem that the briquette manufacturing apparatus becomes large. Also, when the outer diameter D1 of the briquette increases, the thickness between the inner and outer peripheral surfaces of the briquette B decreases,
If this ratio exceeds 0.60, there is a problem in that it is easily collapsed due to a small thickness. When this ratio is small, the effect of increasing the surface area is not sufficient, and when this ratio is less than 0.4, it is difficult to obtain the effect of easily squeezing out the coolant due to the formation of the cavity a. Therefore, the ratio (D2
/ D1) is preferably in the range of 0.40 to 0.60. For example, the outer diameter D1 = 100 mm and the inner diameter D2 = 60 mm.

This briquette B is used as a steel making material. In this case, if the cutting waste contained in the briquette B is a bearing steel, a high quality steelmaking material is obtained. As described above, when the grinding waste is a high-quality steel material such as a bearing steel, even if the briquette B contains a trace amount of grinding abrasives, there is no hindrance to its use as a steel material, and a high-quality steel material can be manufactured. .

Next, an example of a method and an apparatus for producing the briquette B will be described. 4 and 5 are a block diagram and a schematic diagram showing a briquette manufacturing method, respectively. In the grinding line 1, grinding is performed by a grinding machine 2 using coolant supplied from a coolant tank 3. Grinding sludge composed of grinding chips and coolant generated in the grinding machine 2 is filtered by a filtering means 4, and the concentrated sludge generated by the filtration is solidified into briquettes B by pressing in a briquetting apparatus 5 which is a solidifying means. . The filtration device 4 and the briquette manufacturing device 5 constitute a solidifying device 6. A coolant generated by the filtration by the filtration means 4,
The coolant generated by the pressing in the briquetting apparatus 5 is collected by the grinding lines 1 and 8 through the recovery paths 7 and 8, respectively.
Return to the coolant tank 3. From collection paths 7 and 8,
The coolant is returned to the coolant tank 3 via the filter and the pump. The coolant is supplied from the coolant tank 3 to the grinding machine 2 via a filter and a pump. The briquette B solidified by the briquetting apparatus 5 is transported to a steel maker 9 and
Used for steelmaking. The briquette B is transported in a transport container 1 called a flexible container bag or the like as shown in FIG.
0 is stored in a plurality of trucks. In the steelmaking maker 9, the briquette B is used as a steelmaking material in the arc furnace 11 or the like. The manufactured steel material is used as a material of an object to be ground.

The object to be ground in the grinding line 1 is a hardened part, such as a bearing steel material such as a bearing steel. Oil-based coolant is used. The grinding sludge generated in the grinding machine 2 is a fluid having a coolant amount of 90 wt% or more, and the rest is powdery grinding dust and a small amount of grinding grains. In the state of the concentrated sludge filtered by the filtering means 4, this grinding sludge contains almost half of the coolant.
The components of the concentrated sludge are, for example, approximately 50 wt% of grinding waste made of bearing steel and the like, and approximately 50 wt% of coolant, and are trace abrasive grains.

As shown in FIG. 5, the filtering means 4 includes a settling facility 15 and a filter facility 16. Grinding line 1
The grinding sludge generated in the above is first led to the sedimentation facility 15,
The precipitated grinding sludge is guided to the filter equipment 16 by the pump 17 and filtered again. Filter equipment 16
A pressurized belt filter that uses a filter belt 18 and performs pressure filtration with compressed air using grinding sludge is used. The briquette manufacturing apparatus 5 includes a primary press unit 31 that stores a predetermined amount of concentrated sludge and pre-presses the same, and a secondary press unit 32 that presses the pre-pressed sludge with a predetermined pressure to solidify the sludge. The primary press section 31 has a heating means (not shown) for heating the internal sludge to a predetermined temperature range. A recovery path 8 for recovering the coolant from the briquette manufacturing apparatus 5 to the coolant tank 3 includes:
The coolant that has been filtered is collected through the settling facility 15A. Instead of the settling equipment 15A, a filtering means for filtering by another method may be provided.

According to the method of solidifying or treating the grinding sludge, the grinding sludge is filtered to form a concentrated sludge containing approximately half of the coolant, and the concentrated sludge is solidified by pressing. Even the grinding sludge containing the oil-based coolant of the steel material can be solidified. Further, in the briquette manufacturing apparatus 5, the grinding sludge concentrated by filtration is supplied to the primary pressing unit 3
In order to squeeze the pre-squeezed sludge and solidify the pre-squeezed sludge further in the secondary press unit 32, the sludge may be a grinding sludge of a quenched part or a grinding sludge containing an oily coolant. Can also be solidified.

FIG. 6 is an enlarged sectional view of the briquette manufacturing apparatus 5, more specifically, an enlarged sectional view of the secondary press section 32 in the briquette manufacturing apparatus 5. This briquetting equipment 5
Has a cylindrical compression chamber 34, and a pair of pressurizing members 43 and 44 are fitted in the compression chamber 34 so as to be able to move forward and backward. At the peripheral wall of the squeezing chamber 34, there is an inlet 3
4a, grinding sludge supplied from the inlet 34a into the squeezing chamber 34 is squeezed between the pressing members 43 and 44 at a position axially away from the inlet 34a as shown in FIG. Becomes The pressure members 43 and 44 are driven forward and backward by pressure drive sources 45 and 46. Pressing drive source 45,
A piston 45 is provided in the cylinder chambers 45a, 46a.
b, 46b. One of the pressing members 44 is provided with a core 49 from the center of the end surface serving as a pressing surface.
Are provided so as to be freely retractable and driven by a core driving drive 50. The core projecting drive source 50 is a hydraulic cylinder including a cylinder chamber 50a and a piston 50b provided in the pressurizing member 44. Both side portions of the piston 50b of the cylinder chamber 50a are connected to hydraulic supply / discharge means (not shown) through oil passages 51 and 52, respectively. The pressing member 43 facing the pressing member 44 provided with the core 49 includes a core 49.
A core escape hole 53 into which the tip of the core is inserted is provided on the end surface serving as a pressing surface. The escape hole 53 is open to the outside via a coolant discharge hole 54.

The grinding sludge squeezed in the squeezing chamber 34 is pressed between the pressing members 43 and 44 with the core 49 penetrating through the center as shown in FIG. Solidified into briquettes B. At the time of squeezing, the coolant squeezed out of the grinding sludge, as shown by the arrow in the figure, the gap between the inner peripheral surface of the squeezing chamber 34 and the outer peripheral surfaces of the pressing members 43 and 44, and the core 49 and the core. It is discharged to the gap between the escape hole 53 and the inner peripheral surface. Briquette B solidified
Is pushed out of the squeezing chamber 34 by retracting one pressing member 44 and advancing the other pressing member 43. In the above description, the apparatus in FIG. 6 has been described as the secondary press unit 32 in the briquette manufacturing apparatus 5 in FIG. 5, but the apparatus in FIG. 6 may be entirely an independent briquette manufacturing apparatus. In that case, the grinding sludge is solidified without preliminary pressing.

[0025]

The solidified product of the grinding sludge of the present invention is:
Grinding sludge containing oil-based coolant generated in the grinding line of the quenched parts is a solidified material obtained by solidifying by pressing, and this solidified material is formed into a column shape having a hollow portion in the center, so that the coolant is easily squeezed out and solidified. It can be made into a strong solidified material that is easily formed and hard to collapse. When the solidified material is obtained from the grinding sludge of the iron-based component of the rolling bearing, it becomes a high-quality solidified material as a steelmaking material, and is easily reused in steelmaking.

[Brief description of the drawings]

FIG. 1 is a perspective view of a briquette according to an embodiment of the present invention.

FIG. 2 is a plan view showing a comparison of dimensional relationships between a cylindrical briquette and a briquette according to an embodiment.

FIG. 3 is a perspective view showing a dimensional relationship between a cylindrical briquette and a briquette of the embodiment in comparison.

FIG. 4A is a block diagram showing a manufacturing process of the briquette, and FIG. 4B is an explanatory diagram showing an example of its use.

FIG. 5 is a schematic explanatory view of each device in the briquette manufacturing process.

FIG. 6 is a sectional view of a briquette manufacturing apparatus.

FIG. 7 is a perspective view of a conventional briquette.

FIG. 8 is a block diagram showing a conventional method for treating grinding sludge.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Grinding line 2 ... Grinding machine 3 ... Coolant tank 4 ... Filtration means 5 ... Briquette production equipment 15 ... Sedimentation equipment 16 ... Filtration equipment 31 ... Primary press part 32 ... Secondary press part 34 ... Compression chambers 43, 44 ... Pressure member 49 ... Core B ... Bricket (solidified material) a ... Cavity

Claims (5)

[Claims] 1. Grinding sludge containing oil-based coolant generated in a grinding line of a quenched part, which is a solidified product solidified by pressing and formed into a cylindrical shape having a hollow central portion. Solidified. 2. The solidified grinding sludge according to claim 1, wherein the hollow portion is a through hole penetrating both end surfaces of the solidified material. 3. The ratio of the inner diameter D2 of the hollow portion to the outer diameter D1 of the solidified product is D2 / D1 = 0.40 to 0.60.
The solidified product of the grinding sludge according to claim 2, which is: 4. The solidified grinding sludge according to claim 1, wherein the coolant in the solidified substance is oily, and the amount thereof is 5 to 10% by weight. 5. The solidified grinding sludge according to claim 1, wherein the quenched component is an iron-based component of a rolling bearing.