JP2005262287A - Method for solidifying grinder swarf sludge, and solidified material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for easily solidifying grinder swarf sludge which is hard to become solid, by mixing a binder containing a cellulosic fiber which is easily available at a low cost, is effective with a small quantity, is not an environmental burden, is flammable without generating harmful gas, and does not solidify itself due to mixing, and to provide a solidified material. <P>SOLUTION: In the invented method for producing a solidified material B by squeezing the grinder swarf sludge, the binder mainly comprising the cellulosic fiber is mixed into the grinder swarf sludge. It is preferable that the cellulosic fiber is a natural cellulosic fiber made of wood. The grinder swarf sludge comes from a grinding line for quenched parts and contains an oily coolant. The sludge is concentrated and then is squeezed for solidification, with the binder of the cellulosic fiber mixed, by advancing a piston 22 in a cylindrical mold 21. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing a solidified product of a grinding sludge produced by grinding a grinding sludge generated in a grinding line for hardened parts, for example, iron-based components such as inner and outer rings of rolling bearings, rolling elements, and other steel materials. It relates to the solidified product.

Iron-based components such as inner and outer rings and rolling elements of rolling bearing parts are subjected to grinding on the rolling surfaces after quenching. Powdered grinding waste generated by grinding is discharged out of the machine as sludge together with coolant, and after filtration, the coolant is reused for grinding. The grinding sludge remaining after filtration is landfilled as sludge.
Although the amount of grinding waste generated by grinding is smaller than that of cutting, the amount generated is large in mass production lines such as bearings. It is clear that landfilling of grinding sludge is not preferable from the viewpoint of the environment, and that landfill processing will not be possible in the future due to the dead end of the industrial waste treatment plant.

For this reason, while grind | pulverizing grinding sludge and solidifying and recycle | reusing the squeezed coolant, reusing the solidified material as a steelmaking material is examined (for example, patent document 1). This solidified product is called briquette or the like.
JP 2003-71594 A

Solidification processing of grinding sludge has already been put into practical use, but sometimes solidification is difficult. The following factors can be considered as the cause.
・ When grinding sludge contains a large amount of oil.
・ When grinding sludge contains a large amount of abrasive components.
・ When grinding sludge is very fine.
・ When grinding sludge has brittle properties.
In such a case, the grinding scraps are drained during the solidification process, but the metal components that are the remaining grinding scraps are weak in bonding force, making it difficult to maintain the shape and recycling the grinding sludge. This is an obstacle to the solidification process.

In order to facilitate the solidification of grinding sludge that is difficult to solidify, it is conceivable to mix a binder for binding metal components that are grinding scraps by some method. The characteristics required for the binder are as follows.
-Easy to obtain and inexpensive.
-The effect of easy solidification can be obtained with a small amount of mixing.
-Substances that do not cause environmental impact.
・ The substance must be combustible and do not generate harmful gases.
-The binder itself does not solidify by mixing.
As described above, the binder for facilitating solidification of the grinding sludge is required to have a wide variety of characteristics, and no suitable binder satisfying all of them has been found. For example, when the binder is made of a synthetic resin, there arises a problem that the binder itself becomes hard in the solidification processor and the machine cannot be operated.

  The object of the present invention is that a binder to be mixed for easily solidifying grinding sludge that is difficult to solidify is easily available and inexpensive, can be obtained in a small amount, is not an environmental burden, and can be burned. It is an object to provide a method for producing a solidified product of ground sludge and a solidified product thereof, in which cellulose fibers are mixed that does not generate harmful gas and that does not solidify the binder itself when mixed.

The method for producing a solidified product of grinding sludge according to the present invention is a method for producing a solidified product of grinding sludge by solidifying the grinding sludge by pressing. The grinding sludge to be compressed is mixed with a binder mainly composed of cellulose fibers. It is characterized by doing.
When cellulose fibers were used as the binder, it was confirmed by tests that grinding sludge that is difficult to solidify can be easily solidified. The reason why solidification is facilitated by cellulose fibers is considered to be as follows. Grinding debris constituting the grinding sludge is a thin thread curled with metal shaved with a grindstone. When slender thread-like cellulose fibers are mixed with this grinding sludge, they are entangled with each other. It is considered that the immobilization process is facilitated. Even after the solidification treatment, the compressed grinding scraps are combined with cellulose fibers to increase the strength of the solidified product, and the shape retention ability is improved. In addition, when the binder is a cellulose fiber, it is easy to obtain and inexpensive, an effect can be obtained in a small amount, it does not become an environmental burden, it is combustible and does not generate harmful gases, and the binder itself is mixed by mixing. A material that does not solidify can be selected.

  In particular, the cellulose fibers are preferably natural cellulose fibers made from wood. Natural cellulose fibers made from wood are chemically stable, non-toxic to humans, highly safe, environmentally friendly, and produce no harmful substances when burned.

  The mixing amount of the cellulose fibers is preferably in the range of 0.2 to 1.0% by weight ratio to the grinding sludge before pressing. If it is less than 0.2%, solidification may be insufficient. Even if the cellulose fiber is mixed in excess of 1.0%, the ease of solidification and the strength of the solidified product are the same as in the case of 1.0% or less, and the cellulose fiber is wasted.

The grinding sludge may be an oil-based coolant-containing grinding sludge generated in a hardened part grinding line. In that case, after concentration, the cellulose fiber binder is mixed and squeezed. The coolant may be oily or water soluble.
Oil-based coolant has higher viscosity than water-based coolant, and it is difficult to squeeze the coolant and solidify. In particular, grinding scraps of quenched parts are difficult to solidify because they are fine and hard. However, when cellulose fibers are mixed, even in the case of such grinding scraps that are difficult to solidify, solidification can be easily performed and the strength of the solidified product can be secured. Grinding sludge containing oil-based coolant needs to be concentrated to facilitate the solidification process. By mixing the cellulose fiber binder after this concentration, the mixed cellulose fibers are discharged together with the coolant of the grinding waste. This is effective for efficient solidification.

  In this invention, the grinding sludge is preferably squeezed by the advancement of the piston in a cylindrical mold. The grinding sludge can be squeezed using an opposing open / close mold or a roller having a concave portion for molding. However, these methods make it difficult to solidify depending on the state of the grinding sludge. From the aspect of easy solidification, it is preferable to squeeze with a piston in a cylindrical mold, and in this case, cellulose fibers can be used to solidify easily even in the case of grinding sludge that is difficult to solidify. In addition, the solidified product can be made difficult to collapse.

The solidified product of the grinding sludge according to the present invention is a solidified product obtained by solidifying the ground sludge by pressing, and is characterized by containing cellulose fibers.
Since cellulose fibers are contained, as explained in the production method of the present invention, solidification is easy and it is difficult to collapse during handling. When the binder is cellulose fiber, it is inexpensive and requires only a small amount, and a solidified sludge can be produced at low cost. Moreover, while the binder is included, the binder does not become an environmental load, can be burned when reused as a steelmaking material, and does not generate harmful gases.

  The method for producing a solidified product of grinding sludge according to the present invention is a method for producing a solidified product of grinding sludge by solidifying the grinding sludge by pressing. The grinding sludge to be compressed is mixed with a binder mainly composed of cellulose fibers. Therefore, even grinding sludge that is difficult to solidify can be easily solidified, and the binding material for easy solidification is easy to obtain, inexpensive, effective in a small amount, combustible without causing environmental impact In this case, no harmful gas is generated, and by mixing, there is an advantage that the binder itself does not solidify.

  An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a conceptual diagram from generation of grinding sludge to solidification treatment and reuse. In the grinding line 1, grinding is performed by the grinding machine 2 using the coolant supplied from the coolant tank 3. Grinding sludge composed of grinding waste and coolant generated in the grinding machine 2 is concentrated by filtering with the filtering means 4. The concentrated sludge is mixed with a hopper 5 with a binder mainly composed of cellulose fibers (hereinafter referred to as “cellulose fiber binder”). The ground sludge mixed with the cellulose fiber binder is solidified by pressing with the solidification device 6 to obtain a solidified product B. The coolant generated by filtration by the filtering means 4 and the coolant generated by squeezing by the solidifying device 6 are returned to the coolant tank 3 of the grinding line 1 by the recovery paths 7 and 8, respectively. The recovery path 8 has a precipitation facility 15A so that the filtered coolant is returned.

  The solidified product B thus solidified is transported to the steelmaker 9. A plurality of the solidified products B are stored in a transport container 10 called a flexible container bag or the like, and are carried by a truck or the like. The steelmaker 9 uses the solidified material B for steelmaking materials such as the arc furnace 11. The steel material made of steel is used as a material for an object to be ground.

Details of each of the above processes will be described. The filtering means 4 includes a precipitation facility 15 and a filter facility 16. The grinding sludge generated in the grinding line 1 is first guided to the precipitation facility 15, and the ground sludge precipitated here is guided to the filter facility 16 by the pump 17 and is filtered again by using the belt filter 18 in the tank 19.
In the hopper 5, grinding sludge and a predetermined ratio of cellulose fiber binder are put and stirred by stirring means such as a built-in stirring blade (not shown).

  As shown in an enlarged view in FIG. 2, the solidifying device 6 is a device that squeezes and solidifies grinding sludge by the advancement of a piston 22 in a cylindrical mold 21. One end of the mold 21 is covered with a lid member 23 that can be freely opened and closed, and the piston 22 is made to enter from the other end, and grinding sludge is compressed in the space between the lid member 23 and the piston 22 in the mold 21. Is done. The piston 22 is advanced and retracted by an advancing / retreating drive source 24 such as a hydraulic cylinder, and the lid member 23 is opened and closed by an opening / closing drive source 25 such as a hydraulic cylinder. The mold 21 and the forward / backward drive sources 24 and 25 are installed on a common base 26.

  The mold 21 has a sludge inlet 27 on the upper surface, and a concentrated ground sludge mixed with the above cellulose fiber binder is quantitatively supplied from a hopper 29 via a guide path 28. The hopper 29 shown in FIG. 2 may be the binding material mixing hopper 5 in FIG. 1, or may be provided in the subsequent stage separately from the hopper 5 in FIG. 2. The hopper 29 in FIG. 2 incorporates a screw conveyor 30 for conveyance. Between the hopper 29 and the mold 21, means (not shown) for further increasing the concentration of the grinding sludge supplied to the mold 21 by preliminary squeezing or the like may be provided.

  A columnar solidified product B as shown in FIG. 3 is produced by pressing in the mold 21. The solidified product B has a size belonging to the briquette, and its diameter D is, for example, about 30 to 100 mm, and the height H is about 30 to 100 mm.

  In FIG. 1, an object to be ground in the grinding line 1 is a hardened part, such as a bearing steel material such as bearing steel. The hardened parts are steel parts for bearings, for example, iron parts of rolling bearings. Specifically, the hardened part is an inner ring, an outer ring, or a rolling element of a rolling bearing, and is made of bearing steel. Examples of the steel for bearing include a high quenching material of high carbon chromium steel (SUJ2 etc.), an induction hardening material of medium carbon steel (S53C etc.), and a carburizing quenching material of case hardening steel (SCR415 etc.). As the coolant, an oil-based one is used, and an oil-based paraffin-based coolant may be used. In addition, also when a coolant is aqueous, the solidified product manufacturing method and solidified product of the grinding sludge of this embodiment are applicable.

  The grinding sludge generated in the grinding line 1 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 abrasive grains. In the state of the concentrated sludge filtered by the filtering means 4, this grinding sludge contains 50 to 80 wt% of coolant. The components of the concentrated sludge are, for example, a small amount of grinding abrasive grains such as grinding scraps made of bearing steel and the like, approximately 50 to 80 wt%, and coolant approximately 20 to 50 wt%. A cellulose fiber binder is added to such concentrated sludge with a hopper 5 and mixed by stirring. The coolant content in the state of solidified product B is less than 10%.

The cellulose fiber binder to be mixed may not be a pure cellulose fiber but may be a material mainly composed of cellulose fibers. For example, an appropriate binder containing about 80% or more of cellulose fibers may be used. In that case, what has components other than the cellulose fiber in a binder, for example, an ash, a water | moisture content, etc. can be used. The cellulose fiber in the cellulose fiber binder to be mixed is preferably a natural cellulose fiber made of wood.
The appropriate mixing amount of the cellulose fiber binder varies depending on the cellulose fiber content in the cellulose fiber binder, but when it is substantially pure cellulose fiber, the grinding sludge before pressing by the mold 21 of the solidifying device 6. The weight ratio is preferably 0.2 to 1.5%, and more preferably 0.2 to 1.0%. When the cellulose fiber binder is not substantially pure cellulose fiber, the ratio of the cellulose fiber contained in the binder to the grinding sludge is preferably in the range of 0.2 to 1.5% as described above, More preferably, it is in the range of 2 to 1.0.

  As a natural cellulose fiber which used said wood as a raw material, what is marketed as a cellulose fiber additive for asphalt pavement can be used, for example. For example, Top Cell (Cosmore Sphalt Co., Ltd.) or Cell Road (Yamakyo Seiko Co., Ltd.) can be used. These cellulose fiber products are sold as additives for asphalt pavement as described above, and are used in technical fields that are completely different from the manufacturing industry for hardened parts. It has a good property to solidify sludge. Cellulose fibers using wood as a raw material are generally for filters, but those for filters are high quality and expensive, and are too expensive to be used for solidifying grinding sludge. However, the asphalt pavement additive as described above is low in purity but can be obtained at a low cost, and sufficient performance can be obtained for solidifying grinding sludge.

  The result of the test (1) (result of the test in which cellulose fibers for asphalt pavement are mixed) will be described. The grinding sludge used for the test is a grinding sludge generated by grinding a roller in a needle roller bearing, and solidification is unstable and cannot be solidified without mixing the binder. Since the same grinding sludge was tested with a high-purity cellulose fiber for a filter as a binder, the test was conducted when cellulose fibers for asphalt pavement were used as a binder.

The test conditions are as follows.
Cellulose fiber binder: Top Cell J (manufactured by Cosmo Alfalt Co., Ltd.), which is an additive for asphalt pavement.
Grinding sludge: This is grinding sludge for rollers in needle roller bearings, and the contained coolant is water-soluble.
Solidification conditions: Manual operation was performed using the solidification device 6 of FIG. 2, and the piston 22 was squeezed at a forward speed of 5 mm / sec and a pressure of 2000 kgf / cm ² .
The amount of grinding sludge used to solidify one solidified product B is 1000 g, and the amount of cellulose fiber binder is 10 g.

  The top cell J used as the cellulose fiber binder is cotton-like, and its components are cellulose fiber content: about 80%, ash content: 10% or less, moisture content: 7% or less, bulkiness Density: 20 to 36 g / L.

As a result of the above test, there was obtained a very good solidified product B that had no collapsed part and did not collapse during handling. The cellulose fiber binder used this time was of low purity for aphalt (cellulose fiber content: about 80%), but even if such a low purity cellulose fiber binder was used, a very good solid It was confirmed that the compound B could be manufactured. The size of the produced solidified product B is approximately 70 mm in diameter, approximately 40 mm in thickness, approximately 500 g in weight, and approximately 3.0 g / cm ³ in density.
When solidified under the same conditions without including the binder, there was a case where the corners collapsed or cracks occurred entirely, and solidification was impossible.
In addition, although the grinding sludge mixed with the cellulose fiber binder was left for one day, it did not harden. From this, it is estimated that the problem does not occur due to solidification in the supply path, for example, hoppers 5, 29, etc., to the mold 21 of the solidifying device 6.

  The results of other test (2) will be described. In this test, the cellulose fiber binder was mixed in various amounts and solidified. A high-purity cellulose fiber for a filter was used as the cellulose fiber binder. Other test conditions are the same as the above test (1). As a result of this test, the results shown in the following Table 1 were obtained. The mixing ratio of the cellulose fiber binder is a weight ratio to the grinding sludge.

  From Table 1, it can be seen that the mixing ratio of the cellulose fiber binder is preferably 0.2 wt% or more in order to ensure solidification. When the mixing amount of the cellulose fiber binder was 0.5 wt% or more, the solidification quality did not change even when the mixing amount was increased to 1 wt% or 3 wt%. Therefore, even if the mixing ratio of the cellulose fiber binder is increased too much, the material is wasted and uneconomical, and it is considered to be preferably 1.0 wt% or less in view of poor stirring during mixing. That is, the mixing ratio of the cellulose fiber binder is preferably in the range of 0.2 wt% to 1.0 wt%.

  In addition, although each said test (1), (2) is a case where the coolant of a grinding sludge is water-soluble, it is thought that solidification can be performed favorable also when the coolant of a grinding sludge is oily. In addition, each of the tests (1) and (2) described above is caused by grinding of the roller in the needle roller bearing and is a hardened part grinding sludge. In the case of a raw material grinding sludge, Solidification is easy, and in this case as well, good solidification can be achieved even if the content of the cellulose fiber additive is reduced as compared with the case of the ground sludge of the quenched part.

It is a processing system diagram showing a solidification manufacturing method of grinding sludge concerning one embodiment of this invention. It is a fracture front view of the solidification device. It is a perspective view of the manufactured solidified material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Grinding line 4 ... Filtration means 5 ... Hopper 6 ... Solidification apparatus 21 ... Mold 22 ... Piston B ... Solidified material

Claims (6)

  In a method for producing a solidified product of a grinding sludge by solidifying the grinding sludge by pressing, a ground sludge solidified product comprising mixing a binder mainly composed of cellulose fibers with the grinding sludge to be compressed. Production method.   The method for producing a solidified product of ground sludge according to claim 1, wherein the cellulose fiber is a natural cellulose fiber made of wood.   3. The method for producing a solidified product of ground sludge according to claim 1 or 2, wherein the mixing amount of the cellulose fibers with respect to the ground sludge before pressing is 0.2 to 1.0% by weight.   The grinding sludge according to any one of claims 1 to 3, wherein the grinding sludge is coolant-containing grinding sludge generated in a hardened part grinding line, and after mixing, the cellulose sludge is mixed and compressed. The solidified product manufacturing method.   5. The method for producing a solidified product of grinding sludge according to claim 1, wherein the grinding sludge is squeezed by advancing the piston in a cylindrical mold.   A solidified product of ground sludge, which is solidified by pressing and contains cellulose fibers.

Images