JP4532657B2 - Waste oil regeneration method and apparatus for hot rolling oil for aluminum and aluminum alloy - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a method and apparatus for reclaiming hot rolled oil for aluminum and aluminum alloys, and more particularly to a method for regenerating waste oil for hot-rolled oil for water-dispersed aluminum and aluminum alloys mixed with a cationic polymer compound. It relates to the device.
[0002]
[Prior art]
In hot rolling of aluminum and aluminum alloys, the longer the rolling oil is used, the higher the degree of deterioration of the oil. Therefore, the rolling oil must be largely replaced in a certain period.
Accordingly, the present inventors have developed a cationic rolling oil that can be sufficiently prevented from deterioration only by scum-out of the upper layer portion of the coolant tank (by discharging the upper layer portion into the scum pit), and disclosed in JP-A-7-150189. Proposed to.
[0003]
[Problems to be solved by the invention]
When using a water-dispersed rolling oil composition comprising a cationic polymer compound, there are many organic metals such as iron oleate, aluminum oleate, and aluminum wear powder in the upper part of the dirty oil tank after long-term use. Will come to do.
[0004]
Since iron oleate and aluminum oleate are oil-soluble, they are incorporated into a large amount of oil in a protective colloid film made of a polymer compound to increase the particle size. For this reason, the average particle diameter of the whole rolling oil is increased, the rising speed of the rolling oil particles to the upper layer of the tank is increased, and the variation of the oil particle diameter in the dirty oil tank is also increased. As a result, instability of rolling lubricity is caused, and sheet surface seizure due to insufficient lubrication (due to insufficient lubrication, transfer of metal material from the surface of the material to be rolled to the surface of the work roll at the time of rolling becomes uneven, so-called roll coating. The later plate surface is roughened, resulting in black spots and black streak-like surface defects), roll slip due to over-lubrication, poor biting, coil crushing, and contamination due to residual oil on the plate surface. .
[0005]
Aluminum wear powder contained in the so-called scum oil scumed out from the upper part of the dirty oil tank is separated and removed relatively easily by various solid-liquid separation means such as centrifugal separation, evaporator and filtering. However, since organic metals such as iron oleate and aluminum oleate are oil-soluble, they cannot be separated or removed at all by various two-phase separation means such as centrifugation, evaporator, and filtering. There was no removal method. For this reason, it is impossible to reuse the extracted oil as recycled oil for a long time in applications such as rolling oil or hydraulic oil. Rolled oil that has deteriorated to a certain level is discharged and disposed of as waste oil. There was no other way.
[0006]
Therefore, the cationic rolling oil proposed in the above-mentioned Japanese Patent Application Laid-Open No. 7-150189 can greatly reduce the amount of discharged oil as compared with the anionic hot rolling oil. From the standpoint of characteristic control, the scum-out frequency is high, and a large amount of rolling oil is still discharged as waste oil.
[0007]
In view of the above circumstances, the present invention is for aluminum and aluminum alloys, from which the extracted oil can be obtained as recycled oil to obtain oil that can be reused for applications such as rolling oil or hydraulic oil. An object of the present invention is to provide a method and an apparatus for recycling waste oil from hot rolled oil.
[0008]
[Means for Solving the Problems]
A first aspect of the present invention that solves the above-described problems is a method for reclaiming waste oil of water-dispersed aluminum and aluminum alloy hot rolling oil mixed with a cationic polymer compound, which is a deteriorated rolling oil after use. Add a mixture of citric acid as a chelating agent in the ratio of oil to oil, mix and stir to replace the organic metal with a solid metal salt of citrate. Oil By centrifugation A solid / water separation step of removing the solid and sludge content and water through a separation means; Include A waste oil recycling method for hot rolling oils for aluminum and aluminum alloys.
[0009]
The second aspect of the present invention that has solved the above-mentioned problems is a method for regenerating waste oil from water-dispersed aluminum and aluminum alloy hot rolling oil mixed with a cationic polymer compound, which is a deteriorated rolling oil after use. The By centrifugation Separating water and sludge components through a separating means and extracting oil, and adding and mixing citric acid as a chelating agent at a predetermined ratio in oil to oil extracted in this oil separation step, The organic metal substitution removal step of stirring and replacing the organic metal with a solid metal citrate salt, and the oil treated in this organic metal substitution removal step By centrifugation A solid matter removing step for removing the solid matter through a solid-liquid separation means; Include A waste oil recycling method for hot rolling oils for aluminum and aluminum alloys.
[0010]
According to a third aspect of the present invention that solves the above-mentioned problems, in the first or second aspect, in the organometallic substitution removal step, as a chelating agent having a ratio of 10 to 50% by mass with respect to the deteriorated rolling oil. A waste oil recycling method for hot rolled oil for aluminum and aluminum alloys, characterized in that citric acid is added so that the organic metal concentration of the recycled oil is 1500 ppm by mass or less.
[0011]
A fourth aspect of the present invention that solves the above-described problems is a water dispersion type waste oil reclaiming apparatus for hot rolled oil for aluminum and aluminum alloy in which a cationic polymer compound is mixed, wherein the upper part of the dirty oil tank A discharge means for discharging the deteriorated rolling oil from the mixture, and citric acid as a chelating agent in a predetermined ratio to the oil ratio is added to the discharged deteriorated rolling oil, mixed, and stirred to convert the organic metal into a solid metal citrate salt. Organometallic substitution removing means for substitution, and the solids, sludge and water from the oil treated by the organometallic substitution removing means. By centrifugation A waste oil recycling apparatus for hot rolled oil for aluminum and aluminum alloys, comprising: separating means for separating and removing; and transporting means for transporting the reclaimed oil purified by the separating means to the dirty oil tank. .
[0012]
A fifth aspect of the present invention that solves the above-mentioned problems is a water dispersion type waste oil reclaiming apparatus for hot rolled oil for aluminum and aluminum alloy in which a cationic polymer compound is mixed, and is an upper layer part of a dirty oil tank. Discharge means for discharging deteriorated rolling oil from water, and separating the water and sludge from the discharged deteriorated rolling oil and extracting the oil By centrifugation Separation means and addition of citric acid as a chelating agent in a predetermined ratio by oil ratio to the oil extracted by this separation means, mixing and stirring to replace the organic metal with a solid metal citrate salt The solid matter from the removal means and the oil treated by the organometallic substitution removal means By centrifugation Separate and remove Ru A waste oil recycling apparatus for hot rolled oil for aluminum and aluminum alloys, comprising: a liquid separation means; and a transport means for transporting the reclaimed oil purified by the separation means to the dirty oil tank.
[0013]
In the first to fifth embodiments of the present invention, citric acid as a chelating agent is not only citric acid but also citric acid substituents, citrate esters, citrates and the like having chelating action. It shall mean an acid derivative.
[0014]
(Function)
If comprised like the said 1st aspect, when the citric acid is added to a scum oil scum out from the dirty oil tank at a predetermined ratio, mixed and stirred, the oil-soluble oleic acid dissolved in the oil Organic metals such as iron and aluminum oleate are decomposed and replaced with solid metal citrate. By separating and removing the solid matter, sludge content, and water from the mixture of the oil thus obtained and the solid matter, sludge content (aluminum wear powder, etc.) and water with a separating means, a regenerated oil with a low organic metal content. Can be easily obtained.
[0015]
If comprised like the said 2nd aspect, the sludge content and water in the scum oil scumed out from the dirty oil tank can be separated and removed using the separating means, and the oil content is extracted. When citric acid is added to the extracted oil at a ratio of oil to oil, mixed and stirred, the oil-soluble organic metal such as iron oleate and aluminum oleate dissolved in the oil is decomposed and solids of metal citrate salt Is replaced by If the solids are separated and removed from the mixture of oil and solids thus obtained by solid-liquid separation means such as centrifugation or filtering, a reclaimed oil with a low content of organic metal can be obtained.
[0016]
The reasons for limiting the numerical values configured as in the third aspect are as follows.
That is, when the concentration of citric acid added is less than 10% by mass, the organometallic concentration in the rolling oil in the recycled oil exceeds 1500 mass ppm.
On the other hand, when the concentration of citric acid added exceeds 50% by mass in the oil ratio, it becomes difficult to separate the scum oil that has been reused as hot rolling oil and then returned to the dirty oil tank. Will not work.
[0017]
According to the fourth aspect, the deteriorated rolling oil is discharged from the upper layer part of the dirty oil tank by the discharging means, and the discharged deteriorated rolling oil is queried as a chelating agent at a predetermined ratio by the organometallic replacement means. An acid is added, and the mixture is stirred and mixed, and the organic metal is replaced with a solid substance such as iron citrate or aluminum citrate to be removed. The oil treated by the organic metal substitution removing means is regenerated by separating and removing water, the solid matter and the sludge by a separating means such as a self-draining vertical centrifuge. The purified regenerated oil is circulated by being transported to the dirty oil tank by transport means.
[0018]
If comprised like the said 5th aspect, deteriorated rolling oil will be discharged | emitted by the discharge means from the upper layer part of a dirty oil tank, and the discharged deteriorated rolled oil is separation means, such as a self-discharge type vertical centrifuge The water and sludge are separated and removed, and the oil is extracted. The extracted oil component is added with citric acid as a chelating agent in a predetermined ratio from the organic metal replacement means, and stirred and mixed to replace the organic metal with a solid material such as iron citrate or aluminum citrate to be removed. . The oil treated by the organic metal substitution removing means is separated and removed through a centrifuge such as a decanter or a solid-liquid separation means such as a filter to be regenerated. The purified regenerated oil is circulated by being transported to the dirty oil tank by transport means.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of a waste oil recycling apparatus for hot rolled oil for aluminum and aluminum alloy according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a schematic system diagram showing the overall configuration of a first embodiment of a waste oil recycling apparatus for hot rolled oil for aluminum and aluminum alloy according to the present invention.
[0020]
As shown in FIG. 1, a dirty oil tank DT provided alongside a clean oil tank CT has a scum oil (oil content, moisture content, sludge content) scumed out by a mechanical skimmer (mechanical scraping device) MS as a discharge means. Scum pit 1 for temporarily storing a mixture of From the scum pit 1, a scum oil transport pipe 2 is connected to a scum oil storage tank 4 via a scum oil transport pump 3 in the middle.
[0021]
The discharging means is not limited to the mechanical skimmer, but a method of discharging scum oil from the dirty oil tank DT to the scum pit 1 (water surface control method), discharging by vacuum suction (flow pump method), It is also possible to employ a method in which scum is entangled with an iron chain and discharged (belt skimmer method) or a combination of these.
Further, when a scum oil storage tank is disposed below the scum pit 1, an open / close valve (not shown) may be provided instead of the scum oil transfer pump 3.
[0022]
The scum oil storage tank 4 is provided with a citric acid water addition device 5 and a stirrer 6 for stirring and mixing the scum oil and the citric acid water in the scum oil storage tank 4, and the whole is replaced with an organic metal. The removal means 7 is comprised.
Here, the citric acid to be added is configured to be added as citric acid water here, but powder may be used.
Furthermore, it may be citric acid as a chelating agent capable of taking out solid matter as iron citrate or aluminum citrate from iron oleate or aluminum oleate dissolved in scum oil. Citric acid derivatives such as esters and citrates may be used.
[0023]
From the scum oil storage tank 4, an organometallic replacement removal oil content transporting pipe 8 is connected to a self-draining vertical separator plate type centrifugal separator 10 as a separating means with a transport pump 9 interposed in the middle. This vertical separation plate type centrifugal separator 10 is provided with a water discharge pipe 10a and solid and sludge content discharge means 10b.
[0024]
A regenerated oil transport pipe 11 is connected to the dirty oil tank DT through a regenerated oil transport pump 12 in the middle of the vertical separating plate centrifugal separator 10.
[0025]
The action of the first embodiment of the regenerating apparatus for hot rolled oil of aluminum and aluminum alloy according to the present invention and the method for regenerating the hot rolled oil of aluminum and aluminum alloy according to the first aspect of the present invention. Embodiments will be described below.
[0026]
A. Preliminary process
(1) The scum oil is discharged from the upper layer of the dirty oil tank DT to the scum pit 1 by the mechanical skimmer MS.
(2) A predetermined amount of scum oil scum out from the dirty oil tank DT and accumulated in the scum pit 1 is sent to the scum storage tank 4 through the scum oil transport pipe 2 and the scum oil transport pump 3 and stored.
[0027]
B. Organic metal substitution removal process
(1) The citric acid water addition device 5 adds citric acid water as a chelating agent in a predetermined ratio in an oil-to-oil ratio to a predetermined amount of scum oil stored in the scum oil storage tank 4. The amount of citric acid water added is 10 to 50% by mass as the citric acid content in the oil to oil ratio.
[0028]
When the citric acid addition concentration is less than 10% by mass in the oil to oil ratio, the organometallic concentration in the rolling oil in the recycled oil exceeds 1500 mass ppm. Since the organic metal is a metal soap such as iron oleate and aluminum oleate, the kinematic viscosity is high and the adhesion to the metal is also high, so if the concentration of the organic metal in the rolling oil exceeds 1500 mass ppm, the rolled product plate Also causes frequent surface contamination. In addition, when rolling a pure aluminum material with low material strength, the kinematic viscosity increases with the increase in the organic metal concentration, so that the surface frictional shear force during coiling decreases, and coil winding looseness and coil collapse occur. In addition, when using sodium nitrite as a rust preventive material, if the organic metal concentration in the rolling oil exceeds 1500 mass ppm, the oil tends to float, resulting in insufficient lubrication, such as seizure of the plate surface. Problems often occur.
[0029]
On the other hand, when the concentration of citric acid added exceeds 50% by mass in the oil ratio, it becomes difficult to separate the scum oil that has been reused as hot rolling oil and then returned to the dirty oil tank. Will not work.
[0030]
(2) The scum oil and citric acid water in the scum oil storage tank 4 are stirred and mixed by the stirrer 6. As a result, oil-soluble organic metals such as iron oleate and aluminum oleate in scum oil are decomposed and replaced with solids such as iron citrate and aluminum citrate, and the organic metals are removed from the oil.
[0031]
C. Solid / water separation process
(1) The oil after completion of the organic metal replacement removal process is continuously supplied from the scum oil storage tank 4 to the self-draining vertical separation plate centrifuge 10 through the organic metal replacement removal oil transport pipe 8 and the transport pump 9. To supply. The vertical separating plate type centrifugal separator 10 separates and removes water and the solids and sludge from the oil and discharges them through the water discharge pipe 10a and the solid / sludge discharge means 10b, respectively.
(2) The reclaimed oil discharged from the oil drain pipe of the vertical separator plate centrifuge 10 is returned to the dirty oil tank DT via the reclaimed oil transport pipe 11 and the reclaimed oil transport pump 12.
[0032]
Next, a second embodiment of the waste oil recycling apparatus for hot rolled oil for aluminum and aluminum alloy according to the present invention will be described with reference to the accompanying drawings.
FIG. 2 is a schematic system diagram showing the overall configuration of the second embodiment of the waste oil recycling apparatus for hot rolled oil for aluminum and aluminum alloy of the present invention.
[0033]
As shown in FIG. 1, the dirty oil tank DT provided alongside the clean oil tank CT temporarily stores scum oil (a mixture of oil, moisture and sludge) scumed out (discharged) by the mechanical skimmer MS. Scum pit 1 is attached. A first scum oil transport pipe 2 is connected from the scum pit 1 to the scum oil storage tank 4 via a scum oil transport pump 3 in the middle thereof.
[0034]
A second scum oil transport pipe 20 is provided in the middle of the first scum oil storage tank 4 with a second scum oil transport pump 21 interposed therebetween, and is a self-discharge type vertical separator plate type centrifugal separator 22 as a separating means. It is connected to. The vertical separator 22 is provided with a water discharge pipe 22a and sludge discharge means 22b. An extracted oil transport pipe 23 is connected to an extracted oil storage tank 26 via an extracted oil transport pump 24 in the middle from the oil discharge pipe of the vertical separator centrifuge 22.
[0035]
The extracted oil storage tank 26 is provided with a citric acid water adding device 27 and a stirrer 28 for stirring and mixing the extracted oil and the citric acid water in the extracted oil storage tank 26 as a whole. The removal means 25 is comprised.
[0036]
From the extracted oil storage tank 26, an organic metal replacement removal oil transportation pipe 29 is connected to a centrifuge 31 such as a decanter as a solid-liquid separation means via a transportation pump 30 in the middle.
[0037]
In addition, if a self-discharging type vertical separation plate type centrifuge is used as the centrifuge 31, it is possible to function as a three-phase separation means. In this case, the centrifuge has a water discharge pipe and a solid discharge. Means are attached.
Furthermore, the solid-liquid separation means may be a filter using a filter.
[0038]
The action of the second embodiment of the regenerating apparatus for hot rolled oil of aluminum and aluminum alloy of the present invention and the method of regenerating hot rolled oil of aluminum and aluminum alloy of the present invention according to the second aspect This embodiment will be described below.
[0039]
A. Preliminary process
(1) The scum oil is discharged from the upper layer of the dirty oil tank DT to the scum pit 1 by a mechanical skimmer MS as a discharging means.
(2) The scum oil scummed out from the dirty oil tank DT and accumulated in the scum pit 1 is sent to the first scum storage tank 4 via the first scum oil transport pipe 2 and the first scum oil transport pump 3 and stored. To do.
(3) A predetermined amount of scum oil stored in the first scum oil storage tank 4 is sent to the second scum oil storage tank 7 through the second scum oil transport pipe 5 and the second scum transport pump 6. Of scum oil.
[0040]
B. Oil separation process
(1) The scum oil is continuously supplied from the scum oil storage tank 4 through the second scum oil transport pipe 20 and the transport pump 21 to a self-discharge type vertical separation plate type centrifugal separator 22 as a separating means. The vertical separator centrifuge 22 separates and removes water and sludge from the oil and discharges them through the water discharge pipe 13a and the solid / sludge discharge means 13b, respectively.
(2) The extraction oil discharged from the oil discharge pipe of the vertical separator centrifuge 22 is sent to the extraction oil storage tank 26 via the extraction oil transport pipe 23 and the extraction oil transport pump 24, and a predetermined amount of the extracted oil is supplied. Accumulate.
[0041]
C. Organic metal substitution removal process
(1) The citric acid water adding device 8 adds citric acid water as a chelating agent at a predetermined ratio in oil ratio to a predetermined amount of extracted oil stored in the extracted oil storage tank 26. The amount of citric acid water added is 10 to 50% by mass as the citric acid content in the oil to oil ratio. Note that the upper and lower limits of the amount of citric acid added are limited for the same reason as described above.
(2) The extracted oil and the citric acid water in the extracted oil storage tank 26 are stirred and mixed by the stirrer 28. Thereby, the organic metal such as oil-soluble iron oleate and aluminum oleate in the extracted oil is replaced with a solid substance such as iron citrate and aluminum citrate, and the organic metal is removed from the oil.
[0042]
D. Solid matter separation process
(1) The oil treated in the organic metal substitution removal step is continuously supplied from the extraction oil storage tank 26 to the centrifugal separator 31 such as a decanter as a solid-liquid separation means via the organic metal substitution removal oil content transportation pipe 29 and the transportation pump 30. To supply. The centrifuge 31 separates and removes the solid matter from the oil, and discharges it through the solid matter 31b.
(2) The regenerated oil discharged from the oil discharge pipe of the centrifuge 31 is returned to the dirty oil tank DT via the regenerated oil transport pipe 32 and the regenerated oil transport pump 33.
[0043]
In the configuration of FIG. 2, the regenerated oil that has been separated and removed by the centrifuge 31 and purified is transported to the dirty oil tank DT via the transport pump 30. From the above, it is possible to increase the degree of purification of the regenerated oil by having a transportation path that branches to the extracted oil storage tank 26 again. That is, it is possible to bring the organometallic concentration as close as possible to 0 mass ppm by repeatedly performing the treatment. Therefore, if the transport path from the downstream side of the transport pump 30 can be switched and used as necessary, the degree of purification can be adjusted conveniently according to how the regenerated oil becomes dirty.
[0044]
(Example)
Using the hot rolling oil composition for aluminum and aluminum alloy mixed with the cationic polymer compound disclosed in JP-A-7-150189 having the following composition, the heat of the aluminum and aluminum alloy coil under the following conditions: Hot rolling was performed.
[0045]
"Composition of rolling oil composition"
Paraffinic mineral oil (viscosity 30 cSt / 40 ° C.) 85.5% by mass
Dibutyl phosphate 2.5% by mass
Polymer dispersant 1.0% by mass
{(Diethylaminopropylamide: acrylamide)
: Potassium acrylate = 70:10:20)
Compound succinic acid neutralized product (M _W = 300,000)}
Antioxidant 1.0% by mass
Rust / corrosion inhibitor 1.0% by mass
[0046]
"Hot rolling conditions"
(1) Hot finish rolling mill specifications: 4-high rolling mill x 4 stands
(A) Work roll diameter: 725 mm
(B) Work roll barrel length: 3900 mm
(C) Backup roll diameter: 1590 mm
(D) Backup roll barrel length: 3900 mm
(2) Rolling oil temperature: 60 ° C
(3) Reduction ratio: 30 to 60%
(4) Initial pass entry side material temperature: 300-550 ° C
[0047]
The waste oil recycling apparatus for rolled oil was regenerated using the apparatus shown in FIG. 2 and rolled for two weeks continuously. For oiliness, the organometallic concentration of the oil before and after regeneration was measured by FTIR (Fourier Infrared Spectrometer), and for the sheet surface properties, the hot finish rolled product was anodized and scored visually. Regarding lubricity, rolling load data was accumulated. Regarding the emulsion stability, a rolling oil sample was taken, stirred with a stirrer, allowed to stand for 8 minutes, and the oil concentration in both the upper and lower layers was measured, respectively. ESI (Emulsion Stability Index) = {(Oil concentration in the lower layer portion) / (Oil concentration in the upper layer portion)} × 100 (%) was calculated.
[0048]
In FIG. 3, in the relationship between the citric acid addition concentration (mass% of oil) and the organic metal concentration (ppm of oil mass), the case where the rolling was good is indicated by symbol ◯, coil crushing, plate surface contamination and oil particles The case of occurrence of rolling defects such as seizure due to an increase in the ascent speed is indicated by symbol x.
In addition, in FIG. 4, in the relationship between the citric acid addition concentration (mass% to oil) and ESI (%), the case where the rolled product plate surface is good is indicated by symbol ○, and the oil-water separation process (regeneration process). The case where it is difficult is indicated by Δ, and the case where the surface of the rolled product is defective due to the occurrence of image sticking or black spots is indicated by symbol x.
[0049]
According to FIG. 3, good rolling is achieved if the conditions within the range of the present invention, that is, the citric acid addition concentration is in the range of 10 to 50 mass% in terms of oil ratio and the organometallic concentration is in the range of 1 to 1500 mass ppm in terms of oil ratio. It is understood that is possible.
Further, according to FIG. 4, if the conditions within the range of the present invention, that is, the citric acid addition concentration is 10 to 50% by mass in the oil ratio, ESI (%) is also within the allowable range of 25 to 70%. It turns out that it is in the range, the emulsification stability is good, and the plate surface quality is excellent and stable rolling is possible.
Furthermore, the corrosion of the rolling mill peripheral member was not seen by addition of the rust preventive and anticorrosive agent to the rolling oil.
[0050]
Although the said Example described the case where it regenerated using the thing shown in FIG. 2 as a waste oil regeneration apparatus of rolling oil, the substantially same result was obtained about the case where it regenerated using what was shown in FIG. .
[0051]
【The invention's effect】
The present invention has the following excellent effects.
(1) According to the present invention according to claim 1 and claim 4, in the case where a cationic polymer compound is mixed and water-dispersed hot rolling oil for aluminum and aluminum alloy is used, iron oleate Degraded oil (waste oil) whose organic metal concentration has risen above a certain level, such as aluminum and aluminum oleate, with a very simple device configuration by adding a predetermined amount of citric acid to the oil ratio and using separation means The sludge content, moisture, and organic metal in the inside can be separated and removed, and the reusable oil can be reused as a recycled oil having an organic metal concentration of 1 to 1500 ppm by mass.
[0052]
(2) According to the present invention according to claim 2 or claim 5, simple apparatus is obtained by using a separating means, adding a predetermined amount of citric acid to oil ratio, mixing and using a decanter as a solid-liquid separating means. With the configuration, it is possible to obtain the same effect as described above.
[0053]
(3) According to the third aspect of the present invention, by adding citric acid having an oil ratio of 10 to 50% by mass, a good regenerated oil having an organometallic concentration of 1500 ppm by mass or less can be obtained. Can be used effectively.
[Brief description of the drawings]
FIG. 1 is a schematic system diagram showing an overall configuration of a first embodiment of a waste oil recycling apparatus for hot rolled oil for aluminum and aluminum alloy according to the present invention.
FIG. 2 is a schematic system diagram showing an overall configuration of a second embodiment of a waste oil recycling apparatus for hot rolled oil for aluminum and aluminum alloy according to the present invention.
[Figure 3] In the relationship between the concentration of citric acid added (mass% of oil) and the concentration of organic metal (ppm of oil), the symbol “◯” indicates that rolling was good, coil collapse, plate surface contamination, and oil particles It is the figure which each showed the case of rolling defect generation | occurrence | production of seizure etc. by the ascent rate rise of this by x.
[Fig. 4] In the relationship between the citric acid addition concentration (mass% of oil) and ESI (%), the case where the rolled product plate surface is good is indicated by symbol ◯, and oil-water separation treatment (regeneration treatment) is difficult. It is the figure which showed the case where it is (triangle | delta), and the case where a sticking, a black spot, etc. generate | occur | produced and a rolled product board surface is unsatisfactory is shown by the symbol x.
[Explanation of symbols]
CT clean oil tank
DT Dirty oil tank
MS Mechanical Skimmer
1 Scumpit
4 Scum oil storage tank
5,27 Citric acid water addition device
6,28 Stirrer
7,25 Organometallic substitution removal means
10, 22 Vertical separator plate centrifuge
26 Extracted oil storage tank
31 Centrifuge (decanter)

Claims (5)

A method for reclaiming waste oil of hot-rolled oil for water-dispersed aluminum and aluminum alloys mixed with a cationic polymer compound,
An organic metal replacement removing step of adding citric acid as a chelating agent in a predetermined ratio to the deteriorated rolled oil after use, mixing, and stirring to replace the organic metal with a solid of a citric acid metal salt;
A solid / water separation step of removing the solids, sludge content and water from the oil treated in the organic metal substitution removal step through a separation means by centrifugation ;
A method for recovering waste oil of hot rolled oil for aluminum and aluminum alloys, comprising: A method for reclaiming waste oil of hot-rolled oil for water-dispersed aluminum and aluminum alloys mixed with a cationic polymer compound,
An oil separation step for separating the water and sludge from the deteriorated rolled oil after use through a separation means by centrifugation , and extracting the oil;
An organic metal substitution removing step of adding citric acid as a chelating agent in a predetermined ratio to the oil extracted in this oil separation step, mixing and stirring to replace the organic metal with a solid metal salt of citric acid; ,
A solid matter removal step of removing the solid matter through solid-liquid separation means by centrifugation of the oil treated in this organometallic substitution removal step;
A method for recovering waste oil of hot rolled oil for aluminum and aluminum alloys, comprising:   In the organic metal substitution removal step, citric acid as a chelating agent having a ratio of 10 to 50% by mass to the deteriorated rolled oil is added to make the organic metal concentration of the regenerated oil 1500 ppm or less. The waste oil reproduction | regeneration method of the hot rolling oil for aluminum and aluminum alloy of Claim 1 or Claim 2. A water dispersion type waste oil recycling apparatus for hot rolled oil for aluminum and aluminum alloy mixed with a cationic polymer compound,
Discharging means for discharging deteriorated rolling oil from the upper layer of the dirty oil tank;
The deteriorated rolling oil discharged by this discharging means is stored, citric acid as a chelating agent in a predetermined ratio by oil ratio is added to the deteriorated rolling oil, mixed and stirred, and the organic metal is solidified with a metal citrate salt. Organometallic substitution removing means for substitution with,
Separation means for separating and removing the solids, sludge and water from the oil treated by the organic metal substitution removing means by centrifugation ;
Transport means for transporting the regenerated oil purified by the separation means to the dirty oil tank;
A waste oil recycling apparatus for hot rolled oil for aluminum and aluminum alloys, comprising: A water dispersion type waste oil recycling apparatus for hot rolled oil for aluminum and aluminum alloy mixed with a cationic polymer compound,
Discharging means for discharging deteriorated rolling oil from the upper layer of the dirty oil tank;
Separating means by centrifugation for separating water and sludge from the deteriorated rolled oil discharged by this discharging means, and extracting the oil;
An organic metal substitution removing means for adding citric acid as a chelating agent at a predetermined ratio in an oil ratio to the oil extracted by the separation means, mixing and stirring to replace the organic metal with a solid metal citrate salt,
A solid-liquid separation means for separating and removing the solid matter from the oil treated by the organometallic substitution removal means by centrifugation ;
Transport means for transporting the regenerated oil purified by the solid-liquid separation means to the dirty oil tank;
A waste oil recycling apparatus for hot rolled oil for aluminum and aluminum alloys, comprising:

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