JP2004268215A - Regenerating method of abrasive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a regenerating method of an abrasive, and a regenerating method of a rib material for forming a reusable metallic abrasive, by recovering lead oxide of a toxic substance without polluting an environment by treating a used metallic abrasive by sand blast work without applying special treatment when manufacturing the metallic abrasive. <P>SOLUTION: A waste material is separated into coarse powder and fine powder, and the respective powders are classified and recovered. The recovered coarse powder is washed by alkali, and is washed by water. Since the coarse powder is finally dried after acid washing and water washing a material dissolved into an alkaline solution sticking to the metallic abrasive 5 recovered by separation-classification is removed by alkaline washing. A material dissolved into an acid solution such as lead glass 8 sticking to the metallic abrasive 5 is removed by acid washing. The metallic abrasive 5 having no sticking material is formed, and used again as a new abrasive, and cost is largely reduced. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for regenerating an abrasive discharged by sandblasting. Further, the present invention relates to a method for regenerating a rib material discharged by sandblasting.
[0002]
[Prior art]
Generally, glass beads, alumina, and calcium carbonate can be used as an abrasive in sandblasting, but a metal abrasive having a relatively high specific gravity is required to shorten the processing time of sandblasting and improve accuracy after the processing. used. Since this metal abrasive is expensive compared to an abrasive made of glass beads, alumina and calcium carbonate, it must be used repeatedly. For example, it is used by circulating using a general rib forming equipment shown in FIG. Was. Hereinafter, the operation of the rib forming equipment for the metal abrasive will be described with reference to FIG.
[0003]
A general plasma display panel (hereinafter referred to as PDP) rib forming apparatus shown in FIG. 1 applies an abrasive to a rib material 2 formed by applying a rib paste material on a glass substrate 1 and drying it. A sandblast gun 4 to be injected, a processing chamber 10 into which a glass substrate 1 in which the sandblast gun 4 and the rib material 2 are formed on one side is put, and a rib material cut by a metal abrasive 5 injected from the sandblast gun 4 2 is fed out, a cyclone 6 for classifying the metal abrasive 5 and the rib material 2 using centrifugal force, a mesh filter 7 disposed between the cyclone 6 and the sandblast gun 4, a processing chamber 10, The abrasive tank 11 is interposed between the cyclones 6 and temporarily holds the metal abrasive 5.
[0004]
The operation of this general PDP rib forming apparatus is as follows. First, the glass substrate 1 coated with the rib material 2 is put into the processing chamber 10 and the sand blast gun 4 injects the metal abrasive 5 to form the rib material 2 into a predetermined shape. To cut. Simultaneously with this cutting, the metal abrasive 5 and the rib material 2 cut by the metal abrasive 5 are sent out to the cyclone 6 via the abrasive tank 11, and light fine powder is discharged through the outlet above the cyclone 6 by centrifugal force. 6A, and similarly heavy coarse powder is discharged from the outlet 6B below the cyclone 6 by centrifugal force. The coarse powder discharged from the outlet 6B below the cyclone 6 is filtered by the mesh filter 7 and only the powder smaller than the mesh hole of the mesh filter 7 falls into the sandblast gun 4 and is used again as the metal abrasive 5. . By repeating the above operation, the metal abrasive 5 is repeatedly used until it is filtered by the mesh filter 7. The fine powder discharged from the discharge port 6A above the cyclone 6 is discarded.
[0005]
[Patent Document 1]
Japanese Patent No. 2923464
[0006]
[Patent Document 2]
JP-A-8-141913
[0007]
[Patent Document 3]
JP-A-9-295268
[0008]
[Patent Document 4]
JP-A-2002-114968
[0009]
[Problems to be solved by the invention]
Conventionally, in sandblasting in a general PDP rib forming apparatus, the metal abrasive 5 is repeatedly used as described above, and since the rib 2 cut by the metal abrasive 5 has a low specific gravity, the metal abrasive 5 above the cyclone 6 is used. It was discharged from the discharge port 6A and discarded. However, there were problems as shown in the following specific examples.
[0010]
In the PDP rib forming step of chamfering a 42-inch PDP, a rib paste material of about 1100 [gr] is applied onto the glass substrate 1 and then pre-baked, and a resist is applied to the sintered body which has become 800 [gr] after firing. After pattern formation by performing predetermined pattern exposure after application, sandblasting is performed. At this time, since the pattern is formed at a volume ratio of about 40 [%], 60 [%] of the material, that is, 480 [gr] per glass substrate unit is removed by cutting during rib formation.
[0011]
When 500 glass sheets are sandblasted per day, the amount of rib material supplied is 400 [kg]. Since 60 [%] of the supplied rib material is 240 [kg] as a cutting process amount, 160 [kg] is a portion to be formed on the glass substrate 1 as a finished product. Further, when the injection amount of the metal abrasive 5 sprayed from the sandblast gun 4 in the sandblasting process is set to 7 [kg / min], 10 [t] of the metal abrasive 5 per day is circulated, and about 3 [%] That is, it is necessary to supply 300 [kg] of the new metal abrasive 5 per day.
[0012]
As described above, 240 [kg] of the rib material and 300 [kg] of the abrasive are consumed per day in the sandblasting. Most of this was discharged from the outlet 6A above the cyclone 6 via the cyclone 6, and was finally disposed of as industrial waste.
Therefore, in the sand blasting process, which is one of the production processes of the PDP, the more the glass sheets are processed, the more metal abrasives and ribs are generated as waste, and all of them must be discarded. It had the first problem. Further, since the rib material produced by sandblasting contains lead oxide, which is a harmful substance, it has a second problem of causing environmental pollution when disposed as industrial waste.
[0013]
Regarding the first problem, a foreign matter separation / classification method and apparatus described in Japanese Patent No. 2923464, a blast processing apparatus described in Japanese Patent Application Laid-Open No. Hei 8-141913, and a method described in Japanese Patent Application Laid-Open No. 9-295268 are described. However, as described in Japanese Patent Application Laid-Open No. 2002-114968, it is difficult to separate and recycle an object to be processed and an abrasive material. The problem of deterioration in polishing efficiency has not been solved by using a material. Further, the abrasive and the polishing method using the abrasive described in Japanese Patent Application Laid-Open No. 2002-114968 produce an abrasive having magnetism, hardness, and uniform size. After the used sandblasting process, the abrasive and the object to be processed are appropriately separated and collected by using magnetism. However, such special treatment is not applied to already manufactured ordinary abrasives that have not been subjected to manufacturing. It has the problem that it cannot be dealt with, and in addition to the high cost of taking special measures during the production of abrasives, a magnetic separation device that considers the effect of magnetism on other equipment is also required, and the introduction cost is also low It has the problem of being expensive.
[0014]
The present invention has been made in order to solve the above-mentioned problems, without performing a special treatment at the time of the production of metal abrasives, a metal abrasive that can be used again by applying treatment to the metal abrasive used in sandblasting. In addition, an object of the present invention is to provide a method for regenerating an abrasive and a method for regenerating a rib material for recovering lead oxide, which is a harmful substance, without polluting the environment.
[0015]
[Means for Solving the Problems]
The method of regenerating an abrasive according to the present invention is to separate a waste material consisting of a processing target formed material and a metal abrasive discharged by sand blasting into coarse powder and fine powder, and classify the separated coarse powder and fine powder. A separation / classification step of collecting each, a first washing step of washing the coarse powder with alkali and washing with water, and a second washing step of washing the coarse powder after the first washing step with acid and washing with water. And a drying step of drying the coarse powder that has passed through the second washing step. As described above, in the present invention, the waste material is separated into coarse powder and fine powder, each of which is classified and collected, the collected coarse powder is washed with alkali and washed with water, and further, the coarse powder is washed with acid and washed with water. Finally, since it is dried, substances dissolved in the alkali solution adhering to the separated and classified metal abrasive are removed by alkali washing, and the acid such as lead glass adhering to the metal abrasive is removed. The substance dissolved in the solution is removed by acid washing, and a metal abrasive having no deposit can be obtained. By using the metal abrasive again as a new abrasive, a great cost reduction can be achieved. The coarse powder means a powder having a large particle size, and the fine powder means a powder having a large particle size.
[0016]
Further, the method for regenerating a rib material according to the present invention includes separating at least a waste material composed of at least a rib material and a metal abrasive discharged by sand blasting into coarse powder and fine powder, and classifying the separated coarse powder and fine powder. A first classification step of charging the fine powder into a blast furnace to form a metal ingot by refining zinc oxide to form a metal ingot; And a second dissolving step of dissolving the lead into the melt and recovering the lead. As described above, in the present invention, in the first melting step, the fine powder is put into the blast furnace, and once alloyed by refining the coarse zinc oxide of zinc and lead, and in the second melting step, the metal ingot is melted in the blast furnace to form a zinc component. This lead oxide can be reused as a raw material for the production of lead glass because it is removed as coarse lead. As can be reused. Note that crude lead means lead containing impurities before refining and the like, and crude lead oxide means lead oxide containing impurities before refining and the like.
[0017]
Further, the method for regenerating an abrasive according to the present invention, if necessary, the metal abrasive used for sandblasting is composed of at least iron and chromium, and has a composition configuration excellent in alkali resistance and acid resistance. is there. As described above, in the present invention, since the metal abrasive is composed of at least iron and chromium and has a composition having excellent alkali resistance and acid resistance, it can be washed with the alkali solution used in the first washing step. Even when the metal abrasive is washed with the acid solution used in the second washing step, the metal abrasive has almost no reaction and can only remove the attached matter without substantially reacting because of the alkali resistance and the acid resistance. As the material made of iron and chrome, there is a stainless metal polishing material, and further, there is a stainless metal polishing material made of iron, chrome and nickel.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
(First embodiment of the present invention)
A method of regenerating an abrasive according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a conceptual diagram of a PDP rib forming device by sandblasting according to the present embodiment, FIG. 2 is a schematic diagram of rib formation by cutting during sandblasting of a general PDP, and FIG. 3 is metal polishing according to the present embodiment. FIG. 4 is an explanatory diagram of agglomeration of material, FIG. 4 is a particle size distribution characteristic diagram of a waste material at the time of introducing a 3% metal abrasive according to the present embodiment, FIG. FIG. 7 is a particle size distribution characteristic diagram of the waste material after separation according to the present embodiment, and FIG. 7 is a flowchart of a method of regenerating an abrasive according to the present embodiment.
[0019]
Before describing the method of regenerating the abrasive according to the present embodiment, first, the state change over time of the metal abrasive 5, the lead glass and the organic material constituting the rib 2 in sandblasting will be described. When the average particle diameter of the metal abrasive 5 ejected from the sandblast gun 4 is 20 [μm], the energy ejected from the volume and density is unambiguously determined by the flow rate of the fluid and the opening area of the tip of the sandblast gun 4. When the flow rate is 3.75 [m3 / min] and the opening area of the sandblast gun 4 is 4 × 10 −4 [m2], the speed of the metal abrasive 5 injected at the same speed as the air fluid is 9300 [m3 / min]. m / min] (= 558 [km / h]) (see FIG. 2).
[0020]
When the metal abrasive 5 is injected at a high speed onto the rib material 2 made of a mixed composition obtained by kneading lead glass or alumina with ethyl cellulose or an organic solvent, a part of the rib material 2 adheres to the surface of the metal abrasive material 5. Will be done. When the metal abrasive 5 is circulated in the rib forming equipment shown in FIG. 1, the surface of the metal abrasive 5 is contaminated with time. Due to this contamination, the metal abrasive 5 aggregates and the fluidity is remarkably reduced, thereby causing a problem such as a decrease in yield.
[0021]
In the sandblasting, for example, when a stainless abrasive having a density of 8 [gr / mm3], which is an example of the metal abrasive 5, is injected into the rib material 2 at an initial speed of 9300 [m / min], its kinetic energy is extremely high. The thermal energy of 1.4 × 103 [J / s] is generated from the energy 4 × 10 −7 [J] of one particle and the average number of particles ejected per second, and the surface temperature of the metal abrasive 5 increases. become.
[0022]
This heat energy causes the organic substance 9 to adhere to the surface of the new metal abrasive 5 to which no organic substance 9 adheres, and the organic substance 9 contains lead glass 8 (density 9.35 to 9) contained in the rib material 2. .63 [g / m3]) and alumina (density 4.0 [g / m3]) are further adhered to agglomerate the metal abrasive 5 between the particles. 3B from FIG. 3B to FIG. 3C, the probability of existence of aggregated particles in which the metal abrasive 5, the organic substance 9, the lead glass 8 and the alumina are aggregated is increased. As a result of the time-dependent change analysis of the metal abrasive 5, it was found. Naturally, the processing energy is proportional to the mass and speed of the metal abrasive 5, but when the aggregation of the metal abrasive 5 occurs and the equivalent mass of the aggregated particles becomes 2 to 8 times, the resist The film 12 may be directly hit and destroyed, or the rib being formed may be damaged.
[0023]
The cyclone 6 and the mesh filter 7 should function so that the agglomerated particles do not circulate with respect to such a change over time. However, if the agglomerated degree of the agglomerated particles increases, the thermal energy at the time of impact is high, and the cohesion is further improved. Agglomerated particles are formed, resulting in difficulty in dispersion. After the aggregated particles are ejected from the sandblast gun 4 and enter the cyclone 6 via the abrasive flow 5B together with the rib material 2 that has collided with the rib material 2 and cut, the mass of the cyclone 6 due to the air flow splitting is increased. In order to perform the separation, the agglomerated particles having a large mass that have been coagulated and solidified will fall in the direction of the outlet 6B below the cyclone 6, and the lead glass 8 and the like having a small mass that has been weakly fixed during processing will be above the cyclone 6. Is discharged from the discharge port 6A.
[0024]
The strong agglomerated particles increase their energy and are ejected to the object to be processed. However, even after the agglutination occurs, the particles are circulated through the rib forming apparatus until the particles cannot pass through the mesh filter 7. Grows. FIG. 3 (A) shows the appearance of the metal abrasive 5 alone, and FIGS. 3 (B) and 3 (C) show the form of the aggregated particles, showing the process of increasing the diameter of the aggregated particles. In the case of, it was found that the aggregated particles aggregated to generate a larger aggregated particle.
FIG. 4 shows the particle size distribution of the waste material discharged from the discharge port 6A above the cyclone 6 in FIG. 1, that is, the externally discharged waste material. From the figure, a peak of the metal abrasive 5 having an average of 20 [μm] and a peak of the lead glass 8 having an average particle of 3 [μm] are detected in the particle size distribution of the waste material, and the maximum particle diameter of the metal abrasive 5 is 60 μm. The presence of particles much larger than [μm], that is, aggregated particles was also confirmed.
FIG. 5A shows the shape of the waste material. This waste material was composed of a lead glass 8 existing as an aggregate between the metal abrasive 5 and the metal abrasive 5, and an organic substance 9 existing between the lead glass 8 and the metal abrasive 5.
[0025]
Next, a method for regenerating an abrasive according to the present embodiment will be described based on the above-described temporal change in the state of each substance. As shown in FIG. 7, in the method of regenerating the abrasive according to the present embodiment, the waste material including at least the rib material 2 and the metal abrasive 5 discharged by sandblasting is separated into coarse powder and fine powder. A separation and classification step of classifying and collecting the coarse powder and the fine powder, respectively, a first cleaning step of washing the coarse powder with alkali and water, and an acid washing of the coarse powder that has passed through the first cleaning step. It comprises a second washing step of washing with water and a drying step of drying coarse powder that has passed through the second washing step. Each step will be described below. The waste material to be subjected to the method for regenerating the abrasive according to the present embodiment is the waste material discharged from the outlet 6A above the cyclone 6, and the waste material remaining by the mesh filter 7 is subjected to the present regenerating method. The same effect can be obtained by performing the following steps.
[0026]
First, the separation and classification step will be described. In order to return the waste material shown in FIG. 5A to single particles, a step of applying a mechanical impact to the waste material and dispersing it is necessary. A disperser was used to apply this mechanical impact. For example, as a disperser, a classifier manufactured by Seishin Enterprise, which performs dry classification by air flow and has a processing capacity of 1 [t] or more per day, can be used. This disperser has a rotor that rotates the motor by rotating the work with the flow of air by the air flow.By causing the aggregated particles to collide with the rotor that rotates at high speed, the dispersion plate in the rotor collides with the aggregated particles, thereby giving a mechanical impact. The dispersed fine powder is blown to the outer periphery of the dispersion plate by the centrifugal force of the dispersion plate, and further has the ability to separate even relatively strong agglomerated particles into single particles by colliding with the collision plate. The separation and classification as shown in FIGS. 5 (B) and 5 (C) can be made possible by sandwiching the plate and using a vortex generated to provide the separation in a classification chamber for efficiently separating fine powder and coarse powder. Then, through the separation and classification step, the particle size distribution characteristics of the waste material were changed from FIG. 4 to FIG.
[0027]
According to FIG. 6 and the size of the metal abrasive and the size of the lead glass, most of the fine powder is composed of the lead glass 8 having an average particle size of 3 [μm], and most of the coarse powder is composed of the metal abrasive material 5 having an average particle size of 20 [μm]. You can see that. Further, when the fine powder and the coarse powder separated and recovered were chemically analyzed, the fine powder was mainly lead glass 8 and a large amount of alumina and ethylcellulose were detected. Further, the fine powder of the metal abrasive 5 was also contained. On the other hand, in the coarse powder, an organic substance 9 was detected in addition to the stainless steel abrasive, which is an example of the metal abrasive 5, and it was found that the organic substance 9 was ethyl cellulose present as a film on the surface of the metal abrasive 5. .
[0028]
When the waste material 1 [t] was treated using the crush seal, 580 [kg] of coarse powder and 420 [kg] of fine powder could be recovered. That is, the coarse powder occupies 58% of the waste material, and the fine powder occupies 42% of the waste material. When the rib material of 400 [kg] is sandblasted using the metal abrasive 5 of 300 [kg] using the rib forming equipment of FIG. 1, 240 [kg], which is 60 [%] of the inputted rib material. ] Is cut off and becomes a part of the waste material. Since the metal abrasive 5 discharged from the outside from the mesh filter 7 is 20 [kg], the remaining 280 [kg] becomes a part of the waste material and the metal abrasive 5 is a waste material. It can be seen that the rib material 2 accounts for 46% of the waste material. Thus, the ratio of the coarse powder in the waste material (58 [%]) and the ratio of the metal abrasive 5 in the waste material (54 [%]) are substantially the same, and the ratio of the fine powder in the waste material (42 [%]). ) And the ratio (46 [%]) of the rib material 2 in the waste material are substantially the same, and it can be seen that the waste material is appropriately separated and collected by the crash seal. The slight error is caused by the adhesion of the organic substance 9, the lead glass 8 and the alumina to the metal abrasive 5 in the coarse powder.
[0029]
Next, the first cleaning step will be described. As the solution used in the alkaline cleaning in this step, an aqueous solution of sodium hydroxide or an aqueous solution of potassium hydroxide is suitable in view of the metal composition of the metal abrasive 5, and the concentration of 5 to 10 [ %] And a temperature of 25 [° C.]. The coarse powder is alkali-washed and washed with water using this aqueous solution to remove impurities and return to a constant Ph. By this alkali washing, ethyl cellulose adhering to the metal abrasive 5 is dissolved in the alkali solution and can be removed. In the acid washing according to the present embodiment, an aqueous solution of sodium hydroxide or an aqueous solution of potassium hydroxide is used as the alkali solution, but any solution can be used as long as it can dissolve the deposits dissolved in the alkali solution. In addition, alumina and lead glass 8 can be removed from metal abrasive 5 by particle friction by stirring and washing at the time of alkali washing.
[0030]
Next, the second cleaning step will be described. The solution used in the acid cleaning in this step is a dilute nitric acid solution of 5%. However, since the solution used is a dilute nitric acid solution, Ni metal having high reactivity must be excluded from the composition of the metal abrasive. Using this solution, the metal abrasive 5 is acid-washed to remove fine scratches on the surface of the metal abrasive 5 without an etching action, and then washed with water to return to a constant Ph. Here, in order to eliminate the etching action, stirring is performed for the entire cleaning container. By this acid cleaning, PbO, which is the main component of the lead glass 8 attached to the metal abrasive 5, can be dissolved and removed in the dilute nitric acid solution, leaving only the metal abrasive 5 without any attached matter. Here, the amount of the diluted nitric acid solution is desirably 6% or less. In the acid cleaning according to the present embodiment, a dilute nitric acid solution is used as the acid solution, but any acid solution can be used as long as it can dissolve the deposits that dissolve in the acid solution.
[0031]
Finally, in the drying step, the coarse powder becomes only the metal abrasive 5 after passing through the first cleaning step and the second cleaning step, and the metal abrasive 5 to which water has adhered by washing with water is dried. Dry using. In the drying step, the metal abrasive 5 is aggregated, so that the sieve classification is performed after the drying. By performing sieve classification, the particle distribution can be adjusted.
[0032]
As described above, according to the method for regenerating the abrasive according to the present embodiment, the waste material discharged from the cyclone 6 or the like is separated into coarse powder and fine powder, each of which is classified and collected, and the collected coarse powder is washed with alkali. And then the coarse powder is acid-washed, washed with water, and finally dried, so that the ethyl cellulose adhering to the metal abrasive 5 collected by separation and classification is removed by alkali washing. The lead glass 8 adhering to the polishing material 5 is removed by acid cleaning, and the metal polishing material 5 having no adhering matter can be obtained. By using the polishing material again as a new polishing material, the cost can be significantly reduced.
[0033]
Alumina also adheres to the metal abrasive 5, but alumina does not dissolve in general chemicals, so it must be recovered using a specific gravity difference by a cyclone 6 or the like, or separated by mechanical shock or friction. .
Further, in the method of regenerating an abrasive according to the present embodiment, the metal abrasive 5 can be made of at least iron and chrome, and can have a composition having excellent alkali resistance and acid resistance. Even if the substrate is washed with the alkaline solution used in the above step or with the acid solution used in the second washing step, only the deposits can be smoothly removed because of the alkali resistance and acid resistance.
Further, in the method for regenerating an abrasive according to the present embodiment, the surface of the metal abrasive 5 can be dissolved by acid cleaning in the second cleaning step to make the angle of repose 32 degrees, so that the fluidity is good, It can be used as an abrasive.
[0034]
(Second embodiment of the present invention)
A method for regenerating a rib material according to the second embodiment of the present invention will be described with reference to FIG. FIG. 8 shows a flowchart of the rib material recycling method according to the present embodiment.
Referring to FIG. 8, in the method of regenerating the abrasive according to the present embodiment, the waste material including at least the rib material 2 and the metal abrasive 5 discharged by sandblasting is separated into coarse powder and fine powder. Separation step of classifying and collecting fine powder and fine powder, a first melting step of introducing the fine powder into a blast furnace and alloying it into a metal ingot by refining of coarse zinc oxide, and a first melting step And a second melting step in which the metal ingot generated by the above is introduced into a blast furnace to be melted and crude lead is recovered, and each step will be described below.
[0035]
In the first melting step, the fine powder obtained through the separation and classification step of the first embodiment is put into a blast furnace and alloyed once by refining a crude zinc oxide of 65% zinc and 10% lead. I do.
In the second melting step, the metal ingot alloyed in the first melting step is recovered as coarse lead by melting in a blast furnace and removing zinc components. Further, in order to increase the purity of lead, it is desirable to add electric refining to form an ingot as a lead oxide.
[0036]
As described above, according to the rib material recycling method according to the present embodiment, in the first melting step, fine powder is put into the blast furnace, and once refined by coarse zinc oxide of 65 [%] zinc and 10 [%] lead. It is alloyed, and in a second melting step, the metal ingot is melted in a blast furnace to remove zinc components to obtain coarse lead, and the coarse lead is electrorefined to form an ingot as a lead oxide. Can be reused as a raw material for PDP. After the lead glass 8 is formed, it is used as a rib paste-mixing main composition material of 3 [μm] average particles, whereby 100% is used as a material for forming a rib of PDP. Can be. The lead oxide obtained by the method for regenerating a rib material according to the present embodiment has a high purity and can be used in a wide variety of applications for general industry. Reusing the rib material as described above not only achieves cost reduction, but also eliminates waste, especially lead oxide, which is a harmful substance, thereby preventing natural environmental pollution and reusing resources. .
[0037]
In the present embodiment, alloying is performed once by refining crude zinc oxide of 65 [%] zinc and 10 [%] lead in the first melting step, because zinc and lead are separated by a specific gravity difference to lead. The first dissolving step is not necessarily required if the lead is simply purified from fine powder. Therefore, coarse lead can be obtained simply by melting the fine powder in the blast furnace.
[0038]
(Other embodiments)
Another embodiment of the present invention is to separate a waste material comprising at least the rib material 2 and the metal abrasive 5 discharged by sandblasting common to the first and second embodiments to separate coarse powder and fine powder. And separating and classifying the separated coarse powder and fine powder, respectively, and obtaining coarse powder and fine powder from the separation and classification process. First, the first embodiment is applied to the obtained coarse powder. A first cleaning step, a second cleaning step, and a drying step according to the above, to obtain a metal abrasive 5 having no deposits. At the same time, the first dissolving step and the second By applying a melting process to lead oxide, and using each as a metal abrasive 5 and lead oxide again in the rib forming apparatus, a loop type production line can be formed, and sand blasting can be performed very efficiently. can do.
[0039]
In the first embodiment, the object to be processed by sandblasting is the rib material 2 of the PDP. However, the material is not limited to the rib material as long as it can be processed by sandblasting using the metal abrasive 5. For example, plastic can be used as an object to be processed by using sandblasting for forming a plastic, and a silicon wafer can be used as an object to be processed by using sandblasting for forming a silicon wafer.
[0040]
【The invention's effect】
As described above, in the present invention, waste materials are separated into coarse powder and fine powder, each of which is classified and collected, the collected coarse powder is washed with alkali and washed with water, and further, the coarse powder is washed with acid and washed with water. Since it is washed and finally dried, substances dissolved in the alkali solution adhering to the separated and classified metal abrasive are removed by alkali washing, and lead glass and the like adhering to the metal abrasive are removed. The substance dissolved in the acid solution is removed by acid washing, so that a metal abrasive having no deposits can be obtained, and by using it again as a new abrasive, it is possible to achieve a significant cost reduction.
[0041]
Further, in the present invention, in the first melting step, the fine powder is put into the blast furnace, and once alloyed by refining the coarse zinc oxide of zinc and lead, and in the second melting step, the metal ingot is melted in the blast furnace to remove the zinc component. Since it is removed as coarse lead, this lead oxide can be reused as a raw material for the production of lead glass. It has the effect of being able to be used at the time.
[0042]
Further, in the present invention, since the metal abrasive is composed of at least iron and chromium, and has a composition configuration excellent in alkali resistance and acid resistance, it can be washed with the alkali solution used in the first washing step. Even when the metal abrasive is washed with the acid solution used in the second washing step, the metal abrasive has an effect that it can smoothly remove only deposits without substantially reacting because it has alkali resistance and acid resistance. Have.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram of a PDP rib forming apparatus by sandblasting according to a first embodiment of the present invention.
FIG. 2 is a schematic view of rib formation by cutting during sandblasting of a general PDP of the present invention.
FIG. 3 is an explanatory diagram of agglomeration of a metal abrasive according to the first embodiment of the present invention.
FIG. 4 is a graph showing a particle size distribution characteristic of a waste material at a point of time when a 3% new metal abrasive is charged according to the first embodiment of the present invention.
FIG. 5 is a separation transition diagram of aggregated particles according to the first embodiment of the present invention.
FIG. 6 is a particle size distribution diagram of waste materials after separation according to the first embodiment of the present invention.
FIG. 7 is a flowchart of a method of regenerating an abrasive according to the first embodiment of the present invention.
FIG. 8 is a flowchart of a method for regenerating a rib material according to a second embodiment of the present invention.
[Explanation of symbols]
1 Glass substrate
2 rib material
3 rib pattern
4 Sandblast gun
5 Metal abrasive
5A, 5B, 5C, 5D, 5E Abrasive flow
6 Cyclone
6A Outlet above cyclone
6B Lower outlet of cyclone
7 mesh filter
8 Lead glass
9 Organic substances
10 Processing room
11 Abrasive tank
12 Resist film

Claims (3)

A separation and classification step of separating a processing target formed material discharged from sand blasting and a waste material composed of a metal abrasive into coarse powder and fine powder, classifying the separated coarse powder and fine powder, and collecting the separated coarse powder and fine powder, First washing step of washing the base powder with alkali and water, second washing step of washing the coarse powder passing through the first washing step with water by acid washing, and coarse powder passing through the second washing step And a drying step of drying the abrasive. A separation and classification step of separating at least a waste material composed of at least a rib material and a metal abrasive discharged by sand blasting into coarse powder and fine powder, and classifying and collecting the separated coarse powder and fine powder, respectively; And a second melting step in which the metal ingot produced in the first melting step is put into a blast furnace to be melted and lead is recovered. A method for regenerating a rib material, comprising a melting step. The method for regenerating an abrasive according to claim 1,
A method for regenerating an abrasive, characterized in that the metal abrasive used for sandblasting is composed of at least iron and chrome, and has a composition that is excellent in alkali resistance and acid resistance.

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