JP4563203B2 - Silver waste separation method and equipment - Google Patents

Description

  The present invention provides a silver-containing liquid that is periodically or occasionally discharged from a photographic processing solution used in a photographic plant, and after separating silver-based waste from the silver-containing liquid, the silver is returned to the original photographic processing solution. The present invention relates to a system waste separation method and apparatus.

  In a photographic plant including a printing machine, it is necessary to wash with water when developing and fixing a photographic photosensitive material during processing of a printing plate. The photographic processing solution, which is a washing water, contains a predetermined photochemical called a gum solution, and after washing, mercury ions and silver halide dissolve therein, and the dissolved amount gradually increases as it passes through the plate processing machine. A large amount of photographic processing waste liquid is generated. Conventionally, when a photographic processing solution contains a certain amount or more of silver ions and silver halide and turns black, it is generally discharged out of the system as it is. Since the discharged photoprocessing wastewater naturally contaminates the water quality, in recent years, silver emission standards have been strictly regulated for environmental conservation, and the silver-containing liquid that is a photoprocessing wastewater can be discharged to the sewer. It becomes difficult every year.

  In order to clear strict silver emission standards, many silver removal methods have been proposed, such as JP-A-7-331350. In these methods, since silver ions and silver halide can hardly be removed by simple filtration, it is common to add a chemical such as a polymer chelating agent to the photographic processing waste liquid. In the case of chemical addition, the chemical reaction time is usually much slower than the increase in photographic processing waste liquid, so the waste liquid treatment equipment increases in size and waste water along with the increase in waste liquid accompanying the increase in the speed of printing presses and plate processing machines. The increase in cost becomes significant and it is practically impossible to remove the discharged silver to a level of 1 ppm or less.

An electrochemical ion exchange method has been proposed to improve the problem of upsizing of the apparatus, and a DC voltage is applied to the photographic processing waste liquid by a pair of working electrodes, and the working electrodes are used to convert granular ion exchange resin by a resin binder. Possess. Japanese Patent Application Laid-Open No. 7-310195 adds a potential difference between an anode and a cathode through which photographic processing waste liquid flows, and provides a barrier of an ion exchange resin that prevents the processing waste liquid from moving to the vicinity of the anode. The treatment waste liquid substantially flows in the vicinity of the cathode. In addition, it is known from Japanese Patent No. 3236570 and the like that when removing impurities in a fluid, which is a metal ion, in a general filtration technique, the fluid is agglomerated and coarsened in an electric field and filtered.
JP 7-331350 A JP 7-310195 A Japanese Patent No. 3236570

  Japanese Patent Application Laid-Open No. 7-310195 is constructed so that silver ions can be completely removed when photographic processing waste liquid passes through an elongated apparatus, and the processing waste liquid flows through a filter having a cell having an anode and a cathode. Most of the silver ions in the photographic processing waste liquid exit the cell in the form of insoluble particles of silver sulfide, and are separated from the photographic processing waste liquid by the filter. In this apparatus, although the photographic processing waste liquid can be reduced to a silver ion content of 0.1 ppm or less, the flow path of the processing waste liquid is only 5 × 65 × length 340 mm, and the processing of the photographic processing waste liquid is performed. Due to its low capacity, it can only be carried out in very small printing plants. In addition to filter replacement, it is necessary to periodically apply a reverse voltage to the cathode to remove silver sulfide deposits, which is a very complicated operation when a large number of devices are installed.

  If the photographic processing waste liquid is processed according to Japanese Patent No. 3236570, the processing waste liquid circulates in the electric field, so that silver ions are partly aggregated to generate a black liquid powder, and the photographic processing waste liquid can be filtered at a glance. It seems to be. However, when photographic processing waste liquid containing liquid powder is filtered with a filter, the dense filter will clog in less than a few hours, and the complicated filter replacement work will increase dramatically, and in fact the filter will be filtered. Processing was impossible. On the other hand, if the conventional removal method of adding chemicals to photographic processing waste liquid is applied to a system in which a part of photographic processing liquid is taken out and circulated, chemicals such as polymer chelating agent are mixed in the photographic processing liquid. It will not be possible.

  The present invention has been proposed in order to improve the above-mentioned problems relating to the removal of silver salts in a photographic processing solution. After the silver-containing liquid, which is a part of the photographic processing solution, is charged, The object is to provide a method for separating silver-based waste that drops quickly. Another object of the present invention is to remove a part of the photographic processing solution, and filter and circulate it, so that the consumption of the photographic processing solution is significantly reduced and the inside of the plate processing machine can be cleaned. It is to provide a method for separating objects. Another object of the present invention is to provide a silver-based waste separation apparatus that is small in size, has high processing capacity, and requires a small number of filter replacements.

  The method for separating a silver-based waste liquid according to the present invention is a method for separating silver-based waste from a silver-containing liquid that flows out from a photographic processing liquid. In this separation method, the silver-containing liquid passes between the electrode bodies and is charged, and the silver-based coagulated material agglomerated by this charging is sent to the wide waste reservoir portion below while giving a rotating action, and is also an obstacle that extends downward. The silver-containing liquid is allowed to fall from the silver-containing liquid by passing through a plate, and the silver-containing liquid is clarified by filtration.

  The silver-based waste liquid separation method of the present invention is a method in which a part of a silver-based liquid processing solution is taken out as a silver-containing liquid, and the silver-containing liquid is charged by passing between both electrode bodies. In addition to feeding the object to the wide waste storage part below, it is also possible to pass the baffle plate extending downward to promote the fall of the silver-based coagulum from the silver-containing liquid. Further, the silver-containing liquid after separation of the silver-based coagulum is clarified by filtration and then returned to the original photographic processing liquid.

  In the separation method of the present invention, the silver-based waste in the waste reservoir is automatically discharged out of the system by opening the valve when the pressure in the container rises. In addition, the silver waste may be discharged out of the system automatically by periodically opening a valve depending on the setting of a timer or the like.

  A silver-based waste separation device according to the present invention includes an outer cylindrical body that is one electrode body, an intermediate cylindrical body that has a baffle plate that extends downward from the outer cylindrical body, and is the other electrode body. And a cylindrical filter disposed inside the intermediate cylinder and a waste reservoir located below the outer cylinder. The charging path between the outer cylinder and the intermediate cylinder communicates with the lower waste reservoir, so that the silver-containing liquid passes between the outer cylinder and the intermediate cylinder and is charged, and then the baffle plate Pass the filter via.

  In the separation device of the present invention, the silver-based coagulated material aggregated by electrification falls to the lower waste reservoir due to the expansion of the silver-containing liquid because the inner diameter of the waste reservoir is larger than the inner diameter of the outer cylinder. Promote. Further, the silver-based solidified material is dropped into the lower waste reservoir portion, and the lower wall of the reservoir portion is preferably inclined toward one peripheral wall, so that the silver-based solidified material falling into the reservoir portion is reduced by its own weight. Gradually moves toward the solenoid valve.

  The present invention will be described with reference to the drawings. FIG. 1 illustrates a silver-based waste separation device 1 according to the present invention, which has a substantially cylindrical elongated appearance. In the separation apparatus 1, a control box 3, a motor-equipped pump 4 and a transformer 5 are installed, and these installation locations are arbitrary. Even if the separating apparatus 1 is vertically installed on a horizontal base (not shown) by a pair of support frames 2 or other members, it can be attached to the side wall of the printing press or disposed inside the printing press.

  The separation device 1 includes an outer cylinder 6 that is one electrode body, an intermediate cylinder 8 that is the other electrode body, and an elongated inner cylinder 10 that is fitted with a cylindrical filter. The inner cylinder 10 is mounted coaxially with the inner cylinder 10 inside. As schematically shown in FIG. 3, a predetermined pulse current (FIG. 4) is supplied to the outer cylinder 6 and the intermediate cylinder 8 by electrically connecting the power source, that is, the transformer 5, to the outer cylinder 6 and the intermediate cylinder 8. Alternatively, direct current or alternating current is allowed to flow constantly. When direct current is applied, it is possible to charge the outer cylinder 6 to the positive electrode and the intermediate cylinder to the negative electrode, and to set both cylinders to the opposite electrodes.

  The outer cylinder 6 is communicated with the lower waste reservoir 12. A through hole 24 is provided in the upper part of the outer cylinder 6, and the silver-containing liquid flows into the charging path 41 in the apparatus 1 through the through hole. The intermediate cylinder 8 passes through the through hole 29 of the waste reservoir 12 and extends downward, and the lower part through which the intermediate cylinder 8 normally becomes the baffle plate 7 having a circular cross section. The baffle plate 7 may be formed by welding or bonding an integral member or a separate member to the intermediate cylinder 8, and may be made of plastic other than metal as long as it is a separate member. The inner peripheral wall of the outer cylindrical body 6 or the outer peripheral wall of the intermediate cylindrical body 8 on the anode side of the silver-containing liquid may be made of metal such as iron or aluminum that can be easily ionized, or the wall of iron or aluminum may be provided on the wall surface. The sheet may be welded, or a resin added with an anion exchange resin may be laminated by injection molding.

  The lower waste reservoir 12 is connected to the outer cylinder 6 around the central through hole 29 of the upper wall 28. The diameter of the reservoir 12 may be 1.5 to 2.5 times the diameter of the outer cylinder 6, and if it is less than 1.5 times, the fall of the silver-based solidified product due to stagnant expansion does not proceed smoothly. The lower wall 30 of the waste reservoir 12 is preferably inclined toward one peripheral wall, and the silver-based solid matter that has dropped onto the lower wall 30 gradually moves toward the solenoid valve 32 due to its own weight.

  As illustrated in FIG. 3, the solenoid valve 32 is electrically connected to a control device 34 such as a microcomputer or a relay, and is further connected to a pressure gauge 38 interposed in a pipe 36 or in the apparatus 1. And a pressure sensor attached to the reservoir 12 and a concentration sensor in the reservoir 12. The microcomputer 32 can open and close the valve 32 according to the pressure in the pipe line 36, that is, the pressure of each part in the apparatus, and the measurement position can be in the intermediate cylinder 8, the reservoir 12, the filter surface, or the like. Further, the opening and closing of the valve 32 may be set to be opened regularly by a timer in the control device 34.

  The elongated inner cylinder 10 has a fixing ring 44 attached slightly below the upper end 33 of the cylinder. The ring has a height substantially coincident with the lower end of the outer cylinder 6 and extends vertically downward from the ring. The lower wall 30 of the storage part 12 is penetrated and fixed vertically. The outer diameter of the inner cylinder 10 is substantially equal to the inner diameter of the filter cassette 14 that is a cylindrical filter. The upper end of the inner cylinder may be set at substantially the same height as the intermediate cylinder 8, and may be extended vertically downward to penetrate the lower wall 30. If the inner cylinder has a shape that penetrates the center of the filter, a plurality of through holes are formed in the peripheral wall of the inner cylinder above the attachment position of the ring 44, and the filtered liquid is passed through each through hole. Spill. The filtered liquid may be allowed to flow out by providing one large-diameter through hole at the upper end of the inner cylinder or by opening the upper end surface of the inner cylinder. In this case, the inner cylindrical body has an outer diameter smaller than the inner diameter of the cylindrical filter, and when the filter is accommodated, there is a slight cylinder between the inner peripheral surface of the filter and the outer peripheral surface of the inner cylindrical body. It is necessary to provide a gap.

  The filter cassette 14 that is a cylindrical filter accommodates a relatively thick cylindrical filter (not shown) in a metal outer cylinder 56 (FIG. 5). This cylindrical filter is composed of 3 to 6 layers such as fiber web, felt, non-woven fabric, woven fabric, synthetic paper, etc., and the fiber web, felt or non-woven fabric in each filter layer is polyolefin-based such as polypropylene, polyvinyl chloride, It consists of synthetic fibers such as polyamide, polyvinyl acetate, acrylic, cotton, and viscose. As this cylindrical filter, it is also possible to use a polypropylene fiber web alone, carbon fiber or other conductive fiber web, an ultra-precision filtration membrane such as an MF filtration membrane or a UF filtration membrane, an RO filtration membrane, or the like.

  The filter cassette 14 can be stored in two or more stages as desired. If the inner cylinder has a length corresponding to the entire length of the apparatus 1, the filter cassette may be placed on the ring 44 through the inner cylinder and fixed with a holding fitting (not shown). The filter cassette 14 may have a structure as shown in FIG. 6 and has a sheet-like fiber filter 50 whose both surfaces are reinforced with fine nets 47 and 48, and is folded in a zigzag shape so that the fiber filter becomes a circular plane. Increase the contact area. The fiber filter 50 may be a single layer of a polypropylene fiber web, or may have a two-layer structure including a polypropylene fiber web having a thinner inner layer and a polypropylene fiber web having a thicker outer layer, and glass wool may be added as desired. Good.

  In a photographic plant including a printing machine and a plate processing machine, a silver waste separation method according to the present invention allows a part of a liquid to flow out from a stock solution tank of a photographic processing liquid, and from the silver-containing liquid that is the effluent. After removing the silver-based coagulum, return to the stock solution tank. The method of the present invention first charges the silver-containing liquid, separates the agglomerated black liquid powder from the silver-containing liquid by the expansion of the silver-containing liquid and the intervening baffle, and reliably removes only the separated silver-based solidified product. As a result, the amount of waste liquid for photo processing can be drastically reduced, preventing pollution and contributing to environmental conservation.

  The separation method of the present invention does not discard the dirty photographic processing solution as it is, but removes a large portion of the photographic processing solution and constantly circulates it, thereby reducing the amount of photochemical added and the amount of overflow of the photographic processing solution. It can be reduced and is very economical. Moreover, since the clear photographic processing liquid always circulates inside the plate processing machine by the method of the present invention, each part of the plate processing machine is substantially washed by the clear photographic processing liquid. . For this reason, the contamination of the printing press itself is reduced, the number of times that the photographic plant including the printing press is stopped and the entire apparatus is washed is reduced, and the mechanical life of the printing plate processing machine is extended.

  The silver-based waste separation device according to the present invention does not immediately filter this silver-based coagulated material, even if silver ions aggregate due to the charging of the silver-containing liquid and a black liquid powder is generated. A large portion of the silver-based coagulum is dropped into the lower waste reservoir by the rapid expansion of the liquid volume and the baffle plate, and only the silver-containing liquid in which some silver ions remain is filtered. The separation device of the present invention does not filter the entire amount of the photographic processing solution, but quickly cleans a part of it, so that it has a high processing capacity even with a small size, and the number of times of replacing a contaminated filter is remarkably small. Become.

  Next, the present invention will be described based on examples, but the present invention is not limited to the examples. 1 and 2 show a silver-based waste separation apparatus 1 according to the present invention. The separator 1 is usually made of stainless steel, has a substantially cylindrical appearance, and is bolted vertically on a horizontal base (not shown) by a pair of support frames 2 and 2. In the separating apparatus 1, a control box 3 including a control panel is attached to the front side surface, and a pump 4 with a motor is installed below the rear side surface and a transformer 5 is installed above.

  The separation apparatus 1 includes an intermediate cylindrical body 8 having a large-diameter outer cylindrical body 6 that is one electrode body and a baffle plate 7 that is the other electrode body and extends downward from the outer cylindrical body 6. And an elongated inner cylinder 10 that is mounted with a cylindrical filter and is located in the center, and these cylinders are all arranged coaxially. Below the outer cylinder 6, a waste reservoir 12, which is a cylindrical body having a larger diameter, is closely connected coaxially. The filter is, for example, a cylindrical filter cassette 14 and is attached coaxially above the inner cylinder 10 inside the intermediate cylinder 8.

  The outer cylinder body 6 is coaxially coupled to the waste reservoir 12 at the lower end thereof and communicates with the reservoir. At the upper peripheral end of the outer cylinder 6, the circular lid 16 and the support plate 18 are bolted horizontally, and further tightly fastened with an annular belt 20, and an air vent cock 22 is attached to the circular lid 16. A through hole 24 connected to the elbow 23 (FIG. 2) is provided in the upper part of the outer cylindrical body 6, and the silver-containing liquid flows into the apparatus 1 through the elbow. Further, the insulator 25 is attached in communication with the upper part of the outer cylinder 6 and the intermediate cylinder 8, and the power source (FIG. 3), that is, the electric wires 26 and 27 from the transformer 5 are passed through the insulator 25 to the outer cylinder 6 or the intermediate cylinder. By connecting to 8, a predetermined pulse current (FIG. 4) or a direct current flows constantly to the outer cylinder 6 and the intermediate cylinder 8.

  In the lower cylindrical waste reservoir 12, the diameter of the central through hole 29 of the upper wall 28 is substantially equal to the inner diameter of the outer cylindrical body 6, and is welded to the outer cylindrical body 6 around the through hole. The diameter of the reservoir 12 may be about twice the diameter of the outer cylinder 6. For example, the outer cylinder 6 has a diameter of 100 mm and the reservoir 12 has a diameter of 200 mm. The lower wall 30 of the waste reservoir 12 is inclined toward one peripheral wall, and the solenoid valve 32 is attached to the peripheral wall of the reservoir 12 at the lower end thereof. For this reason, the silver-based solidified material that has fallen into the reservoir 12 gradually moves toward the valve 32 by its own weight along the inclined lower wall 30.

  As shown in FIG. 3, the solenoid valve 32 is electrically connected to a control device 34 including a microcomputer and a relay, and the control device is connected to a pressure gauge 38 interposed in the pipe 36 to read the pressure value. . The pressure gauge 38 is preferably disposed on the side wall of the outer cylinder 6 and is a liquid crystal display. Since the pipe line 36 communicates with the outer cylinder body 6 via the elbow 23, the valve 32 is opened according to the pressure in the pipe line, that is, the set pressure inside the outer cylinder body 6, under the control of the microcomputer. Further, the valve can be opened every predetermined time by microcomputer control.

  As shown in FIG. 1, the intermediate cylinder 8 is held vertically by a circular support plate 18 positioned at the upper end, and is fixed to the outer cylinder 6 with a plurality of horizontal bolts 40. The intermediate cylinder 8 passes through the through hole 29 of the waste reservoir 12 and extends downward, and the lower part that has passed through becomes the baffle plate 7. The intermediate cylinder 8 is electrically connected to the outer cylinder 6 and is charged. A charging path 41 is between the inner peripheral surface of the outer cylindrical body 6 and the outer peripheral surface of the intermediate cylindrical body 8, and the charging path communicates with the reservoir 12 through the through hole 29. The outer peripheral wall of the intermediate cylinder 8 or the inner peripheral wall of the outer cylinder 6 on the anode side of the silver-containing liquid is preferably made of a metal that is easily ionized, such as iron or aluminum, and a cylindrical sheet of iron or aluminum on the wall surface. May be attached.

  The elongated inner cylinder 10 has an outer diameter equal to the inner diameter of the filter cassette 14, and a large-diameter fixing ring 44 is fixed to the cylinder upper end 33 slightly below. A circular plate 45 for supporting the filter is attached to the upper end surface of the fixing ring 44, and the plate has a shallow dish shape to which the filter cassette 14 can be fitted. The height position of the fixing ring 45 substantially coincides with the lower end of the outer cylinder 6, that is, the upper wall 28 of the reservoir 12. On the other hand, a circular plate 46 having the same shape is attached to the support plate 18 so as to correspond to the lower circular plate 45, and the plate 46 can be displaced in the vertical direction via a link (not shown) fitted with a coil spring 42. is there. The inner cylinder 10 extends vertically downward and penetrates and adheres to the lower wall 30 of the waste reservoir 12, and then the elbow 43 is screwed, and the elbow communicates with the conduit 62 (FIG. 3). .

  The filter cassette 14 (FIG. 5) is mounted on the circular plate 45 of the fixing ring 44, pressed by the upper circular plate 46 via the spring 42, and mounted vertically by closing the support plate 18 and fixing it horizontally. . In the filter cassette 14, the filtered liquid flows into the inner cylinder 10 through the cassette center hole. In addition, a predetermined cylindrical gap is provided between the outer peripheral surface of the filter and the inner peripheral surface of the intermediate cylinder 8, and the flow path 49 for the silver-containing liquid that has passed through the baffle plate 7 is configured. The filter cassette 14 can be easily removed and replaced by opening the circular lid 16 and the support plate 18 and removing the circular plate 46.

  The filter cassette 14 accommodates a relatively thick cylindrical filter (not shown) in an outer cylinder 56 (FIG. 5) made of a punched steel plate, and the cylindrical filter includes the outer cylinder 56 and donut-shaped end plates 55 and 57. And is covered by. This cylindrical filter has a pore diameter of 0.5 or 1.0 μm and is composed of five layers such as a fiber web, felt, nonwoven fabric, and synthetic paper.

  The filter cassette may have a structure as shown in FIG. This filter cassette has a sheet-like fiber filter 50 whose both surfaces are reinforced by fine nets 47 and 48 having a hole of about 7 μm, and the contact area is increased by folding the fiber filter into a zigzag shape so as to form a circular plane. . The fiber filter 50 has a two-layer structure in which the inner layer is composed of a polypropylene fiber web having a diameter of 3 μm and the outer layer is a polypropylene fiber web having a diameter of 10 μm. The thickness after press molding is about 2 mm, and glass wool is further added as desired. To do.

  The motor-equipped pump 4 is installed on the side wall of the apparatus 1 as shown in FIG. 1, and a silver-containing liquid is taken out from a stock solution tank 52 (schematically shown) of a photographic processing solution in a photographic plant through a pipeline 54, and a pipeline 36 ( 3), the pressure is fed into the outer cylinder 6 while being pressurized. Manual cocks 56 and 58 are attached to the inlet and outlet of the pump 4, respectively. In addition, when the pressure switch 60 is attached to the pipe line 36 and the pressure in the pipe line, that is, the pressure inside the outer cylindrical body 6 rises rapidly, the pressure switch 60 is activated to stop the pump 4.

  A photographic plant including a printing machine includes a plurality of chemical cartridges (not shown), a photographic processing solution stock tank 52, a printing plate processing machine, and the like for finishing a photo. Photoprocessing solutions are supplied in appropriate amounts from multiple chemical cartridges containing photochemicals, and when a silver halide image is formed by a plate processing machine, a small amount of silver ions and silver halide dissolve in the development and bleaching steps. In addition, a large amount of silver ions and silver halide are dissolved in the fixing step. The photographic processing liquid containing silver ions and silver halide passes through the printing plate processing machine and returns to the stock solution tank 52 through the printing plate processing machine.

  The separating apparatus 1 takes out a part of the photographic processing solution from the stock solution tank 52 via the pipe line 54 periodically or at any time, and automatically sets this extraction amount to an appropriate value according to the degree of contamination of the photographic processing solution. The silver-containing liquid that has flowed out of the tank 52 flows into the separation device 1 through the pump 4 and the pipe line 36. In the separation device 1, the silver-containing liquid passes between the outer cylinder 6 and the intermediate cylinder 8, which are both electrode bodies, and is charged. By this charging, a large amount of silver-based coagulum is obtained from silver ions and silver halide. Aggregate. Since this silver-containing liquid is pressurized by the pump 4 and flows into the apparatus from the through hole 24 above the outer cylinder 6, it rotates between the outer cylinder 6 and the intermediate cylinder 8, that is, in the charging path 41. While moving down.

  The agglomerated silver-based solidified product is sent to the wide waste reservoir 12 below while rotating the silver-containing liquid, and the volume of the rotating silver-containing liquid rapidly expands as shown by the arrows in FIG. , Easily separated from the silver-containing liquid. Next, the silver-containing liquid passes through the circular baffle plate 7 extending downward and flows into the intermediate cylinder 8, thereby further facilitating the fall of the silver-based solidified product from the silver-containing liquid and feeding it into the filter cassette 14. Reduce silver-based coagulum as much as possible.

  The silver-containing liquid passes through the thick cylindrical filter from the outer peripheral surface of the filter cassette 14 in the radial direction. As a result, a small amount of the silver-based coagulum remaining in the silver-containing liquid is filtered by passing through the cylindrical filter, thereby further clarifying the silver-containing liquid. With respect to this cylindrical filter, even if some silver-based solidified material adheres, the filtration capacity is hardly lowered, and the remaining silver-based solidified material itself is small. In addition, the silver-based solid matter adheres to the outer peripheral surface of the filter by continuing operation, and when this amount of deposit reaches a certain amount, the deposit is peeled off from the cylindrical filter and falls into the reservoir portion 12, so the cylindrical filter is clogged. Will be resolved and use can be continued. For this reason, the filter cassette 14 provided with the cylindrical filter can be sufficiently used continuously for several months or more.

  The clarified liquid passes through the through hole 46 and flows into the inner cylinder 10, and further returns to the stock solution tank 52 through the pipe line 62. As a result, the content of silver ions and silver halide in the tank 52 does not exceed a predetermined value due to the installation of the separation device 1, and it is not necessary to discard the entire photographic processing solution in the stock solution tank 52. Even if the printing machine speeds up, the size of the waste water treatment device and the drainage cost will not increase.

  On the other hand, the silver-based coagulated material staying in the lower waste reservoir portion 12 is automatically collected gradually toward the solenoid valve 32 because the lower wall 30 of the reservoir portion is inclined to one side. The valve 32 is controlled so as to be opened regularly, and gradually sends a high-concentration silver-based coagulum to the silver removal tank 64. What is necessary is just to adjust the liquid discharge | emission amount from the valve | bulb 32 according to the gum liquid supply amount from a some chemical | medical agent cartridge.

  In the silver removal tank 64 (FIG. 3), for example, chemicals such as a polymer chelating agent may be added to chemically separate silver. Even if the time of this chemical reaction is slow, the absolute amount of silver-based coagulated material to be processed is small, so there is no need to increase the size of the tank, and it is easy to reduce the level to 1 ppm or less.

  In a photographic plant, a plurality of chemical cartridges may automatically supply gum solution and water according to the amount of photographic processing solution discharged or the amount of natural evaporation, and a constant amount of photographic processing solution is always supplied into the stock solution tank 52. Hold. When the separation apparatus 1 is installed, the chemical cartridge is rarely operated, and the usage amount of the gum liquid that is a photochemical chemical is drastically reduced.

It is a schematic sectional drawing which shows the principal part of the separation apparatus which concerns on this invention. It is a schematic side view which shows the separation apparatus seen from the right side of FIG. It is explanatory drawing which shows the process through which the photographic processing liquid which flowed out from the stock solution tank of a photographic plant circulates. It is a graph of the pulse current which is an example of the electric current sent to an outer cylinder and an intermediate cylinder. It is a perspective view which shows an example of the filter cassette used by this invention. It is a partial top view which cuts off and shows another example of a filter cassette partially.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Separator 6 Outer cylinder 7 Baffle plate 8 Intermediate cylinder 10 Inner cylinder 12 Waste storage part 14 Filter cassette

Claims (7)

  A method for separating silver-based waste from silver-containing liquid that flows out from a photographic processing solution, wherein the silver-containing liquid passes between both electrode bodies and is charged, and the silver-based coagulated material aggregated by this charge is rotated. Silver that is sent to the wide waste reservoir below while exerting an action, passes through a baffle plate extending downward, promotes the fall of the silver-based coagulum from the silver-containing liquid, and further clarifies the silver-containing liquid by filtration System waste liquid separation method.   A method for separating silver-based waste from a silver-containing liquid flowing out from a photographic processing solution, wherein a part of the silver-containing liquid is taken out from the circulating photographic processing solution, and the silver-containing solution passes between both electrode bodies. Then, the silver-based coagulated material agglomerated by this electrification is sent to the wide waste reservoir below, and a baffle plate extending downward is passed through to promote the fall of the silver-based coagulated material from the silver-containing liquid. A method for separating a silver-based liquid waste that is clarified by filtration and then returned to the original photographic processing solution.   The separation method according to claim 1 or 2, wherein the silver-based waste in the waste reservoir is automatically discharged out of the system by opening a valve when the pressure in the container increases.   The separation method according to claim 1 or 2, wherein the silver waste in the waste reservoir is automatically discharged out of the system by periodically opening a valve by setting a timer or the like.   An outer cylindrical body that is one electrode body, an intermediate cylindrical body that has a baffle plate extending downward from the outer cylindrical body and that is the other electrode body, and a cylindrical filter that is disposed inside the intermediate cylindrical body And a waste reservoir located below the outer cylinder, and the charge path between the outer cylinder and the intermediate cylinder communicates with the lower waste reservoir so that the silver-containing liquid is A silver-based waste separator that passes between a body and an intermediate cylinder and is charged and then passes through a baffle plate and then passes through a filter.   The silver-containing liquid is charged by passing between the outer cylinder and the intermediate cylinder, and the silver-based coagulated material aggregated by this charging is due to the fact that the inner diameter of the waste reservoir is larger than the inner diameter of the outer cylinder. The apparatus according to claim 5, wherein the falling of the silver-containing liquid promotes the fall to the waste reservoir portion below.   The silver-containing liquid is charged by passing between the outer cylinder and the intermediate cylinder, and the silver-based coagulated material aggregated by this charging is dropped to the lower waste reservoir, and the lower wall of the reservoir is one side. 6. The apparatus according to claim 5, wherein the silver-based solid matter that has fallen into the reservoir portion gradually moves toward the solenoid valve by its own weight by inclining toward the peripheral wall.

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