Classifications

• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21F—PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR
  • G21F9/00—Treating radioactively contaminated material; Decontamination arrangements therefor
  • G21F9/28—Treating solids
  • G21F9/30—Processing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
  • B01F27/80—Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis
  • B01F27/90—Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis with paddles or arms 
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F33/00—Other mixers; Mixing plants; Combinations of mixers
  • B01F33/80—Mixing plants; Combinations of mixers
  • B01F33/83—Mixing plants specially adapted for mixing in combination with disintegrating operations
  • B01F33/833—Devices with several tools rotating about different axis in the same receptacle
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F33/00—Other mixers; Mixing plants; Combinations of mixers
  • B01F33/80—Mixing plants; Combinations of mixers
  • B01F33/836—Mixing plants; Combinations of mixers combining mixing with other treatments
  • B01F33/8361—Mixing plants; Combinations of mixers combining mixing with other treatments with disintegrating
  • B01F33/83613—Mixing plants; Combinations of mixers combining mixing with other treatments with disintegrating by grinding or milling
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21F—PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR
  • G21F9/00—Treating radioactively contaminated material; Decontamination arrangements therefor
  • G21F9/04—Treating liquids
  • G21F9/06—Processing
  • G21F9/12—Processing by absorption; by adsorption; by ion-exchange
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21F—PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR
  • G21F9/00—Treating radioactively contaminated material; Decontamination arrangements therefor
  • G21F9/28—Treating solids
  • G21F9/30—Processing
  • G21F9/301—Processing by fixation in stable solid media
  • G21F9/302—Processing by fixation in stable solid media in an inorganic matrix
  • G21F9/304—Cement or cement-like matrix

Definitions

• the invention relates to a lonenSerharzzerklein mecanicsvoriques comprising a tank for receiving an aqueous lonenSerharzsuspension, provided in the tank agitator, provided outside the tank grinding device and a pumping device for conveying the aqueous ion exchange resin suspension from the tank to the grinding device.
• ion exchanger resins are used in conventional power plants and nuclear facilities and power plants for purifying water or wastewater.
• the radioactively loaded ion exchanger resins have to be treated and disposed of in a complicated manner.
• methods such as dewatering, drying or solidification in a cement matrix are often used.
• the spherical ion exchange resins can either be processed directly or they are previously ground.
• mills are used, such as corundum disk mills.
• the ion exchanger resins are suspended with water and passed through the mill in a recirculation cycle in order to achieve the desired grinding result. Milling of ion exchanger resins may be required to achieve better results in subsequent processes, such as: The reduced tendency to float of ground resins during cementing,
• Patent EP0963588 B1 discloses a device or a method in which an ion exchange resin suspension contained in a first container is fed to an outer corundum disk mill and collected after the grinding process in a second container, from which the ion exchange resin suspension recirculates the corundum disk mill is supplied.
• corundum disk mill By means of the corundum disk mill mentioned in the prior art, a fine grinding of the ion exchange resins in the suspension takes place by means of two corundum disks. These corundum disks are hard, brittle and usually have a porous structure.
• the high porosity of the corundum discs causes a strong contamination of the discs with finely ground ion exchange resin, since the fine powder penetrates deep into the pores. This contamination is very difficult to remove. Since ion exchanger resins can have a high dose rate, this contamination poses an extreme hazard for the personnel.
• the brittle properties of the corundum disk have the disadvantage that the disks can break easily and then an immediate replacement is required. Since such an exchange can only be done manually, a dose burden of the staff involved is inevitable.
• the ion exchange resin is passed after passing through the corundum mill in a separate tank.
• This first comminution step with the corundum mill is necessary in order to make the ion exchange resin suspension pumpable and to allow a recirculation loop.
• Spherical, uncomminuted ion exchanger resins would sediment rapidly.
• the ion exchange resins are then further comminuted.
• This circulation operation also has the disadvantage that it can lead to a mixing of already ground and unground ball resins, or there is a mixing of material which has already passed the mill several times, with that which has passed the corundum mill only in the first grinding step.
• an object of the invention to provide an improved comminution device for ion exchange resins, which is as compact as possible, in which as few components are contaminated and in which the lowest possible radiation exposure for the operating or maintenance personnel is given.
• the object of the invention is also to provide a corresponding method.
• the core idea of the invention is to divide the grinding process into two different grinding steps, which are carried out by two different grinding units.
• a first milling step is provided, namely a pre-shredding operation in order to make the ion exchange resin suspension pumpable.
• a second grinding step the actual grinding process then takes place to a fine-grained powder.
• the inventive arrangement of the first Mahlaggregates - the pre-crushing device - directly in the tank is advantageously allows that the ion exchange resin suspension can be made pumpable in the tank.
• the ion exchanger resin contained therein is Pre-crushed particles so that the ion exchange resin suspension by means of the pumping device to the second grinding unit - the grinding device - can be supplied. Due to the pre-comminution of the ion exchanger resin particles that has already taken place, a single pass through the grinding device is sufficient to achieve the desired grinding result or the desired particle size distribution.
• the inventive modular division of the crushing task in pre-crushing and grinding can thus account for a second tank advantageously. As a result, both the contaminated surface and the space requirement of the comminution device are advantageously minimized.
• pre-shredding in the tank eliminates recirculation operation with the mill and the associated uncertainties with regard to particle size distribution and sedimentation tendency. Splitting the shredding into two steps, pre-shredding and grinding ensures that each particle passes through the grinder exactly once.
• the division of the comminution of the ion exchange resins on two grinding units allows flexible adaptation of the existing components of the comminution device to the respective comminution task. Is to achieve the respective process goal / example, a minimization of Floatationne Trent, no grinder required, so only the pre-crushing device integrated into the tank can be used and the grinding device are bypassed by a corresponding bypass.
• the pre-comminution device is a disperser.
• Dispersers operate on the rotor-stator principle, are suitable for the production of emulsions and suspensions and can be structurally particularly easy to integrate into the tank.
• the rotor / stator ring used has a pitch of ⁇ 1 mm and is integrated in the tank.
• the grinding device is a colloid mill.
• a colloid mill crushes according to the rotor-stator principle. Between the toothed surfaces of the rotor and stator disks, thin-bodied to highly viscous products are comminuted, dispersed or homogenized in a narrow gap. The narrow gap and the high speed result in a high shear rate, which is responsible for the comminution effect.
• a colloid mill which is suitable according to the invention is preferably characterized in that the rotor or stator are conical. In the upper area are ideally provided fields and trains and in the lower area a rough grinding surface. Such a configuration leads to a particularly good grinding result for the ion exchange resins to be ground. Suitable materials for the grinding surface are, for example, metal carbides or ceramics.
• the colloid mill has a rotor / stator ring with an adjustable gap spacing.
• the shear rate can thus be adjusted continuously via the grinding gap and the properties of the milled ion exchange resin are thus influenced in an advantageous manner according to the respective process objective.
• the setting of the desired particle size distribution of the product at the outlet of the colloid mill is carried out over the duration of Vormahlung in the tank, a corresponding adjustment of the grinding gap of the colloid mill, the solids content of the product, but also on the adjustable via the pump product pressure before the colloid mill.
• the stirring device in the tank is designed as an anchor agitator.
• Anchor stirrers are particularly suitable for keeping a volume of a suspension in a storage tank in constant motion and thus preventing sedimentation.
• the ion exchanger resin comminution device has a dewatering device for adjusting the water content of the aqueous ion exchange resin suspension.
• a dewatering device for adjusting the water content of the aqueous ion exchange resin suspension.
• this optionally has a different water content.
• the ion exchange resin grinder is designed so that a fixed water content is adjustable. In order to achieve this water content, the ion exchange resin suspension is first dehydrated and then a defined amount of water is added again. Therefore, in the case that the ion exchange resin suspension has too low a water content, a supply device for water is provided.
• a drainage device has, for example, a suction pipe opening at the bottom of the tank with a filter.
• the ion exchange resins are not comminuted but spherical, the ion exchange resins can not pass this filter.
• the water is drained during dewatering by means of a pump via the suction pipe and the associated filter and filled in a transport water tank.
• a subsequent adjustment of the water content via metered return of the water in the tank. If the ion exchange resins contain too much water, the surplus water is returned to the power plant.
• the grinding device is arranged below the tank.
• the tank is designed for example as a stationary hollow cylinder with a funnel-like narrowing in its bottom area outlet opening. When the tank is raised, the grinder can be positioned under the tank to save space.
• the object according to the invention is also achieved by an ion exchanger resin comminution method with an ion exchange resin comminution device according to the invention and comprises the following steps:
• a tank according to the invention comprises, for example, a volume in the range from 5001 to 20001 and at the beginning of the process according to the invention is to be infested with the desired amount of an ion exchange resin suspension to be comminuted, preferably with an ion exchange resin suspension having a defined water / solids content.
• This is followed by the pre-shredding process, which, depending on the process target, for example, takes 60 minutes. can take.
• the ion exchange resin suspension is pumped out via an outlet in the lower region of the tank and fed to the grinding device.
• the ion exchange resin suspension or the resin particles contained therein are completely comminuted.
• the water content of the aqueous ion exchange resin suspension is adjusted before the pre-comminution by the pre-comminuting device. A constant water content has an advantageous effect on the grinding result or the particle size distribution as well as the process stability.
• the milled aqueous ion exchange resin suspension is subsequently dried. Then it is better to perform a final disposal, for example by high pressure compression.
• a final disposal for example by high pressure compression.
• Fig. 1 shows an exemplary ion exchange resin grinder.
• FIG. 1 shows an exemplary ion exchange resin shredder 10 in a schematic view.
• a tank 12 is filled with a lonenSerharzsus- pension 14, wherein the level level is indicated by line with the reference numeral 32.
• the tank 12 is made of stainless steel and has a filling volume of, for example 800L or significantly more. In its upper part, it is designed as a hollow cylinder and tapers in its bottom area funnel-like to an outlet opening. But there are also embodiments without such a narrowing possible.
• an inlet 30 for an ion exchange resin suspension is provided, which can be closed by a shut-off valve 28.
• a plurality of inlet valves may be provided, so that the final suspension is formed only in the tank 12.
• a stirring device 16 in the tank 12 Centrally protrudes from above a stirring device 16 in the tank 12, which is driven by an external drive 18.
• the stirring device 16 keeps the suspension 14 in a continuous motion by a rotational movement and prevents sedimentation of ion exchange resin particles.
• a pre-shredding device 24 is integrated in the latter, in this case a disperser. Integrated in the context of this invention means that at least the components of the disperser, which must be in contact with the ion exchange resin suspension 14 for dispersion purposes, project at least partially into the tank. A complete arrangement of all components of the pre-shredding device 24 within the tank 12 is not required.
• a shut-off valve 26 connected to the outlet of the tank is opened and the pre-shredded ion exchange resin suspension 14 is pumped in the direction of arrow 34 by a pumping device 22 to a grinder 20. Because of the pre-crushing, the ion exchange resin suspension 14 has become pumpable in the first place.
• the grinding device 20 is in this case designed as a colloid mill and comminutes the pre-shredded resin particles of the ion exchange resin suspension 14 into a fine powder depending on the boundary parameters such as, for example, grinding gap or pump pressure. Via a drain 36, the milled ion exchange resin suspension 14 is then fed to its further use.
• a filter 38 and a suction pipe 40 of a dewatering apparatus is further shown, by means of which the ion exchange resin suspension 14 located in the tank 12 can be dehydrated.
• the uncomminuted ion exchange resin particles are approximately spherical and can not pass through the filter 38.
• a suction by means of a pump 42 thus water from the ion exchange resin suspension is pumped into a transport water tank 44 until the Is dewatered ion exchange resin suspension.
• the tank 12 is again fed via a return 46 so much water until the desired water content is reached.

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• Chemical & Material Sciences (AREA)
• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• High Energy & Nuclear Physics (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Inorganic Chemistry (AREA)
• Disintegrating Or Milling (AREA)
• Crushing And Grinding (AREA)
• Crushing And Pulverization Processes (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=47228574

Family Applications (1)

Country Status (7)

Cited By (2)

Families Citing this family (6)

Citations (5)

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• 2012
  • 2012-06-28 DE DE102012012828A patent/DE102012012828A1/de not_active Withdrawn
• 2013
  • 2013-06-28 ES ES13759434.7T patent/ES2579089T3/es active Active
  • 2013-06-28 EP EP13759434.7A patent/EP2867902B1/de active Active
  • 2013-06-28 CN CN201380034271.2A patent/CN104428842B/zh active Active
  • 2013-06-28 JP JP2015518893A patent/JP6157612B2/ja not_active Expired - Fee Related
  • 2013-06-28 CA CA2872705A patent/CA2872705A1/en not_active Abandoned
  • 2013-06-28 WO PCT/EP2013/001902 patent/WO2014000890A1/de not_active Ceased

Patent Citations (6)

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