JP2013173085A - Treatment system of aqueous muddy material containing ferrous metals particle and heavy metals - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a treatment system of aqueous muddy material in which heavy metals can be removed from the aqueous muddy material containing the heavy metals and, meanwhile, ferrous metals particles can be removed as ferrous raw material.SOLUTION: A treatment system T1 of aqueous muddy material includes a heavy metals treating device 13, a wet type drum magnetic separator 14 and a pressure filter 16. The heavy metals treating device 13 removes heavy metals in the aqueous muddy material and produces the aqueous muddy material containing no heavy metals. The wet type drum magnetic separator 14 adsorbs and separates the ferrous metals particles by virtue of a magnetic force from the aqueous muddy material which does not contain the heavy metals discharged from the heavy metals treating device 13 to recover the ferrous metals particles. The pressure filter 16 subjects the aqueous muddy material discharged from the wet type drum magnetic separator 14 to pressure filtration to produce dehydrated cake. In the heavy metals treating device 13, a fixed bed of chelate resin, ion exchange resin, iron powder or activated carbon is arranged in a tower and a packed tower in which the aqueous muddy material is circulated through void parts in fixed beds is used.

Description

  The present invention removes heavy metals from an aqueous mud containing iron particles and heavy metals, while recovering iron particles in the aqueous mud as an iron-making raw material or an iron-based material. The present invention relates to a material processing system.

  In general, when civil engineering and construction work such as excavation, renovation or creation of land, or construction or repair of roads, a large amount of a mineral mixture containing soil, sand, stones, and the like is generated. Therefore, such a mineral mixture is classified using a wet classifier or subjected to crushing treatment using a crusher and then classified using a wet classifier to produce reclaimed sand, reclaimed gravel, etc. Various regeneration systems for mineral materials have been proposed (see, for example, Patent Document 1).

  By the way, such a mineral mixture may contain harmful heavy metals and / or heavy metal compounds or ions thereof (hereinafter collectively referred to as “heavy metals”). For example, heavy metals are inevitably mixed in a mineral mixture generated by excavation or creation of land contaminated with heavy metals. In this case, the aqueous mud containing heavy metals is discharged from the wet classifier. Therefore, various mineral material regeneration systems have been proposed in which heavy metals in aqueous mud are treated to recover harmless mineral materials from which heavy metals have been removed (for example, Patent Document 2). reference).

Japanese Patent Laid-Open No. 04-114780 Japanese Patent Laid-Open No. 06-343948

  On the other hand, in general, in the soil or in the debris, sand iron or other iron or iron oxide particles (hereinafter collectively referred to as “iron particles”) having a relatively small particle diameter are mixed. In a conventional mineral material regeneration system using a wet classifier, such iron particles are contained in the aqueous mud discharged from the wet classifier. In addition, it is estimated that the ratio of the iron particle contained in soil is usually 2-3 mass%.

  And in the reproduction | regeneration system of the conventional mineral material which processes the aqueous mud containing a heavy metal, the iron particles contained in an aqueous mud will be discarded finally. If such iron particles are recovered by some means, they can be used as an iron-making raw material or used for heavy metal treatment of wastewater by the iron powder method. However, at present, there is no regenerative system for mineral materials capable of recovering such iron particles as an iron-making raw material or an iron-based material in the technical field.

  The present invention has been made in order to solve the above-described conventional problems, and removes heavy metals from an aqueous mud containing heavy metals, while producing iron particles contained in the aqueous mud. It is an object to be solved to provide a comprehensive aqueous sludge treatment system that can be recovered as a raw material or an iron-based material.

  An iron particle containing at least one of iron particles and iron oxide particles and at least one of heavy metals and heavy metal compounds (or ions thereof) according to the present invention made to solve the above-mentioned problems. The processing system of the aqueous sludge containing heavy metals containing is equipped with the heavy metal processing apparatus, the wet magnetic separation apparatus, and the dehydration apparatus. Examples of the iron particles include iron sand. Examples of heavy metals include chromium, manganese, mercury, copper, lead, cadmium, zinc, nickel, and compounds thereof, and ions thereof. The “aqueous muddy material” means a muddy material (slurry) in which a relatively small-diameter mineral solid component such as soil or sand is suspended or dispersed in water.

  In the aqueous sludge treatment system according to the present invention, the heavy metal treatment apparatus treats and removes heavy metals in the aqueous sludge. A wet magnetic separation device (for example, a wet drum magnetic separator) collects and collects iron particles by magnetic force from the aqueous mud that does not contain the heavy metals discharged from the heavy metal processing device. A dehydrator (for example, a pressure filter) performs pressure filtration on the aqueous mud discharged from the wet magnetic separator to generate a dehydrated cake.

  In the aqueous sludge treatment system according to the present invention, the heavy metal treatment apparatus includes a chelate resin or chelate polymer that captures heavy metals, an ion exchange resin, iron powder, or a fixed bed of activated carbon disposed in the tower. It may be a packed tower in which aqueous mud is circulated through the voids in the fixed layer.

  In the aqueous sludge treatment system according to the present invention, the heavy metal treatment device includes a fluid bed type chelating agent mixer that mixes a chelating agent with the aqueous sludge and traps the heavy metal in the chelating agent, and a dehydrator. The apparatus group provided with the heavy metal collection | recovery apparatus which collect | recovers heavy metals from the filtered water discharged | emitted from A may be sufficient.

  In the aqueous sludge treatment system according to the present invention, the heavy metal treatment apparatus includes a fluid bed type chelating agent mixer in which a chelating agent is mixed in the aqueous sludge and the heavy metal is captured by the chelating agent, and a chelating agent. An oil mixer that dissolves the chelating agent in the mixture of the aqueous mud and the chelating agent discharged from the agent mixer and agitate the oil to dissolve the chelating agent in the oil. Further, it may be a device group including an oil separation device that floats and separates the mixture of the chelating agent and the oil from the mixture of the aqueous mud, the chelating agent, and the oil by gravity or centrifugal force.

  In the aqueous mud treatment system according to the present invention, the heavy metal processing apparatus includes a fluidized bed type iron powder mixer that mixes iron powder in the aqueous mud and captures the heavy metal in the iron powder, and iron powder. The apparatus group provided with the iron powder collection | recovery apparatus which adsorb | sucks and isolate | separates iron powder from the mixture of the aqueous muddy substance discharged | emitted from the mixer and iron powder with magnetic force may be sufficient.

  In the aqueous mud treatment system according to the present invention, the heavy metal processing apparatus includes a fluidized bed type iron powder mixer that mixes iron powder in the aqueous mud and captures the heavy metal in the iron powder, and iron powder. The apparatus group provided with the specific gravity difference separation apparatus which isolate | separates iron powder by the specific gravity difference from the mixture of the aqueous sludge discharged | emitted from the mixer and iron powder may be sufficient.

  The aqueous sludge treatment system according to the present invention produces a concentrated slurry by causing the solid components in the aqueous sludge to settle by gravity or centrifugal force from the aqueous sludge discharged from the wet magnetic separator. A slurry concentrating device for supplying the concentrated slurry to the dehydrating device may be provided. Moreover, you may provide the drying apparatus which dries the dewatering cake produced | generated by the dehydration apparatus and produces | generates a clot. The aqueous sludge treatment system according to the present invention reduces the iron particles recovered by the wet magnetic separation device in a non-molten state or a semi-molten state by mixing and heating with the carbon powder. There may be provided a reducing device for generating particles or lumps of the particles.

  According to the aqueous sludge treatment system according to the present invention, it is possible to remove a heavy metal from an aqueous sludge containing heavy metals to produce a harmless dehydrated cake or a soil mass, so that environmental pollution due to heavy metals can be prevented. Can be prevented. At the same time, iron particles contained in the aqueous mud can be recovered and used as an iron-making raw material, an iron-based material, etc., so that resources can be effectively used. That is, from the viewpoint of preventing the diffusion of heavy metals and effective use of resources, the aqueous mud containing iron particles and heavy metals can be treated comprehensively and rationally.

After crushing a mineral mixture containing soil, sand, stones, rocks, concrete fragments, etc. contaminated with heavy metals, sand products and gravel-like products not containing heavy metals are recovered, while irons are used as a by-product. It is a block diagram which shows the structure of the collection system of the mineral material which produces | generates the aqueous mud containing particle | grains and heavy metals. It is a block diagram which shows the structure of the processing system of the aqueous sludge containing the iron particles and heavy metals which concern on Embodiment 1 of this invention. It is a block diagram which shows the structure of the processing system of the aqueous mud containing the iron particles and heavy metals which concern on Embodiment 2 of this invention. It is a block diagram which shows the structure of the processing system of the aqueous mud containing iron particles and heavy metals which concern on Embodiment 3 of this invention. It is a block diagram which shows the structure of the processing system of the aqueous mud containing the iron particles and heavy metals which concern on Embodiment 4 of this invention. It is a block diagram which shows the structure of the processing system of the aqueous mud containing the iron particle and heavy metal which concern on Embodiment 5 of this invention.

  Hereinafter, an aqueous sludge treatment system according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings. First, with reference to FIG. 1, a specific example of the generation form of the aqueous mud containing iron particles and heavy metals will be described. As will be described later, in the specific example shown in FIG. 1, the aqueous mud containing iron particles and heavy metals is a mineral mixture containing soil, sand, stones, rocks, concrete fragments, etc. contaminated with heavy metals. After being crushed and classified by a wet classifier, it is produced as a by-product when a sand product and gravel-like product not containing heavy metals are recovered. However, the aqueous mud containing iron particles and heavy metals targeted by the present invention is not limited to those produced by the form of generation shown in FIG. Therefore, the present invention can be widely applied to the treatment of all aqueous sludges containing iron particles and heavy metals generated by various generation forms.

  As shown in FIG. 1, the mineral material regeneration system R is provided with a pretreatment screen 1, a jaw crusher 2, and a rod mill breaker 3 as crushing equipment. The mineral mixture is received and stored in the receiving pit after undergoing an acceptance inspection in the receiving storage yard. This mineral mixture is charged into the pretreatment screen 1 continuously or intermittently by a belt conveyor or a tire shovel (not shown).

  The pretreatment screen 1 is a dry-type sieving device, and a mineral mixture containing various agglomerates having various particle sizes, for example, agglomerates having a particle size of 90 mm or more (or 60 mm or more). Sieving into a mixture containing and a mixture containing agglomerates having a particle size of less than 90 mm (or less than 60 mm). The agglomerates having a particle size of 90 mm or more are transferred to the jaw crusher 2 by a belt conveyor or the like. On the other hand, agglomerates having a particle size of less than 90 mm are transferred to the rod mill breaker 3 by a belt conveyor or the like.

  Although not shown in detail, the jaw crusher 2 has a fixed plate and a movable plate arranged to face each other, and rotates the rotating body to reciprocate the movable plate with respect to the fixed plate. This is a crusher that crushes crushed materials. For example, by changing the closest approach distance between the fixed plate and the movable plate, the size or particle size of the crushed material can be easily adjusted. The jaw crusher 2 crushes (coarse crushing) agglomerates having a particle size of 90 mm or more (or 60 mm or more), for example, and generates agglomerates having a particle size of less than 40 mm, for example. The agglomerates are transferred to the rod mill breaker 3 by a belt conveyor or the like.

  Although not shown in detail, the rod mill breaker 3 is a drum in which a plurality of steel rods (for example, 10 75 mmφ × 2 m steel rods) are arranged as a crushing tool in the drum. Rolls in parallel with each other and makes line contact, and the impact breaks up the agglomerates existing between the rods. The mixture is mixed with water (industrial water, tap water, well water, treated water, etc.) supplied from a water supply facility (not shown) before entering the rod mill breaker 3. When the lump is crushed in the rod mill breaker 3, some of the heavy metals adhering to or bonding to the lump are separated into the water by peeling or dissolving.

  In addition, the regeneration system R is provided with a wet jet trommel 4 to which water is supplied from a water supply facility and a wet cyclone 5 as wet classification equipment. In both the jet trommel 4 and the wet cyclone 5, the lump is in contact with a large amount of water and the individual lump is rubbed against each other, so that the heavy metals attached to or bonded to the lump are separated, dissolved, etc. Almost completely leaves the water.

  Although not shown in detail, the jet trommel 4 is a sieving device having a receiving tank capable of storing water, and a substantially cylindrical drum screen arranged to be inclined with respect to a horizontal plane. The screen can be rotated around its central axis (cylindrical central axis) by a motor. Also, water can be supplied in the form of a spray into the drum screen. Instead of supplying water into the drum screen in the form of a spray, a part (lower part) of the drum screen may be immersed in water or turbidity stored in the receiving tank.

  Then, the drum screen is rotated while water is supplied into the drum screen, and the mixture is introduced into the drum screen from the rod mill breaker 3 via the upper opening end (the higher position) of the drum screen. Basically moves toward the lower opening end (lower position) by gravity. At that time, agglomerates finer than the mesh of the drum screen, for example, agglomerates having a particle size of less than 5 mm (hereinafter referred to as “small-diameter agglomerates”) pass through the mesh of the drum screen together with water, and go out of the drum screen and are received by the receiving tank Get inside. In the receiving tank, the small-diameter agglomerates and water are mixed with each other to form an aqueous mixture.

  On the other hand, a lump coarser than the mesh of the drum screen, for example, a lump having a particle size of 5 mm or more (hereinafter referred to as “large-diameter agglomerate”) cannot pass through the mesh of the drum screen, so And is discharged to the outside of the drum screen and transferred to the coarse screen 10. In this jet trommel 4, the agglomerates come into contact with a large amount of water and the agglomerates rub against each other, so that heavy metals attached to or bound to the agglomerates are released into the water by peeling, dissolution, or the like.

  The aqueous mixture composed of the small-diameter agglomerates and water in the receiving tank of the jet trommel 4 is transferred to the wet cyclone 5. Although not shown in detail in the wet cyclone 5, the aqueous mixture is pumped into a substantially conical cylinder that narrows downward to generate a swirling flow, and the centrifugal force generated thereby is used to make the aqueous mixture Among the small-diameter agglomerates, those having a relatively large particle size, for example, those having a particle size of 0.5 mm or more (hereinafter referred to as “recycled sand”), and those having a relatively small particle size, for example, having a particle size of 0.1. Separated into an aqueous mud containing less than 5 mm (hereinafter referred to as “finely collected product”). In this wet cyclone 5, the lump particles come into contact with a large amount of water and the lump particles rub against each other, so that heavy metals adhering to or bonding to the lump particles are separated into the water by peeling, dissolution or the like.

  And the reclaimed sand separated by the wet cyclone 5 is transferred to the sand scrubber 6 which is a part of the post-processing equipment. The aqueous mud is transferred to the mud tank 12 as described later. Hereinafter, the specific structure and function of the post-processing equipment for recycled sand will be described. The post-treatment facility for reclaimed sand includes a sand scrubber 6, a jet ladder chute 7, a sand screen 8, and a dewatering screen 9.

  Water is supplied to the sand scrubber 6 from a water supply device. Although not shown in detail, the sand scrubber 6 is sent out by padding the reclaimed sand in water with a paddle mixer, and the foreign matter adhering to the surface of the reclaimed sand is removed by friction between the reclaimed sand. To do. In the unlikely event that heavy metals remain in the reclaimed sand, these heavy metals are detached from the reclaimed sand into the water.

  The regenerated sand from which foreign matter has been removed by the sand scrubber 6 is transferred to a jet ladder chute 7 to which water is supplied from a water supply device together with drainage. The jet ladder chute 7 causes water to flow at a predetermined pressure and water amount, and rinses and cleans the reclaimed sand. In the unlikely event that foreign matter or heavy metals remain on the surface of the reclaimed sand, they are separated from the reclaimed sand by this rinsing treatment.

  The reclaimed sand that has been rinse-washed by the jet ladder chute 7 is transferred to a sand screen 8 to which water is supplied from a water supply device together with drainage. The sand screen 8 causes water to flow at a predetermined pressure and amount of water to rinse the reclaimed sand, and collects and removes foreign matter if it remains. Further, in the sand screen 8, the regenerated sand is dewatered in water, becomes high-quality washing sand, and is transferred to the dewatering screen 9. The waste water from the sand screen 8 is transferred to the mud tank 12. Since the waste water contains almost no solid component, the waste water may be discharged to the waste water treatment device without being transferred to the mud tank 12.

  In the dewatering screen 9, the final rinse cleaning process is performed on the recycled sand and the chelate process is performed. The drainage of the dewatering screen 9 is returned to the wet cyclone 5. This waste water is discharged to a waste water treatment device. The waste water may be transferred to the mud tank 12. As a result, the reclaimed sand becomes a high quality sand product and falls naturally into the storage yard. This sand product is transferred to a predetermined storage place by, for example, a slide belt conveyor and stored. If it is discovered by quality inspection or the like that the sand product contains heavy metals, the sand product may be returned to the sand scrubber 6 and washed again to remove heavy metals.

  The aqueous mud containing fine recovered material, that is, the aqueous mud containing iron particles and heavy metals, discharged from the wet cyclone 5 is transferred to the mud tank 12 (see FIG. 2). Then, as will be described later, the aqueous mud is processed and rendered harmless by the processing system T shown in FIG.

  As described above, the large-diameter agglomerates (mineral agglomerates having a particle diameter of 5 mm or more) discharged from the jet trommel 4 are transferred to the coarse screen 10. The coarse screen 10 has a large-diameter granule having a particle size of 40 mm or more (hereinafter referred to as “needed material”) and a particle size of less than 40 mm (hereinafter referred to as “gravel-like product”). Sift into. The crushed material is transferred to the impact crusher 11, crushed by the impact crusher 11, and then returned to the coarse screen 10. Therefore, all large-diameter agglomerates become less than 40 mm and are discharged from the coarse screen 10.

  On the other hand, gravel-like products, that is, mineral agglomerates having a particle size of 5 mm or more and less than 40 mm, naturally fall into the storage yard. This gravel-like product is transferred to a predetermined storage place by, for example, a slide belt conveyor and stored. In addition, when it is discovered by quality inspection etc. that a heavy metal is contained in a gravel purification product, it is sufficient to return this gravel purification product to the jet trommel 4 to remove heavy metals.

(Embodiment 1)
Hereinafter, with reference to FIG. 2, a treatment system for an aqueous mud containing iron particles and heavy metals according to Embodiment 1 of the present invention will be described. As shown in FIG. 2, in the aqueous sludge treatment system T <b> 1 according to the first embodiment, the aqueous sludge containing iron particles and heavy metals discharged from the regeneration system R in the sludge tank 12. Things are being stored. Although not shown in detail, the aqueous mud in the mud tank 12 is stirred by a stirrer, and solid components are distributed or dispersed almost uniformly in the aqueous mud.

  The aqueous mud in the mud tank 12 is transferred to the heavy metal processing device 13 by a mud supply unit such as a slurry pump. In the heavy metal processing device 13, the heavy metal treatment is performed on the aqueous mud, the heavy metal is removed from the aqueous mud, and an aqueous mud containing no heavy metal is generated. Examples of heavy metals include chromium, manganese, copper, lead, cadmium, mercury, zinc, nickel, tin, cobalt, compounds of these heavy metals, or ions of these heavy metals or compounds.

  The heavy metal treatment device 13 is a packed tower in which a fixed bed of a chelate resin or a chelate polymer that captures heavy metals is disposed in the tower, and aqueous mud is circulated through the voids in the fixed layer. Can be used (chelation method). Specifically, for example, a packed tower in which a columnar space between the ceiling plate and the bottom plate in the tower is filled with particles of a chelate resin or a chelate polymer can be used.

  In the heavy metal treatment device 13, when the aqueous mud flows through the packed tower, the heavy metals are captured or adsorbed by the chelate resin or the chelate polymer, and the heavy metals in the aqueous mud are removed. The chelate resin or chelate polymer is exchanged or regenerated when saturated with heavy metals. Here, in place of the chelate resin or the chelate polymer, water-insoluble inorganic porous powder, particles, or lumps in which a chelating agent is fixed may be used.

Further, as the heavy metal processing device 13, a packed tower in which a fixed bed formed of iron powder that captures heavy metals is arranged in the tower, and aqueous mud is circulated in the voids in the fixed bed may be used ( Iron powder method). Here, as the iron powder, it is preferable to use, for example, iron powder having a large specific surface area (for example, 250,000 cm ² / g or more), for example, iron powder surface-treated with iron (II) sulfate. In this case, when the aqueous mud flows through the packed tower, heavy metals are adsorbed to the iron powder, and heavy metals in the aqueous mud are removed. The iron powder is exchanged or regenerated when the adsorption amount of heavy metals is saturated.

  In addition, as the heavy metal treatment device 13, a packed tower in which a fixed bed formed of activated carbon that captures heavy metals is arranged in the tower and aqueous mud is circulated in the voids in the fixed bed may be used. Alternatively, a packed bed in which a fixed bed formed of an ion exchange resin that captures heavy metals is disposed in the tower and aqueous mud is circulated in the voids in the fixed bed may be used. In these cases, when the aqueous mud flows through the packed tower, the heavy metals are adsorbed on the activated carbon or captured by the ion exchange resin, and the heavy metals in the aqueous mud are removed.

  In any of the heavy metal processing apparatuses 13 described above, it is preferable to attach an ultrasonic generator to the packed tower and apply ultrasonic waves to the aqueous mud in the packed tower. In this case, heavy metals that adhere to or bind to the solid component in the aqueous mud or are contained in the solid component are released or dissolved in water by ultrasonic energy (ultrasonic cleaning). Furthermore, the capture or adsorption of heavy metals that are free or dissolved in water by the fixed bed is promoted. In addition, as the heavy metal processing apparatus 13, you may use what connected arbitrary some of the said various packed towers in parallel or in series.

The aqueous mud containing no heavy metals discharged from the heavy metal processing device 13 is transferred to a wet magnetic separator 14 which is a “wet magnetic separation device”. Specifically, as the wet magnetic separator 14, for example, “WD1115A type wet drum type magnetic separator” available from Mitsubishi Nagasaki Kiko Co., Ltd. can be used. In the wet magnetic separator 14, the iron particles in the aqueous mud are adsorbed and separated by the magnetic force and collected. Here, the magnet or magnetized portion that adsorbs the iron gastric particles of the wet magnetic separator 14 is iron particles containing iron oxide, for example, FeO, Fe ₂ O ₃ , Fe ₃ O _4, etc. (relative permeability is less than 1000). It is preferably set in a range that adsorbs most of the amount.

  The iron particles recovered by the wet magnetic separator 14 are transferred to a cleaning device 18 and washed with water, and fine foreign matters adhering to the iron particles are removed. The iron particles cleaned by the cleaning device 18 are transferred to a dryer 19 and dried. As the dryer 19, for example, an air flow dryer or a fluidized bed dryer can be used. The iron particles recovered in this way can be used, for example, as an iron making raw material. Therefore, the particles of iron or iron oxide can be sold to a waste product collector or a steel manufacturer, for example, in the same manner as scrap iron.

  Moreover, you may independently make iron using the recovered iron particles. The iron particles are usually only iron oxide particles or a mixture of iron particles and iron oxide particles. In this case, since the processing amount is relatively small, the indirect iron making method (molten pig iron method) adopted by general steel manufacturers, that is, the ironmaking raw material (iron ore) is heated to a relatively high temperature (for example, blast furnace, converter) It is extremely difficult to use an iron making technique in which iron is produced by reduction while melting at about 1500 ° C.). Therefore, without melting the iron-making raw material, the iron-making raw material and the carbon powder are mixed and heated at a relatively low temperature (for example, 500 to 1000 ° C.), and reduced in a non-molten state or a semi-molten state to form a sponge or lump. It is practical to carry out iron making by a direct iron production method for producing the iron (bulk wrought iron), for example, the Tatara iron production method. In addition, since the iron produced | generated in this way has a low carbon-containing material and is good quality, it can be used as a raw material of a knife (a knife, a sword, etc.), for example.

  In addition, you may use the collect | recovered iron particles in the state as it is for the water treatment by an iron powder method. According to the experiments by the present inventors, both iron particles and iron oxide particles (mainly ferric oxide and ferric tetroxide) in iron particles have the ability to adsorb heavy metals. It was confirmed. Therefore, when iron particles are used to remove heavy metals in wastewater by the iron powder method, there is no need to distinguish whether the particles are iron or iron oxide, and the “iron powder” Can be used as

  The aqueous mud from which the iron particles have been removed by the wet magnetic separator 14 is transferred to a thickener 15 which is a “slurry concentrator”. In thickener 15, the solid components in the aqueous mud are settled by gravity. As a result, the aqueous mud is separated into a concentrated slurry in which the solid component is concentrated and a supernatant liquid containing almost no solid component. In addition, when the density | concentration or ratio of the solid component of an aqueous mud is high, since an aqueous mud cannot be concentrated so much, the thickener 15 does not need to be provided. Further, the thickener 15 can be omitted even when the concentration or ratio of the solid component of the aqueous mud is low.

  The concentrated slurry generated by the thickener 15 is transferred from the thickener 15 to a pressure filter 16 (filter press), which is a “dehydrating device”, by slurry supply means such as a slurry pump. Specifically, as the pressure filter 16, for example, a filter cloth fixed filter frame type “FM type filter press” available from Kurita Machinery Co., Ltd. can be used. Although not shown in detail, the pressure filter 16 is a batch or continuous pressure filter, and applies pressure filtration to the concentrated slurry received from the thickener 15 to generate a dehydrated cake and filtered water. To do. The filtration pressure of the pressure filter 16 is preferably set such that the water content of the dewatered cake is 60 to 70%, for example. In addition, as a dehydrator, you may use dehydrators other than a pressure filter, for example, a vacuum filter (Oliver type filter) etc.

  The dewatered cake generated by the pressure filter 16 is dried by the dryer 17 and becomes a dry soil mass or dry particles. When the dewatered cake is discarded as it is, it is not necessary to provide the dryer 17. Here, the dewatered cake generated by the pressure filter 16 may be modified by adding a modifying material to generate improved soil. Such improved soil can be used as, for example, embankment material.

  As mentioned above, according to the processing system of the aqueous mud according to the first embodiment, it is possible to remove the heavy metals from the aqueous mud containing heavy metals to produce harmless dehydrated cakes or earth clumps. Environmental pollution can be prevented. Moreover, since the iron particles contained in the aqueous mud can be recovered and used as an iron-making raw material, an iron-based material, etc., effective use of resources can be achieved. That is, from the viewpoint of preventing the diffusion of heavy metals and effective use of resources, the aqueous mud containing iron particles and heavy metals can be treated comprehensively and rationally.

(Embodiment 2)
Hereinafter, with reference to FIG. 3, an aqueous mud treatment system T2 containing iron particles and heavy metals according to Embodiment 2 of the present invention will be described. However, the treatment system T2 of the aqueous mud according to the second embodiment is different from the treatment system T1 of the aqueous mud according to the first embodiment shown in FIG. The configuration and functions of the other components are the same as those of the aqueous mud treatment system T1 according to the first embodiment. Therefore, in the following, in order to avoid duplication of description, the configuration and function of the heavy metal processing apparatus will be mainly described. Note that, in the aqueous mud treatment system T2 according to the second embodiment, the same reference numerals as those in the first embodiment are given to components common to the aqueous mud treatment system T1 according to the first embodiment. Yes.

  As shown in FIG. 3, in the aqueous sludge treatment system T <b> 2 according to the second embodiment, the heavy metal treatment device includes a chelating agent mixer 20, a chelating agent supply device 21, and a heavy metal collection device 30. It is configured. In the aqueous mud treatment system T2, the aqueous mud in the mud tank 12 is transferred to the chelating agent mixer 20 by a mud supply means such as a slurry pump. On the other hand, a chelating agent (for example, EDTA, DTPA) or an aqueous solution thereof is supplied from the chelating agent supply device 21 to the chelating agent mixer 20.

  Although not shown in detail, in the chelating agent mixer 20, for example, a mixture of the aqueous mud and the chelating agent is stirred and flowed by a stirrer, and heavy metals are captured by the chelating agent. That is, the chelating agent mixer 20 is a fluidized bed mixer or reactor. Moreover, in this chelating agent mixer 20, the heavy metal which adheres or couple | bonds with the solid component in an aqueous sludge, or is contained in a solid component is extracted in water with a chelating agent (solid extraction or leaching). Is done. In addition, this heavy metal extraction effect | action is accelerated | stimulated, so that it improves, if the intensity | strength of stirring of an aqueous mud is raised.

  Here, it is preferable to attach an ultrasonic generator to the chelating agent mixer 20 and apply ultrasonic waves to the aqueous mud in the chelating agent mixer 20. In this case, heavy metals that adhere to or bind to the solid component in the aqueous mud or are contained in the solid component are released or dissolved in water by ultrasonic energy (ultrasonic cleaning). The aqueous mud containing the chelating agent that captures heavy metals discharged from the chelating agent mixer 20 is transferred to the wet magnetic separator 14 by a mud supply means such as a slurry pump, and is the same as in the first embodiment. In addition, iron particles in the aqueous mud are adsorbed and separated by magnetic force and recovered.

  Further, in the aqueous mud treatment system T <b> 2 according to the second embodiment, the filtered water discharged from the pressure filter 16 and containing the chelating agent capturing the heavy metals is returned to the chelating agent mixer 20. That is, the chelating agent is recycled. When the amount of heavy metal captured by the chelating agent or the content of heavy metals exceeds a preset allowable value, or when saturated, the filtered water is transferred to the heavy metal recovery device 30 and is added to the filtered water. Heavy metals are recovered or processed. In addition, collection | recovery or processing of heavy metals can be easily performed by, for example, adding a flocculant to filtered water containing a chelating agent that captures heavy metals to precipitate the chelating agent or heavy metals, and then separating them by sedimentation. Can do.

  In the aqueous mud treatment system T2 according to the second embodiment, as in the case of the aqueous mud treatment system T1 according to the first embodiment, from the viewpoint of prevention of diffusion of heavy metals and effective use of resources, Aqueous mud containing iron particles and heavy metals can be treated comprehensively and rationally.

(Embodiment 3)
Hereinafter, with reference to FIG. 4, a processing system T3 for an aqueous mud containing iron particles and heavy metals according to Embodiment 3 of the present invention will be described. However, the aqueous mud treatment system T3 according to the third embodiment is the aqueous mud treatment system T1 according to the first embodiment shown in FIG. 2 or the aqueous mud treatment according to the second embodiment shown in FIG. The system T2 is different from the system T2 only in the configuration and functions of the heavy metal processing apparatus, and the configurations and functions of the other components are the same as those of the aqueous mud processing system T1 according to the first embodiment. Therefore, in the following, in order to avoid duplication of description, the configuration and function of the heavy metal processing apparatus will be mainly described. In addition, in the aqueous mud treatment system T3 according to the third embodiment, the same components as those in the first or second treatment system T1 or T2 according to the first or second embodiment are the same as those in the first or second embodiment. A reference number is attached.

  As shown in FIG. 4, in the aqueous sludge treatment system T3 according to the third embodiment, the heavy metal treatment device includes a chelating agent mixer 20, a chelating agent supply device 21, an oil mixer 22, and an oil. A tank 23 and an oil separator 24 are included. In the aqueous mud treatment system T3, the aqueous mud in the mud tank 12 is transferred to the chelating agent mixer 20 by a mud supply unit such as a slurry pump. On the other hand, a chelating agent (for example, EDTA, DTPA) or an aqueous solution thereof is supplied from the chelating agent supply device 21 to the chelating agent mixer 20.

  Although not shown in detail, in the chelating agent mixer 20, as in the case of the aqueous mud treatment system T3 according to the second embodiment, the mixture of the aqueous mud and the chelating agent is stirred and flows. , Heavy metals are captured by the chelating agent. In addition, also in the aqueous sludge treatment system T3 according to Embodiment 3, an ultrasonic generator is added to the chelating agent mixer 20 for the same reason as in the case of the aqueous sludge treatment system T3 according to Embodiment 2. It is preferable to attach an ultrasonic wave to the aqueous mud in the chelating agent mixer 20.

  The aqueous mud containing the chelating agent that captures heavy metals discharged from the chelating agent mixer 20 is transferred to the oil mixer 22 by a mud supply means such as a slurry pump. On the other hand, oil that is not miscible with water, for example vegetable oil such as soybean oil, is supplied from the oil tank 23 to the oil mixer 22 while dissolving the chelating agent. Although not shown in detail, in the oil mixer 22, for example, the mixture of the aqueous mud, the chelating agent and the oil is stirred and flowed by a stirrer, and the chelating agent is detached from the aqueous mud. Dissolves or elutes in oil. In short, the chelating agent dissolved in water moves from water to oil by liquid / liquid extraction. Instead of the oil, a liquid other than the oil that dissolves the chelating agent and is not miscible with water may be used.

  The mixture of the aqueous muddy material from which heavy metals have been removed and the oil containing the chelating agent that has captured the heavy metals discharged from the oil mixer 22 is transferred to the oil separator 24 by a muddy material supply means such as a slurry pump. Be transported. In the oil separation device 24, the aqueous mud and the mixture of the chelating agent and the oil are separated by gravity or centrifugal force. That is, a mixture of a chelating agent and an oil that is immiscible with an aqueous mud and has a specific gravity (density) smaller than that of the aqueous mud floats on the aqueous mud. The mixture of chelating agent and oil can be easily separated.

  The mixture of the chelating agent and oil floated and separated by the oil separation device 24 is returned to the oil tank 23 and circulated. When the concentration of the chelating agent in the oil exceeds a preset allowable value or reaches a saturated concentration, the oil is transferred to the oil incinerator 25 and incinerated. Here, since heavy metals do not burn, they remain as ash in the oil incinerator 25. In addition, the ash containing heavy metals is disposed of by concrete solidification, for example.

  The aqueous mud containing no heavy metals discharged from the oil separator 24 is transferred to the wet magnetic separator 14 and then treated in the same manner as in the first embodiment of the present invention to recover the iron particles. On the other hand, a dry soil mass is generated. In the aqueous mud treatment system T3 according to the third embodiment, as in the case of the aqueous mud treatment system T1 according to the first embodiment, from the viewpoint of prevention of diffusion of heavy metals and effective use of resources, Aqueous mud containing iron particles and heavy metals can be treated comprehensively and rationally.

(Embodiment 4)
Hereinafter, with reference to FIG. 5, a processing system T4 for an aqueous mud containing iron particles and heavy metals according to Embodiment 4 of the present invention will be described. However, the aqueous mud treatment system T4 according to the fourth embodiment is different from the aqueous mud treatment system T1 according to the first embodiment shown in FIG. 2 only in the configuration and functions of the heavy metal treatment apparatus. The configuration and functions of the other components are the same as those of the aqueous mud treatment system T1 according to the first embodiment. Therefore, in the following, in order to avoid duplication of description, the configuration and function of the heavy metal processing apparatus will be mainly described. Note that, in the aqueous mud treatment system T4 according to the fourth embodiment, the same reference numerals as those in the first embodiment are given to components common to the aqueous mud treatment system T1 according to the first embodiment. Yes.

  As shown in FIG. 5, in the aqueous sludge treatment system T4 according to the fourth embodiment, the heavy metal treatment device includes an iron powder mixer 26, an iron powder supply device 27, and an iron powder recovery device 28. It is configured. In this aqueous mud treatment system T4, the aqueous mud in the mud tank 12 is transferred to the iron powder mixer 26 by mud supply means such as a slurry pump. On the other hand, iron powder is supplied from the iron powder supply device 27 to the iron powder mixer 26. Although not shown in detail, in the iron powder mixer 26, for example, a mixture of aqueous mud and iron powder is stirred and flowed by a stirrer, and heavy metals are captured or adsorbed by the iron powder. That is, the iron powder mixer 26 is a fluidized bed type mixer or adsorption tank. The iron powder is the same as that used in the aqueous mud treatment system T1 according to Embodiment 1 of the present invention.

  Here, it is preferable to attach an ultrasonic generator to the iron powder mixer 26 and apply ultrasonic waves to the aqueous mud in the iron powder mixer 26. In this case, heavy metals that adhere to or bind to the solid component in the aqueous mud or are contained in the solid component are released or dissolved in water by ultrasonic energy (ultrasonic cleaning). Furthermore, capture or adsorption of heavy metals that are free or dissolved in water by iron powder is promoted.

The mixture of the aqueous muddy material from which heavy metals are removed and the iron powder that has captured or adsorbed heavy metals discharged from the iron powder mixer 26 is recovered by an iron powder recovery device 28 by a muddy material supply means such as a slurry pump. It is transferred to. As the iron powder recovery device 28, for example, “WD1115A type wet drum type magnetic separator” available from Mitsubishi Nagasaki Kiko Co., Ltd. can be used. Here, the magnet or magnetized portion that adsorbs the iron powder of the iron powder recovery device 28 adsorbs iron powder (relative magnetic permeability is 5000 or more), while iron oxide such as FeO, Fe ₂ O ₃ , Fe ₃ O _4. Etc. (relative magnetic permeability is 1000 or less) is preferably set in a range in which iron particles are not adsorbed.

  In the iron powder recovery device 28, iron powder that has captured or adsorbed heavy metals is collected and recovered by magnetic force from the aqueous mud. The iron particles are not attracted to the magnet or magnetized portion of the iron powder recovery device 28. The iron powder recovered by the iron powder recovery device 28 is returned to the iron powder mixer 26 for circulation. The iron powder is exchanged or regenerated when the adsorption amount of heavy metals is saturated.

  The aqueous mud containing no heavy metals discharged from the iron powder recovery device 28 is transferred to the wet magnetic separator 14 and then processed in the same manner as in the first embodiment of the present invention to recover the iron particles. Meanwhile, a dry soil mass is generated. Also in the aqueous sludge treatment system T4 according to the fourth embodiment, as in the case of the aqueous sludge treatment system T1 according to the first embodiment, from the viewpoint of prevention of diffusion of heavy metals and effective use of resources, Aqueous mud containing iron particles and heavy metals can be treated comprehensively and rationally.

(Embodiment 5)
Hereinafter, with reference to FIG. 6, an aqueous mud treatment system T5 containing iron particles and heavy metals according to Embodiment 5 of the present invention will be described. However, the aqueous muddy matter treatment system T5 according to the fifth embodiment is composed of the aqueous muddy matter treatment system T4 according to the fourth embodiment shown in FIG. 5 and the iron powder recovery device that constitutes the heavy metal treatment device. The other components are the same as those in the aqueous mud treatment system T4 according to the fourth embodiment. Therefore, in the following, in order to avoid duplication of explanation, the configuration and function of the heavy metal processing apparatus, particularly the iron powder recovery apparatus, will be mainly described. Note that, in the aqueous mud treatment system T5 according to the fifth embodiment, the same reference numerals as those in the fourth embodiment are given to components common to the aqueous mud treatment system T4 according to the fourth embodiment. Yes.

  As shown in FIG. 6, in the aqueous sludge treatment system T5 according to the fifth embodiment, the heavy metal treatment device includes an iron powder mixer 26, an iron powder supply device 27, and a specific gravity difference separation device 29. It is configured. In this aqueous mud treatment system T5, the aqueous mud in the mud tank 12 is transferred to the iron powder mixer 26 by mud supply means such as a slurry pump. On the other hand, iron powder is supplied from the iron powder supply device 27 to the iron powder mixer 26. As in the case of the fourth embodiment, in the iron powder mixer 26, for example, a mixture of aqueous mud and iron powder is stirred and flowed by a stirrer, and heavy metals are captured or adsorbed by the iron powder. The iron powder is the same as that used in the aqueous mud treatment system T1 or T4 according to Embodiment 1 or 4 of the present invention. In the aqueous mud treatment system T5 according to the fifth embodiment, an ultrasonic generator is installed in the iron powder mixer 26 for the same reason as in the aqueous mud treatment system T4 according to the fourth embodiment. It is preferable to attach an ultrasonic wave to the aqueous mud in the iron powder mixer 26.

  The mixture of the aqueous muddy material from which the heavy metals have been removed and the iron powder that has captured or adsorbed the heavy metals discharged from the iron powder mixer 26 is a wet specific gravity difference separation device by a muddy material supply means such as a slurry pump. 29. Although the specific gravity difference separation device 29 is not shown in detail, it utilizes the fact that the specific gravity of the iron powder is significantly larger than the specific gravity of other solid components (iron particles, soil, etc.) in the aqueous mud. The iron powder is separated from the aqueous mud. The specific gravity of iron powder is about 7.9, the specific gravity of iron particles (iron oxide) is about 5.1 to 5.5, and the specific gravity of soil or sand is about 2.1 to 2.5. is there.

  Specifically, the specific gravity difference separating device 29 settles an aqueous mud in a vertical cylindrical body (bottom of an inverted cone), and settles in an aqueous mud of iron particles having a small specific gravity (in water). It is made to flow upward in a laminar flow at a lower flow velocity than the settling velocity (relatively high speed) in the aqueous muddy substance (in water) of iron powder having a larger specific gravity than the velocity (relatively slow) While the aqueous mud containing no iron powder is allowed to flow out from the top, the iron powder is separated from the aqueous mud by pulling out the iron powder slurry from the bottom. The iron powder recovered by the specific gravity difference separation device 29 is returned to the iron powder mixer 26 and is circulated. The iron powder is exchanged or regenerated when the adsorption amount of heavy metals is saturated.

  While the aqueous mud containing no heavy metals discharged from the specific gravity difference separation device 29 is transferred to the wet magnetic separator 14, it is treated in the same manner as in the fourth embodiment, and the iron particles are recovered. A dry soil mass is produced. In the aqueous mud treatment system T5 according to the fifth embodiment, similarly to the aqueous mud treatment system T4 according to the fourth embodiment, from the viewpoint of prevention of diffusion of heavy metals and effective use of resources, irons. Aqueous mud containing particles and heavy metals can be treated comprehensively and rationally.

  R Mineral material regeneration system, T1 to T5 aqueous sludge treatment system, 1 pretreatment screen, 2 jaw crusher, 3 rod mill breaker, 4 jet trommel, 5 wet cyclone, 6 sand scrubber, 7 jet ladder chute, 8 Sand screen, 9 Dewatering screen, 10 Coarse screen, 11 Impact crusher, 12 Mud tank, 13 Heavy metal processing equipment, 14 Wet magnetic separator, 15 Thickener, 16 Pressure filter, 17 Dryer, 18 Washer, 19 Dryer, 20 Chelating agent mixer, 21 Chelating agent supply device, 22 Oil mixer, 23 Oil tank, 24 Oil separation device, 25 Oil incineration device, 26 Iron powder mixer, 27 Iron powder supply device, 28 Iron powder recovery device 29 Specific gravity difference separator, 30 Heavy metals Recovery device.

Claims (11)

An aqueous mud treatment system containing iron particles containing at least one of iron particles and iron oxide particles, and heavy metals containing at least one of heavy metals and heavy metal compounds,
A heavy metal treatment apparatus for treating and removing the heavy metals in the aqueous mud,
A wet magnetic separation device that adsorbs and separates the iron particles by magnetic force from the aqueous mud discharged from the heavy metal processing device, and recovers it as an iron-making raw material or an iron-based material;
An aqueous mud treatment system, comprising: a dewatering device that performs pressure filtration on the aqueous mud discharged from the wet magnetic separation device to generate a dewatered cake.   In the heavy metal processing apparatus, a fixed bed of chelate resin, ion exchange resin, iron powder or activated carbon that captures heavy metals is disposed in the tower, and the aqueous mud is distributed through the voids in the fixed layer. The aqueous mud treatment system according to claim 1, further comprising a tower. The heavy metal processing apparatus,
A fluid bed type chelating agent mixer that mixes a chelating agent with the aqueous mud and captures the heavy metals in the chelating agent, and heavy metals that recover the heavy metals from the filtered water discharged from the dehydrator The aqueous mud treatment system according to claim 1, further comprising a recovery device. The heavy metal processing apparatus,
A fluid bed type chelating agent mixer that mixes a chelating agent with the aqueous mud and captures the heavy metals in the chelating agent;
An oil mixer that mixes and stirs oil that dissolves the chelating agent in the mixture of the aqueous mud and the chelating agent discharged from the chelating agent mixer, and dissolves the chelating agent in the oil;
An oil separation device that floats and separates the mixture of the chelating agent and the oil from the mixture of the aqueous mud discharged from the oil mixer, the chelating agent, and the oil by gravity or centrifugal force. The processing system for aqueous mud according to claim 1, wherein The heavy metal processing apparatus,
Mixing iron powder into the aqueous mud, fluidized bed type iron powder mixer for capturing the heavy metals in the iron powder,
An iron powder recovery device for adsorbing and separating the iron powder by a magnetic force from the mixture of the aqueous mud and the iron powder discharged from the iron powder mixer is provided. Item 4. A system for treating an aqueous mud according to Item 1. The heavy metal processing apparatus,
Mixing iron powder into the aqueous mud, fluidized bed type iron powder mixer for capturing the heavy metals in the iron powder,
The apparatus according to claim 1, further comprising a specific gravity difference separating device that separates the iron powder from the mixture of the aqueous mud and the iron powder discharged from the iron powder mixer by a specific gravity difference. The aqueous mud treatment system described.   The aqueous mud discharged from the wet magnetic separation device is allowed to settle by solid or solid force in the aqueous mud by gravity or centrifugal force to generate a concentrated slurry, and the concentrated slurry is supplied to the dehydrator. The system for treating an aqueous mud according to any one of claims 1 to 6, further comprising a slurry concentrating device.   The aqueous mud treatment system according to any one of claims 1 to 7, further comprising a drying device that dries the dewatered cake generated by the dewatering device to generate a lump. .   The aqueous mud treatment system according to any one of claims 1 to 8, wherein the wet magnetic separator is a wet drum magnetic separator.   The system for treating an aqueous mud according to any one of claims 1 to 9, wherein the dehydrator is a pressure filter.   The iron particles collected by the wet magnetic separation device are mixed with carbon powder and heated to reduce in a non-molten or semi-molten state to produce iron particles or lumps. The processing system of the aqueous mud according to any one of claims 1 to 10, wherein

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