JP2012179549A - Material recycling system for yielding sand product from mineral mixture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system for yielding a heavy metal-removed material from a mineral mixture which is produced by civil engineering and building construction work and to the surface of which heavy metals are stuck or bonded.SOLUTION: In a material recycling system RS, a crushing facility A applies a crushing treatment to the mineral mixture. A wet classification facility B classifies the crushed mineral mixture by using water into a plurality of kinds of materials having particle diameters different from one another and separating heavy metals from the mineral mixture in water. A heavy metal removing facility C removes heavy metals from the drainage water discharged from the wet classification facility B. A drainage water treatment facility D treats the heavy metal-removed drainage water and precipitating water-insoluble materials in the drainage water to separate the drainage water into sludge and treated water. A treated water supply facility E supplies the treated water to the wet classification facility B. A sludge dehydration facility F dehydrates the sludge and dries the dehydrated sludge. A post treatment facility G applies post treatment such as cleaning treatment to recycled materials.

Description

  The present invention relates to a plurality of mineral agglomerates having different dimensions, and heavy metals and / or heavy metal compounds attached or bonded to or near the surface of the mineral agglomerates, which are generated by civil engineering construction or mining activities. The material reproduction | regeneration system which reproduces | regenerates the material for civil engineering or construction from which the said heavy metal and / or heavy metal compound were removed from the mineral mixture containing these.

  In general, when performing civil engineering and construction work such as repairing or dismantling concrete structures, excavating ground, modifying soil, creating land, building or repairing roads, or performing mining activities such as mining minerals, A large amount of mineral mixture is generated, including various mineral agglomerates such as sand, stone, rock, concrete pieces, metal ores. If such a mineral mixture is appropriately crushed and classified, it can be reused as a civil engineering and building material such as recycled sand, recycled gravel, or mining material. Therefore, the applicant of the present invention has already accepted a residual soil containing rocks, concrete galley, sand, soil, etc., crushed coarse materials in the residual soil and classified, and then obtained a mixture containing sand or particulates of a desired particle size. A product sand production apparatus or a production method which is regenerated as product sand has been proposed (see Patent Document 1).

JP 2005-342655 A

  By the way, harmful heavy metals and / or heavy metal compounds or ions thereof may adhere or bind to the surface of such a mineral mixture or in the vicinity thereof (hereinafter, these are collectively referred to as “heavy metal etc.”). . For example, heavy metals or the like are inevitably adhered or bonded to a mineral mixture generated by excavation or creation of soil or ground contaminated with heavy metals or the like. However, the conventional recycling system for civil engineering and building materials has a problem that such heavy metals cannot be sufficiently removed. Moreover, when water is used when reclaiming or recovering civil engineering and building materials, there is a problem in that wastewater containing heavy metals and the like is discharged to the surroundings, and heavy metals and the like diffuse into the surroundings.

  The present invention was made to solve the above-mentioned conventional problems, and even when heavy metals or the like are attached or bonded to the surface of the mineral mixture generated by civil engineering construction work or mining activities or near the surface, It is an object to be solved to provide a material recycling system capable of regenerating or recovering materials from which heavy metals are removed from the mineral mixture and preventing the heavy metals from diffusing to the outside. .

  The material recycling system according to the present invention made to solve the above-described problems is a plurality of mineral agglomerates having different dimensions, which are generated by civil engineering construction work or mining activities (for example, excavation and extraction of metal ore). And a mineral mixture containing heavy metals or the like (heavy metal and / or heavy metal compound or ions thereof) attached or bonded to the surface of the mineral agglomerate or in the vicinity of the surface (very shallow portion below the surface), The material from which the heavy metals and the like are removed is regenerated or recovered. In the basic mode, the material recycling system includes a crushing facility, a wet classification facility, a heavy metal removal facility, a wastewater treatment facility, and a treated water supply facility.

  Here, the crushing equipment crushes the mineral mixture, and crushes the mineral agglomerates having a size larger than a preset size. The wet classification equipment classifies the mineral mixture subjected to the crushing treatment into a plurality of kinds of materials having different particle diameters using water, while separating the heavy metals and the like from the mineral mixture into water. The heavy metal removal equipment removes the heavy metals and the like from the waste water discharged from the wet classification equipment. The wastewater treatment facility treats the wastewater from which the heavy metals and the like are removed, and separates the wastewater into sludge and treated water by precipitating water-insoluble matter in the wastewater. The treated water supply facility supplies treated water to the wet classification facility.

  The material recycling system according to the present invention includes a post-processing facility for performing post-processing including cleaning processing on at least one kind of civil engineering and building material among various materials classified by the wet classifying equipment. preferable. In this case, it is preferable that the treated water is supplied from the treated water supply facility to the post-treatment facility, while the waste water of the post-treatment device is transferred to the heavy metal removal facility.

  The material regeneration system according to the present invention preferably includes a sludge dewatering facility for performing a dewatering process on the sludge discharged from the wastewater treatment facility. In this case, it is preferable that the sludge dewatering equipment includes a filter press that applies pressure filtration to the sludge discharged from the wastewater treatment equipment to dehydrate, and the sludge dehydrated by the filter press is dried to generate dry sludge. It is particularly preferred to have a sludge dryer.

  In the material recycling system according to the present invention, the crushing equipment preferably includes a rod mill breaker that crushes the mineral mixture. The wet classification equipment preferably includes a jet trommel and a wet cyclone. The heavy metal removal equipment preferably includes a heavy metal processing apparatus for removing the heavy metals and the like by a ferrite method. The wastewater treatment facility includes a pH adjustment tank for adjusting the pH of the wastewater, a reaction tank for adding a flocculant to the wastewater whose pH has been adjusted to perform a coagulation treatment, and a thickener for separating the wastewater into sludge and treated water. It is preferable to provide.

  In the material recycling system according to the present invention, the mineral mixture or mineral agglomerates generated by civil engineering construction work or mining activities are soil, sand, stone, rock, concrete pieces, asphalt pieces, glass pieces, brick pieces, tile pieces , At least one of ceramic pieces and metal ore pieces. Examples of the heavy metal contained in the heavy metal include chromium, manganese, mercury, copper, lead, cadmium, zinc, nickel and the like.

  According to the material recycling system according to the present invention, even when heavy metals or the like are attached to or bonded to the surface of the mineral mixture generated by civil engineering construction work or mining activities or in the vicinity thereof, the mineral mixture substantially does not contain the above. The material from which heavy metals and the like are removed can be regenerated or recovered, and the heavy metals and the like can be reliably prevented from diffusing to the outside.

It is a block diagram which shows the basic composition of the material reproduction | regeneration system which reproduces | regenerates or collect | recovers the material from which the said heavy metal etc. was removed from the mineral mixture which the heavy metal etc. adhered or couple | bonded to the surface or surface vicinity based on this invention. It is a block diagram which shows a part of specific structure of the material reproduction | regeneration system shown in FIG. It is a block diagram which shows the remaining part of the specific structure of the material reproduction | regeneration system shown in FIG. It is a block diagram which shows the structure of a part of post-processing apparatus in case a mineral mixture contains a metal ore as a mineral agglomerate.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, referring to FIG. 1, a plurality of types of mineral agglomerates of various sizes and attached to or bonded to the mineral agglomerates generated by civil engineering construction work or mining activities are harmful and harmful. Basic configuration of a material recycling system according to the present invention, which regenerates or recovers a material from which a heavy metal or the like has been substantially removed from a mineral mixture containing a heavy metal or the like (that is, a heavy metal and / or a heavy metal compound or an ion thereof). Will be explained.

  In this specification, “mineral agglomerates” are generated by civil engineering and construction such as repair or dismantling of concrete structures, excavation of the ground, soil modification, land creation, road construction or repair, or the like. Powdered, granular or massive objects such as soil, sand, stones, rocks, concrete pieces, etc. formed from various minerals, minerals, etc. generated by mining activities such as metal ore extraction or excavation It means asphalt pieces, glass pieces, brick pieces, tile pieces, ceramic pieces, metal ore pieces, etc. The “mineral mixture” means a mixture containing a plurality or types of mineral agglomerates.

  As shown in FIG. 1, the material regeneration system RS according to the present invention includes a crushing facility A, a wet classification facility B, a heavy metal removal facility C, a wastewater treatment facility D, a treated water supply facility E, and a sludge dewatering facility. F and post-processing equipment G are provided.

  Here, the crushing equipment A crushes the mineral mixture and crushes the mineral agglomerate having a size larger than a preset size. The wet classifier B classifies the mineral mixture that has been crushed into a plurality of types of materials having different particle sizes using water, while separating or dissolving the heavy metals and the like from the mineral mixture into water. . The heavy metal removal equipment C removes the heavy metals and the like from the waste water discharged from the wet classification equipment B. The wastewater treatment facility D treats the wastewater from which the heavy metals and the like have been removed, and precipitates the water-insoluble matter in the wastewater to separate the wastewater into sludge and treated water. The treated water supply facility E supplies treated water to the wet classifier B (circulates and uses). The sludge dewatering facility F dehydrates sludge and dries it if necessary.

  The post-processing equipment G performs post-processing such as cleaning processing and re-crushing processing on the material classified by the wet classification equipment B so as to be suitable as a product. Treated water supplied from the treated water supply facility E is used as water required in the post-treatment facility G, for example, water for cleaning treatment. Further, the waste water discharged from the post-treatment facility G is transferred to the heavy metal removal facility C.

  In the material regeneration system RS, all the waste water discharged from each facility is treated by the waste water treatment facility D after the heavy metals are removed by the heavy metal removal facility C, and separated into sludge and treated water. On the other hand, the water required for each facility is almost entirely covered with treated water except for a small amount of makeup water. That is, in the material recycling system RS, water is almost completely circulated and does not discharge waste water to the outside. That is, the material regeneration system RS is a so-called closed system with respect to the use of water. As described above, since the waste water is not discharged from the material regeneration system RS, the diffusion of the heavy metal and other harmful substances from the material regeneration system RS to the outside is completely prevented.

  In this material recycling system RS, the heavy metals attached or bonded to or near the surface of the mineral agglomerates are detached or dissolved in water in the wet classifier B, so that various types of waste discharged from the wet classifier B The material does not substantially contain the heavy metal or the like. Therefore, it is possible to regenerate or recover mining materials such as reclaimed sand, reclaimed gravel, etc., or mining materials such as metal ore, from the mineral mixture containing the heavy metals.

  And the said heavy metal etc. in the waste_water | drain discharged | emitted from the wet classification equipment B are removed by the heavy metal removal equipment C, or are reduced significantly. In addition, most of the other water-polluting substances in the wastewater are treated in the wastewater treatment facility D, for example, by coagulation sedimentation treatment and removed from the wastewater together with sludge, removed or reduced from the wastewater by activated carbon adsorption, or by biological treatment. Removed or reduced from wastewater. The sludge is dehydrated by the sludge dewatering facility F or dried and then appropriately treated or disposed of.

  Wastewater from which heavy metals and water contaminants have been removed or reduced becomes treated water that can be reused. Thus, the heavy metals and other water pollutants that are continuously brought into the material regeneration system RS by the mineral mixture are continuously discharged from the material regeneration system RS by the heavy metal removal equipment C and the wastewater treatment equipment D. Therefore, even if the treated water is circulated, the above heavy metals and water pollutants are not accumulated or concentrated in the treated water, and the treated water is in a state suitable for use in each facility. Maintained.

Hereinafter, a specific configuration and function of the material recycling system RS according to the present invention will be described with reference to FIGS. 2 and 3.
As shown in FIGS. 2 and 3, in the material recycling system RS, the crushing equipment A includes a pretreatment screen 1, a jaw crusher 2, a first magnetic separator 3 and a rod mill breaker 4. 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 carried 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 sieving device, and a mineral mixture containing various mineral agglomerates having various particle sizes, for example, a particle size d of 90 mm or more (or 60 mm or more). Sieving into a mineral mixture containing mineral agglomerates and a mineral mixture containing mineral agglomerates having a particle size d of less than 90 mm (or less than 60 mm). The mineral agglomerates having a particle diameter d of 90 mm or more are transferred to the jaw crusher 2 by a belt conveyor or the like. On the other hand, mineral agglomerates having a particle size d of less than 90 mm are transferred to the rod mill breaker 4 via the first magnetic separator 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 (roughly crushes) mineral agglomerates having a particle size of 90 mm or more (or 60 mm or more), for example, and generates a mineral agglomerate having a particle size of less than 40 mm, for example. The mineral agglomerates are transferred to the rod mill breaker 4 via the first magnetic separator 3 by a belt conveyor or the like.

  The first magnetic separator 3 sucks and removes a paramagnetic or ferromagnetic metal such as an iron piece or an iron-based alloy piece in the mineral mixture by a powerful magnet disposed above the mineral mixture. Since the removed metal can be reused as a resource, it is sold to a predetermined supplier. In the first magnetic separator 3, foreign matter can be removed by manual sorting, and this foreign matter can be reused as fuel if it is combustible (thermal recycling).

  Although not shown in detail, the rod mill breaker 4 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. Roll in parallel with each other and come into line contact, and the impact causes the mineral agglomerates existing between the rods to be finely crushed. The mineral mixture is mixed with the treated water supplied from the treated water supply facility E (see FIG. 1) before entering the rod mill breaker 4. When the mineral agglomerates are crushed in the rod mill breaker 4, a part of the heavy metal or the like adhering to or binding to the mineral agglomerates is detached into the water by peeling or dissolution.

  The wet classification equipment B includes a wet jet trommel 5 to which treated water is supplied from the treated water supply equipment E, a wet first cyclone 6, and a wet second cyclone 7. In the jet trommel 5, the first cyclone 6 and the second cyclone 7, the mineral agglomerates come into contact with a large amount of water and the individual mineral agglomerates rub against each other. The bonded heavy metals and the like are almost completely separated into water by peeling, dissolving, and the like.

  Although not shown in detail, the jet trommel 5 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, when the drum screen is rotated while supplying water into the drum screen, and the mineral mixture is introduced into the drum screen from the rod mill breaker 4 via the upper opening end (the higher position) of the drum screen. The mineral mixture basically moves toward the lower open end (lower position) by gravity. At that time, mineral agglomerates finer than the mesh of the drum screen, for example, mineral 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. Exit and enter the tank. In the receiving tank, the small-diameter agglomerates and water are mixed with each other to form an aqueous mixture.

  On the other hand, mineral agglomerates coarser than the mesh of the drum screen, for example, mineral agglomerates having a particle size of 5 mm or more (hereinafter referred to as “large-diameter agglomerates”) cannot pass through the mesh of the drum screen. Is then discharged out of the drum screen and transferred to the second magnetic separator 13. In this jet trommel 5, the mineral agglomerates come into contact with a large amount of water and the mineral agglomerates rub against each other, so that heavy metals adhering to or bound to the mineral agglomerates are separated from the water by peeling, dissolving, etc. break away.

  The aqueous mixture composed of the small-diameter agglomerates and water in the receiving tank of the jet trommel 5 is transferred to the first cyclone 6. Although not shown in detail, the first cyclone 6 pumps the aqueous mixture into a substantially conical cylinder that narrows downward to generate a swirling flow, and utilizes the centrifugal force generated thereby to generate an aqueous system. Among the small-diameter agglomerates, the mixture has a relatively large particle size, for example, a particle size of 0.5 mm or more (hereinafter referred to as “recycled sand”), and a relatively small particle size, for example, a particle size of Separated into water-based turbid material containing less than 0.5 mm (hereinafter referred to as “finely collected material”). In the first cyclone 6, the mineral agglomerates come into contact with a large amount of water and the mineral agglomerates rub against each other. Therefore, the heavy metal adhering to or bound to the mineral agglomerates is peeled off or dissolved. Leave in the water.

  Then, the recycled sand separated by the first cyclone 6 is transferred to a sand scrubber 8 which is a part of the post-processing equipment. 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 8, a jet ladder chute 9, a sand screen 10, and a first dewatering screen 11.

  Treated water (circulated water) is supplied to the sand scrubber 8 from the treated water supply device 24. Although not shown in detail, the sand scrubber 8 is sent out while the reclaimed sand is squeezed 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. If the heavy metal or the like remains in the reclaimed sand, the heavy metal or the like is detached from the reclaimed sand into the water.

  The reclaimed sand from which foreign matter has been removed by the sand scrubber 8 is transferred to the jet ladder chute 9 to which treated water is supplied from the treated water supply device 24 together with drainage. The jet ladder chute 9 causes the treated sand (circulated water) to flow at a predetermined pressure and an amount of water to rinse the reclaimed sand. In the unlikely event that foreign matter, the above heavy metal, or the like remains on the surface of the reclaimed sand, these are separated from the reclaimed sand by this rinsing treatment.

  The reclaimed sand that has been rinse-washed by the jet ladder chute 9 is transferred to the sand screen 10 to which treated water is supplied from the treated water supply device 24 together with drainage. The sand screen 10 causes the treated water (circulated water) to flow at a predetermined pressure and amount of water to rinse the reclaimed sand, and collects any foreign matter that remains. The foreign matter collected by the sand screen 10 is reused as fuel if it is combustible (thermal recycling). Further, in the sand screen 10, the regenerated sand is dewatered in water to become high-quality washing sand and transferred to the first dewatering screen 11. The waste water from the sand screen 10 is transferred to the heavy metal processing device 15.

In the first dewatering screen 11, the recycled sand is subjected to a final rinse cleaning process and a chelate process. The drainage of the first dewatering screen 11 is returned to the first cyclone 6. Note that this waste water may be discharged to the heavy metal processing device 15. 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. In the storage yard or reservoir, the quality of the sand product is inspected to determine the presence or absence of heavy metals in the sand product. For example, sand product 100m ³ each to be collected specimen subjected to quality inspection, also once a month, subject to inspection of public institutions. Only sand products that have passed the quality inspection, that is, sand products that do not contain heavy metals are used or sold as civil engineering and building materials. In addition, the sand product which has failed the quality inspection, that is, the sand product containing the heavy metal or the like is returned to the sand scrubber 8 and washed again to remove the heavy metal or the like.

  Mineral mixtures or mineral agglomerates are metal ores, such as iron ores (eg hematite, pyrite), copper ores (eg, hematite, chalcopyrite), lead ores (eg, galena), zinc ores (zinc zinc) Ore), manganese ore, nickel ore, and the like, these metal ores are separated from the recycled sand discharged from the first dewatering screen 11.

  Specifically, as shown in FIG. 4, when the mineral mixture or mineral agglomerate contains metal ore, the regenerated sand discharged from the first dewatering screen 11 is transferred to the first specific gravity difference separation device 31. Here, it is separated into particles made of metal ore (hereinafter referred to as “ore”) and other particles, that is, sand products regenerated from rock or concrete and not containing metal ore. As the first specific gravity difference separation device 31, for example, a wet specific gravity difference separation device that separates the ore and the sand product with a specific gravity difference by a water flow flowing upward in a vertically extending cylinder can be used. While the specific gravity of the ore exceeds 4, while the specific gravity of the sand product is in the range of 2.2 to 2.6, separation due to the specific gravity difference between the ore and the sand product is very easy. The ore is sold as a mining material to a predetermined trader.

  As described above, the water-based turbid material containing the finely recovered material discharged from the first cyclone 6 is transferred to the second cyclone 7. Although not shown in detail, the second cyclone 7 pumps water-based turbidity into a substantially conical cylinder that narrows downward to generate a swirling flow, and utilizes the centrifugal force generated thereby, Among the finely collected materials, the mixture has a relatively large particle size, for example, a particle size d of 0.075 mm or more (hereinafter referred to as “recycled fine sand”), and a relatively small particle size, for example, a particle. Separated into turbid water (drainage) containing one having a diameter d of less than 0.075 mm (hereinafter referred to as “fine matter”).

  Then, the regenerated fine sand separated by the second cyclone 7 is transferred to a second dewatering screen 12 which is a post-treatment facility for the regenerated fine sand. On the other hand, the turbid water (drainage) containing fine substances is transferred to the heavy metal processing device 15.

  In the second dewatering screen 12, the regenerated fine sand is subjected to a final rinse cleaning process and a chelate process. The drainage of the second dewatering screen 12 is returned to the first cyclone 6. Note that this waste water may be discharged to the heavy metal processing device 15. As a result, the regenerated fine sand becomes a high-quality fine sand product and falls naturally into the storage yard. This fine sand product is transferred to a predetermined storage place by, for example, a slide belt conveyor and stored. In the storage yard or reservoir, the quality inspection of the fine sand product is performed as in the case of the sand product described above, and only the fine sand product that has passed the quality inspection is used or sold as a civil engineering building material. The fine sand product that has failed the quality inspection is returned to the first cyclone 6 or the second cyclone 7, and washed again to remove heavy metals and the like.

  When the mineral mixture or mineral agglomerates contain metal ore, the regenerated sand discharged from the second dewatering screen 12 using a specific gravity difference separation device (not shown) as in the case of sand products. From these, these metal ores can be separated.

  As described above, the large-diameter agglomerates (mineral agglomerates having a particle diameter d of 5 mm or more) discharged from the jet trommel 5 are transferred to the coarse screen 14 via the second magnetic separator 13. Here, the second magnetic separator 13 is a paramagnetic or ferromagnetic metal in the large-diameter lump that has not been removed by the first magnetic separator 3 by a powerful magnet disposed above the large-diameter lump. For example, an iron piece or an iron-based alloy piece is sucked and removed.

  The coarse screen 14 has large-diameter agglomerates having a particle size d of 40 mm or more (hereinafter referred to as “needed material”) and particles having a particle size d of less than 40 mm (hereinafter referred to as “gravel product”). ) And sieve. Then, the crushed material is transferred to the impact crusher 25, crushed by the impact crusher 25, and then returned to the coarse screen 14. Therefore, all large-diameter agglomerates are less than 40 mm and are discharged from the coarse screen 14.

  On the other hand, gravel-like products, that is, mineral agglomerates having a particle size d 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 the storage yard or storage place, as in the case of the sand product described above, the quality of the gravel-like product is inspected, and only the gravel-like product that has passed the quality inspection is used or sold as a civil engineering building material. The gravel-like product that has failed the quality inspection is returned to the jet trommel 5 to remove heavy metals and the like.

  When the mineral mixture or mineral agglomerate contains metal ore, as shown in FIG. 4, the second specific gravity difference separation device 32 is used to remove these from the gravel product discharged from the coarse screen 14. What is necessary is just to isolate | separate a metal ore. The configuration of the second specific gravity difference separation device 32 is basically the same as the configuration of the first specific gravity difference separation device 31.

Hereinafter, specific configurations and functions of the heavy metal removal facility C, the wastewater treatment facility D, the treated water supply facility E, and the sludge dewatering facility F will be described.
The heavy metal removal equipment C includes a heavy metal processing device 15 that removes the heavy metals and the like in the waste water. Then, wastewater discharged from the second cyclone 7 and the sand screen 10 is introduced into the heavy metal processing device 15. The heavy metals and the like in the waste water are removed or greatly reduced by the heavy metal processing device 15. Examples of the heavy metal include chromium, manganese, copper, lead, cadmium, mercury, zinc, nickel, tin, cobalt, compounds of these heavy metals, or ions of these heavy metals or compounds.

  As the heavy metal processing apparatus 15, for example, a heavy metal processing apparatus using a ferrite method can be used. The ferrite method itself is well known to those skilled in the art and will not be described in detail. For example, the ferritic heavy metal treatment apparatus adds, for example, divalent iron ions to the wastewater and uses the above heavy metal in the wastewater. After reacting with the above, etc., it is oxidized in the wastewater to produce a water-insoluble and ferromagnetic ferrite having a spinel lattice structure, and this ferrite is separated from the wastewater with a magnetic separator, so that the heavy metals in the wastewater, etc. Is to be removed. Since ferrite has a large specific gravity (for example, 4.8 to 4.9), it may be precipitated and separated from waste water.

Moreover, you may use the heavy metal processing apparatus by an iron powder method as the heavy metal processing apparatus 15. FIG. The heavy metal processing apparatus by the iron powder method adds, for example, iron powder having a large specific surface area (for example, one having a surface area of 250,000 cm ² / g or more), for example, iron powder subjected to surface treatment with iron (II) sulfate, to the wastewater. The heavy metal in the waste water is adsorbed on the iron powder to remove the heavy metal in the waste water, and then the iron powder is separated from the waste water by a magnetic separator. In addition, since iron powder has a large specific gravity (for example, 7.8 to 7.9), it may be precipitated and separated from waste water. Moreover, you may use the heavy metal processing apparatus of the form of the packed tower with which iron powder was filled inside. In this case, when the wastewater flows through the packed tower, the heavy metal or the like is adsorbed to the iron powder, and the heavy metal or the like in the wastewater is removed.

  Furthermore, as the heavy metal processing apparatus 15, a heavy metal processing apparatus using a chelate method may be used. As a heavy metal processing apparatus by a chelate method, for example, a packed tower filled with a chelate resin can be used. In this case, when the wastewater flows through the packed tower, the heavy metals and the like are captured or adsorbed by the chelate resin, and the heavy metals and the like in the wastewater are removed. The chelate resin is exchanged or regenerated when saturated with the heavy metal or the like. Instead of the chelate resin, an ion exchange resin that captures the heavy metal or the like may be used.

  In addition, as a heavy metal treatment apparatus using a chelate method, a heavy metal treatment tank may be used in which a water-soluble liquid chelating agent is added to wastewater, and the heavy metal or the like in the wastewater is captured or adsorbed by the chelating agent. In this case, the chelating agent that has captured or adsorbed the heavy metal or the like can be precipitated and separated from the waste water. Instead of the chelating agent, water-insoluble inorganic porous powder or particles with the chelating agent fixed are added to the waste water, and the heavy metals in the waste water are captured or adsorbed on the inorganic porous powder or particles. You may make it make it. Also in this case, the powder or particles that capture or adsorb the heavy metal can be separated from the waste water by precipitation. In addition, a paramagnetic substance may be included in the inorganic porous powder or particle, and the powder or particle that has captured or adsorbed the heavy metal may be separated from the waste water by a magnetic separator.

  The wastewater treatment facility D includes a PH adjustment tank 16, a reaction tank 17, a raw water layer 18, and a thickener 19. The treated water supply facility E includes a treated water tank 23 and a treated water supply facility 24. The sludge dewatering facility F includes a filter press 20, a sludge improver 21, and a sludge dryer 22.

  The heavy metal treatment device 15 may be provided not on the upstream side of the PH adjustment tank 16 but on the downstream side of the PH adjustment tank 16 with respect to the flow direction of the drainage. For example, the heavy metal processing device 15 may be provided between the PH adjustment tank 16 and the reaction tank 17.

  In the pH adjustment tank 16, an acidic liquid (for example, hydrochloric acid, sulfuric acid, etc.) or an alkaline liquid (for example, a sodium hydroxide aqueous solution, a calcium hydroxide aqueous solution, etc.) is added to the waste water, and the pH (hydrogen ion concentration) of the waste water is predetermined. (E.g., 8 to 9 PH, or 9 to 10 PH). Although not shown in detail, in the PH adjustment tank 16, the pH of the wastewater is automatically adjusted by a PH automatic control device equipped with a PH meter and the like. The wastewater whose pH has been adjusted is transferred to the reaction tank 17.

  In the reaction tank 17, a predetermined inorganic flocculant (for example, ferric chloride aqueous solution, aluminum sulfate aqueous solution, polyaluminum chloride aqueous solution, etc.) and a polymer flocculant are added to the waste water. As a result, water-insoluble metal hydroxide flocs are generated, and water pollutants or suspended solids in the wastewater are adsorbed on or adhered to the metal hydroxide flocs, or the heavy metal ions remain. In this case, the heavy metal ion becomes a water-insoluble metal hydroxide to form a floc. The wastewater containing such flocs is sent to the raw water tank 18, where the flocs grow in the raw water tank 18, and the adsorption, adhesion or bonding of water pollutants or suspended matters in the wastewater to the flocs is promoted. The

  The waste water including the floc in the raw water tank 18 is transferred to the thickener 19. The thickener 19 is not shown in detail, but the water-insoluble floc is settled by gravity while the drainage is almost stationary, and the sludge layer located below (for example, the solid content ratio is 2-3%) ) And a supernatant water (treated water) layer which is located at the top and hardly contains floc. The sludge accumulated in the lower portion of the thickener 19 is taken out of the thickener 19 as appropriate or continuously, by gravity or using a slurry pump (not shown), and transferred to the filter press 20.

  Although not shown in detail, the filter press 20 is a batch-type or continuous-type pressure filter, and filters the sludge received from the thickener 19 to generate a sludge cake and filtered water. The filtration pressure of the filter press 20 is preferably set so that, for example, the moisture content of the sludge cake is 30 to 40%. Here, the filtered water (drainage) of the filter press 20 is returned to the thickener 19. A filter other than the filter press, for example, a vacuum filter (Oliver type filter) or the like may be used. The sludge cake discharged from the filter press 20 is transferred to the sludge improving machine 21. In this sludge improving machine 21, in order to improve the properties of sludge, an auxiliary agent is added to the sludge cake and stirred and kneaded. Thereafter, the sludge cake is transferred to a sludge dryer 22 and dried to become dry sludge. This dried sludge is appropriately treated or disposed of. If it is not necessary to dry the sludge, the sludge dryer 22 may not be provided.

  The treated water discharged from the thickener 19 is transferred to the treated water tank 23 and stored. The treated water stored in the treated water layer 23 is supplied to each facility requiring water by a treated water supply device 24 equipped with a pump or the like. In addition, when the treated water stored in the treated water tank 23 decreases due to water leakage, evaporation, etc., the treated water tank 23 is appropriately replenished with tap water.

  As described above, according to the material regeneration system RS according to the embodiment of the present invention, even when the mineral mixture generated by civil engineering construction or generated by mining activities includes the heavy metal, the heavy metal, etc. It is possible to regenerate the civil engineering and building material or the mining material from which is removed, and it is possible to reliably prevent the heavy metals and the like from diffusing to the outside.

  The material recycling system according to the present invention occurs when civil engineering and construction work such as demolition of concrete structures, ground excavation, soil modification, land creation, road construction or repair, or mining activities are performed. Since the mineral mixture to be reproduced can be regenerated as civil engineering and building materials or mining materials, it can be used in the field of civil engineering and building business or mining, and material costs in civil engineering and building business or mining can be reduced.

  RS material regeneration system, A crushing equipment, B wet classification equipment, C heavy metal removal equipment, D wastewater treatment equipment, E treated water supply equipment, F sludge dewatering equipment, G posttreatment equipment, 1 pretreatment screen, 2 jaw crusher, 3 First magnetic separator, 4 rod mill breaker, 5 jet trommel, 6 first cyclone, 7 second cyclone, 8 sand scrubber, 9 jet ladder chute, 10 sand screen, 11 first dewatering screen, 12 second dewatering screen, 13 first 2 magnetic separator, 14 coarse screen, 15 heavy metal processing equipment, 16 PH adjustment tank, 17 reaction tank, 18 raw water tank, 19 thickener, 20 filter press, 21 sludge improver, 22 sludge dryer, 23 treated water tank, 24 treated water Supply device, 25 impact crusher, 31 1st specific gravity difference separator , 32 second gravity difference separation unit.

The present invention relates to a plurality of mineral agglomerates having different dimensions, and heavy metals and / or heavy metal compounds attached or bonded to or near the surface of the mineral agglomerates, which are generated by civil engineering construction or mining activities. It is related with the material reproduction | regeneration system which produces | generates the sand product from which the said heavy metal and / or heavy metal compound were removed from the mineral mixture containing these.

The present invention was made to solve the above-mentioned conventional problems, and even when heavy metals or the like are attached or bonded to the surface of the mineral mixture generated by civil engineering construction work or mining activities or near the surface, The problem to be solved is to provide a material recycling system capable of generating or recovering sand products from which heavy metals are removed from the mineral mixture and preventing the heavy metals from diffusing to the outside. To do.

The material recycling system according to the present invention made to solve the above-described problems is a plurality of mineral agglomerates having different dimensions, which are generated by civil engineering construction work or mining activities (for example, excavation and extraction of metal ore). And a mineral mixture containing heavy metals or the like (heavy metal and / or heavy metal compound or ions thereof) attached or bonded to the surface of the mineral agglomerate or in the vicinity of the surface (very shallow portion below the surface), A sand product from which the heavy metals and the like are removed is generated or recovered. In a basic mode, this material recycling system includes a crushing facility, a wet classification facility, a heavy metal removal facility, a wastewater treatment facility, a treated water supply facility, and a post-treatment facility .

Here, the crushing equipment has a wet rod mill breaker that crushes the mineral mixture and crushes the mineral agglomerates having a size larger than a preset size. The wet classification equipment has a wet cyclone that separates the reclaimed sand from the mineral mixture that has been subjected to the crushing treatment using water, while allowing the heavy metals and the like to escape from the mineral mixture into water. The heavy metal removal equipment removes the heavy metals and the like from the waste water discharged from the wet classification equipment. Wastewater treatment facility includes a reactor for performing coagulation treatment by adding a coagulant to the wastewater in which the heavy metals which is discharged from the heavy metal removal equipment has been removed, the water-insoluble in the effluent waste water flocculation treatment has been performed and a thickener to separate the precipitated things as sludge and treated water. The treated water supply equipment supplies treated water to the crushing equipment and the wet classification equipment for circulation . The post-processing equipment performs post-processing including cleaning treatment on the regenerated sand separated by the wet classification equipment to finish the sand product.

In the material reproducing system according to the present invention, while supplying treated water to the post-processing equipment from treatment water supply equipment, it is preferable to transfer the drainage of the post-processing apparatus to heavy metal removal system.

In the material reproducing system according to the present invention, moisture classifier equipment preferably includes a jet Tron main Le.

In the material recycling system according to the present invention, the mineral mixture or mineral agglomerate generated by civil engineering or mining activities includes at least one of soil, sand, stone, rock, and concrete pieces . Examples of the heavy metal contained in the heavy metal include chromium, manganese, mercury, copper, lead, cadmium, zinc, nickel and the like.

According to the material recycling system according to the present invention, even when heavy metals or the like are attached to or bonded to the surface of the mineral mixture generated by civil engineering construction work or mining activities or in the vicinity thereof, the mineral mixture substantially does not contain the above. Sand products from which heavy metals and the like are removed can be generated or recovered, and the heavy metals and the like can be reliably prevented from diffusing to the outside.

Claims (10)

Mineral properties containing a plurality of mineral agglomerates of various sizes and heavy metals or heavy metal compounds adhering to or bonding to the surface of the mineral agglomerates or in the vicinity of the surfaces, generated by civil engineering construction work or mining activities A material regeneration system (RS) for regenerating a material from which a heavy metal or a heavy metal compound is removed from a mixture,
A crushing facility (A) for crushing a mineral mixture and crushing a mineral agglomerate having a dimension larger than a preset dimension;
Wet classification facility (B) for classifying the mineral mixture subjected to the crushing treatment into a plurality of kinds of materials having different particle diameters using water, while separating the heavy metal or heavy metal compound from the mineral mixture into water. When,
A heavy metal removal facility (C) for removing the heavy metal or heavy metal compound from waste water discharged from the wet classification facility (B);
A wastewater treatment facility (D) for treating the wastewater from which the heavy metal or heavy metal compound has been removed, and for precipitating water-insoluble matter in the wastewater to separate the wastewater into sludge and treated water,
A material recycling system comprising a treated water supply facility (E) for supplying treated water to the wet classification facility (B). A post-treatment facility (G) for performing a post-treatment including a cleaning treatment on at least one of the various materials classified by the wet classification facility (B);
The treated water is supplied from the treated water supply facility (E) to the post-treatment facility (G), while the waste water of the post-treatment device (G) is transferred to the heavy metal removal facility (C). The material recycling system according to claim 1.   The material regeneration system according to claim 1 or 2, further comprising a sludge dewatering facility (F) for dewatering the sludge discharged from the wastewater treatment facility (D).   The said sludge dewatering equipment (F) is provided with the filter press (20) which performs a pressure filtration to the sludge discharged | emitted from the said waste water treatment equipment (D), and dehydrates. Material recycling system.   The said sludge dewatering equipment (F) is equipped with the sludge dryer (22) which dries the sludge dehydrated with the said filter press (20), and produces | generates dry sludge, The Claim 4 characterized by the above-mentioned. Material recycling system.   The material recycling system according to any one of claims 1 to 5, wherein the crushing equipment (A) includes a rod mill breaker (4) for crushing a mineral mixture.   The material regeneration system according to any one of claims 1 to 6, wherein the wet classification equipment (B) includes a jet trommel (5) and a wet cyclone (6, 7). .   The material according to any one of claims 1 to 7, wherein the heavy metal removal equipment (C) includes a heavy metal treatment device (15) for removing the heavy metal or heavy metal compound by a ferrite method. Playback system.   The waste water treatment facility (D) includes a pH adjustment tank (16) for adjusting the pH of the waste water, a reaction tank (17) for adding a flocculant to the waste water whose pH has been adjusted to perform a coagulation treatment, and sludge for the waste water. The material regeneration system according to any one of claims 1 to 8, further comprising a thickener (19) that separates into water and treated water.   The mineral mixture includes at least one of soil, sand, stone, rock, concrete pieces, asphalt pieces, glass pieces, brick pieces, tile pieces, ceramic pieces and metal ore pieces as mineral agglomerates. The material recycling system according to any one of claims 1 to 9, wherein

Images