JP2012006814A - Method of producing sulfur solidified body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing sulfur solidified bodies capable of continuously producing sulfur solidified bodies of high strength and of certainly controlling elution of harmful substances.SOLUTION: The method of producing sulfur solidified bodies includes: a mixing step of mixing incinerated ash, fine and coarse aggregates into molten sulfur; and a pressing step of heating and kneading the mixture produced in the mixing step and pressing it in an extruder 50. In the mixing step, the incinerated ash, fine and coarse aggregates are separately mixed to the molten sulfur and then the mixture is supplied to the extruder 50.

Description

  The present invention relates to a method for producing a sulfur solidified body.

  Sulfur solidified material obtained by mixing aggregate with molten sulfur and cooling and solidifying this is also called sulfur concrete, and it is superior in terms of strength, acid resistance, corrosion resistance, sealing properties, etc. compared to cement concrete. For this reason, it is being used for various structures such as harbor civil engineering, fisheries, and architecture. As a manufacturing method of a sulfur solidified body, what was disclosed by patent document 1 is known, for example. In the method for producing a sulfur solidified body disclosed in Patent Document 1, an intermediate material is generated by mixing refined sulfur obtained by mixing a modifier with molten sulfur and fine powder such as coal ash or silica sand. The intermediate material is mixed with an aggregate such as natural stone or steel slag to produce a sulfur-containing material. And after putting this sulfur containing material into a hopper and extruding it in a mold via a cylinder, a sulfur solidified body can be taken out by slowly cooling the sulfur containing material in a mold.

JP 2009-227551 A

  According to the conventional method for producing a sulfur solidified body, when the molten sulfur is mixed with the fine powder to produce the intermediate material, not only the contact area between the fine powder and the molten sulfur is large, but also contained in the fine powder. Due to the high water absorption of the incinerated ash, a large amount of sulfur may be consumed. On the other hand, increasing the content ratio of molten sulfur has a limit because it causes a decrease in the strength of the solidified sulfur. For this reason, when the aggregate is mixed with the intermediate material, it is difficult to spread a small amount of molten sulfur remaining in the intermediate material over the entire surface of the aggregate, and elution of heavy metals contained in the aggregate is ensured. There was a problem that could not be prevented. In particular, in order to be able to continuously produce a solidified sulfur and to reduce the size of the production equipment, it is required to uniformly mix the intermediate material and the aggregate in a short time. It became more prominent.

  Then, this invention aims at provision of the manufacturing method of the sulfur solidified body which can manufacture a high intensity | strength sulfur solidified body continuously and can suppress the elution of a harmful substance reliably.

  The object of the present invention is to mix molten sulfur with incinerated ash, fine aggregate, and coarse aggregate, and to heat and knead the mixture produced in the mixing process in an extruder, pressurize it, and discharge the compressed mixture The mixing step is achieved by a method for producing a solidified sulfur product, wherein the incinerated ash, fine aggregate and coarse aggregate are individually mixed with molten sulfur and then supplied to the extruder. Is done.

  Alternatively, the object of the present invention is to provide a mixing step in which molten sulfur is mixed with incinerated ash and aggregate, and a compression step in which the mixture produced in the mixing step is heated and kneaded in an extruder and pressurized, and a compressed mixture is discharged. The mixing step is achieved by a method for producing a solidified sulfur product, wherein the incinerated ash and aggregate are individually mixed with molten sulfur and then supplied to the extruder.

  Alternatively, the object of the present invention is to mix a molten sulfur with fine aggregate and coarse aggregate, and to heat and knead the mixture produced in the mixing process in an extruder, pressurize it, and discharge the compressed mixture A compression step, and the mixing step is achieved by a method for producing a sulfur solidified body, wherein the fine aggregate and the coarse aggregate are individually mixed with molten sulfur and then supplied to the extruder.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to manufacture a highly strong sulfur solidified body continuously, the manufacturing method of the sulfur solidified body which can suppress the elution of a harmful | toxic substance reliably can be provided.

It is a whole flow figure of the manufacturing method of the sulfur solidification object concerning one embodiment of the present invention. It is a principal part side view which shows an example of the apparatus used for manufacture of the sulfur solidified body of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is an overall flow diagram of a method for producing a sulfur solidified body according to an embodiment of the present invention, and FIG. 2 is a side view of a main part of an apparatus used for producing the sulfur solidified body. In this embodiment, incinerated ash, fine aggregate and coarse aggregate are mixed with molten sulfur to produce a sulfur solidified body.

  As shown in FIG. 1, the incineration ash stored in the primary storage 10 is conveyed to the dryer 12 by the belt conveyor 11a, and then accommodated in the incineration ash storage 13 by the belt conveyor 11b. The incineration ash in the incineration ash storage 13 is preferably sufficiently dried by the dryer 12 so as to reliably prevent the elution of harmful substances such as heavy metals from the finally obtained sulfur solidified body. It is preferable to maintain the water content at 3% or less. The incineration ash is, for example, incineration ash such as municipal waste, papermaking, sewage sludge, and includes not only general waste but also industrial waste. Further, not only main ash (bottom ash) but also fly ash (fly ash) or a mixture thereof is included. Since these incineration ash is generally porous and has a large specific surface area, it is preferable to distinguish them from other aggregates described later.

  The fine aggregate and the coarse aggregate are distinguished from each other and stored in the fine aggregate pit 20 and the coarse aggregate pit 30, and are stored in the fine aggregate storage 22 and the coarse aggregate storage 32 by the tire excavators 21 and 31, respectively. The The fine aggregate and coarse aggregate in the fine aggregate storage 22 and the coarse aggregate storage 32 are also maintained in a dry state with a low water content (for example, 3% or less) for the same reason as in the case of incinerated ash. It is preferable.

  Fine and coarse aggregates are river sand, crushed sand, gravel, crushed stone, clay, shells, stainless slag, steel slag, cast iron slag, zinc slag, copper slag, fired slag, molten slag, abrasive scraps, debris, various fibers The aggregates such as are classified according to the particle size. In general, a 5 mm sieve is 85% or more in mass and the 10 mm sieve passes through all aggregates, and 5 mm sieve is 85% or more in aggregate. It is not limited, and can be set as appropriate according to the type and size of aggregates included. In addition to distinguishing fine aggregates and coarse aggregates by particle size, fine aggregates and coarse aggregates may be distinguished by other criteria having a correlation with the specific surface area of the material, such as particle size and specific gravity.

  The incinerated ash, fine aggregate, and coarse aggregate stored in the incinerated ash storage 13, the fine aggregate storage 22, and the coarse aggregate storage 32 are respectively fed to the quantitative feeders 41, 42 by the belt conveyors 11c, 23, 33. , 43. The fixed amount of molten sulfur stored in the molten sulfur tank 40 in a heated state is supplied to each of the quantitative feeders 41, 42, and 43 by a quantitative pump 49. Molten sulfur can be used by heating, for example, simple sulfur obtained as a by-product of petroleum refining to a melting point (for example, 110 to 140 ° C.). If the temperature is 150 ° C. or higher, the viscosity of molten sulfur is not preferable.

  The fixed amount feeders 41, 42, and 43 have a known configuration capable of continuously supplying a fixed amount of material introduced into the hopper by screw extrusion, and each material is provided by a rotary blade provided on a rotary shaft extending vertically in the hopper. (Incinerated ash, fine aggregate or coarse aggregate) can be mixed separately with molten sulfur. It is preferable to provide a heater on the side wall of the hopper, the rotating shaft, and the rotating blade so that the molten state of sulfur can be maintained. As shown in FIG. 2, the mixtures supplied from the quantitative feeders 41, 42, and 43 are all supplied to a mixing hopper 46, and are stirred and mixed by a rotating blade (not shown) in the mixing hopper 46.

  By balancing the flow rate of molten sulfur supplied to each quantitative feeder 41, 42, 43 by the quantitative pump 49 with the supply amount of the mixture from each quantitative feeder 41, 42, 43, the mixing ratio of sulfur is substantially constant. A certain mixture can be continuously fed from each metering feeder 41, 42, 43 to the mixing hopper 46. The mixing ratio of sulfur in the mixture mixed in the mixing hopper 46 is preferably 15 to 35% by mass, and more preferably 19 to 30% by mass with respect to the whole. If the mixing ratio of sulfur is out of this numerical range, the strength tends to decrease. In particular, if the mixing ratio of sulfur is too small, elution of heavy metals contained in incineration ash and aggregates may not be effectively prevented.

  The mixing ratio of sulfur in the mixture in each quantitative feeder 41, 42, 43 can also be set with the above numerical range as a guide, but the incinerated ash, fine aggregate and the aggregate supplied to each quantitative feeder 41, 42, 43 In consideration of the fact that the coarse aggregate has different sulfur absorbability, it is preferable that the higher the sulfur absorbability, the higher the sulfur content. That is, the mixing ratio of sulfur contained in each sulfur mixture of incineration ash, fine aggregate and coarse aggregate can be set to the same, but the sulfur mixture of incineration ash is the highest, and coarse aggregate It is preferable to set so that the sulfur mixture becomes the lowest.

  In the present embodiment, in addition to the quantitative feeders 41, 42, and 43 that mix incinerated ash, fine aggregate, and coarse aggregate with molten sulfur, quantitative determination is performed to supply the additive stored in the additive storage 44. A feeder 45 is provided. As an additive, the well-known thing for improving a flame retardance, corrosion resistance, etc. and producing | generating a modified sulfur can be used, and an olefin type compound etc. can be illustrated. Although not shown in FIG. 2, the quantitative feeder 45 supplies the additive to the mixing hopper 46 together with the mixture from the quantitative feeders 41, 42, and 43. The mixture mixed in the mixing hopper 46 is introduced into a distribution pipe 47, and is distributed and supplied to a plurality of extruders 50 to 54 as shown in FIG.

  Each of the extruders 50 to 54 has the same configuration, and FIG. 2 shows one of them. As shown in FIG. 2, the extruder 50 is arrange | positioned so that the mixture distributed by the distribution pipe 47 may be introduce | transduced via the shooter 50a and the hopper 50b. The extruder 50 has a known configuration in which the mixture supplied to the base side from the hopper 50b can be conveyed toward the tip while being kneaded by rotation of the screw, and extruded from the discharge port 50c. Either of two axes may be used. It is preferable to set the discharge pressure of the extruder 50 to, for example, 10 to 20 MPa so that the mixture can be sufficiently pressurized and compressed in the extruder 50. Also in the extruder 50, it is preferable to heat the housing and the screw in order to maintain the molten state of sulfur in the same manner as the quantitative feeders 41, 42, and 43.

  The mixture supplied from each of the extruders 50 to 54 is a compressed mixture that is sufficiently compressed, and these are merged again, and are conveyed toward the mold heat insulation table 60 by the screw conveyor 55 while maintaining the heating state. The A mold frame (not shown) is installed on the mold heat insulation table 60. The compressed mixture is poured into the mold in a state where the mold is heated and vibrated by the mold heat-insulating table 60, and finally the compressed mixture is cooled and solidified to obtain a desired shape. The sulfur solidified body which has can be manufactured. The solidified sulfur obtained in this way is used for marine products such as revetment sheet piles, artificial reefs, wave-dissipating blocks, sand drift prevention blocks, harbor civil engineering structures such as ground reinforcements, fishing reefs, seaweed beds breeding blocks, sea current adjustment mountain blocks, etc. It can be used for various applications such as structures or construction structures such as sewage facilities, sewage fume pipes, X-ray room protection walls, radioactive waste protection walls, etc. By appropriately adjusting the number of installed units and capacity, it is possible to cope with the size and production volume of the sulfur solidified product.

  Sulfur solidified material prevents the elution of heavy metals and other harmful substances by fully dissolving molten sulfur in the crystalline phase of the material mixed with molten sulfur by utilizing the solid solution phenomenon at low temperature, which is a characteristic of sulfur. At the same time, since high strength can be obtained, it is required that molten sulfur be surely infiltrated into the pores, which are voids in the solid phase of the material. In this case, if the variation of the specific surface area of the material mixed with the molten sulfur is large, the molten sulfur is easily consumed by a fine material or a porous material having a large specific surface area. Since there is a possibility that it may not be sufficiently distributed, a uniform solid solution may not be obtained.

  According to the method for producing a sulfur solidified body of the present embodiment, in each quantitative feeder 41, 42, 43, molten sulfur is individually mixed with incineration ash, fine aggregate, and coarse aggregate to generate a mixture. Therefore, each material having the same specific surface area can be brought into contact with molten sulfur to form a uniform solid solution in a short time. And since these mixtures are heated and kneaded in each of the extruders 50 to 54 and pressurized, and the compressed mixture is discharged, the molten sulfur can be surely permeated into the pores, with high strength. It is possible to continuously produce a sulfur solidified body that can reliably suppress the elution of harmful substances.

  As mentioned above, although one Embodiment of this invention was explained in full detail, the specific aspect of this invention is not limited to the said embodiment. For example, in this embodiment, incineration ash, fine aggregate, and coarse aggregate are individually mixed with molten sulfur in each of the quantitative feeders 41, 42, 43, and then merged in the mixing hopper 46 before each extruder. 50 to 54, but it is also possible to directly supply each of the quantitative feeders 41, 42, 43 to the extruder, and each mixture may be mixed (kneaded) inside the extruder. .

  In this embodiment, the material mixed with the molten sulfur is incinerated ash, fine aggregate, and coarse aggregate. However, the fine aggregate and coarse aggregate are separately melted sulfur without using the incinerated ash. You may make it mix with. Or you may make it mix incinerated ash and aggregate separately with molten sulfur, without distinguishing a fine aggregate and a coarse aggregate.

13 Incinerated Ash Storage 22 Fine Aggregate Storage 32 Coarse Aggregate Storage 40 Molten Sulfur Tank 41, 42, 43 Fixed Feeder
49 Metering pump 50 Extruder

Claims (3)

A mixing step of mixing molten sulfur with incineration ash, fine aggregate and coarse aggregate;
A compression step of heating and kneading and pressurizing the mixture produced in the mixing step in an extruder and discharging the compressed mixture;
In the mixing step, the incinerated ash, fine aggregate, and coarse aggregate are individually mixed with molten sulfur and then supplied to the extruder. A mixing step of mixing molten sulfur with incineration ash and aggregate;
A compression step of heating and kneading and pressurizing the mixture produced in the mixing step in an extruder and discharging the compressed mixture;
In the mixing step, the incinerated ash and the aggregate are individually mixed with molten sulfur and then supplied to the extruder. A mixing step of mixing molten sulfur with fine and coarse aggregates;
A compression step of heating and kneading and pressurizing the mixture produced in the mixing step in an extruder and discharging the compressed mixture;
In the mixing step, the fine aggregate and the coarse aggregate are individually mixed with molten sulfur and then supplied to the extruder.

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