JP2011173031A - Method of treating board base paper with stuck plaster - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of treating board base paper with stuck plaster, wherein board base paper with very little plaster can be recovered by dry treatment in a method of treating board base paper with stuck plaster generated in treating waste plasterboards. <P>SOLUTION: When plaster of board base paper 2 with stuck plaster is dry-crushed, and the plaster is isolated from the board base paper to recover the board base paper 5, crushing is performed while plaster fragments 4 isolated from the board base paper by the dry-crushing are removed from a crushing region. To be concrete, the dry crushing is performed on a screen 1 having the meshes through which the isolated plaster fragments can pass through, while the plaster fragments 4 isolated through the screen 1 are removed from the crushing region. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a board base paper with gypsum capable of recovering board base paper with very little gypsum adhesion by a dry process in a method of processing board base paper to which gypsum generated when processing gypsum board waste is treated The processing method is provided.

  The amount of gypsum board waste generated is about 1.5 million tons per year. Of this, about 500,000 tons are scraps from new interior construction work at the time of production and houses, and the gypsum board manufacturer recycles them. The remaining 1 million tons are discharged by land renovation and demolition work for buildings such as houses. The amount of such gypsum board waste generated tends to increase year by year, and an effective treatment method for gypsum board waste is required from the viewpoint of lack of landfill and environmental problems.

  In order to effectively recycle gypsum board waste, it is necessary to separate gypsum and board base paper. Such separation is performed by dry crushing the gypsum board. At this time, a board base paper to which gypsum is adhered is obtained together with a crushed material of only gypsum. The board base paper to which the gypsum adheres generally has gypsum of substantially the same weight as the board base paper. For this reason, it is difficult to recycle the board base paper as waste paper. Also, the gypsum adhering to the board base paper has the fine crystals of the gypsum intertwined with the fibers of the board base paper. For this reason, it was very difficult to separate the gypsum from the board base paper.

  As a method for obtaining the board base paper from which the gypsum has been removed from the board base paper to which the gypsum has adhered, the waste material of the gypsum board in which the gypsum board base paper has adhered to at least a part of the gypsum core is heated, and then water is applied. A method of separating gypsum board base paper from the gypsum core and recovering the separated gypsum board base paper and gypsum constituting the gypsum core has been proposed (see Patent Document 1).

  However, when the wet cleaning treatment is performed in this way, the amount of water used is large, and the usage application of the fine slurry of dihydrate gypsum generated thereby is very limited. On the other hand, in order to obtain a dihydrate gypsum powder by filtering this, an expensive filter such as a filter press is required. In addition, in this treatment method, a baking treatment for once converting gypsum into hemihydrate gypsum is necessary, which increases energy costs and increases equipment.

Japanese Patent No. 3221939

  Accordingly, an object of the present invention is to separate the adhering gypsum from the board base paper while solving the problems caused by using water in the method of recovering the board base paper from the board base paper to which the gypsum has adhered by the wet method. An object of the present invention is to provide a processing method that can be sufficiently performed.

  The inventors of the present invention have made extensive studies to achieve the above object. As a result, a method of dry crushing gypsum of board base paper with gypsum adhered without using water is adopted, and in this dry crushing, gypsum fragments (powder) released from the board base paper by crushing are removed from the crushing area. It was found that the board base paper and gypsum can be efficiently separated by crushing while removing, and the present invention has been completed.

  That is, according to the present invention, the gypsum of the board base paper to which the gypsum adheres is dry crushed, and when the gypsum is released from the board base paper and the board base paper is recovered, the gypsum crush pieces released from the board base paper by the dry crushing are crushed. A board base paper recovery method characterized by crushing while removing from an area.

  In the present invention, the board base paper to which gypsum is adhered is generally obtained by crushing gypsum board waste and separating the crushed material mainly composed of gypsum.

  Also, dry crushing of gypsum on board base paper to which gypsum has adhered is performed on a screen having an opening through which the free gypsum fragments can pass, and the free gypsum fragments are removed through the screen. The embodiment to be performed is preferable.

  Furthermore, in the embodiment using the above screen, a method of rotating a drum type screen obtained by processing the screen into a cylindrical shape and supplying a crushing medium and board base paper to which gypsum adheres to the inside to dry crushing is preferable. It is.

  According to the method of the present invention, it is possible to efficiently recover board base paper with little gypsum adhesion and gypsum fragments from gypsum board waste. Therefore, the board base paper collected in the present invention can be used effectively as waste paper, and does not use water and does not undergo heat treatment, so that the energy and equipment cost in the collection processing are significantly reduced. Is possible.

  The expression mechanism of the above effect is estimated as follows. That is, when dry crushing of board base paper to which gypsum adheres is performed with a general crushing machine such as a ball mill, the gypsum crushing pieces released by crushing remain in the crushing machine without being removed from the board base paper. Therefore, if crushing is continued, the shredded pieces are further refined and buried between the fibers of the board base paper, which makes separation difficult. On the other hand, in the processing method of the present invention, the crushed pieces generated by dry crushing are immediately removed and isolated from the board base paper, so that the gypsum crushed pieces are refined and between the fibers of the board base paper. It is presumed to be due to the effective prevention of the burial of

Schematic which shows the one aspect | mode of the apparatus for enforcing the processing method of this invention, and its usage example Schematic which shows another one aspect | mode of the apparatus for enforcing the processing method of this invention, and its usage example

  In the present invention, the origin of the board base paper to which the gypsum to be treated is attached is not particularly limited as long as the attached gypsum can be dry-crushed. In general, dry crushing of gypsum board waste such as gypsum board produced as a waste material in the gypsum board production process, construction site enforcement process, gypsum board as a residual material, and gypsum board generated as a construction waste material in renovation and demolition work And those obtained by separating a crushed material mainly composed of gypsum.

  Of course, the gypsum board waste material itself is a board base paper to which gypsum is attached, and can be directly processed. However, in order to improve the efficiency of the processing, the gypsum board waste material adheres to the board base paper through the preceding steps. After reducing the gypsum as much as possible, it is preferably subjected to the treatment of the present invention.

  It is preferable to remove the gypsum by the pulverization so that the amount of gypsum attached to the board base paper is 60% by weight or less based on the total weight of the board base paper to which the gypsum is attached.

  Further, in the present invention, the size of the board base paper to which the gypsum is attached is not particularly limited, but when the crushing treatment is performed, the size is generally 10 to 200 mm in the longitudinal direction. This size is also preferred in subsequent processing.

  In the present invention, when the gypsum of the board base paper to which the gypsum adheres is dry-crushed to release the gypsum from the board base paper and collect the board base paper, the gypsum crush pieces released from the board base paper by the dry crushing are removed from the crushing region. It is characterized by crushing while removing.

  Here, it is preferable that the removal of the crushed pieces of gypsum released from the board base paper from the pulverized region is performed as soon as possible after the gypsum is released from the board base paper as a crushed piece by dry crushing. By this operation, the crushed pieces stay in the pulverization region, whereby the pulverization proceeds, and the phenomenon that the pulverized crushed pieces are buried in the board base paper and difficult to remove can be effectively prevented.

  In the present invention, a known method is used as the dry crushing method without any particular limitation. For example, a board base paper to which gypsum adheres is generally stirred together with a grinding medium, and a board base paper to which gypsum adheres is stirred by a stirring blade (paddle).

  In the embodiment using the grinding medium which is one embodiment described above, the grinding medium has an abrasion resistance enough to grind the gypsum by contact with the gypsum adhering to the board base paper of the board base paper to which the gypsum has adhered. The type, size, and shape may be determined as appropriate depending on the structure of the device to be used. Typically, the types of the grinding media include carbon steel, stainless steel, alumina, zirconia, silicon carbide, and the like. Natural minerals can also be used. Examples of such natural minerals include hard sandstone and natural gypsum that are generally used as coarse aggregates of concrete. When the pulverized product of natural gypsum is used as a pulverizing medium, it is possible to prevent foreign matters from being mixed due to wear of the pulverizing medium. As the gypsum used as the grinding medium, natural dihydrate gypsum or anhydrous gypsum large crystals, which are appropriately crushed, are commercially available.

  The size of the grinding medium is preferably 10 to 100 mm, more preferably 20 to 50 mm, in order to efficiently grind and separate gypsum from the base paper with gypsum. Further, the shape is not particularly limited, such as a spherical shape, a saddle shape, and an indeterminate shape, and a single shape or a plurality of types can be combined and used as a grinding medium.

  The amount of the grinding medium used in the present invention is not particularly limited. What is necessary is just to adjust suitably according to the kind of grinding medium to be used. In terms of efficiency, the treatment is preferably performed in an amount of 5 to 30 times by weight, and further 10 to 20 times by weight with respect to the mass of the base paper with gypsum.

  On the other hand, in the method of stirring the board base paper to which gypsum adheres with the stirring blade (paddle), the stirring blade is shaped, sized, and further considering the size and processing amount of the apparatus, and further the crushing efficiency, The rotational speed during operation is determined.

  In the present invention, while performing the dry crushing, there is no particular limitation on the method for removing the gypsum fragments released by crushing from the crushing region, but as a method of performing the most efficient separation, the dry crushing, It is preferable to carry out on a screen having an opening through which a crushed piece of plaster liberated by crushing (mostly a powdery body having a particle size of 1 mm or less) can pass. According to such an aspect, the crushed pieces generated by the pulverization are selectively removed by passing through the screen, and a state in which almost no crushed pieces, particularly fine powders that can pass through the screen, are maintained on the screen.

  In the present invention, the opening size of the screen is preferably 0.5 to 5 mm, more preferably 1 to 3 mm.

  In the present invention, the above-described treatment by dry crushing may be performed either batchwise or continuously.

  Hereinafter, the present invention will be described more specifically with reference to FIGS. 1 and 2 showing typical apparatuses used in the recovery method of the present invention and examples of their use.

  In FIG. 1, a drum-type screen processed into a cylindrical shape is used as the screen 1, and the crushing medium 3 and the board base paper 2 on which gypsum adheres are supplied to the inside while rotating the screen to dry-crush it. The mode which performs is shown. In the drawing, the circle displayed on the right side is a side sectional view of the drum.

  In the figure, the board base paper 2 to which gypsum adheres is supplied into a crushing region, that is, a rotating drum type screen, where it is stirred together with the crushing medium 3 to crush the adhering gypsum. The gypsum fragments 4 released by the crushing are sequentially taken out through the screen 1.

  In the above embodiment, the pulverizing medium 3 may be charged in the drum-type screen 1 or supplied together with the board base paper to which gypsum is adhered. Further, when the board base paper 5 and the grinding medium 3 after dry grinding are taken out together, they can be sorted by an appropriate sorting means, for example, a method such as wind selection based on a difference in specific gravity. Further, if the grinding medium is a magnetic metal such as iron, it may be separated by a magnetic separator. Further, as shown in FIG. 1, the sorted grinding medium 3 may be circulated to the crushing area and reused.

  In the above embodiment, an example in which a rotating drum type screen is used has been shown. However, as shown in FIG. 2, the drum type screen 1 does not rotate, and the bottom of the drum type screen is arranged in the longitudinal direction. Using a device equipped with an extended stirring blade (huddle) 6, the board base paper 2 with gypsum adhered in the drum type screen is supplied and stirred by the stirring blade 6, and thus the board base paper is attached. It is also possible to crush the plaster. The gypsum fragments 4 released by the crushing are sequentially taken out through the screen 1.

  EXAMPLES Hereinafter, examples will be shown to describe the present invention more specifically, but the present invention is not limited to these examples.

  In the following examples and comparative examples, the amount of gypsum adhering to the board base paper was determined by the following method.

  First, the base paper with gypsum was immersed in a sufficient amount of an aqueous solution of sodium hydroxide to react with gypsum adhering to the paper and stirred for 10 minutes or more. Thereafter, this was filtered and washed, and the amount of gypsum adhering to the board base paper was determined by converting the amount of dissolved sulfur in the filtrate and the washing liquid into dihydrate gypsum.

  Moreover, the production method and specifications of the board base paper to which the gypsum used in the experiment is attached are as follows.

  After crushing gypsum board waste using a jaw crusher, it was separated from gypsum powder with a sieve, and a base paper with gypsum having a size of about 50 to 100 mm was collected. The amount of gypsum of this board base paper with gypsum was 60%.

Example 1
As shown in FIG. 1, 10 kg of anhydrous gypsum screened to a size of 20 to 40 mm as a grinding medium 3 is put into a rotating drum type screen 1 having an opening of 3 mm, a diameter of 300 mm and a length of 600 mm, and this is rotated. While operating at several 50 rpm, the board base paper 2 to which gypsum adhered was introduced at a speed of 200 g / h. Anhydrous gypsum, which is the grinding medium 2 discharged from the screen, was separated from the board base paper that came out together by wind separation and then re-introduced into the screen as needed. The operating condition of the screen was set so as to adjust the residence time of the board base paper to 1 hour, and the discharged board base paper was analyzed. As a result, the amount of gypsum adhered was 2%.

Example 2
In Example 1, batch operation was performed. That is, 500 g of board base paper to which gypsum is adhered and 5 kg of hard sandstone having a size of 15 to 20 mm, which is a pulverizing medium 3, are placed in the cylindrical screen and capped, and then 1 at 50 rpm. Stir for hours. Meanwhile, the plaster pieces were discharged out of the cylindrical screen. The weight of the board base paper recovered by separating the grinding media from the cylindrical screen was 450 g, and the amount of gypsum deposited was 1%.

Example 3
As shown in FIG. 2, a stirring blade having a blade diameter of 50 mm, in which a screen having an aperture of 0.5 mm is processed into a cylindrical shape having a diameter of 100 mm and a length of 200 mm, and six stainless steel plates of 10 mm × 16 mm × 1 mmt are arranged. Sixteen stirring blades 6 attached were arranged at the bottom of a cylindrical screen. 10 g of board base paper 2 to which gypsum was adhered was introduced, and both sides of this cylindrical screen were covered. The stirring blade 6 was rotated at a rotation speed of 1200 rpm for 1 minute. Meanwhile, the plaster pieces were discharged out of the cylindrical screen. The weight of the board base paper remaining in the screen after operation was 3.4 g, and the amount of gypsum adhered was 0.5%.

Comparative Example 1
10 g of board base paper to which gypsum adhered was put into a rotary cutter mill having an internal volume of 1 liter. The rotary cutter was operated for 5 minutes at a rotational speed of 1000 rpm. The whole amount was taken out from the mill and sieved with a vibration sieve having an opening of 1 mm. The amount of gypsum attached to the collected board base paper was 23%.
Comparative Example 2 500 g of board base paper to which gypsum was adhered and 5 kg of hard sandstone sieved to a size of 15 to 20 mm were put into a 400 mm diameter, 400 mm long, rotating drum type mill, and mixed and stirred at a rotation speed of 40 rpm for 2 hours. did. The whole amount was taken out from the mill and sieved with a vibrating screen having an opening of 3 mm. The collected amount of gypsum on the board base paper was 21%.

DESCRIPTION OF SYMBOLS 1 Screen 2 Board base paper to which gypsum adhered 3 Grinding medium 4 Gypsum fragment 5 Collected board base paper 6 Stirring blade

Claims (4)

When the gypsum of the board base paper to which the gypsum has adhered is dry-crushed and the gypsum is released from the board base paper to collect the board base paper, it is crushed while removing the gypsum fragments released from the board base paper by the dry crushing from the crushing area. A method for collecting board base paper. 2. The method for recovering board base paper according to claim 1, wherein the board base paper to which gypsum adheres is obtained by crushing gypsum board waste and separating crushed material mainly composed of gypsum. The dry crushing of the gypsum of the board base paper to which the gypsum is adhered is performed on a screen having an opening through which the free gypsum fragments can pass, and the free gypsum fragments are removed through the screen. 3. A method for collecting board base paper according to 1 or 2. 4. The board base paper collecting method according to claim 3, wherein the screen is constituted by a rotary drum type screen, and dry crushing is performed by supplying the board base paper to which the grinding medium and gypsum adhere to the rotary drum type screen.

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