JP3708528B2 - Floss processing method and method for producing recycled paper raw material from waste paper - Google Patents

Description

【００３９】
デフレーキングを行うと、実施例１から実施例５のように、ろ水の白色度が高くなるとともに、フロスの白色度が低くなった。したがって、デフレーキングを行うとフローテーション効果（脱墨効果）が向上することがわかる。
【００４０】
また、デフレーキング処理量を２０ｍ³／ｈｒとした場合（実施例３）は、デフレーキング処理量を３５ｍ³／ｈｒとした場合（実施例２）より、ろ水の白色度が低くなり、フロスの白色度が高くなった。これは、フロス中の繊維分が微細化され、フロス側に移動してしまうためであると、考えられる。したがって、デフレーキングの単位時間当たりの処理量は、少なすぎると好ましくないことがわかる。なお、本実施例においては、デフレーキング処理量が３５ｍ³／ｈｒ以上であると、好ましかったが、これは、実験室レベルでのものであるため、現実の操業においては、適宜設定することが必要である。
【００４１】
さらに、デフレーキング濃度を向上させた場合（実施例４及び実施例５）は、ろ水の白色度が向上した。したがって、デフレーキングに先立って、フロスを濃縮すると好ましいことがわかる。
【００４２】
また、実施例１から５に示されるように、ろ水中にも多くの灰分が残ることがわかる。したがって、この灰分の回収・利用は、大変有用であることがわかる。
【００４３】
【発明の効果】
以上のとおり、本発明によれば、オゾン等の薬剤を使用することなく繊維分及び灰分の白色度を高くすることができ、もって再生紙原料の歩留りを高くすることができるフロスの処理方法及び古紙から再生紙原料を製造する方法となる。
【図面の簡単な説明】
【図１】第１の実施の形態に係るフロスの処理方法を示すフロー図である。
【図２】第２の実施の形態に係るフロスの処理方法を示すフロー図である。
【符号の説明】
１，４…フローテーター、２…濃縮手段、３…デフレーキング手段、５…フロスの処理工程、１１〜１４…移送路、Ｆ…フロス、Ｒ…ろ水。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for treating froth and a method for producing a recycled paper raw material containing waste paper pulp and filler from waste paper. More specifically, the present invention relates to one that uses floss generated when flotation of disaggregated pulp obtained by disaggregating waste paper.
[0002]
[Prior art]
In producing recycled paper raw material from waste paper, generally, the pulp that has been obtained by disaggregating the waste paper is floated and deinked. As is well known, in the production of such recycled paper raw material, it is desired that (1) the recycled paper raw material obtained has high whiteness and (2) the yield of recycled paper raw material is high.
[0003]
Of these, the former (1) has been sought to improve the flotation effect, and various methods such as a method using a flocculant such as a protein and a method of developing and improving a deinking agent are now available. (For example, see Patent Document 1, Patent Document 2, Patent Document 3, Patent Document 4, Patent Document 5, Patent Document 6, and Patent Document 7).
[0004]
However, regarding the latter (2), no consideration is given, but the floss generated during flotation is out of the system even though the floss contains fibers and ash. It was common to release to This is because such a floss has a low concentration of 3 to 5% by mass, a whiteness of around 50%, or as low as 50% or less, and an ink content adhering to fibers and ash is 5 to 100 μm This is because, since it is fine, the flotation effect is extremely low, and the productivity is too low to recover the fiber and ash with high whiteness.
In this respect, the fact that the fiber and ash in the floss can be reused is disclosed in, for example, Patent Document 8, but it does not show how to make it usable.
[0005]
However, the applicant has long recognized the importance of the fiber content in the floss. Specifically, the floss is bleached with ozone gas, and the fiber content in the floss is recovered and used as waste paper pulp. Is disclosed (Patent Document 9).
[0006]
[Patent Document 1]
JP-A-10-273890 [Patent Document 2]
Japanese Patent Laid-Open No. 2001-271284 [Patent Document 3]
Japanese Patent Laid-Open No. 11-1883 [Patent Document 4]
JP 2000-282383 A [Patent Document 5]
JP-A-9-49179 [Patent Document 6]
JP-A-8-60575 [Patent Document 7]
JP-A-9-78480 [Patent Document 8]
JP 2002-285484 A [Patent Document 9]
JP 2002-155383 A
[Problems to be solved by the invention]
According to the ozone bleaching method of the floss, the whiteness of the fiber content in the floss can be increased, so that the fiber content can be recovered and used as waste paper pulp. Therefore, it is considered to be very useful that the yield of waste paper pulp can be increased.
[0008]
However, depending on the method, the whiteness of ash cannot be increased, and since the method uses a chemical such as ozone, the fiber content can be reduced without using a chemical such as ozone. In addition, it was sought whether the whiteness of ash could not be increased.
[0009]
Thus, the main problem of the present invention is that the whiteness of fibers and ash can be increased without using a chemical such as ozone, and the yield of recycled paper raw materials can be increased, and the waste paper can be used. Another object of the present invention is to provide a method for producing a recycled paper raw material.
[0010]
[Means for Solving the Problems]
The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
A method for treating floss generated by flotation of disaggregated pulp obtained by disaggregating waste paper,
Defrosting the floss and then flotating again.
[0011]
(Function and effect)
When flakes are deflaked, friction occurs in the fiber, ash, fiber and ash in the floss, and fine ink adhering to the fiber and ash is released and peeled off. The surface is rubbed and the adhering ink is kneaded away.) Therefore, if the flakes are deflaked prior to re-floating the floss as in the present invention, the flotation effect is remarkably improved, and high whiteness fibers and ash can be recovered. This effect can be achieved without using any medicine.
[0012]
<Invention of Claim 2>
A method for treating floss generated by flotation of disaggregated pulp obtained by disaggregating waste paper,
The froth processing method, wherein the froth is concentrated, deflaked, and then floated again.
[0013]
(Function and effect)
When the floss is deflaked, as described above, the ink adhering to the fiber and ash is liberated and peeled off. However, if the concentration of floss is low, the fiber and ash become floating in the water, so the friction between the fiber, ash, fiber and ash becomes small, and the ink is separated and peeled off. Small effect. Therefore, the present invention concentrates the floss prior to deflaking, thereby increasing the above friction.
[0014]
<Invention of Claim 3>
A method for producing recycled paper raw material containing waste paper pulp and filler from waste paper,
Floss generated when flotation of disaggregated pulp obtained by disaggregating waste paper is deflaked and then floated again, and fiber and ash are recovered as the waste paper pulp or the filler, respectively. A method for producing waste paper pulp.
[0015]
(Function and effect)
Since the fiber content and the ash content contained in the floss are respectively recovered as used paper pulp or filler, the yield of recycled paper raw material is increased. In addition, since such recycled paper raw material is obtained by de-flaking and then flotation again, the whiteness is high. Therefore, the obtained recycled paper raw material has high whiteness.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
[First Embodiment]
In the “method for producing recycled paper raw material from used paper” according to the present embodiment, first, the used paper is disaggregated by a disaggregating means such as a pulper. The kind of used paper that can be used in this case is not particularly limited. For example, from newspapers, such as offset printing newspapers, letterpress printing newspapers, etc., coated flyers, non-coated flyers, flyers, magazines, books, office paper, etc. You can use waste paper that is put out as garbage. In the present invention, the recycled paper raw material means a material containing a filler in addition to waste paper pulp. However, the content of the filler is not limited to an appropriate amount for the recycled paper. Including those that are slightly contained.
[0017]
The disaggregated pulp obtained by disaggregating used paper can be sent to a dust removing means such as a screen to remove contained foreign matters.
[0018]
The disaggregated pulp from which the foreign matter has been removed is sent to the flotator 1 and flotated as shown in FIG. The floss F pressurized and floated by this flotation is transferred to the deflaking means 3 via the transfer path 11 such as a tube, and the filtrate R (dissolved pulp) obtained by flow tension is transferred to the transfer path 12. To the bleaching process.
[0019]
The floss F sent to the deflaking means 3 is deflaked. In the present invention, deflaking refers to a process of kneading floss mechanically. As the deflaking means 3, for example, a deflaker (for example, a super deflaker of Shingen Machinery Co., Ltd.), a kneader, a disperser, or the like can be used. However, since the kneader and the disperser are suitable for a high concentration of floss concentration exceeding 5 mass%, a deflaker is used in the present embodiment.
[0020]
Due to the above deflaking, the fine ink adhering to the fiber and ash in the floss is released and peeled off. Also, the release and peeling of ink by deflaking due to the effect of alkali and other chemicals used for the purpose of promoting disaggregation with a pulper in the previous stage of the previous flotation, and improving foamability in the flotation The effect is significantly improved.
[0021]
The time of deflaking is not particularly limited, and an effect can be obtained if it is performed instantaneously. However, if the deflaking time is too long, the fiber content in the floss will become finer, and in the second flotation, the fiber content will adhere to the bubbles and flow out to the floss side, and the yield of used paper pulp will be sufficient. May not rise. Therefore, it is preferable to appropriately set the deflaking time from the viewpoint of harmony between the improvement in whiteness and the prevention of fiber fineness in consideration of the strength of the fiber. The deflaking time can be, for example, 1 second, 5 seconds, 10 seconds, 15 seconds to less than 1 minute, less than 3 minutes, less than 5 minutes, less than 10 minutes, and the like. The processing amount per unit time can be 10 m ³ / hr or more, 15 m ³ / hr or more, 20 m ³ / hr or more, 30 m ³ / hr or more.
[0022]
The floss F deflaked by the deflaking means 3 is further sent to the flowator 4 via the transfer path 13 and again floated. The filtrate obtained by this flotation and the filtered water containing the ash adhering thereto are mixed into the filtered water in the previous transfer path 12 via the transfer path 14, and are sent to the bleaching process. As a result, the yield of recycled paper raw materials including waste paper pulp (fiber content) and filler (ash content) is increased (of course, filtered water containing fiber content and ash content obtained by flotation is transferred via the transfer path 14). (Yield can be increased by treating and using separately without mixing into the filtered water in the road 12). According to the experiment conducted by the present inventors, when 530 t / day of disintegrated pulp was floated, 180 t / day of floss was generated (conventionally, this floss was discharged to the outside of the system). It was found that 45 t / day was available when the treatment of the present invention was applied, and the yield of waste paper pulp was significantly increased. B. in the figure. R indicates the whiteness (%) based on JIS P 8123, and 45 t / day filtered water that has become available showed a high whiteness of 67%.
[0023]
In addition, during the above flotation, the deinked ash is accumulated at the bottom of the floatator 4. Therefore, it is preferable that this ash is also collected and reused.
[0024]
On the other hand, the disaggregated pulp from the flowator 1 and the disaggregated pulp from the flowator 4 sent to the bleaching step are, for example, hydrogen peroxide, FAS (formamidine sulfonic acid), hydrosulfite (sodium hydrosulfite, hydrosulfite). Bleached with zinc sulfite, hypo (sodium hypochlorite), chlorine dioxide, etc., and used as recycled paper raw material pulp.
[0025]
The recycled paper raw material containing the waste paper pulp (fiber content) and filler (ash content) obtained as described above can be adjusted by adding fillers as appropriate, and then papermaking can be made into recycled paper. As such an additional filler, it is preferable to use the ash previously collected in the floater 4.
[0026]
In the present invention, there is a feature in the method for treating the floss generated in the flowator, and the presence or absence of other steps, the method, etc. are not particularly limited. A known facility can be provided and processed as appropriate.
[0027]
[Second Embodiment]
Next, a second embodiment of the “method for producing recycled paper raw material from waste paper” according to the present invention will be described.
As shown in FIG. 2, the “method for producing waste paper pulp from waste paper” according to the present embodiment basically includes the same steps as those in the first embodiment. That is, firstly, the disaggregated pulp obtained by disaggregating waste paper and removing dust as appropriate is sent to the flotator 1 for flotation. And the filtrate R (disaggregated pulp) obtained by this flotation is subjected to the bleaching step through the transfer path 12, while the floss F that has been floated under pressure is deinked in the floss treatment step 5, Then, it mixes with the filtered water in the transfer path 12, and sends to a bleaching process.
[0028]
However, in the present embodiment, the floss processing step 5 has a feature different from that of the first embodiment. That is, the froth processing step 5 of the present embodiment is provided with a concentrating means 2 for concentrating the floss F generated in the flowator 1. In the concentrating means 2, the floss F is dehydrated and the concentration of the fiber is improved. The concentration of froth F before concentration is usually 3 to 5% by mass, and is more than 5% by mass, preferably 10% by mass or more, and more preferably 20 to 30% by mass. . When the concentration of the floss after concentration is 10% by mass or more, the release / peeling effect of the ink adhering to the fiber and ash due to friction in the fiber, ash, fiber and ash is markedly excellent. Become. On the other hand, when the concentration of the floss after concentration is 30% by mass or less, the load of deflaking does not increase, and the ink component released or separated by deflaking does not have the possibility of reattaching to the fiber component.
[0029]
The type of the concentration means 2 is not particularly limited. For example, a centrifuge or a decanter can be used. In FIG. 2, 11 is a transfer path for sending the froth F generated in the floatator 1 to the concentrating means 2, and 12 is the floss F concentrated by the concentrating means 2 to the deflaking means 3. This is a transfer path. In the case where the concentrating means 2 is provided, in the present embodiment, the concentration of the fiber is about 1% by mass in the middle of the transfer path 13 before the flotation is performed again by the floatator 4. It is preferable to dilute as described above.
[0030]
[Other forms]
As described above, in the first embodiment and the second embodiment, the mode in which the deflaking is performed only once has been described. However, the present invention is not limited to this. An appropriate number of times can be performed, such as two times, three times, four times, or more. Also in this case, the concentration of floss is not limited at all. The concentration may be any of low concentration, medium concentration, and high concentration.
[0031]
【Example】
Examples of the present invention will be described below.
In this embodiment, magazine waste paper was used as the target waste paper. Conventionally, most magazine paper has been incinerated or landfilled for reasons such as difficulty in deinking and low yield.
[0032]
The magazine waste paper was disaggregated and dedusted to obtain disaggregated pulp, and then floated in a flotator (magazine waste paper deinking treatment facility). The floss generated during the flotation was subjected to the following treatment. In addition, the density | concentration of the fiber part of a floss was 3 mass%.
[0033]
[Examples 1-3]
Floose sampled at 500 m ³ , deflaked with a deflaker at a concentration of 3% by mass, diluted to 1% by mass, and then flotated for 10 minutes at a flow rate of 180 l / hr with a laboratory flowmeter. did. The amount of deflaking was changed to 40 m ³ / hr, 35 m ³ / hr, or 20 m ³ / hr.
[0034]
Example 4
Floss was sampled at 500 m ³ , concentrated to a concentration of 10% by mass, and then deflaked with a PFI mill having a mill clearance of 0.1 mm. Others were the same as in Example 2.
[0035]
Example 5
A froth of 500 m ³ was sampled and concentrated to a concentration of 30% by mass.
Others were the same as in Example 4.
[0036]
[Comparative example]
When no treatment was performed (state immediately after the first flotation) as Comparative Example 1, deflaking was not performed, and only flotation was performed again as Comparative Example 2. Concentration to 10% by mass, no treatment, and subsequent dilution to a concentration of 1% by mass followed by re-flotation were performed as Comparative Example 3 for comparison.
[0037]
〔Evaluation item〕
Table 1 shows the amount of floss, the proportion of ash, and the whiteness after the second flotation. In addition, the ratio of ash was measured about each of drainage and floss.
Moreover, the whiteness was measured based on JIS P 8123 for each of drainage and floss. Furthermore, for Comparative Example 1, only the whiteness in the same state was measured.
[0038]
[Table 1]

[0039]
When deflaking was performed, the whiteness of the filtrate increased and the whiteness of the floss decreased as in Examples 1 to 5. Therefore, it can be seen that the flotation effect (deinking effect) is improved by performing deflaking.
[0040]
Further, when the deflaking amount is 20 m ³ / hr (Example 3), the whiteness of the filtrate is lower than when the deflaking amount is 35 m ³ / hr (Example 2), and the froth is reduced. The whiteness of became higher. This is considered to be because the fiber content in the floss is refined and moves to the floss side. Therefore, it can be seen that it is not preferable that the amount of processing per unit time of deflaking is too small. In this example, it was preferable that the amount of deflaking was 35 m ³ / hr or more. However, since this is at the laboratory level, it is appropriately set in actual operation. It is necessary.
[0041]
Further, when the deflaking concentration was improved (Example 4 and Example 5), the whiteness of the filtrate was improved. Therefore, it can be seen that it is preferable to concentrate the floss prior to deflaking.
[0042]
Further, as shown in Examples 1 to 5, it can be seen that much ash remains in the filtrate. Therefore, it can be seen that the recovery and use of this ash is very useful.
[0043]
【The invention's effect】
As described above, according to the present invention, it is possible to increase the whiteness of the fiber and ash without using a chemical such as ozone, and thus to increase the yield of recycled paper raw material, This is a method for producing recycled paper raw material from waste paper.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a floss processing method according to a first embodiment;
FIG. 2 is a flowchart showing a floss processing method according to a second embodiment;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1,4 ... Flotator, 2 ... Concentration means, 3 ... Deflaking means, 5 ... Processing process of floss, 11-14 ... Transfer path, F ... Floss, R ... Filtration water.

Claims (3)

A method for treating floss generated by flotation of disaggregated pulp obtained by disaggregating waste paper,
A flossing method, comprising: defloking the floss and then flotating again. A method for treating floss generated by flotation of disaggregated pulp obtained by disaggregating waste paper,
The froth processing method, wherein the froth is concentrated, deflaked, and then flotated again. A method for producing recycled paper raw material containing waste paper pulp and filler from waste paper,
Floss generated when flotation of disaggregated pulp obtained by disaggregating waste paper is deflaked and then floated again to collect fiber and ash as the waste paper pulp or the filler, respectively. A method for producing waste paper pulp.

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