JPH0585676B2 - - Google Patents
Info
- Publication number
- JPH0585676B2 JPH0585676B2 JP19205687A JP19205687A JPH0585676B2 JP H0585676 B2 JPH0585676 B2 JP H0585676B2 JP 19205687 A JP19205687 A JP 19205687A JP 19205687 A JP19205687 A JP 19205687A JP H0585676 B2 JPH0585676 B2 JP H0585676B2
- Authority
- JP
- Japan
- Prior art keywords
- bleaching
- waste paper
- paper pulp
- pulp
- bisulfite
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 238000004061 bleaching Methods 0.000 claims description 37
- 239000010893 paper waste Substances 0.000 claims description 33
- 229920001131 Pulp (paper) Polymers 0.000 claims description 30
- 238000000034 method Methods 0.000 claims description 15
- 239000011734 sodium Substances 0.000 claims description 13
- 150000002978 peroxides Chemical class 0.000 claims description 12
- GEHJYWRUCIMESM-UHFFFAOYSA-L sodium sulfite Chemical compound [Na+].[Na+].[O-]S([O-])=O GEHJYWRUCIMESM-UHFFFAOYSA-L 0.000 claims description 12
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 10
- 238000006477 desulfuration reaction Methods 0.000 claims description 10
- 230000023556 desulfurization Effects 0.000 claims description 10
- 239000003546 flue gas Substances 0.000 claims description 10
- 239000000203 mixture Substances 0.000 claims description 7
- DWAQJAXMDSEUJJ-UHFFFAOYSA-M Sodium bisulfite Chemical compound [Na+].OS([O-])=O DWAQJAXMDSEUJJ-UHFFFAOYSA-M 0.000 claims description 6
- 235000010267 sodium hydrogen sulphite Nutrition 0.000 claims description 6
- 235000010265 sodium sulphite Nutrition 0.000 claims description 6
- 239000013055 pulp slurry Substances 0.000 claims 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-M Bisulfite Chemical compound OS([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-M 0.000 description 18
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 15
- 239000007844 bleaching agent Substances 0.000 description 8
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 6
- 238000007796 conventional method Methods 0.000 description 4
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical compound OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- JVBXVOWTABLYPX-UHFFFAOYSA-L sodium dithionite Chemical compound [Na+].[Na+].[O-]S(=O)S([O-])=O JVBXVOWTABLYPX-UHFFFAOYSA-L 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 230000002087 whitening effect Effects 0.000 description 3
- KFSLWBXXFJQRDL-UHFFFAOYSA-N Peracetic acid Chemical compound CC(=O)OO KFSLWBXXFJQRDL-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- XQIMLPCOVYNASM-UHFFFAOYSA-N borole Chemical compound B1C=CC=C1 XQIMLPCOVYNASM-UHFFFAOYSA-N 0.000 description 2
- 239000003638 chemical reducing agent Substances 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 239000002761 deinking Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000000295 fuel oil Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 229910001385 heavy metal Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- PFUVRDFDKPNGAV-UHFFFAOYSA-N sodium peroxide Chemical compound [Na+].[Na+].[O-][O-] PFUVRDFDKPNGAV-UHFFFAOYSA-N 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
- 230000008719 thickening Effects 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Landscapes
- Paper (AREA)
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は古紙のパルプの漂白方法に関する。よ
り詳しくは、古紙を通常の方法により過酸化物で
漂白した後、更に排煙脱硫法により生成した亜硫
酸ソーダと重亜硫酸ソーダの混合物（以下、バイ
サルフアイトという）で更に漂白することによ
り、安価に古紙を漂白する方法に関するものであ
る。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for bleaching waste paper pulp. More specifically, waste paper is bleached with peroxide in the usual manner, and then further bleached with a mixture of sodium sulfite and sodium bisulfite (hereinafter referred to as bisulfite) produced by flue gas desulfurization. It concerns a method of bleaching waste paper.
［従来の技術及びその問題点］
従来の木材パルプを過酸化物で漂白する方法に
おいては、過酸化物として過酸化水素、過酸化ナ
トリウム、過酢酸などが知られているが、なかで
も過酸化水素が最も一般的に使用されている。ま
た、還元剤である亜硫酸塩または重亜硫酸塩を
GP（Ground Pulp）の漂白剤として使用すること
も古くから知られているが、その漂白効果は他の
漂白剤に比し弱く、パルプに対する反応も非常に
緩慢であつて、パルプ当り１〜２重量％添加して
漂白する場合でもその増白効果は２〜４ポイント
の増白程度であつて、十分な結果を得るのには12
〜24時間も必要とし実用的ではなかつた。[Prior art and its problems] In the conventional method of bleaching wood pulp with peroxide, hydrogen peroxide, sodium peroxide, peracetic acid, etc. are known as peroxides. Hydrogen is most commonly used. In addition, sulfite or bisulfite, which is a reducing agent,
It has been known for a long time that it can be used as a bleaching agent for GP (Ground Pulp), but its bleaching effect is weaker than other bleaching agents, and its reaction to pulp is very slow. Even when bleaching is performed by adding % by weight, the whitening effect is about 2 to 4 points of whitening, and it takes 12% to achieve a sufficient result.
It was impractical as it required ~24 hours.
また、排煙脱硫（重）亜硫酸ソーダとBorol
（登録商標）（NaBH4）を用いて晒薬品であるソ
ジウムハイドロサルフアイトを製造する方法もあ
るが、Borol法によるソジウムハイドロサルフア
イトの製造に排煙脱硫（重）亜硫酸ソーダを用い
る場合、重金属等を多量に含有していため、市販
のソジウムハイドロサルフアイトに比し晒性が劣
りコストメリツトが生じない。 In addition, flue gas desulfurization (bi)sulfite soda and Borol
(Registered Trademark) (NaBH 4 ) to produce sodium hydrosulfite, which is a bleaching chemical, but when flue gas desulfurization (bi)sulfite is used to produce sodium hydrosulfite by the Borol method, Since it contains large amounts of heavy metals, etc., it has inferior bleaching properties and no cost benefits compared to commercially available sodium hydrosulfite.
パルプ工場においては、多量の蒸気を必要と
し、そのため重油ボイラーを使用しており、排ガ
ス中よりSO2を回収するためNaOH水溶液を用い
るスクラバーを用いているが、この際多量の排脱
（重）亜硫曹（バイサルフアイト）が生成する。 Pulp mills require a large amount of steam, so heavy oil boilers are used, and scrubbers that use NaOH aqueous solution are used to recover SO 2 from the exhaust gas, but in this case, a large amount of waste (heavy) Bisulfite is produced.
反応式を示すと次のとおりである。 The reaction formula is as follows.
NaOH＋SO2→Na2SO3＋H2O
Na2SO3＋H2O＋SO2→2NaHSO3（Na2SO3＋
NaHSO3）／Na2SO3のモル比1.5のバイサルフア
イト水溶液は６前後のPHを有しているため、
RGP（Refiner Ground Wood Pulp）、TMP
（Thermo−Mechanical Pulp）、GP
（GroundwoodPulp）、PGW（Pressure
Goundwood）のH2O2晒後のPH調整等にその少量
が用いられているが、残部は廃棄されているのが
実情である。 NaOH＋SO 2 →Na 2 SO 3 +H 2 O Na 2 SO 3 +H 2 O＋SO 2 →2NaHSO 3 (Na 2 SO 3 +
Since a bisulfite aqueous solution with a molar ratio of NaHSO 3 )/Na 2 SO 3 of 1.5 has a pH of around 6,
RGP (Refiner Ground Wood Pulp), TMP
(Thermo-Mechanical Pulp), GP
(Groundwood Pulp), PGW (Pressure
A small amount of it is used to adjust the pH after exposing H 2 O 2 (Goundwood), but the rest is actually discarded.
［発明の目的］
本発明は、古紙を漂白するに際し、過酸化物を用
いて漂白した後、排煙脱硫により生成するバイサ
ルフアイトを用いて漂白することにより、使用す
る過酸化水素の量を節約すると共に効率的に漂白
しうる方法を提供することを目的とする。[Object of the invention] The present invention saves the amount of hydrogen peroxide used when bleaching waste paper by bleaching it with peroxide and then bleaching it with bisulfite produced by flue gas desulfurization. The purpose of the present invention is to provide a method that can efficiently bleach the product.
［発明の構成］
本発明は、古紙パルプを常法に従い過酸化物で
漂白した後、排煙脱硫に際し生成する亜硫酸ソー
ダと重亜硫酸ソーダとの混合物で更に漂白するこ
とを特徴とする古紙パルプの漂白方法である。[Structure of the Invention] The present invention provides a method for producing waste paper pulp, which is characterized in that the waste paper pulp is bleached with peroxide according to a conventional method, and then further bleached with a mixture of sodium sulfite and sodium bisulfite produced during flue gas desulfurization. This is a bleaching method.
本発明者らは、排煙脱硫に際して生成する亜硫
酸ソーダと重亜硫酸ソーダの混合物であるバイサ
ルフアイト中のこれら両成分が還元剤であること
に着目し、該成分を古紙パルプの漂白に使用する
ことについて種々検討を行なつていたところ、古
紙を過酸化物で漂白した後、更にバイサルフアイ
トで漂白することにより、効率よく漂白しうると
共に、使用する過酸化物等の薬剤を節減しうるこ
とを見いだし本発明をなすに至つた。 The present inventors focused on the fact that bisulfite, which is a mixture of sodium sulfite and sodium bisulfite produced during flue gas desulfurization, is a reducing agent, and proposed the use of these components for bleaching waste paper pulp. As a result of various studies, we discovered that by bleaching waste paper with peroxide and then bleaching it with bisulfite, it is possible to achieve efficient bleaching and reduce the amount of peroxide and other chemicals used. This discovery led to the present invention.
以下、本発明を詳しく説明する。 The present invention will be explained in detail below.
本発明で使用しうる古紙としては、回収した紙
を離解脱墨することにより得られた古紙パルプな
らば何れの古紙パルプを使用してもよい。 As the waste paper that can be used in the present invention, any waste paper pulp obtained by disintegrating and deinking recovered paper may be used.
本発明者らは、先ずバイサルフアイトを漂白剤
として使用することを検討したが、パルプ当り１
〜２重量％添加し加熱漂白する場合、２〜４ポイ
ント程度は増白しうるがその反応は緩慢であり、
十分な結果を得るのには12〜24時間も必要とし、
実用的ではなかつた。 The present inventors first considered using bisulfite as a bleaching agent, but
When ~2% by weight is added and heated for bleaching, whitening can be achieved by about 2 to 4 points, but the reaction is slow;
It takes 12 to 24 hours to get sufficient results,
It wasn't practical.
そこで種々検討を重ねたところ、過酸化物漂白
後の古紙パルプを更にバイサルフアイトを漂白剤
として漂白することにより、従来法におけるより
も少量の過酸化物を用い、更に過酸化物の漂白に
補助添加剤として用いられるNa2SO3を使用する
ことなく極めて有効に漂白しうることを見いだし
た。 After various studies, we found that by further bleaching the waste paper pulp after peroxide bleaching using bisulfite as a bleaching agent, we could use a smaller amount of peroxide than in the conventional method and further supplement the peroxide bleaching process. It has been found that bleaching can be carried out very effectively without using Na 2 SO 3 as an additive.
例えば従来、未晒白色度50％の古紙パルプを
H2O2を用いて白色度53.5％程度まで漂白してい
たが、本発明方法によるときはH2O2で52.0％程
度の白色度まで漂白した後更にバイサルフアイト
で漂白することにより、従来のフローを用いて容
易に白色度53.5％程度の古紙パルプを得ることが
できる。 For example, in the past, waste paper pulp with an unbleached brightness of 50% was used.
H 2 O 2 was used to bleach to a whiteness of about 53.5%, but when using the method of the present invention, the method of the present invention bleaches with H 2 O 2 to a whiteness of about 52.0% and then bleaches with bisulfite. Waste paper pulp with a whiteness of about 53.5% can be easily obtained using this flow.
本発明方法における過酸化物漂白、例えば過酸
化水素による古紙の漂白は常法に従つて実施する
ことができる。即ち、通常古紙パルプに対し、漂
白剤であるH2O2を0.3〜0.8重量％添加し、また
NaOHおよびNa2SiO3を添加し、50℃〜60℃の範
囲内の温度で２時間〜３時間程度処理されるが、
本発明においてはH2O2，NaOH等の使用量が少
なくてよく、古紙パルプに対しH2O20.1〜0.3重量
％を添加し、その他は同一条件で処理すればよ
い。 Peroxide bleaching in the method of the present invention, for example, bleaching of waste paper with hydrogen peroxide, can be carried out in accordance with conventional methods. That is, 0.3 to 0.8% by weight of H 2 O 2 , which is a bleaching agent, is added to waste paper pulp, and
NaOH and Na 2 SiO 3 are added and treated at a temperature within the range of 50°C to 60°C for about 2 to 3 hours,
In the present invention, the amount of H 2 O 2 , NaOH, etc. used may be small, and 0.1 to 0.3% by weight of H 2 O 2 may be added to the waste paper pulp, and the treatment may be otherwise performed under the same conditions.
また、バイサルフアイトの添加量は古紙パルプ
に対しSO2として1.0〜2.0重量％添加すればよく、
パルプ濃度４〜15％、好ましくは10〜13％、温度
25〜50℃、好ましくは40〜50℃、PH6.5〜9.0好ま
しくは6.5〜7.0の範囲内の条件で１〜12時間、好
ましくは５〜12時間処理すればよい。 In addition, the amount of bisulfite added may be 1.0 to 2.0% by weight as SO 2 to the waste paper pulp.
Pulp concentration 4-15%, preferably 10-13%, temperature
The treatment may be carried out for 1 to 12 hours, preferably for 5 to 12 hours, at a temperature of 25 to 50°C, preferably 40 to 50°C, and a pH of 6.5 to 9.0, preferably 6.5 to 7.0.
つぎに、バイサルフアイト中の［Na2SO3＋
NaHSO3／］［Na2SO3］のモル比の漂白に与え
る影響について検討を行なつた。 Next, [Na 2 SO 3 +
The influence of the molar ratio of NaHSO 3 /][Na 2 SO 3 ] on bleaching was investigated.
古紙パルプにバイサルフアイトをSO2として１
％添加し、40℃の温度で６時間晒実験を行なつた
（古紙パルプ濃度12％）ところ前記モル比を1.66
から1.25に下げると古紙パルプの白色度上昇ポイ
ントは2.4から1.99に低下し、更に前記モル比が
1.0（Na2SO3のみ）に低下すると白色度上昇ポイ
ントは0.9にまで低下した。このことから
NaHSO3のモル比の高いバイサルフアイトが有
効であることがわかつた。 Adding bisulfite to waste paper pulp as SO 2
% was added, and an exposure experiment was conducted at a temperature of 40°C for 6 hours (waste paper pulp concentration 12%), and the molar ratio was 1.66.
When the molar ratio is lowered from
When it decreased to 1.0 (Na 2 SO 3 only), the whiteness increase point decreased to 0.9. From this
It was found that bisulfite with a high molar ratio of NaHSO 3 is effective.
種々試験したところ、前記モル比1.2〜2.0特に
1.5〜2.0のものが好ましいことがわかつた。 As a result of various tests, the above molar ratio of 1.2 to 2.0, especially
It was found that a value of 1.5 to 2.0 is preferable.
つぎに、本発明の古紙パルプ回収の概略フロー
を示す第１図を参照しながら実施例を説明する。 Next, an embodiment will be described with reference to FIG. 1, which shows a schematic flow of waste paper pulp recovery according to the present invention.
古紙をパルパー１で離解し、スクリユープレス
２で脱水した後晒塔３に送り、パルプ濃度15％と
とし、対パルプ0.15％のH2O2を添加し、NaOH
を加え、55℃の温度で約２時間漂白し、ついでフ
ローテーターで脱墨した。ついでスクリーン５、
クリーナー６で精選し、エキスト７で脱水した後
完成フイルター８で洗浄脱水した後、原料ストツ
クタンクであるクツシヨンチエスト９に送入し、
該クツシヨンチエストにおいて、パルプ濃度12％
で対パルプ1.0％（SO2として）のモル比1.5のバ
イサルフアイトを添加し、45℃で５時間漂白処理
を行なつた。処理液のPHは6.9であつた。 The waste paper is disintegrated in the pulper 1, dehydrated in the screw press 2, and then sent to the bleaching tower 3 to give a pulp concentration of 15 %.
was added, bleached at a temperature of 55°C for about 2 hours, and then deinked using a floatator. Then screen 5,
After being carefully selected in the cleaner 6, dehydrated in the extract 7, and washed and dehydrated in the finished filter 8, it is sent to the cushion chest 9, which is a raw material stock tank.
In the cushion chest, the pulp concentration is 12%.
Then, bisulfite was added at a molar ratio of 1.5 to 1.0% (as SO 2 ) to the pulp, and a bleaching treatment was carried out at 45° C. for 5 hours. The pH of the treatment solution was 6.9.
ついで濃調タンク１０で濃度を調整した後プロ
ポーシヨナー１２でパルプの配合を行なつた後抄
紙機へ供給した。 Next, the density was adjusted in a thickening tank 10, and the pulp was blended in a proportioner 12 before being supplied to a paper machine.
なお、バイサルフアイトによる漂白は、濃調タ
ンク１０の次に設置することのある中継チエスト
あるいはクツシヨンチエストと中継チエストの両
方で行なつてもよい。 Bleaching with bisulfite may be performed in a relay chest that may be installed next to the concentration tank 10, or in both a cushion chest and a relay chest.
本実施例により得られた古紙パルプの白色度は
53.5％であつた。 The whiteness of the waste paper pulp obtained in this example is
It was 53.5%.
なお、バイサルフアイトによる漂白を行なうこ
となく、H2O2のみを用いて同じ白色度のパルプ
を得るには、対パルプ0.5％のH2O2を添加し、ま
たNaOHおよびNa2SiO3を用い55℃の温度で約２
時間漂白する必要があつた。 In addition, to obtain pulp with the same whiteness using only H 2 O 2 without bleaching with bisulfite, add 0.5% H 2 O 2 to the pulp and also add NaOH and Na 2 SiO 3 . Approx. 2 at a temperature of 55℃
I had to bleach it for a while.
［発明の効果］
排煙脱硫の際の副生物であるバイサルフアイト
を古紙パルプの晒薬品として使用することがで
き、しかもH2O2の使用量を減少せしめることが
可能となり、H2O2の使用量が減少した結果、補
助アルカリであるNa2SiO3の添加量も０にするこ
とができ、バイサルフアイトの添加と相俟つて古
紙パルプ（スラリー）のPHが6.9に下がり、従つ
て、抄紙機に送られる完成パルプのPH調整用の硫
酸バンドの使用量も減少できる。[Effects of the invention] Bisulfite, which is a byproduct during flue gas desulfurization , can be used as a bleaching chemical for waste paper pulp, and the amount of H 2 O 2 used can be reduced. As a result of the reduction in the amount of Na 2 SiO 3 used as an auxiliary alkali, the amount of Na 2 SiO 3 added, which is an auxiliary alkali, can be reduced to 0. Together with the addition of bisulfite, the pH of the waste paper pulp (slurry) decreases to 6.9. The amount of sulfuric acid band used to adjust the pH of the finished pulp sent to the paper machine can also be reduced.
第１図は本発明の古紙パルプ回収方法の概略工
程図を示すものである。
１…パルパー、３…晒塔、４…フローテータ
ー、９…クツシヨンチエスト、１１…中継チエス
ト、１２…プロポーシヨナー。
FIG. 1 shows a schematic process diagram of the waste paper pulp recovery method of the present invention. 1... Pulper, 3... Bleaching Tower, 4... Floatator, 9... Cushion Chest, 11... Relay Chest, 12... Proportioner.
Claims (1)
後、排煙脱硫により生成した亜硫酸ソーダと重亜
硫酸ソーダとの混合物で更に漂白することを特徴
とする古紙パルプの漂白方法。 ２ 古紙パルプ濃度４〜15重量％の古紙パルプス
ラリーに排煙脱硫により生成した亜硫酸ソーダと
重亜硫酸ソーダの混合物をSO2としてパルプ固形
分重量に対し1.0〜2.0重量％添加し、25〜50℃の
温度で１〜12時間漂白する特許請求の範囲第１項
記載の古紙パルプの漂白方法。 ３ 排煙脱硫により生成した亜硫酸ソーダと重亜
硫酸ソーダの混合物の（Na2SO3＋NaHSO3）／
Na2SO3のモル比が1.2〜2.0である特許請求の範
囲第１項または第２項記載の古紙パルプの漂白方
法。 ４ 古紙パルプの漂白を6.5〜9.0の範囲内のPHで
行なう特許請求の範囲第１項、第２項または第３
項記載の古紙パルプの漂白方法。[Claims] 1. A method for bleaching waste paper pulp, which comprises bleaching waste paper pulp with peroxide in a conventional manner, and then further bleaching with a mixture of sodium sulfite and sodium bisulfite produced by flue gas desulfurization. . 2 A mixture of sodium sulfite and sodium bisulfite produced by flue gas desulfurization is added as SO 2 to a waste paper pulp slurry with a waste paper pulp concentration of 4 to 15% by weight, and the mixture is heated to 25 to 50°C. A method for bleaching waste paper pulp according to claim 1, wherein bleaching is performed at a temperature of 1 to 12 hours. 3. (Na 2 SO 3 +NaHSO 3 )/ of the mixture of sodium sulfite and sodium bisulfite produced by flue gas desulfurization
The method for bleaching waste paper pulp according to claim 1 or 2, wherein the molar ratio of Na 2 SO 3 is 1.2 to 2.0. 4. Claims 1, 2, or 3 in which bleaching of waste paper pulp is carried out at a pH within the range of 6.5 to 9.0.
Method for bleaching waste paper pulp as described in Section 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19205687A JPS6440692A (en) | 1987-07-31 | 1987-07-31 | Bleaching of old paper pulp by waste gas desulfurizing product |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19205687A JPS6440692A (en) | 1987-07-31 | 1987-07-31 | Bleaching of old paper pulp by waste gas desulfurizing product |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6440692A JPS6440692A (en) | 1989-02-10 |
| JPH0585676B2 true JPH0585676B2 (en) | 1993-12-08 |
Family
ID=16284881
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19205687A Granted JPS6440692A (en) | 1987-07-31 | 1987-07-31 | Bleaching of old paper pulp by waste gas desulfurizing product |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6440692A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03294589A (en) * | 1990-04-09 | 1991-12-25 | Sanyo Kokusaku Pulp Co Ltd | Treatment of unclassified waste information-recording paper |
-
1987
- 1987-07-31 JP JP19205687A patent/JPS6440692A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6440692A (en) | 1989-02-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| FI63607B (en) | FREQUENCY REFRIGERATION FOR CELLULOSE MASS IN UTBYTESOMRAODET 65-95% | |
| US4459174A (en) | Process for the delignification and bleaching of chemical and semi-chemical cellulosic pulps | |
| US4283251A (en) | Ozone effluent bleaching | |
| AU634665B2 (en) | Two-stage peroxide bleaching process | |
| US5298118A (en) | Preparation of bleached chemithermomechanical pulp | |
| AU606930B2 (en) | Pulp bleaching process | |
| EP0464110B1 (en) | Bleaching process for the production of high bright pulps | |
| JPH0726351B2 (en) | Method for bleaching high-yield paper pulp using hydrogen peroxide | |
| FI96522B (en) | Process for the preparation of bleached chemical thermomechanical masses | |
| JPH04214491A (en) | Manufacture of bleached high yield pulp | |
| NZ205971A (en) | Delignifying bleaching of cellulosic pulp using nitrogen oxides with addition of sodium nitrate | |
| JPH0585676B2 (en) | ||
| JP2787618B2 (en) | Method for peroxide bleaching of cellulose material and lignin cellulose fibrous material | |
| JP3325324B2 (en) | Method for delignification of crude cellulose | |
| JPH0217675B2 (en) | ||
| JPH07145583A (en) | Deinking and bleaching of waste paper | |
| US4070233A (en) | Process of the pulping of bleaching of vegetable material | |
| JPS5927436B2 (en) | Peroxide bleaching method for wood pulp | |
| US4409066A (en) | Bleaching procedure using chlorine dioxide and chlorine solutions | |
| JPH0215669B2 (en) | ||
| JPH0453991B2 (en) | ||
| JP2001192991A (en) | Method of bleaching alkali pulp | |
| JP2630349B2 (en) | Recycled pulp manufacturing method | |
| JP4009790B2 (en) | High whiteness bleaching method for high quality and medium quality waste paper pulp | |
| SU1449605A1 (en) | Method of bleaching sulfate pulp |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |