JPH02264089A - Removal of sodium chloride and potassium salt from pulp digestion chemical - Google Patents
Removal of sodium chloride and potassium salt from pulp digestion chemicalInfo
- Publication number
- JPH02264089A JPH02264089A JP8464989A JP8464989A JPH02264089A JP H02264089 A JPH02264089 A JP H02264089A JP 8464989 A JP8464989 A JP 8464989A JP 8464989 A JP8464989 A JP 8464989A JP H02264089 A JPH02264089 A JP H02264089A
- Authority
- JP
- Japan
- Prior art keywords
- slurry
- water
- ash
- collected
- salt
- 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.)
- Granted
Links
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 title claims abstract description 21
- 239000011780 sodium chloride Substances 0.000 title claims abstract description 17
- 239000000126 substance Substances 0.000 title claims description 19
- XAEFZNCEHLXOMS-UHFFFAOYSA-M potassium benzoate Chemical compound [K+].[O-]C(=O)C1=CC=CC=C1 XAEFZNCEHLXOMS-UHFFFAOYSA-M 0.000 title description 10
- 230000029087 digestion Effects 0.000 title 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 24
- 238000011084 recovery Methods 0.000 claims abstract description 16
- 239000002002 slurry Substances 0.000 claims abstract description 15
- 159000000001 potassium salts Chemical class 0.000 claims abstract description 11
- 239000007787 solid Substances 0.000 claims abstract description 8
- 238000002485 combustion reaction Methods 0.000 claims abstract description 5
- 235000002639 sodium chloride Nutrition 0.000 claims description 24
- 238000000034 method Methods 0.000 claims description 14
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 claims description 6
- 238000010411 cooking Methods 0.000 claims description 6
- 238000005260 corrosion Methods 0.000 abstract description 2
- 230000007797 corrosion Effects 0.000 abstract description 2
- 150000003839 salts Chemical class 0.000 description 9
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 5
- 239000013078 crystal Substances 0.000 description 5
- 229910052938 sodium sulfate Inorganic materials 0.000 description 5
- 235000011152 sodium sulphate Nutrition 0.000 description 5
- 238000000605 extraction Methods 0.000 description 4
- 238000000926 separation method Methods 0.000 description 4
- 239000010802 sludge Substances 0.000 description 4
- 150000004691 decahydrates Chemical class 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- OTYBMLCTZGSZBG-UHFFFAOYSA-L potassium sulfate Chemical compound [K+].[K+].[O-]S([O-])(=O)=O OTYBMLCTZGSZBG-UHFFFAOYSA-L 0.000 description 3
- 229910052939 potassium sulfate Inorganic materials 0.000 description 3
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 2
- 239000012141 concentrate Substances 0.000 description 2
- 238000002425 crystallisation Methods 0.000 description 2
- 230000008025 crystallization Effects 0.000 description 2
- 238000010828 elution Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000011591 potassium Substances 0.000 description 2
- 229910052700 potassium Inorganic materials 0.000 description 2
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 239000007832 Na2SO4 Substances 0.000 description 1
- 241001062472 Stokellia anisodon Species 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- -1 decahydrate salt Chemical class 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 229940079593 drug Drugs 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 235000011151 potassium sulphates Nutrition 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Landscapes
- Paper (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明はバルブ製造工場のソーダ回収ボイラに適用され
るもので、パルプ蒸解薬品中に濃縮・蓄積される不純物
としての食塩及びカリウム塩を除去する方法に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention is applied to a soda recovery boiler in a valve manufacturing factory, and is used to remove common salt and potassium salt as impurities that are concentrated and accumulated in pulp cooking chemicals. Regarding how to.
パルプ蒸解薬品中にカリウム塩を除去方法は、従来実機
に適用されたものはない。No method for removing potassium salts from pulp cooking chemicals has ever been applied to actual equipment.
類似の技術として、食塩除去方法がある。すなわち、ソ
ーダ回収ボイラの排ガスからの捕集灰少量の水と循環液
を用いてスラリー化させ、６０〜７０℃、の温度で水に
食塩を溶解し、スラリー中の固形分を分離回収する方法
である。この方法では薬品中の食塩は容易に除去できる
がカリウム塩の溶解度が小さいため、カリウム塩を除去
しようとする場合、ＮａｚＳＯａが同時に失われるので
薬品損失が大きくなる欠点を有する。A similar technique is the salt removal method. That is, a method in which collected ash from the exhaust gas of a soda recovery boiler is made into a slurry using a small amount of water and circulating fluid, salt is dissolved in water at a temperature of 60 to 70°C, and the solid content in the slurry is separated and recovered. It is. This method can easily remove the common salt in the chemical, but since the solubility of the potassium salt is low, when attempting to remove the potassium salt, NazSOa is simultaneously lost, resulting in a large loss of the chemical.
パルプ蒸解薬品中には、不純物として食塩やカリウム塩
が主としてバルブ原木からもたらされる。これらの不純
物は製品であるバルブや系統外に出る損失薬品に随伴し
て薬品系統を出てゆくが、薬品のクローズド化が進み薬
品回収率が上昇するに従って薬品系統中に濃縮・蓄積す
る傾向が生じる。In pulp cooking chemicals, impurities such as common salt and potassium salt are mainly introduced from bulb logs. These impurities exit the chemical system along with the product valves and the lost chemicals that exit the system, but as chemicals become more closed-circuited and the drug recovery rate increases, they tend to concentrate and accumulate in the chemical system. arise.
濃縮・蓄積した食塩やカリウム塩はイナート物質として
薬品の循環負荷を高めデッドロード増加による経済性の
低下につながるだけでなく、薬品回収系統の腐食性を著
しく高めることはよく知られている。It is well known that concentrated and accumulated salt and potassium salts act as inert substances that increase the circulation load of chemicals, leading to a decrease in economic efficiency due to an increase in dead load, and that they also significantly increase the corrosivity of the chemical recovery system.
特にパルプ廃液を燃焼するソーダ回収ボイラにおいては
食塩及びカリウム塩の存在によりボイラ高温部の伝熱管
の腐食性を高めるだけでなく、伝熱管表面に付着する燃
焼灰の付着性を著しく高め、ソーダ回収ボイラ煙道圧力
損失を増しボイラの連続操業を阻害するに至る。In particular, in soda recovery boilers that burn pulp waste liquid, the presence of common salt and potassium salts not only increases the corrosiveness of heat exchanger tubes in the high temperature section of the boiler, but also significantly increases the adhesion of combustion ash that adheres to the heat exchanger tube surfaces. This increases boiler flue pressure loss and impedes continuous operation of the boiler.
本発明はパルプ蒸解薬品系統中に蓄積濃縮する食塩及び
カリウム塩を除去する方法であって、ソーダ回収ボイラ
の燃焼排ガスから捕集した捕集灰を２０℃以下の低温の
水に混合・分散してスラリー化し、一定時間保持して捕
集灰中の食塩及びカリウム塩を水に溶解した後、スラリ
ー中の固形分を分離、回収することを特徴とするパルプ
蒸解薬品中の食塩及びカリウム塩の除去方法である。The present invention is a method for removing common salt and potassium salts that accumulate and concentrate in a pulp cooking chemical system, in which collected ash collected from the combustion exhaust gas of a soda recovery boiler is mixed and dispersed in water at a low temperature of 20°C or less. A process for preparing common salt and potassium salts in pulp cooking chemicals, which is characterized in that the common salt and potassium salts in the collected ash are made into a slurry and held for a certain period of time to dissolve the common salt and potassium salts in the collected ash, and then the solid content in the slurry is separated and recovered. This is a removal method.
従来の食塩除去方法では、ソーダ回収ボイラの捕集灰を
少量の水で食塩を溶解除去するが、カリウムの場合は水
に対する溶解度が小さいため、必要な除去量を得るまで
水を添加すると、有効薬品である硫酸ソーダの溶出量が
増加し、経済性が悪くなる。In the conventional salt removal method, salt is removed by dissolving the collected ash in a soda recovery boiler with a small amount of water, but since potassium has a low solubility in water, it is effective to add water until the required removal amount is obtained. The elution amount of sodium sulfate, which is a chemical, increases, making it less economical.
そこで、本発明はカリウム塩の除去を主目的として、硫
酸ソーダの溶解度が小さく、従って薬品損失がより少な
い２０℃以下の低温において、硫酸カリウムを溶解除去
しようとするものである。これが、本発明の第一の特徴
である。Therefore, the present invention aims to remove potassium salt by dissolving potassium sulfate at a low temperature of 20° C. or lower, where the solubility of sodium sulfate is low and therefore chemical loss is less. This is the first feature of the present invention.
このような低温の条件では硫酸ソーダは１０水塩となる
ため、水で抽出分離後のスラッジは多量の水を含有する
ので、回収ボイラ系統に戻すとき蒸発損失が生じる。従
って、一般には低温における水による溶解除去は冷却が
必要なことの外に、結晶水による水の持ち込みのため不
利な条件であると言える。本発明の方法では、捕集灰を
低温の水でスラリー化し、低温で水にカリウム塩を溶解
除去する方法であり、低温の一般方法である一旦水に溶
解したのち、冷却して結晶を析出分離する方法に比べて
、１０水塩（Ｎａ２Ｓ０．１０Ｈ２０）の析出が半分以
下に抑制できることが判明しその知見に基いて操作する
ことが本発明の第２の特徴である。本発明の方法によれ
ば、結晶水のもち込みが少なく、従って、全体の経済性
が改善される。Under such low-temperature conditions, sodium sulfate becomes decahydrate, and the sludge after extraction and separation with water contains a large amount of water, resulting in evaporation loss when returned to the recovery boiler system. Therefore, in general, it can be said that dissolving and removing with water at low temperatures is disadvantageous not only because cooling is required but also because water is brought in by crystallization water. In the method of the present invention, the collected ash is slurried with low-temperature water, and the potassium salt is dissolved and removed in the water at low temperatures. The second feature of the present invention is that it has been found that the precipitation of decahydrate (Na2S0.10H20) can be suppressed to less than half compared to the separation method, and that the operation is based on this knowledge. According to the method of the present invention, less water of crystallization is carried over, thus improving overall economic efficiency.
本発明の第３の特徴は、捕集灰を低温の水にスラリー化
させたあとスラッジを分離する必要があるが、その分離
性が低温においても結晶の成長が充分速いため、極めて
良好であることを実験的に見いだしたことである。一般
に捕集灰の粒径はサブミクロンであり、きわめて小さく
分離が容易でない。従来技術の食塩除去方法においては
、捕集灰の結晶をスラリー中に長時間（数時間）保持し
、結晶を成長させて分離性を改善しているが、本発明方
法では結晶の成長が速く濾過性がよいため、滞留時間は
短くてよいことが確認された。The third feature of the present invention is that although it is necessary to separate the sludge after slurrying the collected ash in low-temperature water, the separation performance is extremely good because crystal growth is sufficiently rapid even at low temperatures. This is what we discovered experimentally. Generally, the particle size of collected ash is submicron, which is extremely small and difficult to separate. In the conventional salt removal method, the crystals of collected ash are kept in the slurry for a long time (several hours) to grow the crystals and improve the separation, but in the method of the present invention, the crystals grow quickly. It was confirmed that the residence time could be short because of the good filterability.
第１図はＮａｚＳＯ４−ＫａＳＯａ混合系の溶解度を温
度に対して示したもので、本発明の第１の特徴を説明す
るものである。第１図中、Ｎａ２ｓＯｎ （混合系）
、ＫｓＳ０４（混合系）とはＮａｚＳＯ４−に＊ＳＯ＊
混合系中のＮａｚＳＯ，、に２ＳＯ１の溶解度曲線、Ｎ
ａｌＳ口。FIG. 1 shows the solubility of the NazSO4-KaSOa mixed system versus temperature, and is intended to explain the first feature of the present invention. In Figure 1, Na2sOn (mixed system)
, KsS04 (mixed system) is NazSO4- *SO*
Solubility curve of 2SO1 in NazSO,, in a mixed system, N
alS mouth.
（単独） 、 Ｋ２ＳＯ４（単独）とは夫々の単独系の
Ｎａ２ｓＯｎ、に２Ｓ口、の溶解度曲線を示す。Ｎａ２
ＳＯ２・１０Ｈ２０（単独・混合）は無水塩、十水塩と
も殆ど同じであるので一本の溶解度曲線になっている。(single) and K2SO4 (single) show the solubility curves of 2S and Na2sOn, respectively. Na2
Since SO2.10H20 (single or mixed) is almost the same for anhydrous salt and decahydrate salt, it forms a single solubility curve.
第１図においてに２ＳＯ，の溶解度は温度に対する変化
は少ないが、ｌａ、ｓＯ，の場合は温度の影響が大きく
、低温で溶解度は著しく小さくなる。In FIG. 1, the solubility of 2SO, changes little with temperature, but in the case of la, sO, the influence of temperature is large, and the solubility becomes significantly small at low temperatures.
食塩除去のように、６０〜７０℃で抽出する場合に比べ
ると、例えば１０℃にて抽出を行った場合、同じにｚｓ
Ｏ１除去量に対して、ＮａａｓＯａの溶解による損失は
低温では約１７４になる。同じＮａ２ＳＯ４回収率にす
ると、Ｋ、ＳＯ，溶出量は４倍にすることができる。こ
れが低温における抽出の硬化であり本発明の骨子である
。Compared to extracting at 60 to 70°C, such as when removing salt, for example, when extraction is performed at 10°C, the zs
With respect to the amount of O1 removed, the loss due to dissolution of NaasOa is about 174 at low temperatures. With the same Na2SO4 recovery rate, the amounts of K, SO, and elution can be quadrupled. This is the hardening of extraction at low temperatures and is the gist of the present invention.
第２図の特徴である、１０水塩の抑制については、実施
例で具体的に説明するが、作用としては、もともと低温
の水の中に、溶解度を超えて過剰に捕集灰を供給するた
め、固体のＮａ２５Ｏ＊のままで、スラリー中に固体と
して存在できるからであう。The suppression of decahydrate, which is a feature of Fig. 2, will be explained in detail in the examples, but the effect is to supply an excess of collected ash beyond its solubility into the water, which is originally at a low temperature. This is because solid Na25O* can exist as a solid in the slurry.
第３図の特徴である低温にふいて、スラッジの濾過性が
改善される理由はスラリー中の最初最大２〜３ミクロン
であった固体粒子は１００ミクロン程度の粒子に成長し
、粗粒化していることが確認されたことから明白である
。The reason why the filterability of sludge improves when exposed to low temperature, which is the characteristic of Figure 3, is that the solid particles in the slurry, which were initially 2 to 3 microns at most, grow to particles of about 100 microns and become coarser. It is clear from the fact that it has been confirmed that
Ｎａ、ｓＯ，： ８５．９％、 ＮａＣ１：ａ、ｏ％、
Ｋ２ＳＯ４：１１．１％の捕集灰１００ ｋｇを１０
℃の水２０７．６ｋｇに混合・スラリー化させその温度
に８時間保持したのち結晶をろ別した。スラッジ中のＮ
ａ２ＳＯ４は７４ｋｇを得た。分離液中のＮａａＳＯｓ
は１１．８ｋｇ、に２Ｓ０４は１１．０ｋｇであった。Na, sO,: 85.9%, NaCl: a, o%,
K2SO4: 100 kg of 11.1% collected ash
The mixture was mixed into a slurry with 207.6 kg of water at a temperature of 0.degree. C., kept at that temperature for 8 hours, and then the crystals were filtered out. N in sludge
74 kg of a2SO4 was obtained. NaaSOs in separated liquid
was 11.8 kg, and 2S04 was 11.0 kg.
これは、飽和溶解度にほぼ等しく、水による抽出の目的
を充分達成できたと言える。This is almost equal to the saturated solubility, and it can be said that the purpose of extraction with water was sufficiently achieved.
また、硫酸ソーダ回収率は８６％であり実用性のある方
法であることが示された。なお、食塩の除去率は８０％
以上、に、Ｓ０４の除去率は７０％以上であった。Furthermore, the recovery rate of sodium sulfate was 86%, indicating that the method is practical. Furthermore, the removal rate of salt is 80%.
As mentioned above, the removal rate of S04 was 70% or more.
上記実施例では捕集灰を水に８時間保持したが、その保
持時間はこれに限定されるものではなく、１〜１２時間
の範囲でよい。In the above example, the collected ash was held in water for 8 hours, but the holding time is not limited to this, and may be in the range of 1 to 12 hours.
１ 回収ボイラ排ガスの捕集灰から食塩及びカリウム塩
を除去することにより、薬品系統の塩素およびカリウム
の濃度を低下させることができる。その結果、回収ボイ
ラ煙道の燃焼灰の付着性を改善し、従来、３ケ月程度の
連続操業が食塩及びカリウム塩の除去により６ケ月〜１
ケ年に延長できた。1. By removing common salt and potassium salt from the collected ash of the recovery boiler exhaust gas, the concentration of chlorine and potassium in the chemical system can be reduced. As a result, the adhesion of combustion ash in the recovery boiler flue has been improved, and the conventional continuous operation of about 3 months has been reduced to 6 months to 1 day by removing common salt and potassium salt.
It was extended to 2015.
２ 同時に、伝熱面に付着する灰の除去のために、スー
ツブロワ−に消費する蒸気量が大幅に低減できた。2. At the same time, the amount of steam consumed by the suit blower was significantly reduced due to the removal of ash adhering to the heat transfer surface.
３ 食塩及びカリウム塩の除去により付着灰の融点低下
がなくなり、腐食性が改善された。3. Removal of common salt and potassium salt eliminated the drop in melting point of attached ash and improved corrosivity.
スメルトスパウトの耐用期間が約３倍に延長されるなど
、回収ボイラ各部の腐食性が改善されている。The corrosion resistance of various parts of the recovery boiler has been improved, including extending the service life of the smelt spout by about three times.
第１図はＮａ、ＳＯ，−Ｋ、ＳＯ，混合系のＮａａＳＯ
ｓ。
Ｋ１５Ｏｎの溶解度及びＮａ２５Ｏ，単独系、Ｋ、３口
、単独系の夫々の溶解度を示す図表である。
￥１図Figure 1 shows Na, SO, -K, SO, and mixed NaaSO
s. It is a chart showing the solubility of K15On and the solubility of Na25O, single system, K, 3 ports, and single system. ¥1 figure
Claims (1)
０℃以下の低温の水に混合・分散してスラリー化し、一
定時間保持して捕集灰中の食塩及びカリウム塩を水に溶
解した後、スラリー中の固形分を分離、回収することを
特徴とするパルプ蒸解薬品中の食塩及びカリウム塩の除
去方法。The collected ash collected from the combustion exhaust gas of the soda recovery boiler is
It is characterized by mixing and dispersing in water at a low temperature of 0℃ or less to form a slurry, holding it for a certain period of time to dissolve the common salt and potassium salts in the collected ash, and then separating and recovering the solid content in the slurry. A method for removing common salt and potassium salts from pulp cooking chemicals.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8464989A JP2578199B2 (en) | 1989-04-05 | 1989-04-05 | Method for removing salt and potassium salt from pulp cooking chemicals |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8464989A JP2578199B2 (en) | 1989-04-05 | 1989-04-05 | Method for removing salt and potassium salt from pulp cooking chemicals |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02264089A true JPH02264089A (en) | 1990-10-26 |
| JP2578199B2 JP2578199B2 (en) | 1997-02-05 |
Family
ID=13836556
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8464989A Expired - Lifetime JP2578199B2 (en) | 1989-04-05 | 1989-04-05 | Method for removing salt and potassium salt from pulp cooking chemicals |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2578199B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009050809A (en) * | 2007-08-28 | 2009-03-12 | Toa Nekken Kk | Reduction agent of carbon dioxide in combustion flue gas and carbon dioxide reduction method |
| JP2015093239A (en) * | 2013-11-12 | 2015-05-18 | 王子ホールディングス株式会社 | Processing method and processing unit for recovery boiler collection ash |
| JP2016135931A (en) * | 2015-01-23 | 2016-07-28 | 王子ホールディングス株式会社 | Treatment method and apparatus of ash collected in recovery boiler |
-
1989
- 1989-04-05 JP JP8464989A patent/JP2578199B2/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009050809A (en) * | 2007-08-28 | 2009-03-12 | Toa Nekken Kk | Reduction agent of carbon dioxide in combustion flue gas and carbon dioxide reduction method |
| JP2015093239A (en) * | 2013-11-12 | 2015-05-18 | 王子ホールディングス株式会社 | Processing method and processing unit for recovery boiler collection ash |
| JP2016135931A (en) * | 2015-01-23 | 2016-07-28 | 王子ホールディングス株式会社 | Treatment method and apparatus of ash collected in recovery boiler |
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| JP2578199B2 (en) | 1997-02-05 |
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