JP3431064B2 - Method for producing neutralized gypsum powder - Google Patents
Method for producing neutralized gypsum powderInfo
- Publication number
- JP3431064B2 JP3431064B2 JP34969998A JP34969998A JP3431064B2 JP 3431064 B2 JP3431064 B2 JP 3431064B2 JP 34969998 A JP34969998 A JP 34969998A JP 34969998 A JP34969998 A JP 34969998A JP 3431064 B2 JP3431064 B2 JP 3431064B2
- Authority
- JP
- Japan
- Prior art keywords
- gypsum powder
- seed crystal
- neutralized
- gypsum
- powder
- 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 - Lifetime
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- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、種結晶の存在下で
硫酸と炭酸カルシウムを反応させることにより得られ、
石こうボードの原料として用いられる中和石こう粉末の
製造方法に関するものである。The present invention is obtained by reacting sulfuric acid with calcium carbonate in the presence of seed crystals,
The present invention relates to a method for producing neutralized gypsum powder used as a raw material for gypsum board.
【０００２】[0002]
【従来の技術】石こうボードの原料となる石こうには、
石こう鉱石を粉砕した石こう粉末、排煙脱硫石こう
粉末、硫酸塩と炭酸カルシウムを反応させて作られた
石こう粉末、硫酸と炭酸カルシウムを直接反応させて
作られた中和石こう粉末等が一般に用いられる。これら
の原料の供給業者が複数ある場合、使用原料の品質を安
定させるために、石こうボードの製造工場ではこれらの
石こう粉末を複数種類混合して、原料としている。これ
らの内で上記の中和石こう粉末の製造方法では、図２
に示すように濃硫酸、もしくは濃硫酸を水で希釈した５
０〜９８重量％の硫酸と炭酸カルシウムのスラリーを反
応槽１で混合撹拌し、約６０℃の温度で反応し生成した
中和石こうのスラリーを遠心分離機２により固液分離し
て中和石こう粉末３を得ている。この方法では、製造開
始時に新規な種結晶を反応槽１に加える。この新規な種
結晶により中和石こうを生成した後、この中和石こうを
含むスラリーを反応槽１に循環させ、このスラリーに含
まれる中和石こう粉末を次の連続操業用の種結晶として
いる。この方法によれば、不純物の少ない中和石こう粉
末が得られる利点がある。[Prior Art] Gypsum, the raw material for gypsum board,
Gypsum powder obtained by crushing gypsum ore, flue gas desulfurized gypsum powder, gypsum powder made by reacting sulfate and calcium carbonate, neutralized gypsum powder made by directly reacting sulfuric acid and calcium carbonate, etc. are generally used. . When there are multiple suppliers of these raw materials, in order to stabilize the quality of the raw materials used, a plurality of these gypsum powders are mixed as raw materials in the gypsum board manufacturing plant. Among these, in the method for producing the neutralized gypsum powder described above, FIG.
Concentrated sulfuric acid or diluted concentrated sulfuric acid with water as shown in 5
Slurry of 0 to 98 wt% sulfuric acid and calcium carbonate is mixed and stirred in the reaction tank 1, and the slurry of neutralized gypsum produced by reacting at a temperature of about 60 ° C. is subjected to solid-liquid separation by the centrifugal separator 2 to neutralize gypsum. Powder 3 is obtained. In this method, a new seed crystal is added to the reaction tank 1 at the start of production. After the neutralized gypsum is produced by this novel seed crystal, the slurry containing the neutralized gypsum is circulated in the reaction tank 1, and the neutralized gypsum powder contained in this slurry is used as the seed crystal for the next continuous operation. According to this method, there is an advantage that neutralized gypsum powder with few impurities can be obtained.
【０００３】[0003]
【発明が解決しようとする課題】しかし、上記スラリー
に含まれる中和石こうは針状の結晶であって、図２に示
すようにこのスラリーを反応槽１に戻してスラリーに含
まれる中和石こう粉末全てを種結晶とすると、硫酸と炭
酸カルシウムの反応性が極端に良好になり、製品となる
中和石こう粉末も針状結晶になり、嵩比重が低くなる傾
向があった。このため、石こうボードの製造時に、針状
結晶でない別の種類の石こう粉末と混合する場合、嵩比
重の差に起因して完全に混合することが困難であった。
この不完全に混合した原料石こうを焼成し、この焼成体
を粉砕してスラリーに戻す場合には、そのスラリーの濃
度が微視的に変化し、石こうボードの強度不足を招いた
り、ボードに気泡が混入する問題があった。However, the neutralized gypsum contained in the slurry is acicular crystals, and the slurry is returned to the reaction tank 1 as shown in FIG. When all the powders were used as seed crystals, the reactivity of sulfuric acid and calcium carbonate was extremely good, and the neutralized gypsum powder used as a product also became acicular crystals, tending to have a low bulk specific gravity. Therefore, when the gypsum board is mixed with another type of gypsum powder that is not acicular crystals, it is difficult to completely mix the gypsum board due to the difference in bulk specific gravity.
When this incompletely mixed raw gypsum is fired and the fired product is crushed back into a slurry, the concentration of the slurry changes microscopically, leading to insufficient strength of the gypsum board, and bubbles in the board. There was a problem that was mixed.
【０００４】上記問題を解決するために、硫酸と炭酸カ
ルシウムの反応時に添加剤を加えることにより、中和石
こうの結晶の成長速度を遅らせて非針状の結晶にする方
法、例えばアルミ法による排煙脱硫の技術が試みられて
いるが、この場合、添加剤が不純物として石こう中に残
留する不都合があった。本発明の目的は、嵩比重が高
く、石こうボードを製造する際に異種類の石こう粉末と
容易に混合できる高純度の中和石こう粉末の製造方法を
提供することにある。In order to solve the above problems, a method of delaying the growth rate of neutral gypsum crystals to give non-acicular crystals by adding an additive during the reaction between sulfuric acid and calcium carbonate, for example, the aluminum method The technique of smoke desulfurization has been tried, but in this case, there was a disadvantage that the additive remained as an impurity in the gypsum. It is an object of the present invention to provide a method for producing a high-purity neutralized gypsum powder which has a high bulk specific gravity and can be easily mixed with different types of gypsum powder when producing a gypsum board.
【０００５】[0005]
【課題を解決するための手段】請求項１に係る発明は、
図１に示すように硫酸と炭酸カルシウムを反応槽１３で
反応させて中和石こう粉末を含むスラリー１４を生成
し、このスラリー１４を反応槽１３に循環させ、このス
ラリー１４に含まれる中和石こう粉末を種結晶とするこ
とにより中和石こう粉末を製造する方法において、上記
循環する種結晶を第１種結晶とするとき、この第１種結
晶と別に硫酸と炭酸カルシウムのみを反応させて作られ
る中和石こう粉末と異なる石こう粉末を反応槽１３に第
２種結晶として添加し、この第２種結晶の添加量を製品
となる中和石こう粉末１８の３〜３０重量％とすること
を特徴とする中和石こう粉末の製造方法である。請求項
２に係る発明は、請求項１に係る発明であって、第２種
結晶が排煙脱硫石こう粉末である中和石こう粉末の製造
方法である。請求項３に係る発明は、請求項１に係る発
明であって、第２種結晶が石こう鉱石の粉砕物である中
和石こう粉末の製造方法である。請求項４に係る発明
は、請求項１に係る発明であって、第２種結晶が硫酸塩
と炭酸カルシウムを反応させて作られた石こう粉末であ
る中和石こう粉末の製造方法である。請求項１〜４に係
る発明の製造方法では、第２種結晶として排煙脱硫石こ
う粉末、石こう鉱石の粉砕物、又は硫酸塩と炭酸カルシ
ウムを反応させて作られた石こう粉末などの硫酸と炭酸
カルシウムのみを反応させて作られる中和石こう粉末と
異なる石こう粉末を用いることにより、第２種結晶の表
面で結晶生成反応が起きるため、反応速度が変わらない
にも拘わらず、嵩比重が高く、不純度の少ない中和石こ
う粉末が得られる。The invention according to claim 1 is
As shown in FIG. 1, sulfuric acid and calcium carbonate are reacted in a reaction tank 13 to produce a slurry 14 containing neutralized gypsum powder, and the slurry 14 is circulated in the reaction tank 13 to neutralize gypsum contained in the slurry 14. In a method for producing a neutralized gypsum powder by using a powder as a seed crystal, when the circulating seed crystal is a first seed crystal, it is prepared by reacting only sulfuric acid and calcium carbonate separately from the first seed crystal. A gypsum powder different from the neutralized gypsum powder is added to the reaction tank 13 as the second seed crystal, and the addition amount of the second seed crystal is 3 to 30% by weight of the neutralized gypsum powder 18 as a product. This is a method for producing neutralized gypsum powder. The invention according to claim 2 is the invention according to claim 1, which is a method for producing a neutralized gypsum powder in which the second seed crystal is flue gas desulfurized gypsum powder. The invention according to claim 3 is the invention according to claim 1, which is a method for producing a neutralized gypsum powder in which the second seed crystal is a crushed product of gypsum ore. The invention according to claim 4 is the invention according to claim 1, which is a method for producing a neutralized gypsum powder, wherein the second seed crystal is a gypsum powder produced by reacting a sulfate with calcium carbonate. In the manufacturing method of the invention according to claims 1 to 4, sulfuric acid and carbonic acid such as flue gas desulfurized gypsum powder as a second type crystal, pulverized gypsum ore, or gypsum powder made by reacting sulfate with calcium carbonate. By using a gypsum powder that is different from the neutralized gypsum powder that is produced by reacting only calcium, a crystal formation reaction occurs on the surface of the second seed crystal, so that the bulk specific gravity is high, even though the reaction rate does not change. Neutralized gypsum powder with low purity is obtained.
【０００６】[0006]
【発明の実施の形態】請求項１に係る発明の製造方法で
は、図１に示すように、混合槽１１で濃硫酸を水で希釈
し、混合槽１２で炭酸カルシウム粉末と水とを混合して
炭酸カルシウムのスラリーを調製する。５０〜９８重量
％の硫酸と炭酸カルシウムのスラリーを反応槽１３で混
合撹拌し、約６０℃の温度で反応させることにより中和
石こうのスラリー１４を生成する。この反応のために製
造開始時には新規な種結晶（図示せず）を反応槽１３に
加える。この新規な種結晶により中和石こうを生成した
後、この中和石こうを含むスラリー１４はポンプ１６に
より複数の遠心分離機１７に送られるとともに、反応槽
１３に送られ循環使用される、このスラリー１４に含ま
れる中和石こう粉末を次の連続操業用の第１種結晶とす
る。遠心分離機１７に送られ、そこで固液分離された中
和石こう粉末１８は石こうボードメーカー向けの製品と
なる。遠心分離機１７で得られたろ液はろ液受槽１９に
貯えられ、ろ液の一部は石こうスラリーの濃度調整用と
して反応槽１３に戻され、残部は排水処理設備に送られ
処理される。BEST MODE FOR CARRYING OUT THE INVENTION In the manufacturing method of the invention according to claim 1, as shown in FIG. 1, concentrated sulfuric acid is diluted with water in a mixing tank 11, and calcium carbonate powder and water are mixed in a mixing tank 12. To prepare a calcium carbonate slurry. A slurry of 50 to 98 wt% sulfuric acid and calcium carbonate is mixed and stirred in the reaction tank 13 and reacted at a temperature of about 60 ° C. to produce a neutralized gypsum slurry 14. For this reaction, a new seed crystal (not shown) is added to the reaction tank 13 at the start of production. After the neutral gypsum is produced by the novel seed crystal, the slurry 14 containing the neutral gypsum is sent to a plurality of centrifuges 17 by a pump 16 and also sent to the reaction tank 13 for circulation and use. Neutralized gypsum powder contained in No. 14 is used as the first seed crystal for the next continuous operation. The neutralized gypsum powder 18 sent to the centrifuge 17 and solid-liquid separated therein is a product for gypsum board makers. The filtrate obtained by the centrifuge 17 is stored in the filtrate receiving tank 19, a part of the filtrate is returned to the reaction tank 13 for adjusting the concentration of the gypsum slurry, and the rest is sent to the waste water treatment facility for treatment.
【０００７】本発明の特徴ある点は、この第１種結晶と
は別に第２種結晶を反応槽１３に加えることにある。第
２種結晶の添加量は、製品となる中和石こう粉末１８の
３〜３０重量％、好ましくは５〜２０重量％である。添
加量が３重量％に未満の場合には嵩比重を高めることが
困難となり、３０重量％を超えた場合、石こう分離機の
能力に制限があり、所期の石こう生産量が得られない。
第２種結晶は、図示するように直接反応槽１３に投入し
てもよいが、混合槽１２に入れて炭酸カルシウムと混合
してから反応槽１３に導入してもよいし、或いは循環さ
せるスラリーに添加することにより反応槽１３に導入し
てもよい。A feature of the present invention is that a second seed crystal is added to the reaction tank 13 in addition to the first seed crystal. The amount of the second seed crystal added is 3 to 30% by weight, preferably 5 to 20% by weight of the neutralized gypsum powder 18 to be the product. If the added amount is less than 3% by weight, it becomes difficult to increase the bulk specific gravity, and if the added amount exceeds 30% by weight, the gypsum separator capacity is limited and the desired gypsum production cannot be obtained.
The second seed crystal may be directly charged into the reaction tank 13 as shown in the figure, or may be introduced into the reaction tank 13 after being mixed with the calcium carbonate after being mixed into the mixing tank 12, or a slurry to be circulated. It may be introduced into the reaction tank 13 by adding it to.
【０００８】請求項２〜４に係る発明のこの第２種結晶
を例示すれば、排煙脱硫石こう粉末、石こう鉱石の粉砕
物、又は硫酸塩と炭酸カルシウムを反応させて作られた
石こう粉末が挙げられる。この硫酸塩としては硫酸鉄又
は硫酸アルミニウムが挙げられる。排煙脱硫とは、硫黄
を含む燃料を用いる工場や火力発電所の排煙中に含まれ
るＳＯ2，ＳＯ3や、或いは硫酸プラントの排ガス中のＳ
Ｏ2をそれぞれ除去することである。この排煙脱硫によ
り石こう粉末を製造する方法には、(a)石灰石粉か消石
灰を吸収剤として脱硫し、酸化して石こうとする直接石
灰石こう法と、（ｂ）苛性ソーダやアンモニア水などの
他のアルカリで一度ＳＯｘを吸収した後、石灰石粉か消
石灰で複分解して石こうとする間接石灰石こう法があ
る。その他に（ｃ）苛性ソーダを吸収剤として亜硫酸ソ
ーダのままで副生する方法や、(d)この副生物を更に酸
化して硫酸ソーダにする方法や、(e)活性炭吸着による
乾式法などがある。本発明の排煙脱硫石こう粉末は、上
記(a)〜(e)の製造法のいずれかで作られた石こう粉末で
ある。Examples of the second type crystals of the inventions according to claims 2 to 4 are flue gas desulfurized gypsum powder, pulverized gypsum ore, or gypsum powder made by reacting sulfate with calcium carbonate. Can be mentioned. Examples of the sulfate include iron sulfate and aluminum sulfate. Flue gas desulfurization is SO 2 , SO 3 contained in the flue gas of a factory or a thermal power plant that uses a fuel containing sulfur, or S in the exhaust gas of a sulfuric acid plant.
To remove O 2 respectively. This method of producing gypsum powder by flue gas desulfurization includes (a) a direct lime gypsum method in which limestone powder or slaked lime is desulfurized as an absorbent and oxidized to gypsum, and (b) other methods such as caustic soda and ammonia water. There is an indirect lime-and-gypsum method in which SOx is once absorbed by the alkali and then it is meta-decomposed with limestone powder or slaked lime to form gypsum. Other methods are (c) by-product of sodium sulfite as caustic soda as absorbent, (d) further oxidation of this by-product to sodium sulfate, and (e) dry method by adsorption of activated carbon. . The flue gas desulfurization gypsum powder of the present invention is a gypsum powder produced by any of the above-mentioned production methods (a) to (e).
【０００９】この排煙脱硫石こうを生成するまでの反応
式は、次の式（１）及び（２）で示される。式（１）は
ＳＯ2の吸収を示し、式（２）はその吸収により生成し
た亜硫酸カルシウム（ＣａＳＯ3）の酸化を示す。
ＳＯ2 ＋ ＣａＣＯ3 → ＣａＳＯ3 ＋ ＣＯ2 …（１）
ＣａＳＯ3 ＋ １／２Ｏ2 ＋ ２Ｈ2Ｏ → ＣａＳＯ4・２Ｈ2Ｏ …（２）
このようにして生成した排煙脱硫石こう粉末（ＣａＳＯ
4・２Ｈ2Ｏ）の結晶は針状でなく米粒状である。The reaction equations for producing the flue gas desulfurization gypsum are represented by the following equations (1) and (2). The formula (1) shows absorption of SO 2 , and the formula (2) shows oxidation of calcium sulfite (CaSO 3 ) generated by the absorption. SO 2 + CaCO 3 → CaSO 3 + CO 2 (1) CaSO 3 + 1 / 2O 2 + 2H 2 O → CaSO 4 .2H 2 O (2) Flue gas desulfurization gypsum powder (CaSO) thus produced
4 · 2H 2 O) crystals are rice grain rather than needles.
【００１０】[0010]
【実施例】次に本発明の具体的態様を示すために、本発
明の実施例を比較例とともに説明する。
＜実施例１＞５０重量％硫酸と炭酸カルシウムのスラリ
ーを反応槽で反応させて中和石こう粉末を製造した。こ
のとき製造開始時を除いて、反応により生成した中和石
こうを含むスラリーを反応槽に循環させ、このスラリー
に含まれている中和石こうを第１種結晶とした。この第
１種結晶は製品となる中和石こう粉末の約５００重量％
であった。この第１種結晶に加えて、第２種結晶とし
て、硫酸プラントの排ガス中のＳＯ2から生成した排煙
脱硫石こう粉末を、製品となる中和石こう粉末の２０重
量％の割合で反応槽に添加して上記反応を行った。この
第２種結晶の排煙脱硫石こう粉末は図６の顕微鏡写真
（倍率５０）に示すように、米粒状の細かな結晶形を有
していた。この反応により得られた中和石こう粉末の軽
装嵩比重は０．７７であった。この中和石こう粉末の顕
微鏡写真（倍率５０）を図３に示す。なお、軽装嵩比重
とは石こうボードの原料としての使い易さの目安として
測定した嵩比重であって、乾燥させた中和石こう粉末を
３００ｃｃのガラス容器にふるいを用いて静かに落下さ
せ定規で上面を平らにして、その重量を体積で割ること
により算出した嵩比重を意味する。アスペクト比が小さ
い結晶粉末ほど軽装嵩比重の値が高くなり、石こうボー
ドの原料として使い易い粉末であると評価される。EXAMPLES Next, examples of the present invention will be described together with comparative examples in order to show specific embodiments of the present invention. <Example 1> A slurry of 50% by weight sulfuric acid and calcium carbonate was reacted in a reaction tank to produce a neutralized gypsum powder. At this time, except for the start of production, the slurry containing the neutralized gypsum produced by the reaction was circulated in the reaction tank, and the neutralized gypsum contained in this slurry was used as the first seed crystal. This type 1 crystal is about 500% by weight of the neutralized gypsum powder used as a product.
Met. In addition to the first seed crystal, as a second seed crystal, flue gas desulfurized gypsum powder produced from SO 2 in the exhaust gas of a sulfuric acid plant was added to the reaction tank at a ratio of 20% by weight of the neutralized gypsum powder to be the product. The above reaction was carried out by addition. The flue gas desulfurized gypsum powder of the second type crystals had a fine grain-like crystal form of rice as shown in the micrograph (magnification: 50) of FIG. The lightly loaded bulk specific gravity of the neutralized gypsum powder obtained by this reaction was 0.77. A micrograph (magnification: 50) of this neutralized gypsum powder is shown in FIG. In addition, the lightly loaded bulk specific gravity is the bulk specific gravity measured as an index of the ease of use as a raw material for gypsum board, and the neutralized gypsum powder that has been dried is gently dropped into a 300 cc glass container using a sieve and a ruler is used. It means the bulk specific gravity calculated by flattening the upper surface and dividing the weight by the volume. The smaller the aspect ratio of the crystalline powder, the higher the value of the bulk bulk specific gravity, and it is evaluated that the crystalline powder is easy to use as a raw material for gypsum board.
【００１１】＜実施例２＞第２種結晶として火力発電所
の排煙中に含まれるＳＯ2から生成した排煙脱硫石こう
粉末を使用し、かつ第２種結晶の反応槽への添加量を製
品となる中和石こう粉末の５重量％の割合にした以外
は、実施例１と同様にして中和石こう粉末を製造した。
この第２種結晶の排煙脱硫石こう粉末は図７の顕微鏡写
真（倍率５０）に示すように、米粒のような球状の結晶
形を有していた。この反応により得られた中和石こう粉
末の軽装嵩比重は０．８２であった。この中和石こう粉
末の顕微鏡写真（倍率５０）を図４に示す。Example 2 A flue gas desulfurized gypsum powder produced from SO 2 contained in the flue gas of a thermal power plant was used as the second seed crystal, and the addition amount of the second seed crystal to the reaction tank was set to A neutralized gypsum powder was produced in the same manner as in Example 1 except that the ratio of the neutralized gypsum powder used as a product was 5% by weight.
The flue gas desulfurized gypsum powder of this type 2 crystal had a spherical crystal form like rice grains as shown in the micrograph (magnification: 50) of FIG. 7. The lightened bulk specific gravity of the neutralized gypsum powder obtained by this reaction was 0.82. A micrograph (magnification: 50) of this neutralized gypsum powder is shown in FIG.
【００１２】＜比較例１＞第２種結晶を全く使用せず
に、反応により生成した中和石こうを含むスラリーを実
施例１と同じ割合で反応槽に循環させ、このスラリーに
含まれる第１種結晶のみを種結晶とした以外は、実施例
１と同様にして中和石こう粉末を製造した。この反応に
より得られた中和石こう粉末の軽装嵩比重は０．７０で
あった。この中和石こう粉末の顕微鏡写真（倍率５０）
を図５に示す。<Comparative Example 1> A slurry containing neutralized gypsum produced by the reaction was circulated in the reaction tank at the same ratio as in Example 1 without using the second seed crystal at all. A neutralized gypsum powder was produced in the same manner as in Example 1 except that only seed crystals were used. The lightly loaded bulk specific gravity of the neutralized gypsum powder obtained by this reaction was 0.70. Micrograph of this neutralized gypsum powder (magnification 50)
Is shown in FIG.
【００１３】＜比較評価＞比較例１で得られた中和石こ
う粉末は図５に示すように細長い結晶形を有しており、
上記のように、その軽装嵩比重は０．７０と低い値を示
した。これに対し、実施例１で得られた中和石こう粉末
は図３に示すように小さい結晶形を有しており、比較例
１のような細長い結晶は見られないことが判る。また上
記のように、その軽装嵩比重は０．７７と比較例１より
も高いことが判る。また実施例２で得られた中和石こう
粉末は図４に示すように小さい結晶形を有しており、実
施例１と同様に比較例１のような細長い結晶は見られな
いことが判る。また上記のように、種結晶の添加量が５
重量％と少量でありながら、得られる中和石こう粉末の
軽装嵩比重は０．８２と比較例１よりも更に高いことが
判る。<Comparative Evaluation> The neutralized gypsum powder obtained in Comparative Example 1 has an elongated crystal form as shown in FIG.
As described above, the bulk bulk density of the lightly-worn powder was as low as 0.70. On the other hand, the neutralized gypsum powder obtained in Example 1 has a small crystal form as shown in FIG. 3, and it can be seen that elongated crystals as in Comparative Example 1 are not seen. Further, as described above, it is found that the bulk bulk specific gravity is 0.77, which is higher than that of Comparative Example 1. Further, it is understood that the neutralized gypsum powder obtained in Example 2 has a small crystal form as shown in FIG. 4, and like Example 1, no elongated crystals as in Comparative Example 1 are seen. Further, as described above, the seed crystal addition amount is 5
It can be seen that the neutralized gypsum powder obtained has a lightly loaded bulk specific gravity of 0.82, which is even higher than that of Comparative Example 1, although the amount is as small as wt%.
【００１４】[0014]
【発明の効果】以上述べたように、本発明によれば、従
来の第１種結晶に加えて、硫酸と炭酸カルシウムのみを
反応させて作られる中和石こう粉末と異なる石こう粉末
を第２種結晶として連続的に添加して硫酸と炭酸カルシ
ウムを反応させて中和石こう粉末を製造したので、粉末
の嵩比重が高くなり、異種類の石こう粉末と容易に混合
することができる。また不純物の原因となる添加剤を添
加することなく嵩比重を高めることができるため、良質
で高純度の石こうボード用原料として使用することがで
きる。As described above, according to the present invention, in addition to the conventional type 1 crystal, the type 2 gypsum powder different from the neutralized gypsum powder produced by reacting only sulfuric acid and calcium carbonate is used. Since the neutralized gypsum powder was produced by continuously adding sulfuric acid and calcium carbonate as crystals to produce a neutralized gypsum powder, the bulk specific gravity of the powder is increased, and the gypsum powder of a different type can be easily mixed. Further, since the bulk specific gravity can be increased without adding an additive that causes impurities, it can be used as a raw material for a high-quality and high-purity gypsum board.
【図１】本発明の中和石こう粉末の製造装置の構成図。FIG. 1 is a block diagram of an apparatus for producing neutralized gypsum powder according to the present invention.
【図２】従来の中和石こう粉末の製造装置の構成図。FIG. 2 is a block diagram of a conventional apparatus for producing neutralized gypsum powder.
【図３】実施例１で得られた中和石こう粉末の顕微鏡写
真を示す図。FIG. 3 is a view showing a micrograph of the neutralized gypsum powder obtained in Example 1.
【図４】実施例２で得られた中和石こう粉末の顕微鏡写
真を示す図。FIG. 4 is a view showing a microscope photograph of the neutralized gypsum powder obtained in Example 2.
【図５】比較例１で得られた中和石こう粉末の顕微鏡写
真を示す図。5 is a view showing a microscope photograph of the neutralized gypsum powder obtained in Comparative Example 1. FIG.
【図６】実施例１で第２種結晶として使用された排煙脱
硫石こう粉末の顕微鏡写真を示す図。FIG. 6 is a view showing a micrograph of a flue gas desulfurized gypsum powder used as a second seed crystal in Example 1.
【図７】実施例２で第２種結晶として使用された排煙脱
硫石こう粉末の顕微鏡写真を示す図。FIG. 7 is a view showing a micrograph of flue gas desulfurized gypsum powder used as a second seed crystal in Example 2.
１３ 反応槽 １４ スラリー １８ 製品となる中和石こう粉末 13 Reaction tank 14 Slurry 18 neutralized gypsum powders
フロントページの続き (58)調査した分野(Int.Cl.7，ＤＢ名) C01F 11/46 Continuation of front page (58) Fields surveyed (Int.Cl. 7 , DB name) C01F 11/46
Claims (4)
応させて中和石こう粉末を含むスラリー(14)を生成し、
前記スラリー(14)を前記反応槽(13)に循環させ、前記ス
ラリー(14)に含まれる中和石こう粉末を種結晶とするこ
とにより中和石こう粉末を製造する方法において、 前記循環する種結晶を第１種結晶とするとき、前記第１
種結晶と別に前記硫酸と前記炭酸カルシウムのみを反応
させて作られる中和石こう粉末と異なる石こう粉末を前
記反応槽(13)に第２種結晶として添加し、前記第２種結
晶の添加量を製品となる中和石こう粉末(18)の３〜３０
重量％とすることを特徴とする中和石こう粉末の製造方
法。1. Sulfuric acid and calcium carbonate are reacted in a reaction tank (13) to produce a slurry (14) containing neutralized gypsum powder,
In the method for producing a neutralized gypsum powder by circulating the slurry (14) in the reaction tank (13) and using the neutralized gypsum powder contained in the slurry (14) as a seed crystal, the circulating seed crystal When the first seed crystal is
A gypsum powder different from the neutralized gypsum powder prepared by reacting only the sulfuric acid and the calcium carbonate separately from the seed crystal was added to the reaction vessel (13) as the second seed crystal, and the addition amount of the second seed crystal was Neutralized gypsum powder (18) 3-30
A method for producing a neutralized gypsum powder, characterized in that the content is in% by weight.
請求項１記載の製造方法。2. The method according to claim 1, wherein the second seed crystal is flue gas desulfurized gypsum powder.
請求項１記載の製造方法。3. The method according to claim 1, wherein the second seed crystal is a crushed product of gypsum ore.
反応させて作られた石こう粉末である請求項１記載の製
造方法。4. The method according to claim 1, wherein the second seed crystal is gypsum powder produced by reacting a sulfate with calcium carbonate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34969998A JP3431064B2 (en) | 1998-12-09 | 1998-12-09 | Method for producing neutralized gypsum powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34969998A JP3431064B2 (en) | 1998-12-09 | 1998-12-09 | Method for producing neutralized gypsum powder |
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| Publication Number | Publication Date |
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| JP3431064B2 true JP3431064B2 (en) | 2003-07-28 |
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| JP34969998A Expired - Lifetime JP3431064B2 (en) | 1998-12-09 | 1998-12-09 | Method for producing neutralized gypsum powder |
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| CN107055586A (en) * | 2016-12-30 | 2017-08-18 | 宁夏东吴农化有限公司 | A kind of preparation method of calcium sulfate |
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