JPS6411570B2 - - Google Patents
Info
- Publication number
- JPS6411570B2 JPS6411570B2 JP54020737A JP2073779A JPS6411570B2 JP S6411570 B2 JPS6411570 B2 JP S6411570B2 JP 54020737 A JP54020737 A JP 54020737A JP 2073779 A JP2073779 A JP 2073779A JP S6411570 B2 JPS6411570 B2 JP S6411570B2
- Authority
- JP
- Japan
- Prior art keywords
- aluminum hydroxide
- alumina
- seeds
- precipitation
- bayer
- 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
Links
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 claims description 54
- 238000000034 method Methods 0.000 claims description 33
- 239000002245 particle Substances 0.000 claims description 19
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 16
- 239000002253 acid Substances 0.000 claims description 11
- 150000004645 aluminates Chemical class 0.000 claims description 7
- 238000004519 manufacturing process Methods 0.000 claims description 4
- 238000004062 sedimentation Methods 0.000 claims description 4
- 229910001679 gibbsite Inorganic materials 0.000 claims description 2
- 230000001376 precipitating effect Effects 0.000 claims 1
- 238000001556 precipitation Methods 0.000 description 19
- 238000004131 Bayer process Methods 0.000 description 11
- 239000000243 solution Substances 0.000 description 11
- 238000009826 distribution Methods 0.000 description 9
- 239000000203 mixture Substances 0.000 description 7
- 239000000047 product Substances 0.000 description 7
- 239000002994 raw material Substances 0.000 description 6
- 150000007513 acids Chemical class 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 5
- 238000007922 dissolution test Methods 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 4
- 239000013078 crystal Substances 0.000 description 4
- 239000010419 fine particle Substances 0.000 description 4
- FAHBNUUHRFUEAI-UHFFFAOYSA-M hydroxidooxidoaluminium Chemical compound O[Al]=O FAHBNUUHRFUEAI-UHFFFAOYSA-M 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 239000000725 suspension Substances 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 150000001447 alkali salts Chemical class 0.000 description 3
- AZDRQVAHHNSJOQ-UHFFFAOYSA-N alumane Chemical class [AlH3] AZDRQVAHHNSJOQ-UHFFFAOYSA-N 0.000 description 3
- 239000011362 coarse particle Substances 0.000 description 3
- 230000006911 nucleation Effects 0.000 description 3
- 238000010899 nucleation Methods 0.000 description 3
- 239000012266 salt solution Substances 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- 239000012670 alkaline solution Substances 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 229910001570 bauxite Inorganic materials 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000010790 dilution Methods 0.000 description 2
- 239000012895 dilution Substances 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- 239000008394 flocculating agent Substances 0.000 description 2
- 238000006460 hydrolysis reaction Methods 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 239000000049 pigment Substances 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- DIZPMCHEQGEION-UHFFFAOYSA-H aluminium sulfate (anhydrous) Chemical compound [Al+3].[Al+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O DIZPMCHEQGEION-UHFFFAOYSA-H 0.000 description 1
- ANBBXQWFNXMHLD-UHFFFAOYSA-N aluminum;sodium;oxygen(2-) Chemical compound [O-2].[O-2].[Na+].[Al+3] ANBBXQWFNXMHLD-UHFFFAOYSA-N 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 230000003301 hydrolyzing effect Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000012452 mother liquor Substances 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 238000009790 rate-determining step (RDS) Methods 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910001388 sodium aluminate Inorganic materials 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000006228 supernatant Substances 0.000 description 1
- 238000010333 wet classification Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F7/00—Compounds of aluminium
- C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
- C01F7/04—Preparation of alkali metal aluminates; Aluminium oxide or hydroxide therefrom
- C01F7/14—Aluminium oxide or hydroxide from alkali metal aluminates
- C01F7/144—Aluminium oxide or hydroxide from alkali metal aluminates from aqueous aluminate solutions by precipitation due to cooling, e.g. as part of the Bayer process
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Description
本発明はバイヤー法によつて酸易溶性の水酸化
アルミニウムを製造する方法に関するものであ
る。衆知の如くバイヤー法による水酸化アルミニ
ウム及びアルミナの製造では、通常120℃以上の
温度に於て熱アルカリ溶液でボーキサイトを処理
することによりその中のアルミナ分を抽出し（溶
解工程）、得られたスラリーより酸化鉄等の不溶
解分を分離し（分離工程）、清澄になつた液を冷
却してアルミナが過飽和に溶解したアルミン酸ア
ルカリ溶液に種子として水酸化アルミニウムを添
加し、加水分解反応により過飽和に溶存したアル
ミナ分を水酸化アルミニウムとして析出させる
（析出工程）。析出終了後のスラリーは一般に湿式
分級分離を行い（分級工程）粗粒部分を製品とし
て取り出した細粒部分は種子として循環使用され
る。また固型分が分離されたアルミン酸アルカリ
液は再び溶解工程に送られ、ボーキサイトの処理
に用いられる。
上記析出工程に於て析出する水酸化アルミニウ
ムは添加種子の結晶成長に寄与するものと、核発
生により新たな微細粒子を形成するものとがあ
る。後者の一部は析出工程で起る凝集作用に伴
い、相対的に粗粒である粒子に付着し製品となる
ものもあるが、大部分は種子として循環される。
この循環種子量は通常のバイヤー法では新たに析
出するアルミナ分に対しほぼ等量乃至数倍に及
び、為に核発生により生じた水酸化アルミニウム
粒子は析出工程を数次循環した後製品となるた
め、緩やかな結晶成長により結晶度の高い水酸化
アルミニウム粒子が得られる。
触媒原料或いはアルミニウム塩凝集剤、例えば
ポリ塩化アルミニウム（PAC）の製造原料とし
て、水酸化アルミニウム用いられるが、この
PACを製造する過程で、水酸化アルミニウムの
酸に溶解する反応速度が律速工程となつており、
酸易溶性水酸化アルミニウムは工業上重要な意義
を有している。既述の如き結晶度の高いバイヤー
法水酸化アルミニウムでは、酸易溶性について満
足な性能が得られていなかつた。
このような目的に添うアルミナ原料を作る方法
は従来から提案されてはいるが、これらはバイヤ
ー法で得られる水酸化アルミニウムに比べ価格的
に高くバイヤー法水酸化アルミニウムを代替する
には至つていない。例えば特公昭47−40628或い
は特公昭45−38121の如きアルミニウム塩乃至は
アルミン酸塩の中和によりアルミナ水和物を得る
方法ではアルミナと当量の酸乃至アルカリが消費
されるため、必然的に製造費用が高く且つ得られ
る製品はゲル状物となり、央雑不純物の分離が困
難である。また特公昭50−5159ではアルミン残ア
ルカリの加水分解法を用いてはいるものの、その
加水分解条件は一般バイヤー法に於けるものから
は大きく逸脱しており、且つ比較的多量に用いる
種子の調整に酸・アルカリの消費を伴うため、価
格の上昇は避け得ず、広汎な使用に供せられてい
るとは言い難い。
本発明者らはかかる状況に鑑み、上述の如き価
格の著しい上昇を招くことなく現在のバイヤー法
水酸化アルミニウムに比し、酸類への溶解性が格
段に向上した製品を得る方法を見出すべく鋭意研
究を行つた結果、過飽和にアルミナが溶存したア
ルミン酸アルカリ溶液に少量かつ微細な水酸化ア
ルミニウムを種子として添加することにより水酸
化アルミニウムの比較的微細な粒子の凝集体が得
られ、これを酸に溶解したところ通常のバイヤー
法水酸化アルミニウムに比し、格段に溶解性が向
上していることを見出した。この機構は明らかで
はないが、添加種子量が少いことにより、析出す
るアルミナ分はとして核発生による新たな水酸化
アルミニウム粒子の形成に費やされ、結晶の緩慢
な成長が起り得ず、且つ生成粒子が凝集力に富む
ためであると推定される。尚、従来のバイヤー法
で用いられる種子の添加量を本発明範囲まで減少
させた場合は析出反応が著しく不安定となり、種
子添加後数時間を経過しても析出が開始されぬ場
合もあり、たまたま析出が開始されても粗大粒子
の発生を伴い、且つ該生成物の酸溶解性は通常の
バイヤー法水酸化アルミニウムに比しむしろ劣る
等、本目的に合致することはできない。
添加する種子の粒径が3μを越えると、析出反
応が不安定になつたり、析出水酸化アルミニウム
の酸への溶解性が著しく減少する。なお工業的に
みて、経済的に製造できる粒径は、0.3〜0.5μが
下限である。添加する種子の量が多すぎると、析
出粒子が細かくなり、種子の添加量が７％を越え
ると分級洗浄などの工程に著しい支障をきたす。
種子の添加量は、0.1％以上７％以下が必要であ
り、好ましくは、１％以上４％以下である。
本法で得られる水酸化アルミニウムは通常のバ
イヤー法水酸化アルミニウムと同じ結晶組成形態
（ギブサイト）であり、且つ粒子径もほヾ等しい
ため、夾雑物の洗浄、除去には従来の方法がその
まま応用できる。また本法では使用種子が一般の
バイヤー法水酸化アルミニウムを微粉砕したも
の、又は塗工顔料用に市販されている水酸化アル
ミニウム等、微細なギブザイトであればその調整
法を問わず、且つ使用量も極めて少量であり、析
出母液、析出方法は種子を除けば従来のバイヤー
法がそのまま応用できるため極めて安価に製造で
きる特長がある。即ち、本発明によれば通常のバ
イヤー法で使用されているアルミン酸アルカリ溶
液に種子として微粒の水酸化アルミニウムを少量
添加して水酸化アルミニウムを析出させ、酸への
溶解性の良い水酸化アルミニウムを極めて安価に
製造することができる。以下実施例に基き、本法
を更に詳細に説明するが、実施例は本法を制限す
るものではない。
実施例 １
通常のバイヤー法により得られた水酸化アルミ
ニウム（＋74μｍ 28％、−44μｍ 22％の粒径分
布を持つ）をボールミルにて乾式粉砕し、沈降法
による平均粒子径が2.7μｍの微粉となし、これを
バイヤー法の析出工程に送られる第１表に示す組
成のアルミン酸液4M3に対し26Kg添加し、42時間
析出を行つたところ＋74μｍ 22％、−44μｍ 11
％の粒径分布を持つ水酸化アルミニウムが288Kg
得られた。（液中の溶存アルミナに対する種子と
して添加した水酸化アルミニウムのアルミナ換算
重量比（以下種子率と称す）：3.6％）
The present invention relates to a method for producing easily acid-soluble aluminum hydroxide by the Bayer process. As is well known, in the production of aluminum hydroxide and alumina by the Bayer process, bauxite is usually treated with a hot alkaline solution at a temperature of 120°C or higher to extract the alumina content therein (dissolution process). Insoluble matters such as iron oxide are separated from the slurry (separation process), the clarified liquid is cooled, aluminum hydroxide is added as seeds to an alkaline aluminate solution in which alumina is supersaturated, and a hydrolysis reaction is carried out. Supersaturated dissolved alumina is precipitated as aluminum hydroxide (precipitation step). The slurry after the precipitation is generally subjected to wet classification separation (classification step), and the coarse particles are taken out as a product and the fine particles are recycled and used as seeds. Furthermore, the alkaline aluminate solution from which the solid content has been separated is sent to the dissolution step again and used for the treatment of bauxite. Some of the aluminum hydroxide precipitated in the above precipitation step contributes to the crystal growth of the added seeds, while others form new fine particles through nucleation. Some of the latter adheres to relatively coarse particles due to the agglomeration effect that occurs during the precipitation process and becomes a product, but the majority is recycled as seeds.
In the normal Bayer method, the amount of circulating seeds is approximately equal to several times the amount of newly precipitated alumina, so the aluminum hydroxide particles generated by nucleation become products after being circulated several times through the precipitation process. Therefore, aluminum hydroxide particles with high crystallinity can be obtained due to slow crystal growth. Aluminum hydroxide is used as a catalyst raw material or as a raw material for producing aluminum salt flocculants, such as polyaluminum chloride (PAC).
In the process of manufacturing PAC, the reaction rate of aluminum hydroxide dissolving in acid is the rate-limiting step.
Easily acid-soluble aluminum hydroxide has important industrial significance. With the Bayer process aluminum hydroxide having a high degree of crystallinity as described above, satisfactory performance in terms of easy acid solubility has not been obtained. Methods for producing alumina raw materials for these purposes have been proposed, but these methods are expensive compared to aluminum hydroxide obtained by the Bayer process, and have not been able to replace the Bayer process aluminum hydroxide. do not have. For example, in the method of obtaining alumina hydrate by neutralizing aluminum salt or aluminate, such as in Japanese Patent Publication No. 47-40628 or Japanese Patent Publication No. 45-38121, an acid or alkali equivalent to the alumina is consumed, so it is necessary to The cost is high and the resulting product is a gel-like product, making it difficult to separate the central impurities. In addition, although the Japanese Patent Publication No. 50-5159 uses a method of hydrolyzing residual alkali of aluminium, its hydrolysis conditions differ greatly from those of the general Bayer method, and it requires a relatively large amount of seed preparation. Since this involves the consumption of acids and alkalis, an increase in price is unavoidable, and it is difficult to say that it is widely used. In view of this situation, the present inventors have worked diligently to find a method for obtaining a product that has significantly improved solubility in acids compared to the current Bayer process aluminum hydroxide without causing a significant increase in price as described above. As a result of research, it was found that by adding a small amount of fine aluminum hydroxide as seeds to a supersaturated alkaline aluminate solution containing dissolved alumina, aggregates of relatively fine particles of aluminum hydroxide were obtained. It was found that the solubility was significantly improved compared to ordinary Bayer process aluminum hydroxide. The mechanism is not clear, but because the amount of seeds added is small, the precipitated alumina is used to form new aluminum hydroxide particles through nucleation, and slow crystal growth cannot occur. It is presumed that this is because the generated particles have a high cohesive force. In addition, when the amount of seeds added in the conventional Bayer method is reduced to the range of the present invention, the precipitation reaction becomes extremely unstable, and precipitation may not start even after several hours have passed after adding the seeds. Even if precipitation happens to start, it is accompanied by the generation of coarse particles, and the acid solubility of the product is rather inferior to that of ordinary Bayer process aluminum hydroxide, so that it cannot meet the purpose. If the particle size of the added seeds exceeds 3μ, the precipitation reaction becomes unstable and the solubility of precipitated aluminum hydroxide in acid decreases significantly. From an industrial perspective, the lower limit of the particle size that can be economically produced is 0.3 to 0.5 μ. If the amount of seeds added is too large, the precipitated particles will become fine, and if the amount of seeds added exceeds 7%, steps such as classification and cleaning will be seriously hindered.
The amount of seeds added must be 0.1% or more and 7% or less, preferably 1% or more and 4% or less. The aluminum hydroxide obtained by this method has the same crystal composition form (gibbsite) as the regular Bayer process aluminum hydroxide, and the particle size is almost the same, so conventional methods can be applied to clean and remove impurities. can. In addition, this method can be used regardless of the preparation method as long as the seeds used are fine gibbzite, such as finely ground aluminum hydroxide from the general Bayer process, or commercially available aluminum hydroxide for coating pigments. The amount is extremely small, and the conventional Bayer method can be applied as is for the precipitation mother liquor and precipitation method, except for the seeds, so it has the advantage of being extremely inexpensive to produce. That is, according to the present invention, aluminum hydroxide is precipitated by adding a small amount of fine particles of aluminum hydroxide as seeds to an aluminate alkaline solution used in the usual Bayer method, and aluminum hydroxide having good solubility in acids is produced. can be manufactured at extremely low cost. The present method will be explained in more detail below based on Examples, but the Examples are not intended to limit the present method. Example 1 Aluminum hydroxide (having a particle size distribution of +74 μm 28% and -44 μm 22%) obtained by the usual Bayer method was dry-pulverized in a ball mill, and fine powder with an average particle size of 2.7 μm was obtained by the sedimentation method. None, 26 kg of this was added to 4 M 3 of aluminic acid solution with the composition shown in Table 1 sent to the Bayer method precipitation process, and precipitation was performed for 42 hours. +74 μm 22%, −44 μm 11
288Kg of aluminum hydroxide with particle size distribution of %
Obtained. (Alumina equivalent weight ratio of aluminum hydroxide added as seeds to dissolved alumina in the liquid (hereinafter referred to as seed ratio): 3.6%)
【表】
実施例 ２
通常のバイヤー法分級工程より得られた＋74μ
ｍ 12％、−44μｍ 36％の粒径分布を持つ水酸
化アルミニウムを523ｇ／含む濃厚懸濁液をコ
ニカルボールミルに導き、湿式粉砕を行つたとこ
ろ、懸濁水酸化アルミニウムの沈降法による平均
径は2.1μｍまで減少した。次に懸濁液を第２表に
示す組成のバイヤー法析出工程に送られるアルミ
ン酸液4M3に対し30添加し、42時間析出を行つ
たところ＋74μｍ 18％、−44μｍ 16％の粒径分
布を持つ水酸化アルミニウムが263Kg得られた。
（種子率2.2％）[Table] Example 2 +74μ obtained from normal Bayer classification process
A concentrated suspension containing 523 g of aluminum hydroxide with a particle size distribution of m 12% and -44 μm 36% was introduced into a conical ball mill and subjected to wet pulverization, and the average diameter of the suspended aluminum hydroxide determined by the sedimentation method was 2.1. It decreased to μm. Next, 30% of the suspension was added to 4M3 of an aluminate solution having the composition shown in Table 2, which was sent to the Bayer method precipitation process, and precipitation was performed for 42 hours, resulting in a particle size distribution of +74μm 18% and -44μm 16%. 263Kg of aluminum hydroxide was obtained.
(Seed rate 2.2%)
【表】
実施例 ３
塗工顔料用に市販されている沈降法による平均
径が1.2μｍの水酸化アルミニウムを第３表に示す
組成のバイヤー法析出工程に送られるアルミン酸
液4M3に対し８Kg添加し、36時間析出を行つたと
ころ＋74μｍ 13％、−44μｍ 19％の粒径分布を
持つ水酸化アルミニウムが272Kg得られた。（種子
率1.1％）[Table] Example 3 8 kg of aluminum hydroxide with an average diameter of 1.2 μm obtained by the sedimentation method, which is commercially available for coating pigments, is used for 4M 3 of aluminic acid solution sent to the Bayer method precipitation process with the composition shown in Table 3. When the aluminum hydroxide was added and precipitated for 36 hours, 272 kg of aluminum hydroxide with a particle size distribution of +74 μm 13% and -44 μm 19% was obtained. (Seed rate 1.1%)
【表】
比較例 １
実施例２に於て、＋74μｍ 12％、−44μｍ 36
％の粒径分布を持つ水酸化アルミニウムを523
ｇ／含む濃厚懸濁液をそのまま第２表の組成の
アルミン酸液4M3に対し30添加し、42時間析出
を行つたところ、析出槽壁面にスケール状に水酸
化アルミニウムが析出し、この剥離物と見える薄
片状の水酸化アルミニウムが若干得られたが、粉
体状の水酸化アルミニウムは得られなかつた。
（種子率2.2％）
比較例 ２
実施例２に於て、＋74μｍ 12％、−44μｍ 36
％の粒径分布を持つ水酸化アルミニウムを523
ｇ／含む濃厚懸濁液をそのまま第２表の組成の
アルミン酸液4M3に対し70添加し、42時間析出
を行つたところ、＋74μｍ 68％、−44μｍ ３％
の粒径分布を持つ水酸化アルミニウムが183Kg得
られた。また析出槽壁面には比較例１と同様に、
スケール状の析出物が見られた。（種子率5.2％）
上述の実施例１〜３で得られた水酸化アルミニ
ウム（以下試料１〜３）、比較例２で得られた水
酸化アルミニウム（以下試料４）、及び通常のバ
イヤー法により得られた＋74μｍ 15％、−44μｍ
32％の粒径分布を持つ水酸化アルミニウム（以
下試料５）を以下のような溶解試験により溶解性
を比較した。
溶解試験１
環流冷却器を付けたセパラブルフラスコに
6NH2SO41と試料水酸化アルミニウム156ｇｒ
を投入し、撹拌しつつ100℃で90分保持後希釈、
冷却し、定性紙で過洗浄し、未溶解物の重量
百分率を求めた。結果を第４表に示す。[Table] Comparative Example 1 In Example 2, +74μm 12%, -44μm 36
aluminum hydroxide with particle size distribution of 523%
When the concentrated suspension containing g/g was added as is to 4M3 of aluminic acid solution with the composition shown in Table 2 and precipitation was carried out for 42 hours, aluminum hydroxide was precipitated in the form of scale on the wall of the precipitation tank, and this peeling occurred. A small amount of aluminum hydroxide in the form of flakes that looked like a substance was obtained, but no aluminum hydroxide in the form of powder was obtained.
(Seed rate 2.2%) Comparative example 2 In Example 2, +74 μm 12%, -44 μm 36
aluminum hydroxide with particle size distribution of 523%
When the concentrated suspension containing g/g was added as it was to 4M3 of aluminic acid solution with the composition shown in Table 2 and precipitated for 42 hours, +74μm 68%, -44μm 3%
183Kg of aluminum hydroxide with particle size distribution was obtained. Also, on the wall surface of the precipitation tank, as in Comparative Example 1,
Scale-like precipitates were observed. (Seed rate 5.2%) Aluminum hydroxide obtained in Examples 1 to 3 above (hereinafter Samples 1 to 3), aluminum hydroxide obtained in Comparative Example 2 (hereinafter Sample 4), and the usual Bayer method. Obtained +74μm 15%, -44μm
The solubility of aluminum hydroxide (hereinafter sample 5) having a particle size distribution of 32% was compared using the following dissolution test. Dissolution test 1 In a separable flask equipped with a reflux condenser
6NH 2 SO 4 1 and sample aluminum hydroxide 156gr
and diluted after holding at 100℃ for 90 minutes while stirring.
It was cooled and overwashed with qualitative paper, and the weight percentage of undissolved material was determined. The results are shown in Table 4.
【表】
溶解試験２
グラスライニングを施したオートクレーブに35
％HCl溶液60Kg及び試料水酸化アルミニウム22.4
Kgを投入し、120℃で３時間反応を行わしめたの
ち50Kgの希釈水で希釈し、未溶解物を過、洗浄
し、未溶解物の重量百分率を求め、液はJIS
K1475に則り分析し、塩基度を求めた。結果を第
５表に示す。[Table] Dissolution test 2 35 in a glass-lined autoclave
% HCl solution 60Kg and sample aluminum hydroxide 22.4
After the reaction was carried out at 120℃ for 3 hours, it was diluted with 50 kg of dilution water, the undissolved matter was filtered and washed, and the weight percentage of the undissolved matter was determined.
Basicity was determined by analysis according to K1475. The results are shown in Table 5.
【表】
また上記試料２及び５より得られた塩基性塩溶
液にNaOH濃度144ｇ／、Al2O3濃度102ｇ／
のアルミン酸ソーダ溶液を加え、アルミナ濃度
10.0％塩基度50％のPACを調整し、凝集力を調べ
た。尚、PAC中のNa2O含有量は各々1.4％、21
％であつた。凝集力試験はジヤーテストで行い、
原水濁度168゜PH7.2の試験水１にPACを添加し、
急速撹拌（120rpm）２分、緩速撹拌（30rpm）
８分後10分静置し、上澄液濁度を調べた。結果を
第６表に示す。[Table] In addition, the basic salt solutions obtained from Samples 2 and 5 above had a NaOH concentration of 144 g/, and an Al 2 O 3 concentration of 102 g/
Add sodium aluminate solution and adjust the alumina concentration.
PAC with 10.0% basicity and 50% was prepared and its cohesive force was investigated. In addition, the Na 2 O content in PAC is 1.4% and 21%, respectively.
It was %. The cohesive force test was carried out using the jar test.
Add PAC to test water 1 with raw water turbidity 168° PH 7.2,
Rapid stirring (120rpm) 2 minutes, slow stirring (30rpm)
After 8 minutes, the mixture was allowed to stand for 10 minutes, and the turbidity of the supernatant was examined. The results are shown in Table 6.
【表】
溶解試験３
グラスライニングを施したオートクレーブに35
％HCl溶液60Kg及び試料水酸化アルミニウム30Kg
を投入し、140℃で３時間反応を行わしめたのち
60Kgの希釈水で希釈し、未溶解物を過洗浄し、
未溶解物の重量百分率を求め、液はJIS K1475
に則り分析し、塩基度を求めた。結果を第７表に
示す。[Table] Dissolution test 3 35 in a glass-lined autoclave
%HCl solution 60Kg and sample aluminum hydroxide 30Kg
was added and the reaction was carried out at 140℃ for 3 hours.
Dilute with 60Kg of dilution water, overwash undissolved matter,
Determine the weight percentage of undissolved matter, and check the liquid according to JIS K1475.
The basicity was determined by analysis according to the following. The results are shown in Table 7.
【表】
また上記試料３より得られた塩基性塩溶液を
Al2O3濃度10.0％となるよう希釈し、試料５より
得られた塩基性塩溶液は硫酸アルミニウムを添加
後炭酸カルシウムを添加し、生じた硫酸カルシウ
ムを別することにより、塩基度を50％まで上げ
たのちAl2O3濃度を10.0％に調整し、両者の凝集
力を比較した。尚、後者は塩基度上昇の操作に伴
い液中にカルシウム分がCaとして0.12％溶存して
いる。ジヤーテストの条件は溶解試験２で行つた
場合と同じである。結果を第８表に示す。[Table] Also, the basic salt solution obtained from sample 3 above
The basic salt solution obtained from sample 5 was diluted to have an Al 2 O 3 concentration of 10.0%, and the basicity was reduced to 50% by adding aluminum sulfate and then adding calcium carbonate, and separating the resulting calcium sulfate. After increasing the Al 2 O 3 concentration to 10.0%, the cohesive forces of the two were compared. In addition, in the latter case, 0.12% of calcium is dissolved in the liquid as Ca due to the operation to increase the basicity. The conditions for the jar test were the same as those used in dissolution test 2. The results are shown in Table 8.
【表】
第４表、第５表、第７表より、本発明によつて
得れた水酸化アルミニウムは酸への溶解性が通常
のバイヤー法によつて得られるものに比べて極め
てすぐれていることがわかる。
さらに、第６表、第８表より、本発明により得
られた水酸化アルミニウムより製造されたPAC
は、通常のバイヤー法水酸化アルミニウムより製
造されたPACより凝集力が優れていることがわ
かる。
以上の結果により、本発明によつて、各種化学
品原料特に触媒原料或いは、アルミニウム塩凝集
剤原料として酸への溶解性の極めて良好な水酸化
アルミニウムを、安価に製造することができるこ
とは、明らかである。[Table] From Tables 4, 5, and 7, the solubility of aluminum hydroxide obtained by the present invention in acids is extremely superior to that obtained by the usual Bayer method. I know that there is. Furthermore, from Tables 6 and 8, PAC produced from aluminum hydroxide obtained according to the present invention
It can be seen that the cohesive force of PAC made from the usual Bayer process aluminum hydroxide is superior to that of PAC made from aluminum hydroxide. From the above results, it is clear that aluminum hydroxide, which has extremely good solubility in acids, can be produced at low cost as a raw material for various chemicals, especially as a raw material for catalysts, or as a raw material for aluminum salt flocculants. It is.
Claims (1)
カリ溶液に、種子として、沈降法による平均粒子
径が0.3μ以上3μ以下のギブサイトを、液中溶存ア
ルミナに対してアルミナ換算重量比で0.7〜７％
となるように添加し、析出させることを特徴とす
る酸易溶性水酸化アルミニウムの製造法。1 Add gibbsite with an average particle diameter of 0.3μ to 3μ by sedimentation method as seeds to a supersaturated alkaline aluminate solution in which alumina is dissolved, in an amount of 0.7 to 7% by weight in terms of alumina to the dissolved alumina in the solution.
A method for producing easily acid-soluble aluminum hydroxide, which comprises adding and precipitating the acid so that the following formula is obtained.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2073779A JPS55113616A (en) | 1979-02-26 | 1979-02-26 | Manufacture of acid soluble aluminum hydroxide |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2073779A JPS55113616A (en) | 1979-02-26 | 1979-02-26 | Manufacture of acid soluble aluminum hydroxide |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS55113616A JPS55113616A (en) | 1980-09-02 |
| JPS6411570B2 true JPS6411570B2 (en) | 1989-02-27 |
Family
ID=12035500
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2073779A Granted JPS55113616A (en) | 1979-02-26 | 1979-02-26 | Manufacture of acid soluble aluminum hydroxide |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS55113616A (en) |
-
1979
- 1979-02-26 JP JP2073779A patent/JPS55113616A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS55113616A (en) | 1980-09-02 |
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