JP4211339B2 - Inorganic salt treatment method - Google Patents

Description

【００３４】
［実施例７］過剰酸化剤の還元処理
実施例１と同じ条件で処理し、処理後の液中有効塩素量を測定したところ１０ｐｐｍであった。１％亜硫酸ソーダ水溶液を３．５ｇ添加し、室温で５分間撹拌後に再度有効塩素量を測定したところ検出限界以下（０．５ｐｐｍ）であった。
【００３５】
【発明の効果】
本発明の無機塩中に不純物として含まれるアミノ基を有する有機化合物を酸化剤で処理する方法は設備費も殆どかからず、極めて安価な酸化剤を少量使うことで実施可能であるため、低コストで実施可能であり、工業的に非常に有利である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to inorganic salts used for dyeing, bathing agents and the like, particularly sodium sulfate or an aqueous solution thereof. More specifically, the present invention relates to a method of treating an organic compound having an amino group contained as an impurity in an inorganic salt with an oxidizing agent.
[0002]
[Prior art]
As the sodium sulfate (hereinafter sometimes referred to as “sodium salt”), human silk or byproduct salt is used. Byproduct mirabilite is obtained as a by-product in the production of sodium dichromate, ammonium perchlorate, boric acid, formic acid, and amino acids. Usually, these byproduct mirabilite can be used without problems for various applications. However, when by-product mirabilite is used as a dyeing assistant, which is a major application of mirabilite, if a specific impurity is contained, the dyeing property of the dye is greatly reduced and may not be used in this application.
[0003]
As a method for increasing the purity of mirabilite, there is known a method using a chelate resin as disclosed in JP-A-8-337417 (Patent Document 1). Is less effective. Also, the equipment cost is large. Further, as described in JP-A-2002-104820 (Patent Document 2), there is a method for crystallizing mirabilite in a silicic acid / condensed phosphoric acid dissolved state. In general, mirabilite is a byproduct, and more useful substances are available. In many cases, it is present in the filtrate, and adding new silicic acid, condensed phosphoric acid or the like is not an excellent method.
[0004]
Moreover, the method of removing harmful components with an adsorbent such as activated carbon is expensive in terms of equipment costs and adsorbent costs.
[0005]
[Patent Document 1]
JP-A-8-337417 [Patent Document 2]
Japanese Patent Laid-Open No. 2002-104820 [0006]
[Problems to be solved by the invention]
The present invention requires very little new equipment, is extremely inexpensive, and includes a method for treating an inorganic salt (especially mirabilite) that cannot be used for dyeing because it contains impurities, a production method including the treatment step, It is an object of the present invention to provide a treated inorganic salt and a method of using the inorganic salt for dyeing purposes.
[0007]
[Means for Solving the Problems]
The present inventors have analyzed the non mirabilite used as dyeing auxiliaries, was subjected to a specific interfering compound, an organic compound containing an amino group, particularly found that interfering with amino acid significantly stained. As a result of intensive studies, inorganic salts containing organic compounds containing amino groups (byproduct mirabilite, etc.) can be used for dyeing purposes by treating them with an oxidizing agent, particularly sodium hypochlorite. The present inventors have found that this can be done and have completed the present invention.
[0008]
That is, the present invention relates to items shown in the following [1] to [6] .
[1] A method for treating sodium sulfate , characterized in that sodium sulfate containing amino acids as impurities is treated with an aqueous solution at 30 to 80 ° C., wherein the oxidizing agent is sodium hypochlorite, A method for treating sodium sulfate, which is at least one of potassium manganate and hydrogen peroxide .
[2] The method for treating sodium sulfate according to [1] , wherein the oxidizing agent is sodium hypochlorite.
[3] The method for treating sodium sulfate according to [2] , wherein [ effective chlorine of sodium hypochlorite] / [amino group] (mol / mol) = 1.0 to 10.0.
[4] The method for treating sodium sulfate according to any one of [1] to [3], wherein the amino acid is glycine or alanine.
[5] A method for producing sodium sulfate , the method comprising the method for treating sodium sulfate according to any one of [1] to [4] .
[6] A method for producing sodium sulfate for dyeing comprising the method for treating sodium sulfate according to any one of [1] to [4] in a step.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail.
In the present invention, as the organic compound having an amino group as an impurity, various aliphatic amines, aromatic amines, and amino acids can be mentioned. The treatment method of the present invention is particularly effective when an amino acid is an impurity.
[0010]
Amino acids as impurities include, but are not limited to, glycine, alanine, valine, leucine, phenylalanine, tyrosine, threonine, serine, proline, tryptophan, thyroxine, methionine, cystine, cysteine and the like.
[0011]
Examples of the inorganic salt suitable for the oxidizing agent treatment of the present invention include sodium chloride, potassium sulfate, potassium chloride, sodium sulfate, and the like, but particularly effective in the case of sodium sulfate (sodium salt).
[0012]
Examples of inorganic salts containing an organic compound having an amino group as an impurity include those generated as a by-product during amino acid production. When the inorganic salt is sodium sulfate, it is called by-product sodium sulfate. When a compound having an amino group and a cyano group is used as an amino acid raw material, an amino acid can be obtained by hydrolyzing the cyano group with NaOH to form a COONa group and neutralizing it with sulfuric acid. At this time, sodium sulfate is by-produced. After separation of the amino acid as the target compound, sodium sulfate by-product compound (by-product salt cake) but also separated, amino-product salt cake produced in this way is the target product of the original reaction impurities Will be included.
[0013]
In the present invention, the oxidant treatment of an inorganic salt containing an organic compound having an amino group as an impurity is preferably performed in an aqueous solution of the inorganic salt from the viewpoint of reactivity and ease of operation. The concentration of the inorganic salt in the aqueous solution is not particularly limited. The inorganic salt is preferably used in a concentration range of 15% by mass to 32% by mass. The concentration range is more preferably 20% by mass to 31% by mass, and still more preferably 25% by mass to 31% by mass. If the concentration is lower than this, a large tank is required to treat the same amount of inorganic salt, which is industrially disadvantageous. On the other hand, if the concentration is higher than this, crystals may be deposited, making it impossible to process in a uniform system.
[0014]
As the oxidizing agent of the present invention, hydrogen peroxide solution, potassium permanganate, sodium hypochlorite and the like can be applied, and sodium hypochlorite is particularly preferable. Sodium hypochlorite works satisfactorily even at a low temperature of about 40 ° C. when it is treated in an amount twice as much as an effective chlorine content with respect to the amino group of an organic compound having an amino group as an impurity. In the case of hydrogen peroxide water and potassium permanganate, it is necessary to treat at a high temperature of about 90 ° C. or more, which is disadvantageous in terms of energy.
[0015]
In the following, suitable conditions for treating sodium sulfate containing an organic compound having an amino group as an impurity in an aqueous solution with sodium hypochlorite that is most effective as an oxidizing agent will be described. In the case of a combination of other inorganic salts and oxidizing agents, it can be applied with slight changes in conditions.
[0016]
The outline of the oxidation treatment procedure is as follows.
(1) Prepare an aqueous solution of mirabilite.
(2) Adjust the pH of the aqueous solution.
(3) Add sodium hypochlorite and oxidize at an appropriate time and temperature.
(4) Collect salt cake as needed. (Crystallization, etc.)
[0017]
The treatment temperature is preferably 30 to 80 ° C. More preferably, the treatment is performed at 40 to 60 ° C. If the temperature is lower than this, the processing time becomes longer and the productivity deteriorates. Higher temperatures are disadvantageous in terms of energy.
[0018]
The pH during the treatment is preferably 8-13. More preferably, the treatment is performed at 9 to 12. If the pH is higher than this, a large amount of acid must be used for neutralization after the treatment, which is industrially disadvantageous. In the lower pH range, the chlorine odor is severe and the working environment is deteriorated, which is not preferable. For pH adjustment, caustic soda (NaOH), caustic potash (KOH), or the like can be used.
[0019]
The treatment time is preferably 30 minutes to 3 hours. More preferably, the treatment is performed for 45 minutes to 90 minutes. When shorter than this, the organic compound which has an amino group will remain | survive and it will become difficult to use for a dyeing use. Conversely, even if the length is longer than this, the active ingredient in the sodium hypochlorite is decomposed, so that there is no effect corresponding to the treatment time.
[0020]
The amount of sodium hypochlorite used is preferably such that the effective chlorine content of sodium hypochlorite is 1 to 10 times the mol of the amino group in the organic compound having an amino group. More preferably, the treatment is carried out at 1.5 to 4 mol. If the amount is less than this, the remaining amount of amino groups is large and not suitable for dyeing applications. On the other hand, the effect is not improved even if it is more than this, and it is a wasteful cost. Here, effective chlorine will be described. Aqueous sodium hypochlorite is cause iodine to oxidize potassium iodide, also to the called effective chlorine amount was calculated as the amount of chlorine to generate this same amount of iodine. The measurement conforms to JIS K0102.
[0021]
As sodium hypochlorite, low-sodium sodium hypochlorite is more preferable. This is because it is possible to keep the chloride ion concentration in the treatment liquid low by using the low salt type.
[0022]
Sodium hypochlorite may be added in one batch or divided into several times.
[0023]
Depending on the use of mirabilite, it is preferable to perform a treatment of inactivating the excess oxidizing agent with a reducing agent after the oxidation treatment. The reducing agent is not particularly limited, but sodium sulfite, sodium thiosulfate and the like are suitable. The reducing agent Glauber's salt of applications remained may be used in excess if in any way a negative impact. If the reducing agent has any adverse effect, it is preferable to quantify the excess oxidizing agent and use an amount that is not excessive or deficient.
[0024]
When mirabilite is used as a dyeing assistant, when an organic compound having an amino group is converted to glycine (one compound having one amino group = one molecule of glycine, one compound having two amino groups = two molecules of glycine, Hereinafter, the same is counted), and the glycine equivalent amount is preferably 30 wtppm or less (in terms of solid sodium sulfate).
[0025]
【Example】
The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples. In addition, ppm means wt / wtppm.
The anhydrous mirabilite used in Examples 1 to 3 is byproduct mirabilite which is a by-product during glycine production. This byproduct mirabilite is produced when glycine soda, which is a raw material of glycine, is neutralized with sulfuric acid.
[0026]
<Quantification of amino group>: Ninhydrin method The amino group in this example was quantified by the ninhydrin method. Specific operations are as follows.
(1) Mix 50 ml of sodium nitrate aqueous solution and 50 ml of ethanol. (2) Let stand and settle the precipitate, then collect 20 ml of supernatant and add 5 ml of 0.3% ninhydrin ethanol solution to this. (3) (2) The liquid of ▼ is heated and boiled for about 10 minutes.
(4) The liquid of (3) is made up to 20 ml with pure water (ion exchange water).
(5) Measure the absorbance at 570 nm.
The above operation is performed with an aqueous solution of sodium silicate that has a known glycine concentration, a calibration curve is prepared, and the amino group of the test sample is converted to glycine and quantified.
[0027]
[Example 1]
Pure glycine anhydrous sodium sulfate 300g containing 290ppm (ion exchanged water) was 700g pressurized example completely dissolved. When the glycine concentration of this solution was measured by the ninhydrin method, it was 85 ppm. After adjusting this solution to pH 11 with sodium hydroxide, 1.7 g of an aqueous sodium hypochlorite solution containing 14% of effective chlorine (3 times mol of glycine effective chlorine) was added and stirred at 40 ° C. for 1 hr. When this processing solution was analyzed, the glycine concentration was 1.5 ppm (5 ppm relative to anhydrous sodium sulfate).
[0028]
[Example 2]
Pure water anhydrous sodium sulfate 300g that glycine containing 290ppm was 700g pressurized example completely dissolved. The glycine concentration of this solution was measured and found to be 85 ppm. This example 0.54g pressurized potassium permanganate to the solution and 1hr stirring at 100 ° C.. When this treatment solution was analyzed, the glycine concentration was 2.8 ppm (9.3 ppm relative to anhydrous sodium sulfate). When the same treatment was performed at 40 ° C., the glycine concentration was 41 ppm (137 ppm relative to anhydrous sodium sulfate).
[0029]
[Example 3]
700 g of pure water was added to 300 g of anhydrous sodium sulfate containing 290 ppm of glycine and completely dissolved. The glycine concentration of this solution was measured and found to be 85 ppm. To this solution, 0.33 g of 35% hydrogen peroxide water (3 times mol of glycine) was added and stirred at 100 ° C. for 1 hr. The concentration of glycine was 32 ppm (107 ppm relative to anhydrous sodium sulfate).
[0030]
[Example 4]
78 mg of alanine (special grade reagent manufactured by Junsei Chemical Co., Ltd.) and 300 g of reagent mirabilite (special grade reagent manufactured by Junsei Chemical Co., Ltd.) were added to 700 g of pure water and completely dissolved. It was 70 ppm when alanine of this solution was converted into glycine and measured. This solution was adjusted to pH 11 with caustic soda, and then 1.4 g of an aqueous sodium hypochlorite solution containing 14% of effective chlorine (3 times mol of glycine effective chlorine) was added and stirred at 40 ° C. for 1 hr. When this treatment solution was analyzed, the glycine equivalent concentration of alanine was 1.8 ppm. This is 7.1 ppm alanine (6 ppm in terms of glycine) with respect to anhydrous sodium sulfate.
[0031]
[Example 5]
Methylamine (manufactured by Junsei Chemical Co., Ltd. special grade reagent) 33 mg and the reagent sodium sulfate 300g was completely dissolved was added to the pure water 7 200 g. It was 80 ppm when methylamine of this solution was measured in terms of glycine. After adjusting this solution to pH 11 with caustic soda, 1.6 g of an aqueous sodium hypochlorite solution containing 14% of effective chlorine (3 times mole of effective glycine chlorine) was stirred at 40 ° C. for 1 hr. When this treatment solution was analyzed, the glycine equivalent concentration of methylamine was 1.4 ppm. This is 1.9 ppm methylamine (4.7 ppm in terms of glycine) with respect to anhydrous sodium sulfate.
[0032]
[Example 6]
Dyeing evaluation was performed using the mirabilite solution before treatment with sodium hypochlorite described in Examples 1, 4, and 5 and the mirabilite solution after treatment with sodium hypochlorite. Evaluation was performed as follows.
2 g of 1.3% remazole blue B (manufactured by Dystar), 458 g of pure water, and 10 g of sodium carbonate were mixed, and 66 g each was dispensed into 7 100 ml beakers. 24 g each of 30% aqueous solution prepared with the above-mentioned mirabilite solution or reagent mirabilite (manufactured by Junsei Kagaku, reagent grade) was added. Each of these was immersed in 3 g of gauze, allowed to stand at 70 ° C. for 1 hr, and then taken out, washed well with water and dried, and the degree of blue staining was visually determined.
[0033]
[Table 1]

[0034]
[Example 7] Reduction treatment of excess oxidizing agent Treatment was performed under the same conditions as in Example 1, and the amount of effective chlorine in the liquid after the treatment was measured. When 3.5 g of 1% sodium sulfite aqueous solution was added and stirred for 5 minutes at room temperature and the amount of effective chlorine was measured again, it was below the detection limit (0.5 ppm).
[0035]
【The invention's effect】
The method of treating an organic compound having an amino group contained as an impurity in the inorganic salt of the present invention with an oxidizing agent requires little equipment cost and can be carried out by using a very inexpensive oxidizing agent. It can be implemented at low cost and is very advantageous industrially.

Claims (6)

Sodium sulfate containing an amino acid as an impurity is treated with an aqueous solution and an oxidizing agent at 30 to 80 ° C., wherein the oxidizing agent is sodium hypochlorite or potassium permanganate A method for treating sodium sulfate, characterized in that it is at least one of hydrogen peroxide water . The method for treating sodium sulfate according to claim 1 , wherein the oxidizing agent is sodium hypochlorite. 3. The method for treating sodium sulfate according to claim 2 , wherein [effective chlorine of sodium hypochlorite] / [amino group] (mol / mol) = 1.0 to 10.0. The method for treating sodium sulfate according to any one of claims 1 to 3, wherein the amino acid is glycine or alanine. The manufacturing method of sodium sulfate which includes the processing method of the sodium sulfate as described in any one of Claims 1-4 in a process. The manufacturing method of the sodium sulfate for dyeing which contains the processing method of the sodium sulfate as described in any one of Claims 1-4 in the process.