JPS6236962B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a fine sodium carbonate hydrogen peroxide adduct (2Na ₂ CO ₃ .3H ₂ O ₂ hereinafter referred to as PC). PC, which has been gaining importance in recent years as an oxygen bleaching agent, is usually manufactured as a granular product that is easy to handle. One method for providing this granular form is to granulate powdered crystals, and it is desirable to use as fine a powdered PC as possible as the granulation raw material. A method for producing PC by reacting a sodium carbonate solution or a sodium carbonate suspension with an aqueous hydrogen peroxide solution is known, but if one attempts to obtain fine powdered PC by simply carrying out this reaction, the crystals will be fine. As a result, the hydrogen peroxide aqueous solution and sodium carbonate or its aqueous solution supplied to the mother liquor as raw materials are prevented from quickly dispersing into the reaction mother liquor. However, as a result of the local concentration increase, the liquid quality deteriorates further, and batch-type production is required, in which all of the crystallized crystals are separated by filtration, and then the reaction is carried out again, resulting in extremely low production efficiency. Not only are there serious industrial problems such as poor water quality, but the crystals obtained under these conditions have poor dehydration properties, and the separated cake has an extremely high water content, making it difficult to carry out industrially. is difficult. For this reason, known methods mainly use polyelectrolytes such as polyphosphates or polyacrylates to make the crystals finer or coarser, improving manufacturing operability, and producing PC with good fluidity and wear resistance. However, the formation of fine crystals has been avoided as it impedes filterability and other problems. However, such coarsened PC is not originally suitable for purposes such as granulation, and even if granulated, the characteristics such as high dissolution rate and high dispersibility that granulated particles should originally have are not sufficient. It is not demonstrated. For these reasons, the known methods are unsuitable and cannot be used as industrial methods for producing fine powdered PC.

Therefore, the present inventors have conducted intensive research on a method for producing fine PC with good manufacturing operability, and have found that the desired PC can be easily produced industrially in a slurry state and in a state with good dehydration properties. I found a way to do this and completed it.

That is, the present invention provides a method for continuously or intermittently supplying sodium carbonate and hydrogen peroxide in a mother liquor having a specific composition containing sodium carbonate and hydrogen peroxide.
When reacting and crystallizing PC, a specific amount of Mg ⁺⁺ is added and coexisting, and the amount of silicate compound added to this system as a hydrogen peroxide stabilizer is limited to Mg ⁺⁺ . The present invention relates to a method for producing fine PC in a continuous or batch manner with good manufacturing operability by modifying and modifying the crystals to be crystallized by using the method.

Conventionally, Mg ⁺⁺ has been used as a stabilizer to further improve the stability of PC by being used in combination with a silicic acid compound added as a stabilizer for PC, and is generally added for this purpose. However, for example, according to JP-A-52-117897, Mg ⁺⁺ is used for the purpose of increasing the hardness of particles, and in JP-A-53-146996, it is also used for the purpose of improving the free flow properties and anti-wear properties of particles. It is used. However, these methods are performed in combination with other strong modifiers,
The purpose of use, the method, and the form of the obtained PC are all significantly different from the present invention.

As shown in the examples, the addition and coexistence of Mg ⁺⁺ was found to have a sufficient effect on the dehydration of crystals and the modification of slurry state, but it alone has practical utility as a modifier. To use it,
It has also been found that certain conditions must be met. That is, in order to ensure sufficient stability during storage of PC and to avoid decomposition loss of hydrogen peroxide during production, the coexistence of a silicate compound is essential, and Mg ⁺⁺ alone cannot achieve this purpose. I can't. For this reason, it is impossible to add and coexist a silicic acid compound to the reaction system, but due to this addition and coexistence,
Mg ⁺⁺ significantly inhibits the effect of crystal modification and modification, and depending on the quantitative relationship, the effect cannot be expected to be expressed at all. In order to avoid such inconveniences and produce fine powder PC with industrial value, it is necessary to satisfy a specific relationship between the two and other reaction crystallization conditions. .

According to the present invention, solid sodium carbonate and an aqueous hydrogen peroxide solution are continuously or intermittently supplied into a mother liquor having a controlled composition, and the reaction is carried out while stirring in a reaction vessel, and furthermore, the desired PC is produced. Crystallize, extract the crystals from the container continuously, intermittently, or in batches by extracting the entire amount, perform solid-liquid separation according to conventional methods, and obtain the filtrate immediately or after adjusting the composition. In the method of recycling into the container, the mother liquor composition is 7-20% by weight for sodium carbonate concentration, preferably 9-17% by weight for hydrogen peroxide concentration, 1.5-6% by weight for hydrogen peroxide concentration,
It is preferably 2 to 4% by weight, and the molar ratio of hydrogen peroxide to sodium carbonate is controlled to be 1.3 to 0.2, preferably 0.9 or less. If the molar ratio exceeds the upper limit, particulate coarse PC will be partially formed, which is not desirable. Regarding Mg ⁺⁺ concentration
0.001 to 0.5% by weight, preferably 0.002% by weight or more, and the water-soluble Si concentration is 0.003 to 0.1% by weight,
The molar ratio of Si to Mg ⁺⁺ is maintained at 12 or less, preferably 8 or less. The supplied sodium carbonate can be in the form of an aqueous solution, granules, solid anhydrous powder, or hydrated sodium carbonate; however, in the case of an aqueous solution, coarse granules may be used.
Although it has the advantage that it is difficult to generate PC, it causes an excessive increase in the mother liquor, which requires concentration or partial disposal when recycling the mother liquor, which has a large industrial disadvantage, and solid sodium carbonate cannot be used. It's advantageous. It is also necessary to select and use the hydrogen peroxide concentration to be supplied so as not to cause fluctuations in the amount of mother liquor. Generally 40% by weight
Preferably, an 80% by weight aqueous hydrogen peroxide solution is used.

The supply of Mg ⁺⁺ is not particularly limited as long as it is a magnesium compound that substantially provides Mg ⁺⁺ and is inactive against the decomposition of hydrogen peroxide, but generally magnesium sulfate, magnesium chloride, etc. Such a water-soluble magnesium salt is dissolved in an aqueous solution or an aqueous hydrogen peroxide solution and added continuously or intermittently to the reaction mother liquor.

In order to obtain a sufficient effect for modifying the crystals and improving the slurry state and dehydration properties, the amount of Mg ⁺⁺ added must be adjusted in terms of weight ratio to the supplied sodium carbonate.
Mg ⁺⁺ /Na ₂ CO ₃ = 0.01/100 to 1/100 preferably
The ratio is 0.02/100 or more, more preferably 0.12/100 or more, and this addition causes the PC crystals to change from a needle shape to a plate shape, including intermediate shapes, resulting in a slurry state and deterioration of dehydration properties. As a result of the disentanglement between crystals, which is the main cause of this, the slurry condition and dehydration properties are greatly improved. However, as is known
In order to make the stability of PC sufficient for practical use, it is essential to add a silicic acid compound as a stabilizer, and although this addition improves the stability, the above
The modification effect is significantly inhibited by Mg ⁺⁺ . Therefore, the amount of the silicic acid compound added must be within a limited range in relation to the amount of Mg ⁺⁺ added, and the amount must be such that the resulting PC has sufficient stability for practical use. The amount of silicate compound supplied for this purpose is as water-soluble Si in weight ratio to the supplied sodium carbonate, Si/Na ₂ CO ₃ = 0.02/100 to 0.5/100, preferably 0.04/100 to 0.2/100. , and the molar ratio of Si/Mg ^{++ to Mg ++ is}
It needs to be 2.5 or less, preferably 2.0, more preferably 1.0 or less.

As the silicate compound, known stabilizers such as water glass, various water-soluble sodium silicates such as sodium metasilicate, magnesium silicate, or colloidal silica can be used, but poorly or insoluble silicate compounds Since most of the added substances are suspended in the mother liquor in a substantially insoluble state, the above values do not refer to the absolute amount but to the portion in the water-soluble state or the part that is substantially dissolved in the mother liquor. It should be understood as These silicic acid compounds are usually fed continuously or intermittently as an aqueous solution into the reaction mother liquor or into the circulated mother liquor. Sodium carbonate, hydrogen peroxide, Mg ⁺⁺ , and silicic acid compounds are fed into the reaction vessel while being controlled so that the composition of each component in the mother liquor is within the range to be maintained.

Sodium carbonate and hydrogen peroxide supplied by the above method react in the mother liquor and crystallize and grow as PC, but when the raw material supply rate exceeds the crystallization rate, Since a highly supersaturated system is transiently formed, the crystals become predominant needle-shaped crystals and precipitate rapidly, making it impossible to achieve the purpose. For this reason, the feed rate of sodium carbonate, which is continuously or intermittently fed, is preferably such that the weight ratio of Na ₂ CO ₃ /mother liquor is 50/100 or less, preferably 30/100 or less, per unit time. In addition, in order to obtain a sufficient crystallization rate for modified crystals and to avoid excessively supersaturated system formation, it is necessary to ensure that the crystals suspended in the mother liquor have a sufficient surface area and that the amount of crystallization is Preferably, corresponding crystal growth takes place. From this point of view, it is generally advantageous to have a large amount of PC in the mother liquor, but if it is too large, physical stimulation due to friction between crystals will also increase, making it easier to induce the formation of needle-like crystals. Therefore, it is preferable to draw out the slurry from the reaction vessel so that its concentration is adjusted to 200 g/~400 g/. In continuous reaction crystallization, in order to obtain crystals with a constantly stable particle size, it is necessary to constantly generate new crystals, but this depends not only on the degree of supersaturation but also on various other factors. Therefore, it is not always easy to control it because it is greatly affected. Therefore, when carrying out the present invention, for the purpose of reducing the influence of supersaturation degree and controlling the grain size and size of crystals over a somewhat wide range, it is necessary to supply fine PC as a seed crystal to the reaction crystallization system. By performing the inoculation method, the grain size or size of the crystals can be controlled more reliably.

The seed crystals used for this purpose are preferably plate-shaped crystals that have been pulverized by a conventional method such as a dry or wet method, and are placed in a reaction vessel as a powder or suspended in a circulating mother liquor. Alternatively, a portion of the reaction slurry may be wet-pulverized as it is and circulated within the reaction vessel. The amount of seed crystals used is not particularly limited depending on the desired crystal grain size, etc., but since using a large amount leads to a decrease in production efficiency, it is generally twice the weight ratio of the sodium carbonate to be supplied. It is desirable to use the amount less than 0.5 times the amount, preferably less than 0.5 times the amount.

Feed rate of raw materials, amount of slurry in the reaction vessel,
The average residence time of crystals determined from slurry concentration, slurry withdrawal speed, etc. is important as it combines various conditions, and if it is too short, crystal denaturation may occur due to the formation of an excessively supersaturated system for crystallization. This not only adversely affects the reforming process, but also prevents the complete reaction from proceeding, especially when sodium carbonate is fed in solid form. For this reason, it is theoretically desirable for the residence time to be long, but this is not advantageous from an industrial perspective as it leads to a decrease in production efficiency per unit time or reactor capacity, and in this sense there is an upper limit. has.
In the present invention, the residence time is 20 minutes to 4 hours, preferably 40 minutes or more. The liquid temperature at the stage of reaction crystallization is 10℃ to 40℃, preferably 15℃.
Cooling is performed as necessary to maintain the temperature between 30°C and 30°C, but temperatures exceeding 40°C are undesirable as they will result in significant hydrogen peroxide loss; If the sodium carbonate used is solid, it will be difficult to completely dissolve the raw material in the reaction vessel, and the reaction will be insufficient and it will be discharged.

Therefore, the temperature at this stage must be maintained at a necessary and sufficient temperature. However, since PC exhibits high solubility at high temperatures, the hydrogen peroxide concentration in the mother liquor inevitably increases at high temperatures, increasing hydrogen peroxide loss per unit volume of mother liquor. To avoid such inconveniences, the reaction temperature should be kept at the lowest temperature necessary for complete reaction, and if desired,
It is advantageous to secondarily cool the slurry extracted after the reaction to further crystallize the PC dissolved in the mother liquor, thereby reducing the hydrogen peroxide concentration. According to this method, less than 300 microns85~
Fine powder crystals of 98%, 45-80% below 150 microns are easily obtained, and even 85% below 300 microns.
It is possible to obtain fine powder crystals of ~100% and 45% to 85% below 150 microns, making it suitable as a raw material for granulation and other purposes.When carrying out this method, use other than silicic acid compounds as a stabilizer. Although it is possible to further improve the stability by using a known stabilizer such as phosphorus compounds such as sodium pyrophosphate or sodium tripolyphosphate or an organic chelating agent such as EDTA, the stabilizing effect of these is essentially is based on complex sequestration of metals, which also partially sequesters Mg ⁺⁺ and reduces the effect of Mg ⁺⁺ . Therefore, when these are used in combination in this method, it is desirable to increase the amount of Mg ⁺⁺ added and coexisting in accordance with the combined amount and the Mg ⁺⁺ sequestering ability. Furthermore, when carrying out this method, known crystal modifiers such as polyelectrolytes such as sodium hexametaphosphate and sodium polyacrylate may be used together, but unless specifically desired, their addition is not recommended in this method. Not needed at all.

The present invention will be explained below using examples.

Comparative Example 1 Mother liquor 30 having a composition of 13.9% by weight of sodium carbonate, 2.6% by weight of hydrogen peroxide, and 0.003% by weight of Si was placed in a reaction vessel with a diameter of 40 cm and stirred at a speed of 130 rpm using a stirring blade with a diameter of 22 cm. and set the liquid temperature to 25
Add granular anhydrous sodium carbonate while maintaining at 6.0 °C.
Kg/Hr, 60% hydrogen peroxide 4.97Kg/Hr, 100g/Hr of 20% aqueous solution of No. 3 sodium silicate
was continuously fed into the reaction vessel at a rate of . The viscosity of the slurry increased 25 minutes after the start of the reaction, and the supplied sodium carbonate was not dispersed below the liquid surface but solidified above the liquid surface, making it impossible to continue the reaction any further. Next, this slurry (slurry concentration 111
g/) was taken out from the container and centrifugally dehydrated at 1200G for 2 minutes, the moisture content of the dehydrated cake was 29.4%, and the particle size of the obtained PC was 83.4% by weight of 300μ or less, 70.2% by weight of 150μ or less, The effective oxygen content is 13.3% by weight, and the impurity content is Na ₂ CO ₃
was 12.4% by weight. In addition, in this law
The addition amount ratio of Mg ⁺⁺ to the Na ₂ CO ₃ supply amount (Mg ⁺⁺ /Na ₂ CO ₃ ) is 0% by weight, which is the same as that of water-soluble Si.
Addition ratio to Na ₂ CO ₃ supply amount (Si/Na ₂ CO ₃ )
is 0.045% by weight, and the molar ratio of hydrogen peroxide to sodium carbonate in the mother liquor (H ₂ O ₂ /
Na ₂ CO ₃ ) ranged from 0.5 to 0.8.

Reference Example 1 Using a mother liquor having a composition of 13.9% by weight of sodium carbonate, 2.6% by weight of hydrogen peroxide, 0.007% by weight of Mg ⁺⁺ , and 0.004% by weight of Si, a 20.0% by weight MgSO ₄ aqueous solution was added at a rate of 122g/Hr. The reaction was carried out under the same conditions as in Comparative Example 1, except that it was continuously supplied. reaction 1
After an hour, the slurry (slurry concentration 241g/) was extracted and dehydrated at 1200G for 2 minutes.The moisture content of the cake was 14.8%, and the particle size of the obtained PC was 88.3% by weight below 300μ and 57.5% by weight below 150μ. The effective oxygen content was 13.9% by weight, and the impurity content was 9.0% by weight of Na ₂ CO ₃ . In addition, in this method, the addition amount ratio of Mg ⁺⁺ to the Na ₂ CO ₃ supply amount (Mg ⁺⁺ /Na ₂ CO ₃ ) is 0.082% by weight, and the water-soluble
Addition ratio of Si to Na ₂ CO ₃ supply (Si/
Na ₂ CO ₃ ) is 0.045% by weight, and the added Si
The molar ratio of Mg ⁺⁺ to Si (Si/Mg ⁺⁺ ) is 0.477, and the molar ratio of Mg ⁺⁺ to Si in the mother liquor (Mg ⁺⁺ /
Si) ranges from 0.4 to 0.7, and the molar ratio of hydrogen peroxide to sodium carbonate in the mother liquor (H ₂ O ₂ /
Na ₂ CO ₃ ) ranged from 0.5 to 0.8.

Example 1 Using a mother liquor having a composition of 13.9% by weight of sodium carbonate, 2.6% by weight of hydrogen peroxide, 0.013% by weight of Mg ⁺⁺ , and 0.007% by weight of Si, a 20.0% by weight MgSO ₄ aqueous solution was added at a rate of 234 g/Hr. The reaction was carried out under the same conditions as in Comparative Example 1, except that the water was continuously supplied. One hour after the start of the reaction, slurry (slurry concentration 243g/
) was extracted and subjected to centrifugal dehydration at 1200G for 2 minutes.The moisture content of the cake was 12.5%, and the particle size of the obtained PC was 97.4% by weight below 300μ, 80.7% by weight below 150μ.
The effective oxygen content was 14.4% by weight, and the impurity content was 5.6% by weight of Na ₂ CO ₃ . In addition, in this method, the addition amount ratio of Mg ⁺⁺ to the Na ₂ CO ₃ supply amount (Mg ⁺⁺ /Na ₂ CO ₃ ) is 0.158% by weight, and the addition amount to the Na ₂ CO ₃ supply amount of water-soluble Si is 0.158% by weight. The ratio (Si/Na ₂ CO ₃ ) is 0.045% by weight and is added
The molar ratio of Si to Mg ⁺⁺ (Si/Mg ⁺⁺ ) is 0.248, and the molar ratio of Mg ⁺⁺ to Si in the mother liquor (Mg ⁺⁺ /
Si) ranges from 0.3 to 0.5, and the molar ratio of hydrogen peroxide to sodium carbonate in the mother liquor (H ₂ O ₂ /
Na ₂ CO ₃ ) ranged from 0.5 to 0.8.

Reference Example 2 Mother liquor 30 having a composition of 13.9% by weight of sodium carbonate, 2.6% by weight of hydrogen peroxide, and 0.005% by weight of Mg ⁺⁺
was placed in a reaction vessel with a diameter of 40 cm and stirred at a speed of 100 rpm using a stirring blade with a diameter of 22 cm to maintain the liquid temperature.
Granular anhydrous sodium carbonate while maintaining at 20℃ 5.7
Kg/Hr, 60wt% hydrogen peroxide 4.66Kg/Hr, 20.0
% by weight of _MgSO4 aqueous solution at a rate of 150 g/Hr, a 50% by weight aqueous solution of No. 3 sodium silicate into the reaction vessel at a rate of 110 g/Hr, and the reaction mother liquor composition was 13.5 to 15.0% by weight of sodium carbonate. Hydrogen peroxide is supplied while adjusting the concentration to be 2.5 to 3.5% by weight, until the slurry concentration in the reaction vessel is 250%.
The slurry was continuously extracted from the container so as to maintain g/g/, and the slurry was separated by crystal filtration using a centrifuge.
Continuous reaction crystallization was performed by circulating the filtrate within the reaction vessel. The dehydrated cake obtained after 4 hours had a moisture content of 14.3%, and the crystals after drying had a crystal size of 95.2% by weight below 300 microns, 68.7% below 150 microns, and an effective oxygen content of 14.6% by weight. The impurity content was 4.3% by weight of Na ₂ CO ₃ . In addition, in this method, the addition amount ratio of Mg ⁺⁺ to the Na ₂ CO ₃ supply amount (Mg ⁺⁺ /Na ₂ CO ₃ ) is 0.106% by weight, and the addition amount ratio of water-soluble Si to the Na ₂ CO ₃ supply amount is 0.106% by weight. (Si/Na ₂ CO ₃ ) is 0.131% by weight, and the molar ratio of added Si to Mg ⁺⁺ (Si/Mg ⁺⁺ )
is 1.066, the molar ratio of Mg ⁺⁺ to Si in the mother liquor (Mg ⁺⁺ /Si) ranges from 1.2 to 9.7, and the molar ratio of hydrogen peroxide to sodium carbonate in _the mother liquor ( _H2O2 / _Na2CO3 ) ranged from 0.5 to _0.8 .

Example 2 Using a mother liquor having a composition of 15.5% by weight of sodium carbonate, 2.4% by weight of hydrogen peroxide, and 0.013% by weight of Mg ⁺⁺ , granular anhydrous sodium carbonate was added at 7.0Kg/Hr, 60% by weight while maintaining the liquid temperature at 27°C. % hydrogen peroxide 5.84
Kg/Hr, 20.0% by weight MgSO ₄ aqueous solution 222g/Hr,
50% aqueous solution of No. 3 sodium silicate 84g/
The reaction mother liquor composition is 14.5-16.0 wt% for sodium carbonate, 2.3-3.3 wt% for hydrogen peroxide, and the slurry concentration is
In the same continuous reaction as in Reference Example 2, except that the amount was maintained at 320 g / 8 hours, the cake after dehydration had a water content of 12.2%, and the crystals after drying were 91.7% by weight of 300 microns or less, 150 Micron or less 60.4%
The effective oxygen content was 14.7% by weight, and the impurity content was 3.6% by weight of Na ₂ CO ₃ . In this method, the addition amount ratio of Mg ⁺⁺ to the Na ₂ CO ₃ supply amount (Mg ⁺⁺ /Na ₂ CO ₃ ) is 0.128% by weight, and the addition amount ratio of water-soluble Si to the Na ₂ CO ₃ supply amount is 0.128% by weight. (Si/Na ₂ CO ₃ ) is 0.081% by weight and added
The molar ratio of Si to Mg ⁺⁺ (Si/Mg ⁺⁺ ) is 0.550, and the molar ratio of Mg ⁺⁺ to Si in the mother liquor (Mg ⁺⁺ /
Si) ranges from 0.4 to 5.3, and the molar ratio of hydrogen peroxide to sodium carbonate in the mother liquor (H ₂ O ₂ /
Na ₂ CO ₃ ) ranged from 0.3 to 0.7.

Example 3 As a seed crystal, a part of the wet cake that was continuously extracted and dehydrated after the reaction was resuspended in the circulating mother liquor at a ratio of 1:1 and wet-pulverized to form fine crystals. A continuous reaction was carried out under the same conditions as in Example 2, except that sodium carbonate was continuously fed into the reaction vessel at a ratio of 100:15. After 6 hours of dehydration, the cake has a moisture content of 10.3%.
and the crystal size after drying is less than 300 microns98.2
%, less than 150 microns is 74.5%, the effective oxygen content is 14.7% by weight, and the impurity content is
Na ₂ CO ₃ was 3.2% by weight. In addition, in this method, the addition amount ratio of Mg ⁺⁺ to the Na ₂ CO ₃ supply amount (Mg ⁺⁺ /Na ₂ CO ₃ ) is 0.128% by weight, which indicates that the water-soluble
Addition ratio of Si to Na ₂ CO ₃ supply (Si/
Na ₂ CO ₃ ) is 0.081% by weight, and the amount of Si added is 0.081% by weight.
The molar ratio to Mg ⁺⁺ (Si/Mg ⁺⁺ ) is 0.550, and the molar ratio of Mg ⁺⁺ to Si in the mother liquor (Mg ⁺⁺ /
Si) ranges from 0.4 to 5.3, and the molar ratio of hydrogen peroxide to sodium carbonate in the mother liquor (H ₂ O ₂ /
Na ₂ CO ₃ ) ranged from 0.3 to 0.7.

Claims (1)

[Claims] 1. Solid sodium carbonate and hydrogen peroxide are continuously or intermittently supplied to an aqueous mother liquor, and after reacting and crystallizing them under the following conditions, the produced sodium carbonate peroxide is A method for producing a fine sodium carbonate hydrogen peroxide adduct, which is characterized by separating the hydrogen oxide adduct by filtration to obtain fine crystals. Mother liquor composition is 7 for sodium carbonate concentration.
~20% by weight, 1.5-6 for hydrogen peroxide concentration
wt%, 0.001-0.5 wt% for Mg ⁺⁺ concentration, 0.003-0.1 wt% for Si concentration,
and the molar ratio of Si to Mg ⁺⁺ is maintained below 12, and the molar ratio of hydrogen peroxide to sodium carbonate is maintained below 1.3. Mg ⁺⁺ is added at a weight ratio of Mg ⁺⁺ / _Na2CO3 =0.12/100 to 1/100 to _the sodium carbonate to be supplied. Using silicate or silicic acid as a stabilizer, water-soluble Si is added in weight ratio to sodium carbonate to be supplied.
Add at a ratio of 0.02/100 to 0.5/100 as
In addition, the molar ratio to added Mg ⁺⁺ is 2.0 or less. 2 The particle size of the sodium carbonate hydrogen peroxide adduct produced is 300μ or less 85-100%, 150μ or less 45-85%
The manufacturing method according to claim 1. 3. When carrying out the reaction and crystallization, a fine sodium carbonate hydrogen peroxide adduct is supplied and inoculated at a weight ratio of 1/2 or less to the sodium carbonate to be supplied. Manufacturing method described in section. 4. The production method according to claim 1, characterized in that after the produced sodium carbonate hydrogen peroxide adduct is filtered and separated from the mother liquor, the filtrate is recycled.