RU1748408C - Method of sodium peroxoborate producing - Google Patents

Abstract

FIELD: chemical technology. SUBSTANCE: method of sodium peroxoborate producing involves interaction of oxygen-containing boron derivatives with hydrogen peroxide or sodium carbonate, or their mixture, or sodium metaborate with hydrogen peroxide. Interaction is carried out at the mole ratio of boron and total water content in system 1:(4-10). Prepared mixture is kept at 15-50 C at rest state or at stirring up to its thickening or to additional hardening following by granulation or milling and drying. Granulation of thickened mass is carried out by its extrusion through the holes of required section and disruption of formed product thread for particles of required length. Granulation of hardened mass is carried out by milling with isolation of required fraction and recovery of small fraction for synthesis stage or granulated. Method is used for production of synthetic detergents. EFFECT: improved method of sodium peroxoborate producing. 3 cl, 2 tbl

Description

The invention relates to a technology for the production of peroxols, in particular sodium peroxoborate, which is widely used as a source of active oxygen (O _a ) in the production of synthetic detergents (SMS) and bleaches.

Known methods for producing sodium perborate tetrahydrate (PBN) NaBO ₂ ˙H ₂ O ₂ ˙ 3H ₂ O, or NaBO ₃ ˙ 4H ₂ O by the interaction of aqueous solutions of oxygen-containing compounds of boron, sodium hydroxide or carbonate and hydrogen peroxide with the separation of the resulting crystalline product from the mother solution and further drying of the crystals.

 The disadvantages of this method include the formation in the system of excess water in the form of a mother liquor, which is associated with the need to evaporate it or remove it from the process with the corresponding loss of raw materials and environmental pollution, as well as significant flows of circulating solutions, the presence of a stage of separation of solid and liquid phases, due to additional product losses.

Closest to the proposed method is a method for producing peroxoborates, including the production of sodium peroxoborate with a molar ratio of active oxygen to boron (O _a : B) equal to 1: 1, in which the isolation of solid peroxoborate from the resulting solution (suspension) resulting from the synthesis of the corresponding peroxoborate produced by drying the specified solution (suspension) immediately after synthesis.

According to this method, the synthesis, in particular sodium peroxoborate, with the above molar ratio O _a : B is carried out by introducing boric acid or boric anhydride or sodium tetraborate into a solution of hydrogen peroxide, followed by or simultaneously introducing sodium hydroxide, or introducing sodium metaborate into a solution of hydrogen peroxide based on the molar ratio of O _a : B in the finished product, equal to 1: 1.

Obtained directly after synthesis solution (suspension) is dried at a temperature of 80-200 ^C. coolant and removal time of the liquid phase to 150 s, and the resulting dried particulate product is subjected to granulation with a solution of sodium metaborate or peroxoboroate. Stabilizing additives (sodium, magnesium silicates, etc.) in this method can be introduced both into solutions sent to the synthesis or during the synthesis, and into granular solutions.

 This method eliminates the need for separation of the suspension into solid and liquid phases and, consequently, the formation of mother liquors, simplify the process and reduce product losses. However, a prerequisite for the rapid removal of the liquid phase (up to 150 s) requires intensive drying, which is possible with a sufficient degree of dispersion of the solution (suspension) during the drying process. A high degree of dispersion in the preparation of sodium peroxoborate by this method is achieved by drying relatively dilute solutions (suspensions), which is associated with the need to evaporate significant amounts of water and product losses.

 As a result of a high degree of dispersion and a high drying rate, a finely dispersed product is formed, the average particle size of which is less than 0.05 mm, transportation and further processing of such a product (for example, granulation) presents known difficulties, including from the point of view of sanitary conditions of production from Due to its ability to form dust. The disadvantages of this method include the fact that under conditions acceptable from the point of view of the industry, it allows you to get only a dehydrated product.

 The aim of the invention is to simplify the technology for producing sodium peroxoborate and increase the yield of the product by eliminating the drying of the solution (suspension) of peroxoborate immediately after synthesis and changing the process of formation of the solid phase.

This goal is achieved in that the synthesis of sodium peroxoborate, carried out in an aqueous medium by reacting an oxygen-containing compound of boron, sodium hydroxide or carbonate, or a mixture thereof and hydrogen peroxide, or sodium metaborate and hydrogen peroxide, is carried out at a molar ratio of boron to the total amount of water in the system, equal to 1: 4.0-10.0, and the resulting mixture was kept at 15-50 ^{° C} at rest or while stirring until its thickening or solidification to a subsequent granulation or crushing and drying . In this case, by the total amount of water in the system is meant the water contained in the raw material and resulting from the reactions.

 Granulation of the obtained thickening mass is carried out by molding granules, for example, by passing it through holes of a given cross section, the threads formed after forcing are cut into pieces of a given length and dried. If the reaction mass is aged before solidification, then it is destroyed before or after drying to isolate the desired fraction and the smaller fraction is returned to the synthesis stage or granulated by known methods.

 Well-known stabilizers (silicates, phosphates, sulfates, etc.) can be introduced both into the solutions supplied to the synthesis, and during the synthesis and granulation.

The reaction mass obtained as a result of mixing at this ratio of components is a homogeneous homogeneous solution, which becomes cloudy over time and then gradually thickens, turning into a highly viscous pasty mass, which then turns into a solid product containing 5.7-9 , 3 wt. About _a and 10-45 wt. water. After drying, the gelled or solidified reaction mass at a temperature up to 50 ^{° C} a product with _a content of O 10,0-11,0 wt. that approximately corresponds tetrahydrate sodium peroxoboroate, drying at a temperature of 55 ^{° C} and above produced a product containing about 16 wt. _And O, which corresponds to the monohydrate sodium peroxoboroate.

In the described process, during the interaction of the components in the reaction mass, sodium peroxoborate forms, which after a while begins to crystallize. It can be assumed that under conditions of high concentration, sodium peroxoborate tetrahydrate and partially sodium peroxoborate trihydrate form. This is evidenced by the fact that the water content in the product, dried at low temperature (20-25 ^{° C)} is less than the amount of water corresponding to the content of water of crystallization of sodium peroxoborate tetrahydrate.

 Moreover, under the conditions of this method, the water content in the reaction mixture is selected so that crystallization and the formation of a solid product are possible, as well as the complete capture of all water by the formed solid phase and, therefore, prevention of phase separation (separation of the reaction mass).

 Due to the ability of the reaction mass formed under these conditions to change the viscosity until it hardens completely, it is possible to granulate and dry this mass by the described methods.

PRI me R 1. In a thermostatic reactor with a stirrer at 35 ^about With load of 53 in. h. 32.1 wt. H ₂ O ₂ (17 parts by weight of 100% by weight of H ₂ O ₂ , 0.5 mol), then 31 parts by weight are added with stirring. dry 99.8 wt. H ₃ BO ₃ (30.9 parts by weight of 100 wt. H ₃ BO ₃ , 0.5 mol). To the resulting suspension, 21 parts by weight are added in portions. dry 95 wt. NaOH (20 parts by weight 100 wt.% NaOH, 0.5 mol). In this case, the molar ratio of boron to water, taking into account the water contained in the feed and resulting from the reactions, is 1: 7. Formed transparent homogeneous solution which on standing at ³⁵ ° C and gradually thickens after about 15 minutes is transformed into a viscous mass which has solidified after 5 minutes. The resulting solid product crumbles upon mechanical action. The product is crushed to particles with a size of 0.2-2.0 mm and dried at 60 ^about C. Get a product containing 15.7 wt. O _and which approximately corresponds to the monohydrate sodium peroxoboroate NaBO ₃ ˙H ₂ O.

PRI me R 2. In a thermostatic reactor with a stirrer at 50 ^about With load of 51.2 hours. 33.2 wt. H ₂ O ₂ (17 parts by weight of 100% by weight of H ₂ O ₂ , 0.5 mol). Then add 31 vol. dry 99.8 wt. H ₃ BO ₃ (30.9 parts by weight of 100 wt. H ₃ BO ₃ , 0.5 mol). To the resulting suspension, 48.3 parts by weight are added in portions. 41.4 wt. an aqueous solution of NaOH (20 parts by weight of 100 wt. NaOH, 0.5 mol). In this case, with the same as in the previous and in all subsequent examples, the molar ratio of B: H ₂ O ₂ is 1: 1, the molar ratio of B: H ₂ O is 1:10. It formed a homogeneous clear solution, which was kept at 50 ^C. After 15 min, after entering into the alkali solution becomes thickened viscous mass which is forced through a die 1 mm in diameter. The resulting filament after spinning nozzles cut into particles 0.2-1 mm in length and dried at 50 ° ^C. The product was obtained containing 10.6 wt. _And O, which corresponds to sodium peroxoborate tetrahydrate NaBO ₃ ˙ 4H ₂ O c impurity, likely peroxoboroate sodium trihydrate NaBO ₃ ˙3H ₂ O.

PRI me R 3. In a thermostatic reactor with a stirrer at 30 ^about With load of 49.6 hours. 34.3 wt. H ₂ O ₂ (17 parts by weight of 100 wt. H ₂ O ₂ , 0.5 mol). Then add 47.7 vol. dry 100 wt. borax Na ₂ B ₄ O ₇ ˙ 10H ₂ O (0.125 mol). To the resulting reaction mass was added portionwise 10.53 parts by weight of dry 95 wt. NaOH (10 parts by weight 100 wt.% NaOH, 0.25 mol). The molar ratio of B: H ₂ O is 1: 7.4. It formed a homogeneous clear solution which was kept at 30 ° ^C. After 10 minutes, a solution of the resultant viscous mass is extruded through a die 1 mm in diameter. The hardened threads are crushed into particles of 0.2-1.0 mm and dried at 30 ^about C.

PRI me R 3 (a). The conditions of the experiment and the raw materials used are similar to example 3, but the temperature of keeping the mixture after synthesis is 55 ^about C.

PRI me R 4. In a thermostatic reactor with a stirrer at 45 ^about With load of 49.6 hours. 34.3 wt. H ₂ O ₂ (17 parts by weight of 100 wt.% H ₂ O ₂ , 0.5 mol), then add 31 parts by weight dry 99.8 wt. H ₃ BO ₃ (30.9 parts by weight of 100 wt. H ₃ BO ₃ , 0.5 mol). To the resulting suspension, 21.2 parts by weight are added in portions first. dry anhydrous 100 wt. (0.2 mol) Na ₂ CO ₃ , then 9.35 parts by weight 47.8 wt. NaOH solution (4.0 parts by weight of 100 wt.% NaOH, 0.1 mol). The ratio in the reaction mixture B: H ₂ O is 1: 6.6. Formed a homogeneous solution which was maintained at a temperature of 45 ° ^C. After 10 minutes, the solution gelled, and then after another 5 minutes, turning into a solid crumbling under mechanical action. Product particle size 1.0-10.0 mm cushat ^at 50 ° C and then crushed to a size of 0.2-1.0 mm.

PRI me R 5. In a temperature-controlled reactor with a stirrer at 15 ^about With load 35 in. including 48.6 wt. H ₂ O ₃ (17 parts by weight of 100 wt. H ₂ O ₂ , 0.5 mol). Then add 69 in portions. h. 100 wt. NaBO ₂ ˙ 4H ₂ O (0.5 mol). The molar ratio in the reaction mixture B: H ₂ O is 1: 7.0. Formed a homogeneous solution which was maintained at 15 ° ^C. The solution gelled after 8 min and then after an additional 15 min turning into a solid crumbling under mechanical action. The product is crushed to particles with a size of 0.2-1.0 mm, and then dried at 25 ^about C.

PRI me R 6. In a thermostatic reactor with a stirrer at 30 ^about With load of 42.5 in. h. 40 wt. H ₂ O ₂ (17 parts by weight of 100 wt. H ₂ O ₂ , 0.5 mol). Then add 17.6 in. including dry 100 wt. B ₂ O ₃ (0.5 mol). To the resulting mixture was added in portions 47 in. including 42.6 wt. NaOH (20 parts by weight 100 wt.% NaOH, 0.5 mol). The ratio of B: H ₂ O is 1: 7.33. The solution was kept at 45 ° ^C. After 15 minutes, the solution gelled to a viscous mass state, which at 45 ^C. forced through a spinneret with a diameter of 1 mm. The resulting product thread is cut into particles with a length of 0.2-1 mm and dried at a temperature of 55-60 ^about C.

PRI me R s 7-10 are performed using the same raw materials as in example 1, with the same molar ratios of Na: B: H ₂ O ₂ , but with different molar ratios of B: H ₂ O.

 The conditions for the implementation of specific examples of the described method are given in table 1. The aging of the synthesized mixture was carried out at rest or with stirring.

 To compare the results obtained by this method with the prototype, sodium peroxoborate was obtained by the prototype method (example 11).

PRI me R 11. In a thermostatic mixer at 40 ^about With load of 100 hours 34 wt. H ₂ O ₂ (34 parts by weight of 100% by weight of H ₂ O ₂ , 1 mol) and 302 parts by weight of 21.8 wt. NaBO ₂ (65.84 parts by weight, 100 wt.% NaBO ₂ , 1 mol). The molar ratio of B: H ₂ O ₂ is 1: 1. The molar ratio of B: H ₂ O is 1: 17.8. After 5 minutes of mixing the resultant solution is dried by spraying coolant stream having an inlet temperature in the drying zone of 160 ^{° C} and outlet 80 ° ^C.

The obtained fine powder is granulated in a rotary granulator with its own initial solution. Get a granular product with a content of 15.3 wt. About _a .

 The conditions of the experiments given in the examples and the results of analyzes and determination of the properties of the obtained peroxoborates are presented in Tables 1 and 2, respectively.

 As can be seen from the above examples, the described method allows the use of various types of boron-containing raw materials, such as boric acid (examples 1,2,4,7-10), borax (example 3), sodium metaborate (example 5) and boric anhydride (example 6 )

 The method allows the use of both solid sodium hydroxide (examples 1,3,7-10), and its concentrated solutions (examples 2,4,6), as well as sodium carbonate (example 4).

Examples of specific performance showed that when the molar ratio in the reaction mass B: H ₂ O equal to 1: 3,5 (example 8), it does not thicken.

With an increase in the amount of water in the system to a molar ratio of B: H ₂ O exceeding 1:10 (for example, 1:11, Example 9), a suspension which does not thicken even for 1 h is formed with clearly separated (separated) solid and liquid phases. In this case, both the conditions of the actual synthesis of sodium peroxoborate and further processing of the resulting suspension are carried out by known methods, which, although they allow to obtain a high-quality product, are associated with the complexity of the process (additional operations, the presence of mother solutions with corresponding additional losses and higher cost of the finished product )

Thus, the described method provides a peroxoboroate, when the content of sodium in the reaction mixture per 1 mol of boron from 4 to 10 moles of water and subsequently maintaining said mixture at a temperature of 15-50 ° ^C. Samples sodium peroxoboroate obtained by this method of application properties exceed the samples of sodium peroxoborate obtained by the prototype, with a higher yield of the finished product in comparison with the prototype.

 Moreover, the inventive method differs from the prototype by a significant simplification of the process.

Claims (3)

1. A METHOD FOR PRODUCING SODIUM SODIUM SODIUM, comprising reacting oxygen-containing boron compounds with hydrogen peroxide and sodium hydroxide or carbonate or a mixture thereof or sodium metaborate with hydrogen peroxide in an aqueous medium, followed by granulation of the target product, characterized in that, in order to simplify the process and increase yield product, the interaction of the starting reagents is carried out at a molar ratio of boron and water contained in the reaction mixture equal to 1 (4.0 to 10.0), respectively, followed by exposure of the mixture to 15 50 ^o C prior to gelling or solidification before drying and either before or after granulation.  2. The method according to claim 1, characterized in that, in order to improve the particle size distribution of the product, granulation of the mixture obtained in the process of thickening is carried out by forcing it through holes of a given cross section with the destruction of the formed product strand into particles of a given length.  3. The method according to claim 1, characterized in that the hardened mixture obtained in the process before or after drying is destroyed with the allocation of a given fraction, and the smaller fraction is returned to the interaction stage or granulated.

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