WO2004002885A1

WO2004002885A1 - A process for making sodium percarbonate

Info

Publication number: WO2004002885A1
Application number: PCT/CN2003/000415
Authority: WO
Inventors: Zhigang Zhu
Original assignee: Zhejiang Jinke Chemistry Co.,Ltd
Priority date: 2002-06-27
Filing date: 2003-05-30
Publication date: 2004-01-08
Also published as: CN1463913A; WO2004002942A1; AU2003234899A1; CN1330561C; AU2003234900A1

Abstract

The invention discloses a process for making sodium percarbonate, which pertains to the field of preparing the oxygen-containing bleaching agents. The said process includes a reaction between a suspension of hydrated sodium carbonate, which is obtained by emulsifing and hydrating a sodium carbonate solution, and a 25%-70% aqueous solution of H2O2,, followed by crystallization. During the reaction, sodium chloride or sodium sulfate is added as the salting-out agent, and sodium silicate, organo-phosphoric acid, and ethylenediamine tetraacetic acid and the sodium salt thereof are used as crystallization promoter. The hydration and emusification of the aqueous solution of sodium carbonate substantially accelerate the crystallization of the remaining hydrogen peroxide, while decreasing the content of sodium carbonate present in the mother solution as well. The sodium percarbonate products prepared according to this invention have high yield with low consumption of the starting materials. The sodium percarbonate products prepared according to this invention have advantages in higher content of activated oxygen, bigger particle size, and higher hydrothermal stability in comparison with the products obtained from the common wet process. The practice of this invention affords good economic benefits and environmental benefits.

Description

一种过碳酸钠制备方法 Preparation method of sodium percarbonate

技术领域 Technical field

本发明涉及过碳酸钠的制备方法，属于含氧漂白剂的制备技术领域。背景技术 The invention relates to a method for preparing sodium percarbonate, and belongs to the technical field of preparation of oxygen-containing bleach. Background technique

过碳酸钠又名过氧碳酸钠，分子式为 Na₂C0₃. l. 5HA的碳酸钠过氧水合物，在工业上过碳酸钠常用的名称为 PCS。 PCS最广泛的用途是作为洗涤组合物的漂白剂，特别是作为浓缩和超浓缩组合物的漂白剂。过碳酸钠通常采用双氧水和碳酸钠水溶液反应制备，俗称为湿法结晶加工法。湿法反应包括生成碳酸钠水溶液，使其与过氧化氢水溶液反应，反应条件包括碳酸钠和过氧化氢浓度、温度的选定，反应时间及选定的助剂，合成反应使过碳酸钠从溶液中结晶产生。为了降低过碳酸钠在水中的溶解度，通常需加入盐析剂如氯化钠，硫酸钠等，以提高收率，降低成本。盐析剂的加入使反应向着进一步完成，使较大部份的反应剂转变为所需要的产品。合成反应中需要稳定过碳酸钠中的活性氧，因此也需要加入活性氧稳定剂，称结晶助剂，中国专利 CN1240407A 和 CN1156738 A公开了常用的稳定剂品种。 Sodium percarbonate, also known as sodium peroxycarbonate, has a molecular formula of Na ₂ C0 _3. L. 5HA, sodium carbonate peroxyhydrate, and the common name of sodium percarbonate in the industry is PCS. The most widespread use of PCS is as a bleaching agent for detergent compositions, especially as a bleaching agent for concentrated and ultra-concentrated compositions. Sodium percarbonate is usually prepared by the reaction of hydrogen peroxide and sodium carbonate aqueous solution, commonly known as wet crystallization processing method. The wet reaction includes the generation of an aqueous sodium carbonate solution and the reaction with an aqueous hydrogen peroxide solution. The reaction conditions include the selection of sodium carbonate and hydrogen peroxide concentration, temperature, reaction time, and selected auxiliary agents. Crystals formed in solution. In order to reduce the solubility of sodium percarbonate in water, salting out agents such as sodium chloride and sodium sulfate are usually added to increase the yield and reduce the cost. The addition of a salting-out agent moves the reaction further to completion, which converts a larger portion of the reactant into the desired product. Synthetic reactions need to stabilize the active oxygen in sodium percarbonate, so it is also necessary to add an active oxygen stabilizer, called a crystallization aid. Chinese patents CN1240407A and CN1156738 A disclose commonly used stabilizers.

传统湿法得到的结晶过碳酸钠的活性氧含量一般在 13-13. 5%, 堆积密度也较大。但是，由于上述这种制备方法，合成反应快速，致使反应不够充分，反应得到的结晶产品湿稳定性差。同时反应中碳酸钠消耗也较高，废液排放有一定的水污染。发明内容 The active oxygen content of crystalline sodium percarbonate obtained by the traditional wet method is generally 13-13.5%, and the bulk density is also large. However, due to the above-mentioned preparation method, the synthesis reaction is fast, resulting in insufficient reaction, and the crystalline product obtained by the reaction has poor wet stability. At the same time, the consumption of sodium carbonate in the reaction is also high, and the waste liquid is discharged with some water pollution. Summary of the Invention

本发明的目的是提供一种能使过碳酸钠活性氧含量高，湿热稳定性好，原料消耗低的过碳酸钠制备方法。本发明的任务是通过以下技术方案来实现。 The object of the present invention is to provide a method for preparing sodium percarbonate, which can make sodium percarbonate have a high active oxygen content, good wet heat stability, and low raw material consumption. The task of the present invention is achieved by the following technical solutions.

由碳酸钠溶液与过氧化氢水溶液反应制得过碳酸钠，其特征是按下列步骤进行： The sodium percarbonate is prepared by reacting a sodium carbonate solution with an aqueous hydrogen peroxide solution, which is characterized by the following steps:

笫一步，在水溶液或循环母液中加入无水碳酸钠，经乳化水合反应制得水合碳酸钠悬浮液； In a further step, an anhydrous sodium carbonate is added to an aqueous solution or a circulating mother liquor, and an aqueous sodium carbonate suspension is obtained through an emulsification and hydration reaction;

笫二步，水合碳酸钠悬浮液和过氧化氢水溶液以一定的投加速度导入反应釜中反应，反应制得过碳酸钠结晶产物；第三步，结晶物固液分离，滤液循环使用，结晶物经后处理成制品；碳酸钠与过氧化氢反应摩尔比为 1 : 1. 3-1. 5; (2) In the second step, the hydrated sodium carbonate suspension and the hydrogen peroxide aqueous solution are introduced into the reaction kettle to react at a certain acceleration rate, and the sodium percarbonate crystal product is obtained by the reaction; The third step is the solid-liquid separation of the crystals, the filtrate is recycled, and the crystals are post-processed into products; the molar ratio of the reaction between sodium carbonate and hydrogen peroxide is 1: 1. 3-1. 5;

反应中加入含钠盐析剂和结晶助剂。 A sodium-containing salting-out agent and a crystallization aid are added to the reaction.

所述的水合碳酸钠悬浮液制备是将无水碳酸钠加入到循环母液中，加入量为母液量的 20-5 OU'L化水合反应温度为 20- 45 °C_乳化水合反应时间 5-60 分钟； The hydrated sodium carbonate suspension is prepared by adding anhydrous sodium carbonate to the circulating mother liquor, the amount of which is 20-5 OU'L hydration reaction temperature is 20-45 ° C_ emulsification hydration reaction time 5- 60 minutes;

化合结晶反应温度 16- 30°C , 反应时间为 30- 50分钟。 The compound crystallization reaction temperature is 16-30 ° C, and the reaction time is 30-50 minutes.

所述的过碳酸钠结晶物采用过滤或离心分离，结晶物在温度 80-95 °C下干燥，然后筛分得成品。 The sodium percarbonate crystals are separated by filtration or centrifugation. The crystals are dried at a temperature of 80-95 ° C, and then sieved to obtain a finished product.

所述含钠盐析剂为氯化钠、硫酸钠的一种，投入量为维持其在母液中的浓度 17-22%; The sodium-containing salting-out agent is one of sodium chloride and sodium sulfate, and the input amount is to maintain its concentration in the mother liquor of 17-22%;

所述的结晶助剂选用硅酸钠、有机膦酸、硫酸镁、乙二胺四乙酸或其钠盐、聚丙晞酰胺的一种或数种混合物，投入量为碳酸纳用量的 0. 5-3%; The crystallization aid is selected from one or several mixtures of sodium silicate, organic phosphonic acid, magnesium sulfate, ethylenediaminetetraacetic acid or its sodium salt, and polypropionamide, and the input amount is 0.5 to the amount of sodium carbonate. 3%;

所述的水合碳酸钠的投加速度为 800-1600ml/h , 过氧化氢水溶液的投加速度为 210— 660ml /h。 The hydrated sodium carbonate has a projecting acceleration of 800-1600 ml / h, and a hydrogen peroxide aqueous solution has a feeding rate of 210-660 ml / h.

本发明把湿法工艺的一步反应改为二步反应，尤其是将制备碳酸钠水合物的反应单独设计，在无水碳酸钠制备水溶液时，或者在循环母液中加入无水碳酸钠时，釆用高速的乳化剪切机和搅拌器等设备，使无水碳酸钠与溶液中的水进行水合反应生成水合碳酸钠悬浮液。水合反应中无水碳酸钠的投入量为母液量 20- 50°/», 优先 30- 40°/», 水合反应时间 5- 50分钟，优先 10-30分钟，水合反应温度 20-6 (TC , 优先 25-45 °C。 7 合反应中碳酸钠的水合度通过悬浮液的温度控制实现。悬浮液的温度在 32- 35 °C时，生成七水合碳酸钠，高于或低于这一温度时，将分别生成一水合或十水合碳酸钠。 In the present invention, the one-step reaction of the wet process is changed to a two-step reaction, and in particular, the reaction for preparing sodium carbonate hydrate is designed separately. When an anhydrous sodium carbonate is used to prepare an aqueous solution, or when anhydrous sodium carbonate is added to a circulating mother liquor, Using a high-speed emulsification shearer and agitator, the anhydrous sodium carbonate is hydrated with the water in the solution to form a hydrated sodium carbonate suspension. The amount of anhydrous sodium carbonate used in the hydration reaction is the amount of mother liquor 20- 50 ° / », preferably 30-40 ° /», the hydration reaction time is 5- 50 minutes, preferably 10-30 minutes, and the hydration reaction temperature is 20-6 (TC , 25-45 ° C is preferred. The degree of hydration of sodium carbonate in the 7-synthesis reaction is achieved by the temperature control of the suspension. When the temperature of the suspension is 32-35 ° C, sodium carbonate heptahydrate is formed, which is higher or lower than this. At temperature, sodium carbonate monohydrate or decahydrate will be formed, respectively.

在第二步反应中，水合碳酸钠悬浮液与浓度为 25-70%过氧化氢水溶液混合或同时滴加到反应器中进行化合反应，生成过碳酸钠结晶物。由于碳酸钠溶液经乳化水合后能与过氧化氢充分反应，从而大大减少碳酸钠在双氧水含水中的溶解量，使循环液中的碳酸钠含量降低。在制备过程中由于循环液一部份被排放，含量降低使碳酸钠的流失减少，有利于減轻水污染。 In the second step of the reaction, the hydrated sodium carbonate suspension is mixed with a 25-70% hydrogen peroxide aqueous solution or added dropwise to the reactor at the same time to carry out the compounding reaction to form sodium percarbonate crystals. Since the sodium carbonate solution can fully react with hydrogen peroxide after emulsification and hydration, the amount of sodium carbonate dissolved in hydrogen peroxide water is greatly reduced, and the sodium carbonate content in the circulating fluid is reduced. During the preparation process, part of the circulating liquid is discharged, and the decrease of the content will reduce the loss of sodium carbonate, which will help reduce water pollution.

本发明的另一个支术效果是利用水合反应为放热反应的特点，对乳化水合反应的温度控制只需常规的水冷却即可，这样将大大降低第二步反应的热负荷；其结果在结晶反应过程中，仅需少量的冷冻盐水便可控制反应温度，从而减少冷冻盐水的需用量。 Another technical effect of the present invention is to utilize the characteristics of the hydration reaction as an exothermic reaction. The temperature control of the emulsification hydration reaction only requires conventional water cooling, which will greatly reduce the heat of the second step reaction. The result is that during the crystallization reaction, only a small amount of frozen brine is needed to control the reaction temperature, thereby reducing the amount of frozen brine required.

本发明的反应过程中，含钠盐析剂的加入是不可少的，氯化钠或硫酸钠的加入可提高过碳酸钠的产率，同时，由于盐析剂中的钠是不参加反应的，因此，盐析剂的加入也可降低母液中的碳酸钠含量。盐析剂的加入量以维持其在循环母液中的浓度 15-22%, 优先 Π- ²0%。 In the reaction process of the present invention, the addition of a sodium-containing salting-out agent is indispensable. The addition of sodium chloride or sodium sulfate can improve the yield of sodium percarbonate. At the same time, because sodium in the salting-out agent does not participate in the reaction, Therefore, the addition of the salting-out agent can also reduce the sodium carbonate content in the mother liquor. The salting-out agent is added to maintain its concentration in the circulating mother liquor of 15-22%, preferably Π- ²⁰ %.

本发明需加入的结晶助剂为具有稳定活性氧的作用，如硅酸钠、有机膦酸，乙二胺四乙酸及其钠盐，聚丙烯酰等一种或数种的混合物，结晶助剂的加入量为反应溶液中碳酸钠用量的 0. 5-3%。结晶助剂的加入使过碳酸钠结晶颗粒有较高的均匀性和纯度，从而使产品具有较好的湿、热稳定性。本发明制备的过碳酸钠的热稳定性 > 92% ( 105 °C 2 小时），湿稳定性 > 50%, 产品非常适合于在固体漂白剂，无磷洗涤剂中使用。 The crystallization aid to be added in the present invention has the function of stabilizing active oxygen, such as sodium silicate, organic phosphonic acid, ethylenediaminetetraacetic acid and its sodium salt, a mixture of one or more kinds of polyacryl, etc. 5-3%。 The amount of sodium carbonate in the reaction solution was added in an amount of 0.5-3%. The addition of crystallization aids makes the sodium percarbonate crystal particles have higher uniformity and purity, so that the product has better wet and thermal stability. The thermal stability of the sodium percarbonate prepared by the invention is> 92% (105 ° C for 2 hours), and the wet stability is> 50%. The product is very suitable for use in solid bleaching agents and phosphorus-free detergents.

湿稳定性的测试方法：将 10克过碳酸钠颗粒与 10克 4A沸石混合，放置在敞开的培养亚中，在 32°C下和 80%的相对湿度下放置 48小时，计算试样活性氧的剩余率。 Test method for wet stability: 10 g of sodium percarbonate particles are mixed with 10 g of 4A zeolite, placed in an open culture subculture, and stored at 32 ° C and 80% relative humidity for 48 hours to calculate the sample active oxygen The remaining rate.

以下是由本发明方法制备的过碳酸钠与一般湿法工艺制备的过碳酸钠性能的对比测定结果： The following are the results of a comparative measurement of the performance of sodium percarbonate prepared by the method of the present invention and sodium percarbonate prepared by a general wet process:

项活性氧水分堆积密度平均粒径热稳湿稳备 Term active oxygen water bulk density average particle size thermal stability wet stability

( % ) ( % ) ( G/L ) ( ra ) 定性（％) 定性（％ ) 注实施例 1 14. 2 0. 82 957 512 95. 1 53. 3 实施例 2 14. 5 0. 57 1072 762 94. 7 56. 1 实施例 3 14. 3 0. 66 1032 432 95. 5 51. 7 实施例 4 14. 2 0. 92 981 561 96. 3 52. 4 实施例 5 13. 9 0. 43 760 523 96. 5 51. 6 实施例 6 14. 2 0. 83 983 462 96. 6 53. 8 实施例 7 14. 4 0. 55 940 625 95. 5 55. 4 实施例 8 14. 6 0. 88 1060 912 94. 4 60. 2 对比试 13. 6 0. 92 810 430 92. 3 23. 6 验从上述测试结果比较分析，本发明制备的过碳酸钠的活性氧含量绝大部份在 14%以上，产品含水率降低，平均粒径增大，尤其是湿稳定性大大提高，其效果十分显著。 (%) (%) (G / L) (ra) Qualitative (%) Qualitative (%) Note Example 1 14. 2 0. 82 957 512 95. 1 53. 3 Example 2 14. 5 0. 57 1072 762 94. 7 56. 1 Example 3 14. 3 0. 66 1032 432 95. 5 51. 7 Example 4 14. 2 0. 92 981 561 96. 3 52. 4 Example 5 13. 9 0. 43 760 523 96. 5 51. 6 Example 6 14. 2 0. 83 983 462 96. 6 53. 8 Example 7 14. 4 0. 55 940 625 95. 5 55. 4 Example 8 14. 6 0. 88 1060 912 94. 4 60. 2 Comparative test 13. 6 0. 92 810 430 92. 3 23. 6 According to the comparative analysis of the above test results, the active oxygen content of the sodium percarbonate prepared by the present invention is over 14%, the product moisture content is reduced, the average particle size is increased, and especially the wet stability is greatly improved, and the effect is very significant. .

本发明的实施还能使碳酸钠的消耗降低，减少工艺能耗，有利于环境保护，是一种具有良好的经济效益和环境效益的制备工艺。具体实施方式 The implementation of the present invention can also reduce the consumption of sodium carbonate, reduce the process energy consumption, is beneficial to environmental protection, and is a preparation process with good economic and environmental benefits. detailed description

实施例一 Example one

取母液 840克导入制浆釜，开动剪切乳化机，加入 280克轻质无水碳酸钠， 8 G克氯化钠和 3克硅酸钠；剪切乳化反应 20分钟，生成一水合碳酸钠悬浮液，悬浮液温度控制在 38- 43 °C ; 此反应溶液中含 6. 0%碳酸钠母液 840克，碳酸钠 280克，氯化钠 80克和 3克硅酸钠。将 440克浓度为 27. 5%的过氧化氢水溶液导入双氧水槽，并加入氨基三甲叉膦酸（ATMP ) 4克，乙二胺四乙酸二钠 1克，硫酸镁 2克，搅拌均勾。同时再取母液 250克，加入平均颗粒尺寸为 Ι ΟΟ μ ηι的过碳酸钠 3克作晶种。 Take 840 grams of mother liquor into the pulping kettle, start the shear emulsifier, add 280 grams of light anhydrous sodium carbonate, 8 G grams of sodium chloride and 3 grams of sodium silicate; shear emulsification reaction for 20 minutes to produce sodium carbonate monohydrate Suspension, the temperature of the suspension is controlled at 38-43 ° C; this reaction solution contains 6.0% sodium carbonate mother liquor 840 g, sodium carbonate 280 g, sodium chloride 80 g and 3 g sodium silicate. 440 g of a 27.5% hydrogen peroxide solution was introduced into the hydrogen peroxide tank, and 4 g of aminotrimethylene phosphonic acid (ATMP), 1 g of disodium ethylenediamine tetraacetate, and 2 g of magnesium sulfate were added. At the same time, another 250 grams of mother liquor was taken, and 3 grams of sodium percarbonate with an average particle size of 100 μm was added as seeds.

然后，以每小时 1200ml的总速度导入水合碳酸钠悬浮液，同时以每小时 675ML的总速度导入浓度为 27. 5%过氧化氢水溶液，并保持反应釜母液的过氧化氢 > 0. 7%, 反应过程中温度保持在于 22-23°C , 过程约持续 40分钟，加料结束；反应釜中的结晶反应产物通过离心机与母液分离，滤液入母液槽循环回用，过碳酸钠结晶物在 90°C左右的流化床中干燥 30分钟，得成品 409克。实施例二 Then, a hydrated sodium carbonate suspension was introduced at a total speed of 1200 ml per hour, while a concentration of 27.5% hydrogen peroxide solution was introduced at a total speed of 675 ML per hour, and the hydrogen peroxide in the mother liquor of the reactor was maintained at> 0.7%. During the reaction, the temperature is maintained at 22-23 ° C, the process lasts about 40 minutes, and the feeding is completed. The crystallization reaction product in the reaction kettle is separated from the mother liquor by a centrifuge, and the filtrate is recycled into the mother liquor tank for reuse. Dry in a fluidized bed at about 90 ° C for 30 minutes to obtain 409 g of finished product. Example two

方法步驟与实施例 1相同，不同工艺条件如下：第一步反应，碳酸纳含量 5%的母液 840克，加入无水碳酸钠 280克，氯化钠 80克，反应时间 25分钟，反应温度 ²⁵-3(TC，生成十水合碳酸钠悬浮液；第二步反应，浓度为 27. 5% 的过氧化氢水溶液 450克，晶种 1克，过氧化氢水溶液投料速度 430ml/h, 水合碳酸钠悬浮液投料速度 800ml/h, 加料反应时间 60分钟，反应温度 22-23 °C , 制得过碳酸钠成品 410克。实施例三 The method steps are the same as in Example 1. The different process conditions are as follows: In the first step, 840 g of mother liquor with 5% sodium carbonate content, 280 g of anhydrous sodium carbonate, 80 g of sodium chloride, reaction time 25 minutes, and reaction temperature ²⁵ -3 (TC, to generate sodium carbonate decahydrate suspension; in the second step reaction, 450 g of 27.5% hydrogen peroxide solution, 1 g of seed crystals, hydrogen peroxide solution feed rate 430ml / h, sodium carbonate hydrate The suspension was fed at a speed of 800ml / h, the reaction time was 60 minutes, and the reaction temperature was 22-23 ° C. 410 g of sodium percarbonate was obtained. Example three

方法步骤与实施例 1相同，不同工艺条件如下：第一步反应，含碳酸钠 7%母液 840克，加无水碳酸钠 280克，氯化钠 60克， 7^合反应时间 25分钟，水合反应温度 25- 30°C , 生成十水合碳酸钠悬浮液；第二步反应，浓度为 3⁵% 的过氧化氢水溶液 330克，晶种 5克，水合碳酸钠悬浮液投料速度 960ml/h, 过氧化氢水溶液投料速度 400ml/h, 加料结晶反应时间 50 分种，反应温度 22-23 °C , 得过碳酸钠成品 395克。实施例四 The method steps are the same as in Example 1, and the different process conditions are as follows: The first step is a reaction, containing 840 g of sodium carbonate 7% mother liquor, adding 280 g of anhydrous sodium carbonate, 60 g of sodium chloride, 7 minutes of reaction time 25 minutes, hydration the reaction temperature of 25- 30 ° C, a suspension of sodium carbonate decahydrate generated; the second reaction, a concentration of ³⁵ percent aqueous hydrogen peroxide 330 g seed 5 g, sodium carbonate hydrate suspension feed rate 960ml / h, The hydrogen peroxide solution was fed at a speed of 400 ml / h, and the reaction time for crystallization was 50 minutes, and the reaction temperature was 22-23 ° C. 395 g of sodium percarbonate was obtained. Example 4

方法步驟与实施例 1相同，不同工艺条件如下：第一步反应，含碳酸钠 7. 2%的母液 840克，加无水碳酸钠 280克，氯化钠 60克，水合反应时间 20 分钟，水合反应温度 32-35 °C , 生成七水合碳酸钠悬浮液；第二步反应，浓度为 35%的过氧化氢水溶液 325 克，晶种 3 克，水合碳酸钠悬浮液投料速度 1200ml/h, 过氧化氢水溶液投料速度 500ml/h, 加料结晶反应时间 40分种，反应温度 22- 23 °C , 得成品过碳酸钠 391克。实施例五 The method steps are the same as in Example 1, and the different process conditions are as follows: The first step is a reaction, containing 840 g of sodium carbonate 7.2% mother liquor, adding 280 g of anhydrous sodium carbonate, 60 g of sodium chloride, and a hydration reaction time of 20 minutes. The hydration reaction temperature is 32-35 ° C, and a sodium carbonate heptahydrate suspension is formed. In the second step, 325 g of a 35% hydrogen peroxide aqueous solution, 3 g of seed crystals, and a hydrated sodium carbonate suspension feed rate of 1200 ml / h, The hydrogen peroxide aqueous solution was fed at a rate of 500 ml / h, and the reaction time for crystallization was 40 minutes, and the reaction temperature was 22-23 ° C. 391 g of sodium percarbonate was obtained. Example 5

方法步驟与实施例 1相同，不同工艺条件如下：第一步反应，含碳酸纳 8%的母液 840克，加无水碳酸钠 280克，氯化钠 68克，水合反应时间 15分钟，水合反应温度 38- 43°C , 生成一水合碳酸钠悬浮液；第二步反应，浓度为 35%的过氧化氢水溶液 320克，晶种 8克，水合碳酸钠悬浮液投料速度 1600ml/h_; 过氧化氢水溶液投料速度 660ml /h, 加料反应时间 30分种，反应温度 24-25 °C，得过碳酸钠晶体 394克。实施例六 The method steps are the same as in Example 1, and the different process conditions are as follows: The first step is reaction, 840 g of mother liquor containing 8% sodium carbonate, 280 g of anhydrous sodium carbonate, 68 g of sodium chloride, hydration reaction time 15 minutes, hydration reaction At a temperature of 38-43 ° C, a sodium carbonate monohydrate suspension is formed; in the second step reaction, 320 g of a 35% hydrogen peroxide aqueous solution, 8 grams of seed crystals, and a hydrated sodium carbonate suspension feed rate of 1600 ml / h _; peroxidation The hydrogen hydrogen solution was fed at a speed of 660 ml / h, the reaction time was 30 minutes, and the reaction temperature was 24-25 ° C. 394 g of sodium percarbonate crystals were obtained. Example Six

方法步骤与实施例 1相同，不同工艺条件如下：第一步反应，含碳酸钠 2%的母液 840克，加无水碳酸钠 280克，氯化钠 32克，水合反应时间 20分钟，水合反应温度 2⁵- 3(TC , 生成十水合碳酸钠悬浮液；第二步反应，浓度为 50%的过氧化氢水溶液 235 克，晶种 5 克，水合碳酸钠悬浮液投料速度 1070ml/h, 过氧化氢水溶液投料速度 300ml/h, 加料结晶反应时间 45分种，反应温度 22_23°C , 得过碳酸钠成品 415克。实施例七 The method steps are the same as in Example 1. The different process conditions are as follows: The first step is reaction, 840 g of mother liquor containing 2% sodium carbonate, 280 g of anhydrous sodium carbonate, 32 g of sodium chloride, hydration reaction time 20 minutes, hydration reaction temperature 2 ⁵ - 3 (TC, generates a suspension of sodium carbonate decahydrate; the second reaction, a concentration of over 235 g of 50% aqueous hydrogen peroxide solution, the seed crystal 5 grams of sodium carbonate hydrate suspension feed rate 1070ml / h, over Feeding rate of hydrogen oxide solution is 300ml / h, and the reaction time of feeding crystallization is 45 minutes, The reaction temperature was 22-23 ° C, and 415 g of sodium percarbonate was obtained. Example Seven

方法步骤与实施例 1相同，不同工艺条件如下：第一步反应，含碳酸钠 12%的母液 840克，加无水碳酸钠 280克，氯化钠 16克，水合反应时间 20分钟，水合反应温度 25- 30°C , 生成十水合碳酸钠悬浮液；第二步反应，浓度为 70%的过氧化氢水溶液 180克，晶种 2克，水合碳酸钠投料速度 107 Oml /h, 过氧化氢水溶液投料速度 210ml/h,加料结晶反应时间 45分种，反应温度 22 - 23 °C，得过碳酸钠成品 423克。实施例八 The method steps are the same as in Example 1. The different process conditions are as follows: In the first step, 840 g of mother liquor containing 12% sodium carbonate, 280 g of anhydrous sodium carbonate, 16 g of sodium chloride, hydration reaction time 20 minutes, and hydration reaction At a temperature of 25-30 ° C, a suspension of sodium carbonate decahydrate is formed; in the second reaction step, 180 g of a 70% hydrogen peroxide aqueous solution, 2 g of seed crystals, a sodium hydrate feed rate of 107 Oml / h, and hydrogen peroxide The feed rate of the aqueous solution was 210 ml / h, the reaction time of the crystallization was 45 minutes, and the reaction temperature was 22-23 ° C. 423 g of sodium percarbonate was obtained. Example eight

方法步骤与实施例 1相同，不同工艺条件如下：第一步反应，含碳酸钠 12. 3%的母液 840克，加无水碳酸钠 280克，氯化钠 16克， 7 合反应时间 20 分钟，水合反应温度 32- 35 °C , 生成七水合碳酸钠悬浮液；第二步反应，浓度为 70%的过氧化氢水溶液 188克，晶种 0. 5克。 7J合碳酸钠悬浮液投料速度 1070ml/h, 过氧化氢水溶液投料速度 210ml/h，加料结晶反应时间 90分种，反应温度 22- 23°C , 得成品过碳酸钠 394克。 The method steps are the same as in Example 1, and the different process conditions are as follows: The first step is a reaction, containing 840 g of sodium carbonate 12.3% mother liquor, adding 280 g of anhydrous sodium carbonate, 16 g of sodium chloride, and a reaction time of 20 minutes. 5 克。, Hydration reaction temperature of 32-35 ° C, to generate a sodium carbonate heptahydrate suspension; the second step of the reaction, a concentration of 70% hydrogen peroxide aqueous solution 188 grams, seed 0. 5 grams. The feed rate of 7J sodium carbonate suspension is 1070ml / h, the feed rate of aqueous hydrogen peroxide solution is 210ml / h, the reaction time of crystallization is 90 minutes, and the reaction temperature is 22-23 ° C. 394 g of sodium percarbonate is obtained.

Claims

权利要求书 Claim

1. 一种过碳酸钠制备方法，由碳酸钠水溶液与过氧化氢水溶液反应制得过碳酸钠，其特征是按下列步骤进行： 1. A method for preparing sodium percarbonate, which is obtained by reacting an aqueous solution of sodium carbonate and an aqueous solution of hydrogen peroxide, and is characterized in that the following steps are performed:

第一步，在水溶液或循环母液中加入无水碳酸钠时经乳化水合反应制得水合碳酸钠悬浮液； In the first step, a hydrated sodium carbonate suspension is prepared through the emulsification and hydration reaction when anhydrous sodium carbonate is added to an aqueous solution or a circulating mother liquor;

第二步，水合碳酸钠悬浮液和过氧化氢水溶液投加到反应釜中反应，反应制得过碳酸钠结晶物； In the second step, a hydrated sodium carbonate suspension and an aqueous hydrogen peroxide solution are added to the reaction kettle to react, and a sodium percarbonate crystal is obtained by the reaction;

第三步，过碳酸钠结晶物固液分离，滤液循环使用，结晶物经后处理成制品； The third step is the solid-liquid separation of the sodium percarbonate crystals, and the filtrate is recycled, and the crystals are post-processed into products;

碳酸钠与过氧化氢反应摩尔比 1: 1. 3-1. 5; Molar ratio of sodium carbonate to hydrogen peroxide reaction 1: 1. 3-1. 5;

2. 根据权利要求 1所述的过碳酸钠制备方法，其特征是无水碳酸钠加入量为母液量的 25-50%; 2. The method for preparing sodium percarbonate according to claim 1, characterized in that the amount of anhydrous sodium carbonate added is 25-50% of the amount of the mother liquor;

乳化水合反应温度为 20-45 , 乳化水合反应时间 5-60分钟；结晶反应温度 16- 30°C , 反应时间 30- 50分钟。 Emulsion hydration reaction temperature is 20-45, emulsification hydration reaction time is 5-60 minutes; crystallization reaction temperature is 16-30 ° C, reaction time is 30-50 minutes.

3. 根据权利要求 1和 2所述的过碳酸钠制备方法，其特征是所述的结晶产物采用过滤或离心分离，结晶物在温度 80 - 95 °C下干燥，筛分得成品。 3. The method for preparing sodium percarbonate according to claim 1 and 2, characterized in that the crystallized product is separated by filtration or centrifugation, the crystallized substance is dried at a temperature of 80-95 ° C, and sieved to obtain a finished product.

4. 根据权利要求 1所述的过碳酸钠制备方法，其特征是含钠盐析剂为氯化钠或硫酸钠的一种，投入量为维持其母液中浓度 17-22%; 4. The method for preparing sodium percarbonate according to claim 1, characterized in that the sodium-containing salting-out agent is one of sodium chloride or sodium sulfate, and the input amount is to maintain a concentration of 17-22% in its mother liquor;

5. 根据权利要求 1所述的过碳酸钠制备方法，其特征是所述的结晶助剂选用硅酸钠、有机膦酸，硫酸镁，乙二胺四乙酸或其钠盐，聚丙烯酰胺的一种或数种混合物，投入量为碳酸钠用量的 0. 5-3°/。。 5. The method for preparing sodium percarbonate according to claim 1, wherein the crystallization aid is selected from sodium silicate, organic phosphonic acid, magnesium sulfate, ethylenediaminetetraacetic acid or its sodium salt, and polyacrylamide. 5-3 ° /。 One or several mixtures, the amount of 0.5-3 ° /. .