Two-component foam inhibitor and preparation method therefor, and method for reducing foaming in production process of humic acid urea

Abstract

A two-component foam inhibitor and a preparation method therefor, and a method for reducing foaming in a production process of humic acid urea. A foaming control agent in the two-component foam inhibitor reduces the pH value of a humate solution and the generation amount of ammonia gas in a urea melt, and can also prevent the problems of the condensation of the humate solution and difficulty in adding the humate solution to the urea melt which are caused by a reduction in the pH value. A suspension adsorbent in the two-component foam inhibitor can adsorb free ammonia in the urea melt and the ammonia generated after the humate solution is added. In conclusion, the two-component foam inhibitor provided can effectively reduce a foaming reaction in the production process of humic acid urea, avoid the pulverization of humic acid urea particles, and improve the production efficiency.

Description

A two-component antifoaming agent and its preparation method and a method for reducing foaming in the production process of humic acid urea Technical Field

[0001] The invention belongs to the technical field of value-added urea preparation, and particularly relates to a two-component foam suppressant and a preparation method thereof, and a method for reducing foaming in a humic acid urea production process. Background Art

[0002] Humic acid urea has been widely welcomed by urea manufacturers and farmers in recent years due to its ability to inhibit soil urease activity, slow urea conversion, and reduce ammonia volatilization losses. Currently, the annual production of humic acid urea in China is around 1 million tons, accounting for one-third of China's value-added urea production.

[0003] However, humic acid needs to be added to urea in the form of a humate solution. Because humates (potassium humate, sodium humate, etc.) are alkaline, they instantly produce a large amount of ammonia gas after being added to the urea melt, causing a large amount of foaming in the urea melt. This leads to the following problems: 1) The humate urea granules produced contain bubbles, resulting in low granule strength and easy breakage during storage and transportation; 2) Humic acid urea produces a lot of dust, which reduces production efficiency and increases recycling costs; 3) It affects the enthusiasm of urea companies to produce humic acid urea; 4) The high dust content of the product also affects farmers' enthusiasm for application. Therefore, solving the foaming problem in the humate urea production process is an important part of promoting the healthy development of the humate urea industry.

[0004] Humate solutions only exhibit good fluidity under alkaline conditions and can be precisely added to the urea melt using a metering pump. Therefore, adjusting the pH of the humate solution is an effective way to reduce foaming in the urea melt. However, when the pH of the humate solution drops to a moderately acidic level, the humate solution will coagulate and precipitate, making it difficult to add the humate solution to the urea melt.

[0005] Summary of the Invention

[0006] The present invention aims to provide a two-component foam suppressant and a preparation method thereof, and a method for reducing foaming in the humic acid urea production process. The two-component foam suppressant provided by the present invention can prevent the humate solution from coagulating under non-alkaline conditions and effectively reduce foaming in the humic acid urea production process.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] The present invention provides a two-component foam suppressant, comprising a foam control agent and a suspension adsorbent;

[0009] The raw materials of the foam control agent include lactic acid, acetic acid and metal oxides;

[0010] The raw materials of the suspended adsorbent include vegetable oil, polysaccharide, organic acid and adsorbent;

[0011] The polymerization degree of the polysaccharide is 3 to 10; and the organic acid does not include lactic acid and acetic acid.

[0012] Preferably, the metal oxide includes one or more of zinc oxide, copper oxide, iron oxide, manganese oxide and calcium oxide;

[0013] The lactic acid is a lactic acid solution; the mass concentration of the lactic acid solution is 85%;

[0014] The acetic acid is an acetic acid solution; the mass concentration of the acetic acid solution is 80%.

[0015] Preferably, the mass ratio of the lactic acid to the acetic acid solution is 300-400:100-200;

[0016] The mass ratio of the lactic acid to the metal oxide is 300-400:120-160.

[0017] Preferably, the mass ratio of the vegetable oil to the polysaccharide is 500-600:200-300;

[0018] The mass ratio of the vegetable oil to the organic acid is 500-600:50-100;

[0019] The mass ratio of the total mass of the vegetable oil, polysaccharide and organic acid to the mass of the adsorbent is 1000:30-100.

[0020] Preferably, the vegetable oil includes one or more of palm oil, corn oil and cottonseed oil;

[0021] The polysaccharide includes one or more of maltooligosaccharide, isomaltooligosaccharide, fructooligosaccharide, galacto-oligosaccharide and xylooligosaccharide;

[0022] The organic acid is an organic carboxylic acid;

[0023] The adsorbent includes one or more of silica gel powder and zeolite powder.

[0024] The present invention also provides a method for preparing the two-component foam suppressant described in the above scheme, comprising the following steps:

[0025] (1) heating and mixing lactic acid, acetic acid, a metal oxide, and water to perform a double decomposition reaction to obtain a foam control agent;

[0026] (2) heating and mixing the vegetable oil, polysaccharide, and organic acid to obtain a viscous liquid, and then mixing the viscous liquid with an adsorbent to obtain a suspended adsorbent;

[0027] There is no time sequence requirement for step (1) and step (2).

[0028] The present invention also provides a method for reducing foaming in a humic acid urea production process, comprising a first evaporation section and a second evaporation section, wherein between the first evaporation section and the second evaporation section, the following steps are included:

[0029] (1) mixing a suspended adsorbent and a molten solution of urea to obtain a urea premix solution;

[0030] (2) heating and mixing the humate solution and the foam control agent to obtain a humate premix solution;

[0031] (3) Mixing the urea premix solution and the humate premix solution.

[0032] Preferably, the volume mass ratio of the suspended adsorbent to urea is (2-5) L:1t;

[0033] The volume ratio of the foaming control agent to the humate solution is 50-200:500;

[0034] The mass concentration of the humate solution is 10-18%.

[0035] Preferably, the volume mass ratio of the humate premix to urea is (8-20) L:1t.

[0036] Preferably, the temperature of the heating and mixing is 60-80°C.

[0037] The present invention provides a two-component foam suppressant. On the one hand, the foam control agent in the two-component foam suppressant of the present invention reduces the pH value of the humate solution and reduces the amount of ammonia produced in the urea melt. On the other hand, lactic acid and acetic acid form complexes with metal ions in metal oxides, which can prevent humic acid from combining with metal ions to form precipitation in a short period of time, thereby avoiding the problem of humate solution condensation and difficulty in adding to the urea melt due to lowering the pH value; the suspended adsorbent in the two-component foam suppressant of the present invention can adsorb free ammonia in the urea melt and ammonia produced after adding the humate solution. Therefore, the two-component foam suppressant provided by the present invention can effectively reduce the foaming reaction in the humic acid urea production process, avoid the pulverization of humic acid urea particles, and improve production efficiency.

[0038] The present invention also provides a method for preparing the two-component foam suppressant of the above scheme. The preparation method provided by the present invention has simple steps, convenient operation, high feasibility, and has the prospect of large-scale industrial production.

[0039] The present invention also provides a method for reducing foaming during the humic acid urea production process. This method utilizes a two-component foam suppressant, utilizing its foam control agent and suspension adsorbent, which is mixed with a humate solution and then added to a urea melt. Through both early adsorption and later buffering, the method significantly reduces ammonia production during the humic acid urea production process, thereby eliminating bubbles, increasing the urea granulation rate, strengthening the granules, reducing dust generation, and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0041] FIG1 is a process flow chart of a method for reducing foaming in a humic acid urea production process provided by the present invention;

[0042] FIG2 is a morphology diagram of urea particles in Test Example 1 of the present invention. DETAILED DESCRIPTION

[0043] The present invention provides a two-component foam suppressant, comprising a foam control agent and a suspension adsorbent;

[0044] The raw materials of the foam control agent include lactic acid, acetic acid and metal oxides;

[0045] The raw materials of the suspended adsorbent include vegetable oil, polysaccharide, organic acid and adsorbent;

[0046] The polymerization degree of the polysaccharide is 3 to 10; and the organic acid does not include lactic acid and acetic acid.

[0047] The two-component foam suppressor provided by the present invention includes a foam control agent; the raw materials of the foam control agent include lactic acid, acetic acid, and a metal oxide. In the present invention, the metal oxide preferably includes one or more of zinc oxide, copper oxide, iron oxide, manganese oxide, and calcium oxide; the lactic acid is preferably a lactic acid solution; the mass concentration of the lactic acid solution is preferably 85%; the acetic acid is preferably an acetic acid solution; the mass concentration of the acetic acid solution is preferably 80%.

[0048] In the present invention, the mass ratio of the lactic acid to the acetic acid solution is preferably 300-400:100-200, more preferably 320-380:120-180, and even more preferably 340-360:140-160.

[0049] In the present invention, the mass ratio of the lactic acid to the metal oxide is preferably 300-400:120-160, more preferably 320-380:130-150, and even more preferably 340-360:140.

[0050] The two-component foam suppressor provided by the present invention includes a suspension adsorbent; the raw materials of the suspension adsorbent include vegetable oil, polysaccharide, organic acid and adsorbent; the organic acid does not include lactic acid and acetic acid. In the present invention, the vegetable oil preferably includes one or more of palm oil, corn oil and cottonseed oil; the polysaccharide preferably includes one or more of maltooligosaccharide, isomaltooligosaccharide, fructooligosaccharide, galacto-oligosaccharide and xylo-oligosaccharide; the degree of polymerization of the polysaccharide is preferably 3-9, more preferably 4-8, and further preferably 5-7; the organic acid is preferably an organic carboxylic acid; the organic carboxylic acid preferably includes one or more of dicarboxylic acid and polycarboxylic acid; the dicarboxylic acid preferably includes one or more of oxalic acid, malic acid and succinic acid; the polycarboxylic acid is preferably citric acid; the adsorbent preferably includes one or more of silica gel powder and zeolite powder; the fineness of the adsorbent is preferably above 300 mesh, more preferably above 500 mesh, and further preferably 500-700 mesh.

[0051] In the present invention, the mass ratio of the vegetable oil to the polysaccharide is preferably 500-600:200-300, more preferably 520-580:220-280, and further preferably 540-560:240-260.

[0052] In the present invention, the mass ratio of the vegetable oil to the organic acid is preferably 500-600:50-100, more preferably 520-580:60-90, and even more preferably 540-560:70-80.

[0053] In the present invention, the ratio of the total mass of the vegetable oil, polysaccharide and organic acid to the mass of the adsorbent is preferably 1000:30-100, more preferably 1000:50-90, and even more preferably 1000:60-70.

[0054] The present invention also provides a method for preparing the two-component foam suppressant described in the above scheme, comprising the following steps:

[0055] (1) heating and mixing lactic acid, acetic acid, a metal oxide, and water to perform a double decomposition reaction to obtain a foam control agent;

[0056] (2) heating and mixing the vegetable oil, polysaccharide, and organic acid to obtain a viscous liquid, and then mixing the viscous liquid with an adsorbent to obtain a suspended adsorbent;

[0057] There is no time sequence requirement for step (1) and step (2).

[0058] In the present invention, lactic acid, acetic acid, a metal oxide, and water are heated and mixed (referred to as the first heating and mixing) to undergo a metathesis reaction to obtain a foam control agent. In the present invention, the foam control agent preferably has a solid content of 100 to 200 g / L, more preferably 120 to 180 g / L, and even more preferably 140 to 160 g / L.

[0059] In the present invention, the temperature of the first heating and mixing is preferably 60 to 80°C, more preferably 65 to 75°C, and even more preferably 70°C.

[0060] In the present invention, the apparatus for the metathesis reaction is preferably a reactor; the temperature of the metathesis reaction is preferably 60 to 80°C, more preferably 65 to 75°C, further preferably 70°C, and the insulation time is preferably 15 to 30 minutes, more preferably 20 to 25 minutes; the metathesis reaction is preferably carried out under stirring conditions.

[0061] The present invention heats and mixes vegetable oil, polysaccharide, and organic acid (referred to as the second heating and mixing) to obtain a viscous liquid, and then mixes the viscous liquid with an adsorbent to obtain a suspended adsorbent. In the present invention, the second heating and mixing is preferably performed under anhydrous conditions; the temperature of the second heating and mixing is preferably 100-120°C, more preferably 105-115°C, and even more preferably 110°C, and the holding time is preferably 30-60 minutes, more preferably 40-50 minutes; and the apparatus for the second heating and mixing is preferably a reactor.

[0062] The present invention also provides a method for reducing foaming in a humic acid urea production process, comprising a first evaporation section and a second evaporation section, wherein between the first evaporation section and the second evaporation section, the following steps are included:

[0063] (1) mixing a suspended adsorbent and a molten solution of urea to obtain a urea premix solution;

[0064] (2) heating and mixing the humate solution and the foam control agent to obtain a humate premix solution;

[0065] (3) Mixing the urea premix solution and the humate premix solution.

[0066] The present invention mixes a suspended adsorbent and a molten urea solution to obtain a urea premix. In the present invention, the volume-to-mass ratio of the suspended adsorbent to urea is preferably (2-5) L:1 t, more preferably (3-5) L:1 t, and even more preferably (3-4) L:1 t; the suspended adsorbent is preferably weighed using a metering pump.

[0067] In the present invention, a humate solution and a foam control agent are heated and mixed (referred to as the third heating and mixing) to obtain a humate premix. In the present invention, the volume ratio of the foam control agent to the humate solution is preferably 50 to 200:500, more preferably 80 to 180:500, and even more preferably 120 to 150:500; the mass concentration of the humate solution is preferably 10% to 18%, more preferably 12% to 16%, and even more preferably 14%.

[0068] In the present invention, the temperature of the third heating and mixing is preferably 60-80°C, more preferably 65-75°C, and further preferably 70°C; the heating and mixing device is preferably a buffer tank with a stirring and heating and insulation system.

[0069] After obtaining the urea premix and the humate premix, the present invention mixes the urea premix and the humate premix. In the present invention, the volume mass ratio of the humate premix to urea is preferably (8-20) L:1t, more preferably (10-17) L:1t, and even more preferably (12-15) L:1t.

[0070] In the present invention, the humate premix is ​​preferably weighed using a metering pump.

[0071] Figure 1 is a process flow chart of the method for reducing foaming in the humic acid urea production process provided by the present invention. The present invention is based on the process of preparing humic acid urea. Between the first evaporation section and the second evaporation section, a suspended adsorbent is weighed by a metering pump and mixed with a urea melt to obtain a urea premix. Then, a humate solution and a foaming control agent are weighed by a metering pump and heated and mixed in a buffer tank. The obtained humate premix is ​​then weighed by a metering pump and mixed with a urea premix. After that, the humate premix is ​​subjected to a second evaporation and high-tower granulation to obtain humic acid urea, effectively reducing foaming in the humic acid urea production process.

[0072] In order to further illustrate the present invention, the scheme of the present invention is described in detail below with reference to the accompanying drawings and embodiments, but they should not be understood as limiting the scope of protection of the present invention.

[0073] Example 1

[0074] The preparation of a two-component foam suppressor in this embodiment includes the following steps:

[0075] (1) Preparation of foaming control agent

[0076] Lactic acid with a mass concentration of 85%, acetic acid solution with a mass concentration of 80% and calcium oxide were added to a reactor in a mass ratio of 300:100:120. Then water was added to the reactor, heated to 60°C, and stirred for reaction for 30 minutes to obtain a foaming control agent with a concentration of 100 g / L.

[0077] (2) Preparation of suspended adsorbent

[0078] Vegetable oil, polysaccharide with a polymerization degree of 3 to 10, and organic acid are mixed in a mass ratio of 500:200:50, heated to 100°C in a reactor under anhydrous conditions, and kept warm for 60 minutes to obtain a viscous liquid. Then, an adsorbent with a fineness of more than 300 mesh is added to the viscous liquid in a mass ratio of adsorbent to viscous liquid of 30:1000, and stirred evenly to obtain a suspended adsorbent.

[0079] The vegetable oil is palm oil; the polysaccharide is maltooligosaccharide; the organic acid is oxalic acid; and the adsorbent is silica gel powder.

[0080] Example 2

[0081] The preparation of a two-component foam suppressor in this embodiment includes the following steps:

[0082] (1) Preparation of foaming control agent

[0083] Lactic acid with a mass concentration of 85%, acetic acid solution with a mass concentration of 80% and zinc oxide were added to a reactor at a mass ratio of 400:200:160. Then water was added to the reactor, heated to 80°C, and stirred for 15 minutes to obtain a foaming control agent with a concentration of 200 g / L.

[0084] (2) Preparation of suspended adsorbent

[0085] Vegetable oil, polysaccharide with a polymerization degree of 3 to 10 and organic acid are mixed in a mass ratio of 600:300:100, heated to 120°C in a reactor under anhydrous conditions, and kept warm for 30 minutes to obtain a viscous liquid. Then, an adsorbent with a fineness of more than 300 mesh is added to the viscous liquid in a mass ratio of adsorbent to viscous liquid of 100:1000, and stirred evenly to obtain a suspended adsorbent.

[0086] The vegetable oil is corn oil; the polysaccharide is isomaltooligosaccharide; the organic acid is citric acid; and the adsorbent is zeolite powder.

[0087] Example 3

[0088] The preparation of a two-component foam suppressor in this embodiment includes the following steps:

[0089] (1) Preparation of foaming control agent

[0090] Lactic acid with a mass concentration of 85%, acetic acid solution with a mass concentration of 80%, and manganese oxide were added to a reactor in a mass ratio of 350:150:140. Then water was added to the reactor, heated to 70°C, and stirred for reaction for 20 minutes to obtain a foaming control agent with a concentration of 150 g / L.

[0091] (2) Preparation of suspended adsorbent

[0092] Vegetable oil, polysaccharide with a polymerization degree of 3 to 10 and organic acid are mixed in a mass ratio of 550:250:80, heated to 110°C in a reactor under anhydrous conditions, and kept warm for 50 minutes to obtain a viscous liquid. Then, an adsorbent with a fineness of more than 300 mesh is added to the viscous liquid in a mass ratio of adsorbent to viscous liquid of 60:1000, and stirred evenly to obtain a suspended adsorbent.

[0093] The vegetable oil is cottonseed oil; the polysaccharide is oligofructose; the organic acid is malic acid; and the adsorbent is silica gel powder.

[0094] Example 4

[0095] The preparation of a two-component foam suppressor in this embodiment includes the following steps:

[0096] (1) Preparation of foaming control agent

[0097] Lactic acid with a mass concentration of 85%, acetic acid solution with a mass concentration of 80%, copper oxide and iron oxide (the mass ratio of copper oxide to iron oxide is 1:1) are added to a reactor at a mass ratio of 300:200:130, and then water is added to the reactor. The mixture is heated to 75°C and stirred for 25 minutes to obtain a foaming control agent with a concentration of 180 g / L.

[0098] (2) Preparation of suspended adsorbent

[0099] Vegetable oil, polysaccharide with a degree of polymerization of 3 to 10, and organic acid are mixed in a mass ratio of 580:230:65, heated to 105°C in a reactor under anhydrous conditions, and kept warm for 45 minutes to obtain a viscous liquid. Then, an adsorbent with a fineness of more than 300 mesh is added to the viscous liquid in a mass ratio of adsorbent to viscous liquid of 35:1000, and stirred evenly to obtain a suspended adsorbent.

[0100] The vegetable oil is cottonseed oil; the polysaccharide is galacto-oligosaccharide; the organic acid is succinic acid; and the adsorbent is zeolite powder.

[0101] Application Example 1

[0102] After the first evaporation section and before the second evaporation section:

[0103] (1) First, a suspended adsorbent is added to the urea melt at a rate of 2 L per ton of urea using a metering pump to adsorb the free ammonia in the urea melt and the ammonia generated by the addition of the humate solution to obtain a urea premix;

[0104] (2) A humate solution at 60°C and a mass concentration of 10% is added to a buffer tank equipped with a stirring and heating insulation system (the temperature is maintained at 60°C), and a 60°C foaming control agent and a humate solution are added to the buffer tank in a volume ratio of 50:500 to obtain a humate premix solution, which is then added to the urea premix solution (before the second evaporation stage and after the addition of the suspended adsorbent) via a metering pump. The amount of humate premix solution added to each ton of urea is 8 L.

[0105] Application Example 2

[0106] After the first evaporation section and before the second evaporation section:

[0107] (1) First, a suspended adsorbent is added to the urea melt at a rate of 5 L per ton of urea using a metering pump to adsorb the free ammonia in the urea melt and the ammonia generated by the addition of the humate solution to obtain a urea premix;

[0108] (2) A humate solution at 80°C and a mass concentration of 18% is added to a buffer tank equipped with a stirring and heating insulation system (the temperature is maintained at 80°C), and an 80°C foaming control agent and a humate solution are added to the buffer tank at a volume ratio of 200:500 to obtain a humate premix solution, which is then added to the urea premix solution (before the second evaporation stage and after the addition of the suspended adsorbent) via a metering pump. The amount of humate premix solution added to each ton of urea is 20L.

[0109] Test Example 1

[0110] The two-component foam suppressant prepared in Example 1 was subjected to foaming reaction and humate coagulation tests, and the test methods were as follows:

[0111] (1) Foaming reaction test

[0112] Three treatment groups were set up: T1 (ordinary urea melt), T2 (15 L of humate solution was added to each ton of urea melt), and T3 (4 L of suspended adsorbent was first added to each ton of urea melt, and then a humate premix prepared by mixing 15 L of humate solution and 1.5 L of foaming control agent was added). The urea melt was aspirated with a dropper and quickly dropped into liquid paraffin to obtain urea granules. The density of the urea granules was measured (which can indicate the amount of foaming in the urea granules, and the lower the density, the more foaming).

[0113] Determination of urea granule density: The density of urea granules was determined by the water displacement method. 6.5 g of T1, T2, and T3 urea granules were weighed and placed in a 50 mL graduated cylinder containing 30 mL of liquid paraffin. The volume at this time was recorded. The volume of the urea granules V1 (5.3 mL), V2 (6.0 mL), and V3 (5.1 mL) was calculated by the difference subtraction method. Finally, the density of the urea granules was calculated. The results are shown in Table 1.

[0114] Wherein, urea granule density = urea granule mass / urea granule volume.

[0115] Table 1 Effects of humate and two-component antifoam agent on urea granule density

[0116] As shown in Table 1, compared with ordinary urea granules (T1), the density of humate urea granules (T2) is reduced by 11.5%, and the density of humate + two-component antifoaming agent urea granules (T3) is increased by 4.1% and 17.6% compared with T1 and T2, respectively. This shows that the two-component antifoaming agent provided by the present invention can solve the problem of foaming in the production process of humate urea.

[0117] The morphology of the urea granules was observed, and the foaming of the urea granules was observed. The results are shown in Figure 2. As can be seen from Figure 2, the T1 urea granules have uniform particle size and a smooth and rounded surface; the T2 urea granules have low particle size and poor appearance, and the surface of the urea granules is not smooth and has pores; the T3 urea granules have high particle size and good appearance, and the surface of the urea granules is smooth without bubbles.

[0118] (2) Humate coagulation test

[0119] Set up 3 treatment groups: H1, H2 and H3.

[0120] H1: Place a 10% humate solution (pH 10.09) at 60°C in a beaker and place it on an 85-2A digital constant temperature and speed magnetic stirrer (maintained at 60°C) and stir for 5 minutes.

[0121] H2: Place a 60°C, 10% mass concentration humate solution in a beaker and place it on the above-mentioned magnetic stirrer (maintained at 60°C). Then add a 60°C foaming control agent (the volume ratio of foaming control agent to humate solution is 50:500) and stir for 5 minutes to obtain a humate premix solution. The pH at this time is measured to be 6.10.

[0122] H3: Place a 60°C, 10% mass concentration humate solution in a beaker and place it on the above-mentioned magnetic stirrer (maintain the temperature at 60°C). Then slowly add potassium dihydrogen phosphate solution to the humate solution to adjust the pH value of the humate solution to 6.10, and stir the reaction for 5 minutes.

[0123] The viscosity of the H1, H2, and H3 treatments was measured using a digital viscometer (SNB-2; temperature 20°C, speed 60.0 RMP) to characterize the coagulation of the humate solution. The smaller the viscosity, the smaller the coagulation degree and the stronger the fluidity of the humate solution. The viscosity of the humate solution is shown in Table 2.

[0124] Table 2 Determination of viscosity of H1~H3 humate solutions

[0125] Table 2 shows that a 10% humate solution has a viscosity of 1.31 mPa·s, demonstrating good fluidity. Adding a foaming control agent lowers the pH of the humate solution and slightly increases its viscosity. However, adding potassium dihydrogen phosphate to the humate solution causes severe humate coagulation and precipitation, with the viscosity of H3 being 60.7 times that of H2. This demonstrates that the foaming control agent in the two-component foam suppressor provided by the present invention can enhance the anti-coagulation ability and fluidity of the humate solution under moderately to slightly acidic conditions, effectively resolving the foaming problem during the humic acid urea production process.

[0126] Test Example 2

[0127] The two-component foam suppressant of Example 2 was subjected to dust test, particle strength test and production efficiency calculation:

[0128] (1) Dust generation: 5-12 kg of dust is generated for every ton of ordinary humic acid urea produced; this method can reduce the dust generation per ton of humic acid urea to 1-3 kg.

[0129] (2) Particle strength: The particle strength of ordinary humic acid urea is 14-16N; this method can increase the particle strength of humic acid urea to 18-20N.

[0130] (3) Production efficiency: Humic acid urea manufacturers usually reduce production capacity to reduce urea dust generation. Taking the daily urea output of 1,500 tons as an example, the production of humic acid urea needs to be reduced to about 1,200 tons. By adopting this method, the daily output of 1,500 tons can still be maintained, greatly improving production efficiency.

[0131] As can be seen from the above examples, the two-component antifoaming agent provided by the present invention can prevent the humate solution from coagulating under non-alkaline conditions, effectively reducing the foaming phenomenon in the humic acid urea production process. The method provided by the present invention can eliminate bubbles, improve the urea granulation rate, increase the granule strength, reduce dust generation, and improve production efficiency.

[0132] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A two-component defoamer, characterized in that, It includes a foam control agent and a suspension adsorbent; The raw materials of the foam control agent include lactic acid, acetic acid and metal oxides; The raw materials of the suspension adsorbent include vegetable oil, polysaccharide, organic acid and adsorbent; The degree of polymerization of the polysaccharide is 3 - 10; the organic acid does not include lactic acid and acetic acid.

2. The two-component anti-foaming agent according to claim 1, characterized in that, The metal oxides include one or more of zinc oxide, copper oxide, iron oxide, manganese oxide and calcium oxide; The lactic acid is a lactic acid solution; the mass concentration of the lactic acid solution is 85%; The acetic acid is an acetic acid solution; the mass concentration of the acetic acid solution is 80%; 3. The two-component defoamer according to claim 1 or 2, characterized in that, The mass ratio of the lactic acid to the acetic acid solution is 300 - 400:100 - 200; The mass ratio of the lactic acid to the metal oxides is 300 - 400:120 - 160.

4. The two-component defoamer according to claim 1, wherein, The mass ratio of the vegetable oil to the polysaccharide is 500 - 600:200 - 300; The mass ratio of the vegetable oil to the organic acid is 500 - 600:50 - 100; The mass ratio of the total mass of the vegetable oil, polysaccharide and organic acid to the mass of the adsorbent is 1000:30 - 100.

5. The two-component defoamer according to claim 1 or 4, characterized in that, The vegetable oil includes one or more of palm oil, corn oil and cottonseed oil; The polysaccharide includes one or more of maltooligosaccharide, isomaltooligosaccharide, fructooligosaccharide, galactooligosaccharide, xylooligosaccharide; The organic acid is an organic carboxylic acid; The adsorbent includes one or more of silica powder and zeolite powder.

6. The preparation method of the two-component defoamer according to any one of claims 1 to 5, characterized in that, It includes the following steps: (1) Heat and mix lactic acid, acetic acid, metal oxides and water to carry out a metathesis reaction to obtain a foam control agent; (2) Heat and mix vegetable oil, polysaccharide and organic acid to obtain a viscous liquid, and then mix the viscous liquid and the adsorbent to obtain a suspension adsorbent; There is no requirement for the time sequence between step (1) and step (2).

7. A method for reducing foaming in the production process of humic acid urea, including a first-stage evaporation section and a second-stage evaporation section, characterized in that, Between the first evaporation section and the second evaporation section, it includes the following steps: (1) Mix the suspension adsorbent and the molten liquid of urea to obtain a urea premixed liquid; (2) Heat and mix the humate solution and the foam control agent to obtain a humate premixed liquid; (3) Mix the urea premixed liquid and the humate premixed liquid.

8. The method according to claim 7, wherein The volume-mass ratio of the suspension adsorbent to urea is (2 - 5) L:1 t; The volume ratio of the foam control agent to the humate solution is 50 - 200:500; The mass concentration of the humate solution is 10 - 18%; 9. The method according to claim 7, wherein The volume-mass ratio of the humate premixed liquid to urea is (8 - 20) L:1 t.

10. The method according to claim 7, characterized in that, The temperature of the heat mixing is 60 - 80 °C.

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