A method for purifying attapulgite and its application in the preparation of liquid fertilizer

Abstract

This invention discloses a method for purifying attapulgite, comprising: first, crushing the raw attapulgite ore and adding water to prepare a slurry; then, adding a certain amount of oxalic acid to the slurry and reacting for a certain time; next, adding a certain amount of isomeric alcohol polyoxyethylene ether and polyvinylpyrrolidone to the slurry, mixing well, and centrifuging to obtain an upper attapulgite suspension. Compared with the prior art, the method of this invention combines purification and modification into one, thereby simplifying the existing purification and modification operations. The attapulgite obtained by the method of this invention is an excellent fertilizer carrier.

Description

Technical Field

[0001] This invention relates to a method for purifying attapulgite. Background Technology

[0002] Attapulgite, hailed as the "soil of a thousand soils," possesses unique physicochemical properties and strong adsorption capabilities, and is rich in various trace elements such as Na, Ca, Fe, and Al, essential for plant growth and development. However, raw attapulgite ore often contains montmorillonite, kaolinite, hydromica, sepiolite, quartz, opal, and carbonate minerals, requiring purification, dissociation, and even further modification to fully realize its unique advantages. Summary of the Invention

[0003] The purpose of this invention is to combine purification and modification into one, providing a method for simultaneously modifying attapulgite during the purification process.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A method for purifying attapulgite includes: First, crush the raw attapulgite ore and add water to prepare a slurry; Then a certain amount of oxalic acid is added to the slurry, and the reaction is allowed to proceed for a certain period of time. Next, a certain amount of isomeric alcohol polyoxyethylene ether and polyvinylpyrrolidone were added to the slurry, mixed well, and centrifuged to obtain the upper attapulgite suspension.

[0005] Preferably, the amount of oxalic acid used is 2 to 10% of the mass of the attapulgite ore.

[0006] Preferably, the total concentration of isomeric alcohol polyoxyethylene ether and polyvinylpyrrolidone in the slurry is 0.5~1wt%.

[0007] Preferably, the mass ratio of isomeric alcohol polyoxyethylene ether to polyvinylpyrrolidone is 1:1 to 1:5.

[0008] Preferably, the attapulgite ore is crushed and then naturally sun-dried for 3 to 5 months.

[0009] Preferably, the attapulgite ore is prepared into a slurry with a concentration of 5-10 wt%.

[0010] An attapulgite suspension obtained by the above method.

[0011] The application of the attapulgite suspension obtained by the above method in the preparation of liquid fertilizer.

[0012] A method for preparing liquid fertilizer, comprising: (1) The above attapulgite suspension is ultrasonically dissociated for a certain period of time; (2) The attapulgite suspension after dissociation treatment is mixed with plant nutrients, microbial agents and soluble starch.

[0013] Preferably, by weight, the liquid fertilizer contains 10 parts attapulgite, 10 parts potassium humate, 1 part selenium-enriched amino acids, 15 parts urea, 10 parts potassium sulfate, 5 parts diammonium phosphate, 5 parts potassium phosphate, 0.5 parts microbial agent, 0.5 parts chelated iron, 0.2 parts chelated zinc, 0.1 parts chelated manganese, 0.05 parts chelated copper, 0.05 parts borax, 0.05 parts ammonium molybdate, and the soluble starch content in the liquid fertilizer is 2 wt%.

[0014] Preferably, after the attapulgite suspension is ultrasonically dissociated, it is further ground and dissociated for a certain period of time using a nano-ceramic diaphragm slurry grinder. Detailed Implementation

[0015] The technical solution of the present invention will be further described in detail below with reference to the embodiments.

[0016] Example 1 1. Crush the raw attapulgite ore (attapulgite purity of 65%) into 5-10 mm particles and air dry it naturally for 3-5 months to allow the attapulgite particles to weather, which is denoted as ATP-0.

[0017] 2. Mix isomeric alcohol polyoxyethylene ether 1310 and polyvinylpyrrolidone at a mass ratio of 1:1, ball mill at high speed, add water, and homogenize and emulsify at high speed to obtain an emulsion with a concentration of 10wt%, denoted as TJJ-1.

[0018] 3. Weigh ATP-0 to prepare a slurry with a concentration of 5wt%. Add oxalic acid at 2% of the mass of ATP-0, mix well, and react for 24 hours. Then add TJJ-1 at 10% of the slurry volume, stir well, and centrifuge at 200 rpm for 5 minutes.

[0019] 4. Take the supernatant suspension of attapulgite (attapulgite purity 95%, excluding water) after centrifugation, sonicate for 40 minutes, then add it to a nano-ceramic diaphragm slurry grinder (Qingdao Lianrui Precision Machinery Co., Ltd., model 01-HD / 01-HDDM) for thorough grinding and dissociation (500 rpm, 25 degrees Celsius, 20 minutes) to obtain nano-sized attapulgite slurry, denoted as ATP-N. Testing showed that the attapulgite particle size D100 in the slurry was no greater than 90 nanometers, and the attapulgite solid content was 2-2.5%.

[0020] 5. By weight, mix 10 parts of ATP-N (calculated on an attapulgite dry basis), 10 parts of potassium humate, 1 part of selenium-enriched amino acids, 15 parts of urea, 10 parts of potassium sulfate, 5 parts of diammonium phosphate, 5 parts of potassium phosphate, 0.5 parts of compound microbial agent, 0.5 parts of chelated iron, 0.2 parts of chelated zinc, 0.1 parts of chelated manganese, 0.05 parts of chelated copper, 0.05 parts of borax, 0.05 parts of ammonium molybdate, and 100 parts of ultrapure water. Sonicate the mixture for 10 minutes while maintaining the temperature at 5-10 degrees Celsius. Then, add soluble starch at a concentration of 2 wt% and stir until homogeneous to obtain a liquid fertilizer, denoted as ATP-F.

[0021] The compound microbial agent is prepared by mixing one part by weight of each of the following: Bacillus subtilis L5, Bacillus amyloliquefaciens PT6-1, Bacillus megaterium, Bacillus licheniformis A2, Pseudomonas aeruginosa HG28-5, Alcaligenes HY-B, Pseudomonas TR47, Azotobacter, Bacillus mucilaginosus, halophilic archaea, and arbuscular mycorrhizal fungi.

[0022] The attapulgite ore, selenium-rich amino acids, chelated iron, chelated zinc, chelated manganese, chelated copper, and soluble starch of this invention were all purchased from Baiyin Fengbao Agricultural Chemical Technology Co., Ltd.

[0023] Example 2 The preparation of liquid fertilizer is the same as in Example 1, except that in step 4, the nano-ceramic diaphragm slurry grinding machine is not used.

[0024] Comparative Example 1 The preparation of the liquid fertilizer was the same as in Example 1, except that TJJ-1 was not added in step 3. The attapulgite obtained from the supernatant after centrifugation had a purity of 67% (excluding water).

[0025] Comparative Example 2 The preparation of the liquid fertilizer was the same as in Example 1, except that in step 2, isomeric alcohol polyoxyethylene ether 1310 was not added. The attapulgite obtained from the supernatant after centrifugation had a purity of 79% (excluding water).

[0026] Comparative Example 3 The preparation of the liquid fertilizer was the same as in Example 1, except that polyvinylpyrrolidone was not added in step 2. The attapulgite obtained from the supernatant after centrifugation had a purity of 71% (excluding water).

[0027] Application Experiment: This experiment selected saline-alkali land (properties are shown in the blank group), divided it into control and experimental groups, and set up replicate samples. The experimental group was evenly sprayed with 100 kg of the above-mentioned liquid fertilizer per mu (approximately 0.067 hectares). After spraying, the soil was deeply plowed and mixed, and allowed to stand for 7 days before sowing. Soil pH was measured according to NY / T 1377-2007, soil alkalinity was calculated according to LY / T1249-1999, and soil salinity was tested according to NY / T 1121.16-2006. The changes in various indicators of the soil samples after 7 days of aging were compared. Crop emergence rate was calculated by dividing the number of normally germinated seeds by the total number of sown seeds and then multiplying by 100%. By comparing soil salinity parameters and emergence status, the actual effect of this liquid fertilizer on improving saline-alkali land and enriching soil was comprehensively evaluated. The specific results are shown in Table 1.

[0028] Table 1. Improvement effects of applying different liquid fertilizers on saline-alkali land Example 3 1. Crush the raw attapulgite ore into 5-10 mm particles and air dry it naturally for 3-5 months to allow the attapulgite particles to weather, which is denoted as ATP-0.

[0029] 2. Mix isomeric alcohol polyoxyethylene ether 1310 and polyvinylpyrrolidone at a mass ratio of 1:3, ball mill at high speed, add water, and homogenize and emulsify at high speed to obtain an emulsion with a concentration of 10wt%, denoted as TJJ-1.

[0030] 3. Weigh ATP-0 to prepare a slurry with a concentration of 5wt%. Add oxalic acid at 5% of the mass of ATP-0, mix well, and react for 24 hours. Then add TJJ-1 at 10% of the slurry volume, stir well, and centrifuge at 200 rpm for 5 minutes. Take the upper attapulgite suspension after centrifugation.

[0031] Example 4 1. Crush the raw attapulgite ore into 5-10 mm particles and air dry it naturally for 3-5 months to allow the attapulgite particles to weather, which is denoted as ATP-0.

[0032] 2. After mixing isomeric alcohol polyoxyethylene ether 1310 and polyvinylpyrrolidone at a mass ratio of 1:5 and ball milling at high speed, water was added and emulsified at high speed to obtain an emulsion with a concentration of 10wt%, denoted as TJJ-1.

[0033] 3. Weigh ATP-0 to prepare a slurry with a concentration of 5wt%. Add oxalic acid at 10% of the mass of ATP-0, mix well, and react for 24 hours. Then add TJJ-1 at 10% of the slurry volume, stir well, and centrifuge at 200 rpm for 5 minutes. Take the upper attapulgite suspension after centrifugation.

[0034] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for purifying attapulgite, comprising: First, crush the raw attapulgite ore and add water to prepare a slurry; Then a certain amount of oxalic acid is added to the slurry, and the reaction is allowed to proceed for a certain period of time. Next, a certain amount of isomeric alcohol polyoxyethylene ether and polyvinylpyrrolidone were added to the slurry, mixed well, and centrifuged to obtain the upper attapulgite suspension.

2. The method according to claim 1, characterized in that: The amount of oxalic acid used is 2-10% of the mass of the raw attapulgite ore.

3. The method according to claim 1, characterized in that: The total concentration of isomeric alcohol polyoxyethylene ether and polyvinylpyrrolidone in the slurry is 0.5~1wt%.

4. The method according to claim 3, characterized in that: The mass ratio of isomeric alcohol polyoxyethylene ether to polyvinylpyrrolidone is 1:1 to 1:

5.

5. The method according to claim 1, characterized in that: After the raw attapulgite ore is crushed, it is naturally dried for 3 to 5 months.

6. The method according to claim 1, characterized in that: The raw attapulgite ore is prepared into a slurry with a concentration of 5-10 wt%.

7. The attapulgite suspension obtained by any one of claims 1 to 6.

8. The application of the attapulgite suspension according to claim 7 in the preparation of liquid fertilizer.

9. A method for preparing liquid fertilizer, comprising: (1) The attapulgite suspension of claim 7 is ultrasonically dissociated for a certain period of time; (2) Mix the attapulgite suspension after dissociation treatment with plant nutrients, microbial agents and soluble starch; Preferably, by weight, the liquid fertilizer contains 10 parts attapulgite, 10 parts potassium humate, 1 part selenium-enriched amino acids, 15 parts urea, 10 parts potassium sulfate, 5 parts diammonium phosphate, 5 parts potassium phosphate, 0.5 parts microbial agent, 0.5 parts chelated iron, 0.2 parts chelated zinc, 0.1 parts chelated manganese, 0.05 parts chelated copper, 0.05 parts borax, 0.05 parts ammonium molybdate, and the soluble starch content in the liquid fertilizer is 2 wt%.

10. The method according to claim 9, characterized in that: After ultrasonic dissociation, the attapulgite suspension is further dissociated by grinding with a nano-ceramic diaphragm slurry grinder for a certain period of time.

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