CN108424244B

CN108424244B - Fertilizer synergist, preparation method thereof and application of fertilizer synergist in production of synergistic fertilizer

Info

Publication number: CN108424244B
Application number: CN201810372191.2A
Authority: CN
Inventors: 黄志刚
Original assignee: Individual
Current assignee: Yunnan Hezhuang Fertilizer Industry Co ltd
Priority date: 2018-04-24
Filing date: 2018-04-24
Publication date: 2021-08-10
Anticipated expiration: 2038-04-24
Also published as: CN108424244A

Abstract

The invention provides a fertilizer synergist, a preparation method thereof and application in production of a synergistic fertilizer. The fertilizer synergist comprises the following components in percentage by weight based on the total weight of the fertilizer synergist: 35 to 50 parts by weight of cyclodextrin; 0.2 to 2 parts by weight of a trace element fertilizer composition; 20 to 40 parts by weight of zeolite powder; 3 to 10 parts by weight of sodium dodecylbenzenesulfonate; and 10 to 15 parts by weight of activated carbon. The invention also provides a synergistic fertilizer containing the fertilizer synergist, a method for preparing the fertilizer synergist and application of the fertilizer synergist in chemical fertilizer synergism. The invention can realize the obvious synergistic effect on trace elements and/or chemical fertilizers, thereby improving the utilization rate of the trace elements and/or chemical fertilizers and reducing the damage to the physical and chemical properties of soil.

Description

Fertilizer synergist, preparation method thereof and application of fertilizer synergist in production of synergistic fertilizer

Technical Field

The invention relates to the technical field of fertilizers, in particular to a fertilizer synergist and a preparation method and application thereof.

Background

The fertilizer can provide nutrient elements needed by or beneficial to plants, improve soil properties and improve soil fertility level, and is one of the most important agricultural materials in agricultural production.

The nutrient elements necessary for plants include 16 elements such as carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, boron, manganese, copper, zinc, molybdenum, chlorine and the like. The 16 essential nutrients are divided into large, medium and trace nutrients according to their contents in crops. The macronutrient elements in the crop body account for about a few thousandths to a few tens of percent of the weight of dry matters, such as carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium and the like; the medium nutrient elements and the trace nutrient elements account for about a few thousandths to a ten-thousandth of the weight of dry matters in crops, such as calcium, magnesium, sulfur, iron, boron, manganese, copper, zinc, molybdenum, chlorine and the like. Macronutrients, namely nitrogen, phosphorus and potassium, required by plants in soil cannot meet the requirement of crop growth generally, and additional nitrogen, phosphorus and potassium elements are required to be supplemented. Besides chlorine in soil, the trace nutrient elements required by plants need to be supplemented additionally. Supplementation of these nutrients is achieved by applying fertilizers to the soil or other substrate.

However, the utilization rate of the trace elements is low due to leaching and ion antagonism; moreover, these trace elements not utilized by plants also tend to cause soil hardening and deteriorate the soil structure.

The chemical fertilizer is a fertilizer which is prepared by a chemical and/or physical method and contains one or more nutrient elements required by the growth of crops, is generally an inorganic compound, and is only an organic compound, so the chemical fertilizer is also called an inorganic fertilizer at times and comprises a nitrogen fertilizer, a phosphate fertilizer, a potassium fertilizer, a micro-fertilizer, a compound fertilizer and the like. The chemical fertilizer has the advantages of single component, high nutrient content, quick fertilizer effect, strong fertilizer effect and the like, is the most important basis for the growth of crop products, and accounts for more than 30 percent in all yield increasing measures. However, excessive use of chemical fertilizers or low utilization of applied chemical fertilizers may cause release of chemical fertilizers into soil, leading to soil acidification, deterioration of physical and chemical structures, environmental pollution, and the like. Urea is one of the most important chemical fertilizers, only consists of carbon, nitrogen, oxygen and hydrogen, and is also the nitrogen fertilizer with the highest nitrogen content at present, but leaching loss and volatilization loss are easily caused by direct use.

Therefore, how to improve the utilization rate of trace elements and/or chemical fertilizers, especially urea, has been a great topic in the technical field of fertilizers.

Disclosure of Invention

In order to increase the availability of trace elements and/or chemical fertilizers, in particular urea, the invention provides in a first aspect a fertilizer synergist comprising, based on the total weight of the fertilizer synergist: 35 to 50 parts by weight of cyclodextrin; 0.2 to 2 parts by weight of a trace element fertilizer composition; 20 to 40 parts by weight of zeolite powder; 3 to 10 parts by weight of sodium dodecylbenzenesulfonate; and 10 to 15 parts by weight of activated carbon.

In a second aspect of the invention there is provided a fertiliser synergist comprising a fertiliser synergist according to the first aspect of the invention and a chemical fertiliser.

In a third aspect, the present invention provides a process for preparing a fertilizer synergist according to the first aspect of the present invention, said process comprising the steps of: (1) mixing sodium dodecyl benzene sulfonate and cyclodextrin uniformly, then using water to prepare paste, placing and aging for 2 to 5 hours at room temperature, drying to constant weight, and crushing to first powder with the average particle size of not more than 150 micrometers; (2) adding a trace element fertilizer composition accounting for 75% of the total amount into the first powder, and uniformly stirring to obtain second powder; (3) adding zeolite powder into the second powder, introducing saturated steam to fumigate for 1 to 3 hours, drying to constant weight, and crushing to third powder with the average particle size of not more than 150 micrometers; (4) adding activated carbon powder into the third powder, uniformly mixing, adding the rest microelement fertilizer composition, uniformly mixing, and preparing into a granular form with the diameter of 1 mm-5 mm to obtain the fertilizer synergist.

In a fourth aspect, the invention provides a fertilizer synergist obtainable by the process of the third aspect of the invention.

In a fifth aspect, the invention provides the use of a fertiliser synergist according to the first aspect of the invention for the synergistic effect of a chemical fertiliser, especially urea.

The invention can realize the high-efficiency synergistic effect of the trace elements and/or the chemical fertilizers, thereby improving the utilization rate of the trace elements and/or the chemical fertilizers and reducing the damage to the physical and chemical properties of soil.

Detailed Description

The invention provides in a first aspect a fertilizer synergist comprising, based on the total weight of the fertilizer synergist: 35 to 50 parts by weight (e.g., 35, 40, 45, or 50 parts by weight) of a cyclodextrin; 0.2 to 2 parts by weight (e.g., 0.2, 0.3, 0.5, 0.8, 1.0, 1.2, 1.5, 1.8, or 2.0 parts by weight) of a trace element fertilizer composition; 20 to 40 parts by weight (e.g. 20, 25, 30, 35 or 40 parts by weight) of zeolite powder; 3 to 10 parts by weight (e.g., 3, 5, 8, or 10 parts by weight) of sodium dodecylbenzenesulfonate; and 10 to 15 parts by weight (e.g., 11, 12, 13, 14, or 15 parts by weight) of activated carbon.

Cyclodextrin (CD) is a general name of a series of cyclic oligosaccharides produced by amylose under the action of Cyclodextrin glucosyltransferase produced by bacillus, and generally contains 6-12D-glucopyranose units. Molecules containing 6, 7, and 8 glucose units are referred to as α -cyclodextrin, β -cyclodextrin, and γ -cyclodextrin, respectively. Each D (+) -glucopyranose constituting the cyclodextrin molecule is in a chair conformation. Each glucose unit is bonded to form a ring by a 1, 4-glycosidic bond. Cyclodextrins are not cylindrical molecules but rather slightly conical rings, since the glycosidic bond linking the glucose units cannot rotate freely. The cyclodextrin has hydrophobic cavity inside and hydrophilic outside, and may be combined with various small organic molecules or ions to form inclusion compound. For example, pyrethroids are a very important class of insecticides, and the problems of insolubility in water and consumption of a large amount of organic solvents can be solved by using cyclodextrin, so that the pyrethroid is an effective way for solving the problem of environment pollution caused by the pyrethroids.

Zeolite powder is an ore, first discovered in 1756 years. In 1932, McBain proposed the concept of molecular sieves, which are believed to be able to sieve substances at the molecular level. The crystal structure of zeolite powder can be divided into three components: (1) aluminosilicate framework, (2) pore channels and cavities containing exchangeable cations M in the framework, and (3) water molecules of latent phase, namely zeolite powder water. The structure of zeolite powder is somewhat different from the framework of quartz and feldspar. The framework structures of quartz and feldspar are tighter, the specific gravity is 2.6-2.7, and the framework structure of zeolite powder is looser, and the specific gravity is 2.0-2.2. The cavity after dehydration can be as large as 47%. In the zeolite powder structure, metal cations are located between the large and interconnected pore channels or voids of the crystal structure. Thus, cations can freely exchange through the pore channels without affecting their crystalline framework, which is easily done in zeolite powders and not in other minerals such as talc. This form of exchange, which may be the extreme form of ion exchange, is limited to zeolite powder and similar minerals. The association of the water molecules of the zeolite powder with the framework ions and exchangeable metal cations is generally relaxed and weak. These water molecules are more freely movable and accessible to the tunnel than the cations. Under the action of heat, the material can be freely detached and attached without affecting the skeleton structure.

The active carbon is a black porous solid carbon, and is produced by crushing and molding coal or carbonizing and activating uniform coal particles. The main component is carbon and contains a small amount of elements such as oxygen, hydrogen, sulfur, nitrogen, chlorine and the like. The specific surface area of the common activated carbon is 500-1700 m/g. Has strong adsorption performance and is an industrial adsorbent with wide application. The specific surface area is 500-1700 m/g.

Sodium dodecyl benzene sulfonate is an anionic surfactant and has stable chemical properties to alkali, dilute acid and hard water. The sodium dodecyl benzene sulfonate product has wide application, can be used as a detergent, an antistatic agent and an emulsifying dispersant, can also be used as a cotton fabric refining agent, a desizing assistant and a leveling agent during dyeing in the aspect of textile assistants, can be used as a metal degreasing agent in the metal electroplating process, and can be used as a resin dispersant, a felt detergent and a deinking agent in the papermaking industry; as an osmotic degreaser in the leather industry; as an anti-caking agent in the fertilizer industry; the product can be used as air-entraining agent in cement industry, or used alone or as compounding ingredient.

The trace elements in the fertilizer are easy to reduce the utilization rate due to leaching loss or antagonism. The fertilizer synergist disclosed by the invention is used for clathrating trace elements by utilizing the clathration effect of cyclodextrin, the clathration effect is optimized by virtue of sodium dodecyl benzene sulfonate and zeolite powder, and the release rhythm of the trace elements is regulated by being matched with activated carbon, so that the release of the prepared trace elements is closer to the trace element demand curve of plants. Moreover, the fertilizer synergist is matched with a chemical fertilizer such as urea for use, and the chemical fertilizer is restrained by utilizing the residual gaps of the fertilizer synergist, so that the purpose of synergism is achieved, and the synergism of the fertilizer synergist on the chemical fertilizer can be more fully utilized.

In some preferred embodiments, the amount ratio of cyclodextrin to activated carbon is 9:7, and the total amount of cyclodextrin and activated carbon is 80 times the amount of the micronutrient fertilizer composition.

In some preferred embodiments, the cyclodextrin is selected from the group consisting of alpha-cyclodextrin, beta-cyclodextrin, and gamma-cyclodextrin; the specific surface area of the activated carbon is 1000-1500 m²G (e.g. 1000, 1200 or 1500 m)²(iv)/g); the zeolite powder has an average particle diameter of 20 to 50 μmMeter (e.g. 20, 30, 40 or 50 microns).

In some preferred embodiments, the fertilizer synergist is in the form of granules having a particle size of 1mm to 5 mm.

In some preferred embodiments, the trace element fertilizer composition comprises: 10 to 20 parts by weight of iron sulfate heptahydrate; 2 to 5 parts by weight of copper sulfate pentahydrate; 5 to 25 parts by weight of borax; 2 to 10 parts by weight of ammonium molybdate; 2 to 5 parts by weight of zinc sulfate heptahydrate; 5 to 10 parts by weight of manganese sulfate trihydrate.

In a second aspect of the invention there is provided a fertiliser synergist comprising a fertiliser synergist according to the first aspect of the invention and a chemical fertiliser. Preferably, the weight ratio of the fertilizer synergist to the chemical fertilizer is 1:1 to 1: 5; preferably, the chemical fertilizer is any one or more of the group consisting of a nitrogen fertilizer, a phosphate fertilizer and a potassium fertilizer; preferably, the chemical fertilizer is a nitrogen fertilizer, more preferably urea.

In a third aspect, the present invention provides a process for preparing a fertilizer synergist according to the first aspect of the present invention, said process comprising the steps of: (1) mixing sodium dodecyl benzene sulfonate and cyclodextrin uniformly, then using water to prepare paste, placing and aging for 2 to 5 hours at room temperature, drying to constant weight, and crushing to first powder with the average particle size of not more than 150 micrometers; (2) adding a trace element fertilizer composition accounting for 75% of the total amount into the first powder, and uniformly stirring to obtain second powder; (3) adding zeolite powder into the second powder, introducing saturated steam to fumigate for 1 to 3 hours, drying to constant weight, and crushing to third powder with the average particle size of not more than 150 micrometers; (4) adding activated carbon powder to the third powder and mixing uniformly, adding the rest microelement fertilizer composition and mixing uniformly to prepare into a granular form with the diameter of 1mm to 5mm (for example, humidifying with water and preparing into round granules by utilizing the binding action of zeolite powder per se), and obtaining the fertilizer synergist. In some preferred embodiments, the paste prepared in step (1) has a solids content of 85 to 90% by weight.

The method comprises the steps of activating cyclodextrin by utilizing the specific activation effect of sodium dodecyl benzene sulfonate on the hydrophobic space of the cyclodextrin to improve the inclusion effect of the cyclodextrin on the trace element fertilizer composition, adding a first part (about 75%) of the trace element fertilizer composition for inclusion, sealing the hydrophobic space of the cyclodextrin, which is included with the trace element fertilizer composition, by utilizing zeolite powder in the presence of water vapor, and drying to remove the zeolite powder water, so that the sealing is more tight. Activated carbon was added and mixed and a second portion (about 25%) of the micronutrient fertilizer composition was added and mixed well. The second portion of the micronutrient fertilizer composition is primarily immobilized by activated carbon. Through the matching use of the first part of the trace element fertilizer composition which is included by the cyclodextrin inclusion effect and the second part of the trace element fertilizer composition which is adsorbed by the activated carbon adsorption effect, the total release curve of the fertilizer synergist is more consistent with the demand curve of plants for the trace element fertilizer composition, so that the utilization rate of the trace element fertilizer composition is further improved.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Examples

The technical solutions of the present invention will be illustrated below in the form of examples, but the scope of protection of the present invention is not limited to these examples.

Preparation example 1

The sodium dodecyl benzene sulfonate and the beta-cyclodextrin are uniformly mixed, water is used for blending to prepare paste, the paste is placed at room temperature for aging for 3 hours, then the paste is dried to constant weight (5 g of sample is taken for detection, the weight difference between the two times is not more than 1 percent), and the paste is crushed and sieved by a 100-mesh sieve to obtain first powder.

Three-quarter of the trace element fertilizer composition (based on the weight of the trace element fertilizer composition, comprising 15 parts by weight of iron sulfate heptahydrate, 3.5 parts by weight of copper sulfate pentahydrate, 15 parts by weight of borax, 6 parts by weight of ammonium molybdate, 3.5 parts by weight of zinc sulfate heptahydrate and 7.5 parts by weight of manganese sulfate trihydrate) is added to the first powder and uniformly stirred to obtain a second powder.

Adding zeolite powder (sieving with 400 mesh sieve) into the second powder, introducing saturated steam to fumigate for 2 hr, oven drying to constant weight (5 g sample is detected, weight difference between the two times is no more than 1%), and pulverizing to third powder with average particle size no more than 1000 μm;

adding activated carbon powder (specific surface area about 1380 m) to the third powder²/g) and mixing uniformly, adding the rest of the trace element fertilizer composition and mixing uniformly to prepare a granular form with the diameter of 1mm to 5mm, thus obtaining the fertilizer synergist.

Preparation examples 2 and 3

Substantially the same procedure as in preparation example 1 was conducted except for the contents shown in Table 1 below.

Preparation example 4

Substantially the same method as in preparation example 3 was employed except that blocking was performed without adding zeolite powder.

Preparation example 5

Substantially the same method as in preparation example 3 was used except that activation was performed without adding sodium dodecylbenzenesulfonate.

Preparation example 6

Substantially the same method as in preparation example 3 was employed except that supplementary adsorption was not carried out with activated carbon.

Preparation example 7

The method which is basically the same as the preparation example 3 is adopted, except that the zeolite powder is replaced by the attapulgite powder;

preparation example 8

Substantially the same method as in preparation example 3 was used except that sodium dodecylsulfate was used instead of sodium dodecylbenzenesulfonate.

Preparation example 9

The same method as in preparation example 3 was used except that the zeolite powder was added without steaming with water vapor and without a subsequent drying step.

Preparation example 10

The same formulation as in preparation example 3 was used except that all ingredients were poured into a container and then stirred together to be mixed, and then made into a form of granules having a diameter of 1mm to 5mm, to obtain the fertilizer synergist.

Note:

a: zeolite powder is replaced by attapulgite powder;

b: sodium dodecyl sulfate is used to replace sodium dodecyl benzene sulfonate.

The method in the national standard GB/T23348-. The results are shown in table 2 below.

Note: the release period of the trace elements is 3 months.

From the results of preparation examples 1 to 3, it was found that trace elements can be included more firmly by cyclodextrin by utilizing the activation effect of sodium dodecylbenzenesulfonate and the blocking effect of zeolite powder, the initial nutrient release rate is less than 5%, the cumulative nutrient release rate (%) in 28 days of sustained-release of nutrients is about 60%, and the cumulative nutrient release rates (%) in the nutrient release period are all 90% or more. Comparing preparation examples 3, 4 and 7, it can be seen that if zeolite powder is not used for sealing, the initial nutrient release rate is increased to about 10 times, and the cumulative nutrient release rate of the slow release nutrients for 28 days exceeds 80%, but the similar attapulgite powder does not play the sealing role like zeolite powder, and the special framework structure of zeolite powder, especially the water getting (saturated steam fumigation) and losing (drying) of zeolite powder, ensures that the hydrophobic space of cyclodextrin is tightly sealed. As can be seen by comparing preparation examples 3, 5 and 8, if sodium dodecylbenzenesulfonate is not used for activation, the inclusion amount of cyclodextrin is significantly reduced, so that trace elements that are not included are released early. Surprisingly, also anionic surfactants, sodium dodecyl sulfate hardly enhances the inclusion of trace elements by cyclodextrins, and it is suspected that the benzene ring in sodium dodecyl benzene sulfonate may play a key enhancing role therein, but the exact mechanism of this enhancing role has yet to be investigated. It can be seen by comparing preparation examples 3 and 9 that without the loss and gain of water of the zeolite powder, the blocking effect of the zeolite powder is seriously weakened. Comparing preparation examples 3 and 10, it can be seen that if sodium dodecylbenzenesulfonate is not used for activation first and then zeolite powder is used for blocking, the effect of sodium dodecylbenzenesulfonate on increasing the loading of trace elements by cyclodextrin and the effect of zeolite powder on enhancing the inclusion tightness of trace elements by cyclodextrin are seriously weakened.

Example 1

The fertilizer synergist prepared in preparation example 1 and urea are mixed according to the following steps: urea was mixed at a weight ratio of 1:2 and then made into a granular form (a grain size of 93.7%, i.e., a proportion of grains having a grain size in a range of 1.00mm to 4.75 mm of 93.7%), thereby producing a urea synergistic fertilizer containing trace elements.

Examples 2 to 4

The procedure was carried out in substantially the same manner as in example 1 except for the contents shown in Table 3 below.

Example 5

This was done in essentially the same manner as in example 1, except that the weight ratio of fertilizer synergist to urea was 1: 1.

Example 6

This was done in substantially the same manner as in example 1, except that the weight ratio of fertilizer synergist to urea was 1: 5.

The following indexes defined by the national standard GB/T23348-2009 of slow release fertilizers are measured: the initial nutrient release rate of the total trace elements, the cumulative nutrient release rate of the slow-release nutrients for 28 days, and the cumulative nutrient release rate of the nutrient release period were measured. The urea was measured according to the method described in appendix B of GB/T23348-2009 (Rapid measurement of Nitrogen Release-spectrophotometry). The results are shown in table 3 below.

Note: the nutrient release period is 3 months.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A fertilizer synergist, comprising, based on the total weight of the fertilizer synergist:

35 to 50 parts by weight of cyclodextrin;

0.2 to 2 parts by weight of a trace element fertilizer composition;

20 to 40 parts by weight of zeolite powder;

3 to 10 parts by weight of sodium dodecylbenzenesulfonate; and

10 to 15 parts by weight of activated carbon;

wherein the dosage ratio of the cyclodextrin to the activated carbon is 9:7, and the total dosage of the cyclodextrin and the activated carbon is 80 times of that of the trace element fertilizer composition;

the cyclodextrin is selected from the group consisting of alpha-cyclodextrin, beta-cyclodextrin, and gamma-cyclodextrin;

the specific surface area of the activated carbon is 1000-1500 m²/g；

The zeolite powder has an average particle size of 20 to 50 microns;

the fertilizer synergist is prepared by a method comprising the following steps:

(1) mixing sodium dodecyl benzene sulfonate and cyclodextrin uniformly, then using water to prepare paste, placing and aging for 2 to 5 hours at room temperature, drying to constant weight, and crushing to first powder with the average particle size of not more than 150 micrometers;

(2) adding a trace element fertilizer composition accounting for 75% of the total amount into the first powder, and uniformly stirring to obtain second powder;

(3) adding zeolite powder into the second powder, introducing saturated steam to fumigate for 1 to 3 hours, drying to constant weight, and crushing to third powder with the average particle size of not more than 150 micrometers;

(4) adding activated carbon in a powder form into the third powder lot, uniformly mixing, adding the rest of the trace element fertilizer composition, uniformly mixing, and preparing into a granular form with the diameter of 1-5 mm to obtain the fertilizer synergist.

2. The fertilizer synergist of claim 1, wherein said fertilizer synergist is in the form of granules having a particle size of 1mm to 5 mm.

3. The fertilizer synergist of claim 1, wherein the micronutrient fertilizer composition comprises, based on the weight of the micronutrient fertilizer composition itself: 10 to 20 parts by weight of iron sulfate heptahydrate; 2 to 5 parts by weight of copper sulfate pentahydrate; 5 to 25 parts by weight of borax; 2 to 10 parts by weight of ammonium molybdate; 2 to 5 parts by weight of zinc sulfate heptahydrate; 5 to 10 parts by weight of manganese sulfate trihydrate.

4. A enhanced fertilizer characterized in that it comprises the fertilizer synergist of any one of claims 1 to 3 and a chemical fertilizer.

5. The enhanced fertilizer of claim 4, wherein the weight ratio of said fertilizer enhancer to said chemical fertilizer is from 1:1 to 1: 5.

6. The enhanced fertilizer according to claim 4, wherein said chemical fertilizer is any one or more of a group consisting of a nitrogen fertilizer, a phosphate fertilizer and a potassium fertilizer.

7. The enhanced fertilizer of claim 4, wherein said chemical fertilizer is a nitrogen fertilizer.

8. The enhanced fertilizer of claim 4, wherein said chemical fertilizer is urea.

9. A method of preparing the fertilizer synergist of any one of claims 1 to 3, comprising the steps of:

10. The method according to claim 9, wherein the solid content of the paste prepared in step (1) is 85 to 90% by weight.

11. A fertilizer synergist made by the method of claim 9 or 10.

12. Use of a fertilizer synergist according to any one of claims 1 to 3 for chemical fertilizer synergism.

13. Use according to claim 12, wherein the chemical fertilizer is urea.