Synergistic slow-release coated fertilizer and preparation method thereof

Abstract

The invention relates to a preparation method of synergistic slow-release coated fertilizer. The preparation method comprises the following steps of S1, preparation of a first coating material: agitating urea and a 20% to 40% of formaldehyde solution in a reaction tank until the urea is completely dissolved, regulating the pH of a solution to 8 to 9 by using triethanolamine, reacting for 1h to 2hat a normal temperature, regulating the pH to be between 5 to 6.5, heating to 60 DEG C to 80 DEG C while agitating, continuously agitating, and stopping heating until a reaction system approaches a gel state, so as to obtain the first coating material; S2, preparation of a second coating material: uniformly mixing 70% to 99% of humic acid, 0.5% to 1% of activator and 0.5% to 29% of polynucleic acid powder according to percentage by weight, so as to obtain the second coating material; S3, raising the temperature of a urea master batch with a particle size range of 2.0mm to 5.0mm to 60 DEG C to80 DEG C in a revolving drum, spraying the first coating material to the surface of the urea master batch through a sprinkling device, and aeration-drying, so as to complete a first layer of coating;and S4, preheating fertilizer completed in the first layer of coating, preheating to 40 DEG C to 50 DEG C, spray-coating an adhesive (dissolving alginic acid in an alkaline solution) to the surface offluidized fertilizer, and then dispersing the second coating material on the surface of the fertilizer, so as to obtain the synergistic slow-release coated fertilizer.

Description

technical field

[0001] The invention relates to the technical field of fertilizers, in particular to a synergistic slow-release coated fertilizer and a preparation method thereof. Background technique

[0002] At present, with the development of agriculture, fertilizers are getting more and more attention. In order to improve the utilization rate of fertilizers and reduce or avoid the environmental pollution caused by the loss of fertilizers, there are many methods and approaches. Among them, modifying the fertilizer itself and developing slow-release and controlled-release fertilizers are the most rapid and convenient, and the most fundamental solution Hot spot for fertilizer loss problem. The current development of coated slow-release fertilizers mainly focuses on the selection of coating materials. At present, the most commonly used coating agents are sulfur coating and resin coating. Both technologies have deficiencies: (1) The nitrogen content in the sulfur coating i...

Examples

Embodiment 1

[0028] This embodiment provides a synergistic slow-release coated fertilizer, which is prepared according to the following method:

[0029] ①Preparation of the first coating material: Stir 1.8kg of urea and 30% formaldehyde (4.6kg) solution in a reaction tank until the urea is completely dissolved, adjust the pH of the solution to 8~9 with triethanolamine, and react for 1h at room temperature , adjusting the pH to between 5 and 6, heating to 60 to 65°C under stirring, and continuing to stir until the reaction system is close to the gel state and stopping heating to prepare the first coating material for use.

[0030] ② Preparation of the second coating material: uniformly mix 2.82 kg of humic acid, 0.3 kg of potassium hydroxide and 1.5 kg of polynucleic acid powder in a ball mill to prepare the second coating material for use.

[0031] ③ Preheat large-grain urea masterbatch (100kg) with a particle size range of 2.0mm~5.0mm in the rotary drum to 60~65°C, start the rotary drum t...

Embodiment 2

[0034] This embodiment provides a synergistic slow-release coated fertilizer, which is prepared according to the following method:

[0035] ① Preparation of the first coating material: Stir 1.8kg of urea and 30% formaldehyde (6kg) solution in a reaction tank until the urea is completely dissolved, adjust the pH of the solution to 8~9 with triethanolamine, and react at room temperature for 2 hours. Adjust the pH to between 5 and 6, heat to 70 to 80° C. under stirring, and continue stirring until the reaction system is close to a gel state, then stop heating to prepare the first coating material for use.

[0036] 2. prepare the second coating material: the mixture of the humic acid of 2.79kg, the potassium hydroxide of 0.3kg, the polynucleic acid powder of 1.5kg, the zinc sulfate of 0.3kg, borax and ferrous sulfate 1:1:1, in Mix evenly in a ball mill tank to prepare the second coating material for later use.

[0037] ③ Preheat large-grain urea masterbatch (105kg) with a particl...

Embodiment 3

[0040] This embodiment provides a synergistic slow-release coated fertilizer, which is prepared according to the following method:

[0041] ① Preparation of the first coating material: Stir 1.8kg of urea and 30% formaldehyde (6kg) solution in a reaction tank until the urea is completely dissolved, adjust the pH of the solution to 8~9 with triethanolamine, and react at room temperature for 2 hours. Adjust the pH to between 5 and 6, heat to 70 to 80° C. under stirring, and continue stirring until the reaction system is close to a gel state, then stop heating to prepare the first coating material for use.

[0042] ② Preparation of the second coating material: 2.76kg of humic acid, 0.3kg of potassium hydroxide, 1.5kg of polynucleic acid powder, 0.3kg of Bacillus subtilis, rhizobium bacterial agent and nitrogen-fixing bacteria 1:1:1 Mixture, 0.3kg of zinc sulfate, borax, manganese sulfate, ammonium molybdate, copper sulfate and sub-sulfate 1:1:1:1:1:1 mixture, uniformly mixed in a ...

technical field

[0001] The invention relates to the technical field of fertilizers, in particular to a synergistic slow-release coated fertilizer and a preparation method thereof. Background technique

[0002] At present, with the development of agriculture, fertilizers are getting more and more attention. In order to improve the utilization rate of fertilizers and reduce or avoid the environmental pollution caused by the loss of fertilizers, there are many methods and approaches. Among them, modifying the fertilizer itself and developing slow-release and controlled-release fertilizers are the most rapid and convenient, and the most fundamental solution Hot spot for fertilizer loss problem. The current development of coated slow-release fertilizers mainly focuses on the selection of coating materials. At present, the most commonly used coating agents are sulfur coating and resin coating. Both technologies have deficiencies: (1) The nitrogen content in the sulfur coating i...

Examples

Embodiment 1

[0028] This embodiment provides a synergistic slow-release coated fertilizer, which is prepared according to the following method:

[0029] ①Preparation of the first coating material: Stir 1.8kg of urea and 30% formaldehyde (4.6kg) solution in a reaction tank until the urea is completely dissolved, adjust the pH of the solution to 8~9 with triethanolamine, and react for 1h at room temperature , adjusting the pH to between 5 and 6, heating to 60 to 65°C under stirring, and continuing to stir until the reaction system is close to the gel state and stopping heating to prepare the first coating material for use.

[0030] ② Preparation of the second coating material: uniformly mix 2.82 kg of humic acid, 0.3 kg of potassium hydroxide and 1.5 kg of polynucleic acid powder in a ball mill to prepare the second coating material for use.

[0031] ③ Preheat large-grain urea masterbatch (100kg) with a particle size range of 2.0mm~5.0mm in the rotary drum to 60~65°C, start the rotary drum t...

Embodiment 2

[0034] This embodiment provides a synergistic slow-release coated fertilizer, which is prepared according to the following method:

[0035] ① Preparation of the first coating material: Stir 1.8kg of urea and 30% formaldehyde (6kg) solution in a reaction tank until the urea is completely dissolved, adjust the pH of the solution to 8~9 with triethanolamine, and react at room temperature for 2 hours. Adjust the pH to between 5 and 6, heat to 70 to 80° C. under stirring, and continue stirring until the reaction system is close to a gel state, then stop heating to prepare the first coating material for use.

[0036] 2. prepare the second coating material: the mixture of the humic acid of 2.79kg, the potassium hydroxide of 0.3kg, the polynucleic acid powder of 1.5kg, the zinc sulfate of 0.3kg, borax and ferrous sulfate 1:1:1, in Mix evenly in a ball mill tank to prepare the second coating material for later use.

[0037] ③ Preheat large-grain urea masterbatch (105kg) with a particl...

Embodiment 3

[0040] This embodiment provides a synergistic slow-release coated fertilizer, which is prepared according to the following method:

[0041] ① Preparation of the first coating material: Stir 1.8kg of urea and 30% formaldehyde (6kg) solution in a reaction tank until the urea is completely dissolved, adjust the pH of the solution to 8~9 with triethanolamine, and react at room temperature for 2 hours. Adjust the pH to between 5 and 6, heat to 70 to 80° C. under stirring, and continue stirring until the reaction system is close to a gel state, then stop heating to prepare the first coating material for use.

[0042] ② Preparation of the second coating material: 2.76kg of humic acid, 0.3kg of potassium hydroxide, 1.5kg of polynucleic acid powder, 0.3kg of Bacillus subtilis, rhizobium bacterial agent and nitrogen-fixing bacteria 1:1:1 Mixture, 0.3kg of zinc sulfate, borax, manganese sulfate, ammonium molybdate, copper sulfate and sub-sulfate 1:1:1:1:1:1 mixture, uniformly mixed in a ...