CN-122010611-A - Double-coating coated controlled release fertilizer and preparation method thereof

CN122010611ACN 122010611 ACN122010611 ACN 122010611ACN-122010611-A

Abstract

The invention relates to a double-coating coated controlled release fertilizer and a preparation method thereof. The invention adopts a double-coating film coating mode, has the advantages of low cost, environment friendliness, high release precision and suitability for the controlled release fertilizer technology with various crop demands, can improve the fertilizer utilization rate, reduce the agricultural production cost, reduce the ecological environment load and have wide application prospect, the water-based polyacrylate selected by the invention has the characteristics of relatively low price, good film forming property, proper viscosity, easy degradation and the like, and the selected carnauba wax has the characteristics of good adhesiveness, friction and hardness, strong hydrophobicity and no toxicity, and is very suitable for being used as an outer coating of the water-based polymer film coated controlled release fertilizer.

Inventors

LIU JUN
GE CONG
DU CHANGWEN
WANG XIN

Assignees

江苏艾萨斯新型肥料工程技术有限公司

Dates

Publication Date: 20260512
Application Date: 20251229

Claims (4)

1. The double-coating coated controlled release fertilizer is characterized by comprising a fertilizer core and a water-based polymer coating coated on the outer layer of the fertilizer core, wherein a wax coating is sprayed on the surface of the water-based polymer coating; The fertilizer comprises the following components in parts by weight, namely fertilizer core particles, water-based polymer and wax=9:0.7-0.8:1-2.
2. The dual-coated controlled release fertilizer of claim 1, wherein the water-based polymer is water-based polyacrylate and the wax is carnauba wax.
3. A preparation method of a double-coating coated controlled release fertilizer is characterized by comprising the following steps of using fluidized bed coating equipment, firstly placing fertilizer core particles and water-based polyacrylate coating liquid into the fluidized bed coating equipment, wherein the fluidized bed coating control parameters comprise the following ranges: The flow rate of the coating liquid is 2-3 rpm; the air inlet temperature is 45-50 ℃; the temperature of the air outlet is 40-45 ℃; finishing the primary coating process for 1.5-2 h; Drying after coating is finished, adding the prepared carnauba wax coating emulsion into a liquid inlet, starting a coating flow for 2-2.5 hours, and cooling to obtain a double-coating controlled release fertilizer; The secondary fluidized bed coating control parameters range as follows: The flow rate of the coating liquid is 2-3 rpm; the air inlet temperature is 45-50 ℃; The temperature of the air outlet is 40-45 ℃.
4. The preparation method of the double-coating coated controlled release fertilizer according to claim 3, wherein the preparation method of the carnauba wax emulsion is as follows: 1) Oil phase preparation Adding carnauba wax into an oil phase pot with stirring, heating to 90-95 ℃, starting stirring until the carnauba wax is completely melted, adding polysorbate-80, vitamin E and acetate at a stirring speed of 250-300rpm, continuously stirring for 5-10min, and then reducing the stirring speed to 100 rpm and maintaining the temperature for later use; The palm wax is prepared from the following components in parts by weight, polysorbate-80, vitamin E and acetate=70-75:10-15:1-3:8-12; 2) Aqueous phase preparation Adding deionized water and glycerol into a water phase pot, stirring and dissolving, heating to 90-95 ℃, adding phenoxyethanol, stirring until the mixture is completely dissolved, and keeping the stirring speed at 150-200rpm for later use; the weight ratio of the deionized water to the glycerol phenoxyethanol=94-97:4-6:0.2-0.3; 3) Emulsification stage Keeping the temperature of the oil phase and the water phase to be consistent at about 90-95 ℃, slowly pouring the water phase into an oil phase pot at +/-2 ℃, starting a high-speed shearing stirrer, continuously shearing for 10-15 minutes at 1800-2000rpm, and observing the emulsion state until no layering or particles appear; 4) Thermal insulation and cooling Turning off the high-shear mixer, stirring with a paddle, maintaining the temperature, keeping the temperature, enabling the emulsifier to be fully adsorbed on the interface, reducing particle aggregation, slowly cooling to room temperature at a rate of 0.5-1 ℃ per minute, and continuously stirring at a low speed in the cooling process until the emulsion is a uniform milky liquid; On the basis of the prepared carnauba wax emulsion, deionized water is added into the emulsion, and the mixture is stirred uniformly to prepare the coating liquid with the solid content of 10%.

Description

Double-coating coated controlled release fertilizer and preparation method thereof Technical Field The invention belongs to the field of preparation of sustained and controlled release fertilizers, and particularly relates to a double-coating coated controlled release fertilizer and a preparation method thereof. Background In the field of agricultural production, the fertilizer is used as a core input product for guaranteeing crop growth and improving yield, and the application efficiency of the fertilizer is directly related to agricultural economic benefit and ecological environment sustainability. The traditional chemical fertilizer (such as urea, diammonium phosphate and the like) has the characteristics of high nutrient release speed and easy dissolution, and is extremely easy to face multiple problems after application, on one hand, the nutrient release rhythm is seriously different from the requirements of crops in different growth periods, the seedling stage probably causes 'seedling burning' due to concentrated release of the nutrients, the critical growth period causes insufficient fertilizer supply due to early loss of the nutrients, the fertilizer utilization rate is generally low, and on the other hand, the nutrients such as nitrogen, phosphorus and the like which are not absorbed by the crops enter the environment through the surface runoff, underground leaching, ammonia volatilization and other ways, so that a series of ecological problems such as soil hardening, water eutrophication, atmospheric nitrogen sedimentation and the like are caused, and the current agricultural green development requirements are contrary. In order to solve the dilemma, the controlled release fertilizer has the core principle that the nutrient of the fertilizer is coated or modified by physical, chemical or biological means to realize slow and controllable release of the nutrient. At present, most of the controlled release fertilizers on the market are coated controlled release fertilizers, the release rate of the fertilizers is controlled by adjusting the thickness or the porosity of a coating, but the problems of high cost of the coating materials, poor biodegradability, soil pollution caused by residual films and the like are commonly existed, and the problems of nutrient burst release and the like caused by the damage of a coating layer in the operation of agricultural machinery are easily caused, so that the popularization and the application of the fertilizer in the agricultural production are hindered to a certain extent. In addition, the existing controlled release fertilizer also has the outstanding short plates with poor universality, wherein the demand proportion of different crops (such as gramineae and economic crops) and different growing stages on nitrogen, phosphorus, potassium and medium trace elements is extremely different, but the existing products are mostly in a fixed formula and release mode, so that 'crop customization' fertilizer supply cannot be realized, and meanwhile, in a complex field environment, natural factors such as severe temperature fluctuation, uneven precipitation and the like are easy to cause the failure of a controlled release system, so that the large-scale application of the controlled release fertilizer is further limited. Disclosure of Invention The invention aims to provide a double-coating coated controlled release fertilizer and a preparation method thereof, which have the advantages of low cost, environmental friendliness, high release precision and adaptation to the requirements of various crops, and can improve the fertilizer utilization rate, reduce the agricultural production cost and reduce the ecological environment load. The technical scheme adopted by the invention is that the double-coating coated controlled release fertilizer comprises a fertilizer core and a water-based polymer coating coated on the outer layer of the fertilizer core, and a wax coating is sprayed on the surface of the water-based polymer coating; The fertilizer comprises the following components in parts by weight, namely fertilizer core particles, water-based polymer and wax=9:0.7-0.8:1-2. Further, the water-based polymer is water-based polyacrylate, and the wax is carnauba wax. The preparation method of the double-coating coated controlled release fertilizer comprises the following steps of using fluidized bed coating equipment, firstly placing fertilizer core particles and water-based polyacrylate coating liquid into the fluidized bed coating equipment, wherein the fluidized bed coating control parameters range is as follows: The flow rate of the coating liquid is 2-3 rpm; the air inlet temperature is 45-50 ℃; the temperature of the air outlet is 40-45 ℃; finishing the primary coating process for 1.5-2 h; Drying after coating is finished, adding the prepared carnauba wax coating emulsion into a liquid inlet, starting a coating flow for 2-2.5 hours, and cooling to obtain a double-coating