Key Processes and Practices for Granular Fertilizer Production from NPK Raw Materials

fertilizer granulator Sep 30, 2025

Converting elemental nitrogen, phosphorus, and potassium raw materials into granular fertilizer requires scientific proportioning, physical shaping, and precise control to achieve balanced nutrients and convenient application. This npk fertilizer production line not only improves fertilizer utilization but also addresses the challenges of bulk raw materials, such as clumping and transportation difficulties.

The first step is raw material pretreatment and proportioning. Nitrogen sources (such as urea and ammonium chloride), phosphorus sources (superphosphate and diammonium phosphate), and potassium sources (potassium chloride and potassium sulfate) must be crushed to a fineness of 80-100 mesh to ensure uniform mixing. The nitrogen, phosphorus, and potassium ratios are precisely adjusted based on the needs of the target crop. For example, the 15-15-15 general formula commonly used for field crops requires strict control of the tolerance of each raw material within ±0.5%. 5%-8% bentonite is added as a binder to enhance granularity.

The core granulation process often utilizes a rotary drum granulation process. The mixed raw materials are fed into a rotary drum granulator, where a 30%-40% solution of warm water or dilute phosphoric acid is sprayed through a spray device to form “mother balls” within the drum. The drum speed is controlled at 20-25 rpm, and the inclination angle is maintained at 3°-5°. This ensures that the mother balls continuously absorb the raw material powder as they rotate, gradually growing into uniform granules with a diameter of 2-4mm. For the production of high-concentration granular fertilizers, an extrusion granulation process is used. A twin-screw extruder presses the material into a cylindrical shape, which is then sheared into granules by a pelletizer. This is suitable for formulas with low moisture content.

After granulation, the granules undergo drying and cooling. The temperature in the drum fertilizer dryer is controlled at 120-150°C to reduce the moisture content of the granules to below 10% to prevent clumping during storage. The granules then enter a drum fertilizer cooler, where low-temperature air is used to cool them to room temperature to prevent condensation during subsequent packaging. Finally, unqualified granules (overly coarse or fine) are separated by a screening machine and returned to the granulator for reprocessing. The finished product is then sprayed with an anti-caking agent in a coating machine to improve storage stability.

Throughout the entire production process, indicators such as granule strength (should be ≥20N) and disintegration (disintegrates in water within 30 minutes) are monitored in real time to ensure product compliance with national standards. This process transforms nitrogen, phosphorus, and potassium raw materials from bulk to granules, facilitating mechanized fertilization while reducing nutrient loss, providing strong support for improving agricultural quality and efficiency.

Four Common Problems in NPK Fertilizer Production Lines and Solutions

fertilizer granulator Sep 26, 2025

NPK fertilizer production lines involve complex processes and are susceptible to problems due to factors such as raw materials, processes, and equipment. These problems not only affect product quality and production capacity, but can also pose environmental risks and require precise solutions.

Impurities and agglomeration are prominent issues. Stones and metal fragments mixed in with the raw materials can wear the lining of the granulator and clog the screens of the screening machine, causing equipment downtime. Urea and monoammonium phosphate absorb moisture and agglomerate, forming lumps, resulting in uneven mixing and fertilizer nutrient content deviations exceeding 5%. Solutions: Install a magnetic separator and vibration screener machine at the outlet of the raw material silo to separate impurities; equip a pre-crushing system to crush agglomerated materials to 80-100 mesh; and control the humidity in the raw material silo to less than 60% to prevent moisture absorption.

Pelletization and drying are prone to quality problems. Improper moisture content during granulation (less than 15% results in loose granules, while above 18% results in sticking to the pellet wall), as well as imbalanced rotation speed and inclination angle, can lead to uneven granule size and poor roundness (less than 80%). Excessively high drying temperatures (>160°C) can cause nitrogen volatilization (loss rate exceeding 10%), while too low drying temperatures can easily lead to granule agglomeration. Solutions: Install an online moisture meter before granulation to adjust binder dosage in real time; use a frequency converter system to optimize granulator parameters; and equip the drying process with an automatic temperature control system to maintain a stable temperature between 120-150°C.

Dust and wastewater treatment can easily fail to meet standards. Mixing and screening processes generate a lot of dust. If the dust removal equipment’s filter bags become clogged or air volume is insufficient, dust emission concentrations can easily exceed 20mg/m³. Drying condensate and equipment wash water contain nitrogen and phosphorus, which can be directly discharged into water bodies and pollute. Solutions: Clean dust removal filter bags weekly and optimize fan air volume. Establish a wastewater recycling system for treated and reused in granulation to achieve “zero discharge.”

Wear and aging reduce efficiency. Wear and tear of vulnerable components like granulator scrapers and dryer lift plates (e.g., a gap exceeding 15mm between the scraper and the disc) can cause material to stick to the wall and reduce drying efficiency. Oil depletion or aging in the drive system can cause abnormal noise and speed fluctuations. Solutions include establishing a regular inspection system, checking vulnerable parts weekly and replacing them promptly. Lubricate the drive system monthly with specialized lubricant, and perform comprehensive maintenance and calibration quarterly.

Analysis of Key Equipment in NPK Fertilizer Production Lines

fertilizer granulator Sep 25, 2025

In the transformation of NPK fertilizers from raw materials to finished products, key equipment is central to ensuring precise nutrient distribution and high-quality pellets. The core equipment in a complete NPK fertilizer production line can be categorized into three main processes: pretreatment, processing, and post-processing. Each device has a unique mission.

In raw material pretreatment, the crusher and batching system are the first checkpoints. NPK raw materials (such as urea and monoammonium phosphate) are often in lumpy form. The crusher must crush them into a uniform powder of less than 1mm. Uneven particle size can lead to inadequate mixing and result in significant nutrient variations within a single bag of fertilizer. The automatic batching system acts like a “precise steward,” blending nitrogen, phosphorus, and potassium raw materials and auxiliary materials according to a preset NPK ratio (such as 15-15-15), maintaining an error within 0.5%. This is crucial for ensuring that the fertilizer’s nutrient content meets standards.

In the core processing phase, the mixer and granulator are the “heart” of the production line. A twin-shaft mixer uses counter-rotating blades to blend various raw materials for 3-5 minutes, achieving a consistent NPK content per gram. Insufficient mixing time can result in areas with high nitrogen and low phosphorus content, impacting crop absorption. The granulator determines the fertilizer’s form. A rotary drum granulator is suitable for large-scale production. The rotating drum tumbles the material, combined with water mist wetting, kneading the powder into round granules with a diameter of 2-4mm. This creates a good appearance and facilitates mechanized fertilization. An double roller perss granulator, which forms the granules through a die without drying, is suitable for small-scale production lines producing high-concentration fertilizers. However, the granules are irregular and more suitable for customized small-batch production.

In the post-processing stage, the dryer, cooler, and coating machine are “quality guardians.” The dryer uses hot air drying technology to reduce the moisture content of the granulated wet granules from 20% to below 8%. Excessive moisture content can lead to caking and mold. The cooler cools overheated fertilizer granules to a suitable temperature. The coating machine sprays paraffin wax or kaolin to form a protective film on the surface of the granules, preventing clumping during storage and transportation, extending shelf life, and reducing dust pollution during fertilization.

These key equipment are closely linked and together determine the quality, yield, and stability of NPK fertilizers, making them indispensable components of the NPK fertilizer production line.

The Development Direction of NPK Fertilizer Production Lines in the Context of Green Agriculture

fertilizer granulator Sep 22, 2025

Amid the booming development of green agriculture, NPK fertilizer production lines are undergoing profound transformation, striding forward towards environmental protection, high efficiency, and intelligent technologies.

Technological innovation has become the core driving force behind the green development of NPK fertilizer production lines. Controlled-release technology continues to evolve. By optimizing coating materials and processes, it achieves precise nutrient release, tailored to the needs of crops at different growth stages, significantly improving fertilizer utilization and reducing nutrient loss and environmental pollution. For example, the bio-based polyurethane-coated controlled-release fertilizer developed by Weisheng Liansu has increased fertilizer utilization from 35% to 80%. Furthermore, breakthroughs are being made in the research and application of new synergists. For example, the addition of urease inhibitors and nitrification inhibitors effectively inhibits nitrogen conversion and prolongs fertilizer effectiveness.

Production models are shifting towards green, low-carbon, and circular approaches. On the one hand, energy utilization is becoming increasingly efficient, with clean energy sources like solar and wind power gradually being integrated into production lines, reducing dependence on traditional fossil fuels. On the other hand, waste recycling systems are continuously improving, with dust, waste residue, and wastewater from the production process being recycled and treated and re-entered production, maximizing resource utilization.

Product upgrades are closely aligned with the needs of green agriculture. Functional NPK fertilizers are emerging in large numbers, with specialized fertilizers developed for acidification, alkalinity control, and continuous cropping resistance, tailored to different soil types and crop characteristics. Furthermore, organic-inorganic compound NPK fertilizers are gaining popularity, combining the long-lasting properties of organic fertilizers with the quick-acting properties of inorganic fertilizers, improving soil fertility while ensuring crop nutrient availability.

Intelligence and precision are integrated throughout the entire production process. From raw material procurement and blending to production process control and finished product quality testing, sensors, the Internet of Things, and big data technologies enable precise control. This not only enables real-time monitoring of production parameters and timely adjustments and optimization to ensure stable product quality, but also provides farmers with customized fertilizer formulas based on soil testing data and crop growth models, enabling precise fertilization.

Under the trend of green agriculture, NPK fertilizer production lines must continue to innovate to meet agricultural production needs while protecting the ecological environment and achieving sustainable agricultural development.

Common Problems and Solutions in NPK Fertilizer Production Lines

fertilizer granulator Sep 19, 2025

During continuous operation, NPK fertilizer production lines are susceptible to factors such as raw material characteristics, equipment status, and process parameters, leading to various problems that directly impact product quality and production efficiency. The following are three typical problems and their solutions.

Raw material pretreatment often faces the challenge of uneven particle size. Nitrogen, phosphorus, and potassium raw materials vary significantly in hardness and moisture content. For example, urea easily absorbs moisture and clumps, while phosphate slag has a high hardness. Using only a single crusher can result in significant particle size variation, leading to uneven nutrient distribution during subsequent mixing. The solution requires “classified crushing + precise screening”: urea is crushed with a hammer crusher, while phosphate slag is crushed with a crusher. After crushing, the raw materials are graded using multiple vibrating screens to ensure a uniform particle size within the appropriate range, significantly improving mixing uniformity.

Low particle formation rate is a frequent problem in the granulation process. During drum granulation, excessive water spraying can easily cause sticking to the wall and clumping. Excessive water spraying results in loose, fragile particles, resulting in a low particle formation rate. This problem requires dynamic parameter control: A humidity sensor is installed at the drum inlet to monitor the moisture content of the raw materials in real time. The spray volume is automatically adjusted via the PLC system based on moisture content changes. Furthermore, the drum speed is controlled based on raw material characteristics, and the internal lifter angle is adjusted to significantly improve the yield and maintain stability.

Product clumping is a prominent issue after drying and cooling. If the pellet moisture content does not drop to the acceptable standard after drying, or if the temperature difference during cooling is too large, the clumping rate will increase significantly over a period of storage. A two-pronged approach is necessary: ​​first, optimizing the drying process by implementing staged temperature control in the drum fertilizer dryer to ensure that the pellet moisture content at the outlet meets the standard. Second, upgrading the cooling system by using a dual-stage cooling system with air and water cooling to quickly reduce the pellet temperature to near room temperature. Adding an appropriate amount of anti-caking agent can effectively reduce the clumping rate.

Solving these problems requires dynamic adjustments based on the actual operating conditions of the NPK fertilizer production line. Through “precise control + equipment upgrades,” this approach can not only ensure product quality meets standards, but also improve the continuous operation stability of the production line and reduce production costs.

NPK fertilizer production lines are a key enabler for agricultural development

fertilizer granulator Aug 26, 2025

NPK fertilizer (nitrogen-phosphorus-potassium compound fertilizer) production lines are core equipment for modern agriculture. By scientifically blending nitrogen, phosphorus, and potassium, they provide precise nutrients to crops. This is of great significance to high-quality agricultural development, and its impact is reflected in three key areas.

NPK fertilizer production lines are a stabilizer for ensuring food security. With population growth and limited arable land, increasing yields is crucial. NPK fertilizer production lines can customize balanced compound fertilizers based on the fertilizer needs of crops like wheat and rice, addressing the nutrient deficiencies of traditional single fertilizers. Data shows that high-quality NPK compound fertilizers can increase grain yields by 15%-25% per mu, effectively alleviating pressure on food supply and strengthening national food security.

NPK fertilizer production lines are an accelerator for promoting agricultural modernization. Traditional fertilizer production relies on manual labor, resulting in low efficiency and uneven nutrient distribution. NPK production lines, however, fully automate raw material mixing, granulation, drying, and packaging. A modern production line can produce hundreds of tons of fertilizer per day, significantly improving efficiency. Precise temperature and humidity control ensures uniform fertilizer particles and consistent nutrient content, reducing fertilizer waste and helping transform agriculture from extensive to intensive farming.

NPK fertilizer production lines are the “guardians” of sustainable agriculture. Today, NPK production lines can incorporate slow-release technology to produce slow-release compound fertilizers, which slowly release nutrients, prolong fertilizer effectiveness, and reduce soil and water pollution caused by fertilizer runoff. Some lines can also utilize agricultural waste such as straw and livestock manure as auxiliary materials, achieving resource recycling and reducing the environmental impact of chemical fertilizer production, meeting the needs of green agriculture.

In short, by ensuring yield, improving efficiency, and promoting green development, NPK fertilizer production lines have become an indispensable core force in agricultural modernization, injecting lasting momentum into sustainable agricultural development.

How does a NPK fertilizer production line produce fertilizer

fertilizer granulator Aug 25, 2025

A NPK fertilizer production line is a modern production system that scientifically blends the three key elements, nitrogen, phosphorus, and potassium, to create compound fertilizer. From raw material processing to finished product packaging, each step embodies the principles of precision and standardization.

Raw material pretreatment is the foundation of production. Nitrogen fertilizer raw materials, primarily ammonia and urea, require crushing and screening to remove impurities. Phosphorus sources, typically monoammonium phosphate and superphosphate, are ground to a desired fineness. Potassium salts, primarily potassium chloride and potassium sulfate, are dried to reduce moisture. These three raw materials are metered according to crop requirements and precisely mixed using an intelligent batching system.

Mixed granulation is the core step. The pretreated raw materials enter the agitator for thorough homogenization before being fed into the rotary drum granulator. The inclined rotating drum drives the material, while a spray system adds an appropriate amount of water or steam, allowing the material to gradually agglomerate into granules through friction and adhesion. Particle size can be controlled by adjusting the drum speed and the material’s residence time, resulting in rounded granules. This process is highly adaptable and can handle a variety of raw material formulations. It also produces granules with high strength and good water solubility, making it suitable for large-scale continuous production. After granulation, the granules are screened and graded, and unqualified granules are returned for reprocessing to ensure consistent product size.

Post-processing determines fertilizer stability. The granules enter a dryer, where moisture is controlled within a reasonable range at an appropriate temperature to prevent clumping. After cooling, they are sprayed with an anti-caking agent in a film coating machine to form a protective film. Finally, they are packaged in standard bags by a quantitative packing machine for sale.

NPK fertilizer production line transforms chemical raw materials into “nutrient packs” that provide a balanced supply to crops. This not only addresses the nutrient imbalance of single fertilizers, but also improves fertilizer utilization through industrialized production, providing efficient and stable nutrient support for modern agriculture.

NPK compound fertilizer production lines promote green agricultural development

fertilizer granulator Aug 20, 2025

In promoting green agricultural development, NPK compound fertilizer production lines play a key role, providing strong support for sustainable agricultural development.

Traditional fertilization methods often lead to soil degradation and environmental pollution due to nutrient imbalances and low utilization rates. However, NPK compound fertilizer production lines, through scientific processes, produce high-quality fertilizers that meet the needs of green agriculture.

The production line prioritizes the use of natural and renewable raw materials, reducing reliance on synthetic raw materials. Raw materials are meticulously processed to remove impurities, improving fertilizer quality while minimizing environmental risks. Production emphasizes precision fertilization. By precisely controlling the ratios of nitrogen, phosphorus, potassium, and other elements, formulas can be customized for different crops and soils, maximizing crop needs while minimizing waste and pollution.

The production line features environmentally friendly technologies: advanced dust and odor removal equipment reduces dust and odor emissions; energy-saving equipment and processes reduce energy consumption, enabling recycling and green production. This type of fertilizer also improves soil structure. The appropriate nutrient supply promotes soil microbial growth, increases organic matter content, enhances soil fertility and water and fertilizer retention, and reduces soil erosion.

With growing consumer demand for green agricultural products, the fertilizer produced by this production line helps farmers cultivate high-quality crops, increasing the added value of agricultural products and farmers’ income while also meeting market demand for healthy food.

With its scientific production and environmentally friendly approach, the NPK compound fertilizer production line has become a key driver of green agricultural development. It will continue to innovate and contribute to the green transformation of agriculture.

The Critical Role of NPK Compound Fertilizer Production Lines in Agricultural Production

fertilizer granulator Aug 19, 2025

NPK compound fertilizer production lines are the core pillar of modern agricultural high-yield systems. Their systematic production processes directly determine fertilizer quality, which in turn profoundly impacts crop growth and agricultural sustainability. Faced with the conflict between continued population growth and limited arable land, these production lines are crucial for balancing food production and ecological protection.

The production lines utilize a automatic batching system to achieve a precise ratio of nitrogen, phosphorus, and potassium, addressing the nutrient imbalances of traditional single fertilizers. Leveraging electronic scales and automated control technology, these lines can be customized for different crops and soil types. For example, rice fertilizers can increase potassium content to enhance lodging resistance, while fruit and vegetable fertilizers can increase phosphorus to promote fruit enlargement, ensuring precise nutrient delivery to every inch of land.

Processes such as granulation and coating improve fertilizer utilization efficiency. The uniform granules formed by drum granulation facilitate mechanized fertilization, reducing labor costs. Coating technology uses a polymer protective film to achieve slow-release nutrients, extending the fertilizer’s effective life by over 30%, preventing nutrient loss and soil compaction associated with traditional fertilization. In arid areas, this can reduce fertilization frequency by 50%.

The standardized operation of the production line ensures consistent fertilizer quality. From raw material pretreatment, crushing and screening, to nutrient testing during finished product inspection, comprehensive quality control ensures that every batch meets standards. Data shows that standardized compound fertilizers can increase crop yields by an average of 15%-20% while reducing fertilizer usage by 30%, ensuring food security while promoting green agricultural development.

Facing the dual challenges of growing global food demand and scarce arable land resources, modern NPK compound fertilizer production lines, through technological innovation, continuously produce high-efficiency, environmentally friendly, and customized fertilizer products. These production lines have become a key link in agricultural production, injecting lasting momentum into high-quality agricultural development.

How to scientifically maintain the double roller press granulator

fertilizer granulator Aug 18, 2025

As an important organic fertilizer production equipment, the double roller press granulator can always maintain efficient operation, extend its service life, and escort production. Mastering scientific maintenance methods can not only reduce the hidden dangers of failure, but also enable the equipment to output high-quality particles stably for a long time.

Daily maintenance needs to form a standardized process. Before starting the machine, in addition to checking the connection and fasteners of the components, it is necessary to focus on whether the feed port is unobstructed, remove possible foreign matter, and avoid material jamming and damage to the equipment after starting. During operation, in addition to paying attention to the rotation and sound of the rollers, it is also necessary to observe the temperature of the motor. If overheating occurs, the machine should be shut down to cool down to prevent the motor from burning. The cleaning work after shutdown should be thorough. A special brush can be used to clean the residual material in the roller texture, and compressed air can be used to blow the equipment gap to prevent the material from corroding the components after moisture and agglomeration.

Maintenance of key components must be accurate and in place. The parallelism of the rollers needs to be checked every time they run for a period of time. If there is an offset, it should be calibrated in time to ensure uniform extrusion force; when the surface is worn to a certain extent, it can be polished and repaired to extend the service life. Bearing lubrication requires the use of lubricating oil of suitable types, which should be refilled at least once a month. Before refilling, clean the impurities in the oil filling port to prevent contamination of the lubrication system. The chain of the transmission system should be regularly smeared with chain oil, and the gears should be checked for meshing. If abnormal noise or jamming is found, timely adjustments should be made to avoid affecting the granulation efficiency due to poor power transmission.

Well-maintained equipment can reduce downtime, maintain stable granulation efficiency and granule quality, and reduce long-term use costs. Choose a double roller press granulator and cooperate with scientific maintenance to make your organic fertilizer production line continue to be efficient and your profits more guaranteed.