The Technology and Value of the Granulation Process in Organic Fertilizer Production Lines

fertilizer granulator Sep 11, 2025

In organic fertilizer production lines, the granulation stage is the core link between raw material processing and finished product packaging, directly determining the physical properties, ease of application, and market competitiveness of organic fertilizers.

The core task of the granulation stage is to transform crushed organic fertilizer raw materials (such as composted livestock and poultry manure and straw powder) into granules of uniform particle size and moderate hardness through physical or chemical reactions. This process requires addressing two key issues: first, preventing loose raw materials from flying and agglomerating, which can lead to transportation and storage losses; second, controlling the nutrient release rate through granule morphology to improve fertilizer utilization in the soil. Currently, mainstream granulation equipment includes disc granulators, rotary drum granulators, and double roller press granulators. Disc granulators are the preferred choice for small and medium-sized production lines due to their high granulation rate (over 90%) and excellent granule roundness. Rotary drum granulators are suitable for large-scale continuous production, with a single unit capable of producing over 50 tons per day.

Three key factors influence granulation performance: First, the moisture content of the raw materials, which must be controlled between 25% and 35%. A moisture content too high can easily cause pellets to stick together, while a moisture content too low can make them difficult to form. Second, the raw material ratio. By adding small amounts of auxiliary materials such as bentonite and straw powder, the cohesiveness and porosity of the raw materials can be adjusted. Third, equipment parameters, such as the disc pelletizer’s inclination angle (typically 45°-55°) and rotation speed (15-20 rpm), must be dynamically adjusted based on the raw material’s characteristics. For example, in the production of organic fertilizer from chicken manure, if the crude fiber content of the raw material is too high, the disc speed must be increased appropriately, and 1%-2% bentonite must be added to ensure that the pellet hardness meets the industry standard of a compressive strength of ≥2N.

With the increasing demand for green agriculture, the granulation process is also evolving towards intelligent and low-carbon processes. Some advanced production lines have implemented online moisture monitoring systems, allowing real-time adjustment of spray volume to control raw material moisture. Furthermore, by optimizing the granulator’s heating method, replacing traditional electric heating with waste heat recovery, energy consumption per ton of product has been reduced by over 15%. Technological innovation in the granulation process is driving the transformation of organic fertilizer from a “heavy-duty” product to a “refined agricultural input,” injecting critical momentum into the green development of agriculture.

Composting in an Organic Fertilizer Production Line

fertilizer granulator Sep 10, 2025

In an organic fertilizer production line, composting is a core step in achieving both harmlessness and resource utilization of organic waste. Through microbial decomposition, raw materials like livestock manure and straw are transformed into nutrient-rich, mature materials, laying the foundation for subsequent processing.

The first step in composting is raw material preparation, requiring precise control of the key indicator, the carbon-to-nitrogen ratio. Among commonly used raw materials, straw and mushroom residue are high-carbon, while livestock manure is high-nitrogen. These materials should be mixed in a ratio of 25:1-30:1. For example, a mixture of 60% cow manure and 40% pulverized straw can meet microbial activity while minimizing nitrogen loss. Furthermore, the moisture content of the raw materials should be adjusted to 50%-60%. The material should be held firmly in the hand, with water between the fingers but not dripping. If it is too dry, water should be applied; if it is too wet, add dry straw or sawdust.

The composting process requires scientifically controlled environmental conditions. Windrow and trough composting are two common methods used in production lines. Windrow composting involves piling raw materials into long windrows 2-3 meters wide and 1.2-1.5 meters high. Windrow compost is turned every 2-3 days by a windrow compost turning machine to ensure adequate oxygenation within the windrow. Trough composting, on the other hand, takes place in sealed fermentation tanks, equipped with automated turning equipment to precisely control temperature and oxygen levels, making it suitable for large-scale production. During composting, the temperature must be maintained at 55-65°C, which kills insect eggs and pathogens and facilitates microbial decomposition of organic matter. If the temperature is too low, high-nitrogen raw materials should be added; if it is too high, turning should be used to reduce the temperature.

Determining the maturity of compost is crucial to ensuring the quality of subsequent products. Generally, after 20-30 days, the compost is mature when its color turns dark brown, it no longer has a manure odor but instead has a light earthy smell, and it is loose and free of noticeable lumps. At this time, the organic matter content of the composted material is greatly increased, and it is rich in nutrients such as amino acids and humic acid. It can not only provide nutrients for crops, but also improve soil structure. It is an indispensable “nutrient conversion station” in the organic fertilizer production line.

Composting in an Organic Fertilizer Production Line

fertilizer granulator Sep 10, 2025

In an organic fertilizer production line, composting is a core step in achieving both harmlessness and resource utilization of organic waste. Through microbial decomposition, raw materials like livestock manure and straw are transformed into nutrient-rich, mature materials, laying the foundation for subsequent processing.

The first step in composting is raw material preparation, requiring precise control of the key indicator, the carbon-to-nitrogen ratio. Among commonly used raw materials, straw and mushroom residue are high-carbon, while livestock manure is high-nitrogen. These materials should be mixed in a ratio of 25:1-30:1. For example, a mixture of 60% cow manure and 40% pulverized straw can meet microbial activity while minimizing nitrogen loss. Furthermore, the moisture content of the raw materials should be adjusted to 50%-60%. The material should be held firmly in the hand, with water between the fingers but not dripping. If it is too dry, water should be applied; if it is too wet, add dry straw or sawdust.

The composting process requires scientifically controlled environmental conditions. Windrow and trough composting are two common methods used in production lines. Windrow composting involves piling raw materials into long windrows 2-3 meters wide and 1.2-1.5 meters high. Windrow compost is turned every 2-3 days by a windrow compost turning machine to ensure adequate oxygenation within the windrow. Trough composting, on the other hand, takes place in sealed fermentation tanks, equipped with automated turning equipment to precisely control temperature and oxygen levels, making it suitable for large-scale production. During composting, the temperature must be maintained at 55-65°C, which kills insect eggs and pathogens and facilitates microbial decomposition of organic matter. If the temperature is too low, high-nitrogen raw materials should be added; if it is too high, turning should be used to reduce the temperature.

Determining the maturity of compost is crucial to ensuring the quality of subsequent products. Generally, after 20-30 days, the compost is mature when its color turns dark brown, it no longer has a manure odor but instead has a light earthy smell, and it is loose and free of noticeable lumps. At this time, the organic matter content of the composted material is greatly increased, and it is rich in nutrients such as amino acids and humic acid. It can not only provide nutrients for crops, but also improve soil structure. It is an indispensable “nutrient conversion station” in the organic fertilizer production line.

Analysis of Common Problems in the Organic Fertilizer Production Line

fertilizer granulator Sep 4, 2025

Organic fertilizer production lines improve efficiency through continuous operation, but improper integration of various stages can easily lead to problems, impacting production stability and product quality.

The raw material pretreatment stage is prone to conveyor blockage. If raw materials such as straw and manure are not crushed to a particle size of 5-10mm or have a moisture content exceeding 65%, they can easily form lumps in belt conveyors and screw feeders, causing production line downtime. Screener machines should be added to the pretreatment stage to control the particle size. At the same time, the moisture content should be adjusted to 55%-60% through drying or the addition of dry materials to ensure smooth material conveyance.

Uneven compost turning and insufficient oxygen supply are common problems in fermentation systems. If the chain compost turning machine rotates too fast or has an inappropriate stroke setting, the compost will not be turned thoroughly, resulting in local temperatures below 55°C and failure to achieve the desired compost maturity. Insufficient fan pressure can cause oxygen deprivation in the compost, producing harmful gases such as hydrogen sulfide. To address this, adjust the compost turner speed according to the pile height (2-3 rpm is recommended). Regularly check the fan filter to ensure a ventilation rate of 0.3-0.5 m³/min per cubic meter of pile.

The drying process is prone to moisture control imbalances. If the feed rate to the drum fertilizer dryer fluctuates, or if the hot air temperature fluctuates by more than ±5°C, the finished product moisture content will fluctuate (the acceptable standard is 15%-20%), impacting subsequent granulation. Install an automatic feed regulating valve to stabilize the feed rate, employ a temperature control system to precisely control the hot air temperature at 80-100°C, and install a moisture detector at the discharge end for real-time monitoring.

Inaccurate metering and loose sealing are common problems in the packaging process. Aging load cells in quantitative packaging machines can lead to bag weight errors exceeding ±2%. Low temperatures or insufficient pressure in heat sealers can cause cracking in the bag seals and moisture absorption and caking of the finished product. The load cell must be calibrated monthly, the heat sealing temperature must be adjusted to 150-180°C, and the pressure must be controlled at 0.3-0.5 MPa to ensure packaging quality.

Addressing issues in all aspects of the organic fertilizer production line requires strengthening equipment maintenance and process control to achieve continuous and stable production and guarantee the quality of organic fertilizer.

The entire process of organic fertilizer production in agriculture

fertilizer granulator Aug 25, 2025

Organic fertilizer production is an ecological cycle of “turning waste into treasure.” Organic fertilizer production lines transform agricultural waste into nutrients that nourish the soil, and the entire process is guided by a green and environmentally friendly philosophy.

The first step in production is the collection and mixing of raw materials. Common raw materials include plant residues such as crop straw, rice husks, and peanut shells, as well as livestock manure such as chicken, cow, and sheep manure. These raw materials must be strategically combined to achieve a carbon-to-nitrogen ratio of approximately 30:1, for example, a straw-to-manure ratio of approximately 3:1. A small amount of wood ash is added to adjust the pH and create a suitable environment for microbial activity.

Next, the fermentation and composting stage begins, the core of organic fertilizer production. The mixed raw materials are transferred to a fermentation silo where they are regularly stirred by a turning device to maintain a temperature of 55-65°C. This temperature not only kills pathogens, insect eggs, and weed seeds, but also stimulates microbial activity. After 20-30 days of composting, the raw materials will gradually darken and soften, emitting a faint earthy odor, indicating that the organic matter has been fully decomposed.

The composted material needs to be refined. First, it is crushed into a fine powder by a crusher to remove impurities and large particles. Then it enters the granulation stage, where a granulator is used to make the powder into granules with a diameter of 2-5 mm for easy storage and application. Finally, it is screened by a screening device to separate the qualified granules, and the unqualified crushed materials are returned for reprocessing.

The finished product also undergoes quality inspection, testing for organic matter content, pH, and heavy metal content to ensure compliance with national standards. Qualified organic fertilizer granules are uniform, have a moderate moisture content (approximately 20%), and slowly release trace elements such as nitrogen, phosphorus, potassium, and calcium and magnesium.

The entire production process utilizes agricultural waste as a resource, addressing environmental pollution while replenishing natural nutrients to the soil. This “take from the field, return to the field” model is the key to the sustainable development of organic agriculture.

3-5 t/h Bio-organic Fertilizer Projects and Machinery

fertilizer granulator Dec 9, 2020

Production Conditions of 3-5 t/h Bio-organic fertilizer manufacturing process

Using livestock and poultry manure and agricultural straw waste, the production technology of bio-organic fertilizer can reach 3-5 tons per hour.

3-5 t/h Organic Fertilizer Production Process

1. Floor stacking composting, using windrow turning machine. Or the fermentation tank to put the material, using the trough compost turning machine.
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2. Sprinkle fungicides evenly into the fermentation products, mix the materials with the dumper, and compost to achieve the purpose of heating, smelling, maturing and killing weed seeds.

3. Fermentation for 10-15 days. According to the local temperature, the number of treatments of compost dumper is different.

4. Material that is completely fermented and decomposed is fed into organic fertilizer production equipment.

5. Preliminary screening of materials by drum screening machine (the screened powdery organic fertilizer can be sold directly).

6. After the screened bulk materials are crushed by a crusher, they are re-screened.

7. Adding trace elements to powdery organic fertilizer and mixing with horizontal mixer.

8. Granulation with the new type NPK fertilizer granulator.

9. Fertilizer granules are fed into rotary dryer and rotary cooler.

10. Screening of qualified granules by fertilizer drum screener machine.

11. Bio organic fertilizer enters the coating machine.

12. Products can be sold after being packed by automatic packing machines.

Bio-organic fertilizer production and fermentation equipment

Ground windrow turner or trough compost turning machine
The ground turner does not need to build a trough, but directly stacks the materials in strips and uses a material dumper for dumper fermentation.
The use of trough compost turning machine, according to your scale of production to build fermentation tank, fermentation products are continuously put into the fermentation tank, the use of turning machine for turning fermentation, can play the purpose of water regulation and even mixing, thus saving a lot of labor. It can also achieve the purpose of full ripening.

Investment Projects in 3-5 tons of organic fertilizer manufacturing process

1. Facilities investment

Semi-finished products, raw material warehouses, office sites. According to the local construction cost budget.
When the fermentation tank is built, the ground fermentation tank is not needed.

2. Equipment investment

In the selection of fertilizer production equipment, Huaqiang fertilizer granulator manufacturers can configure models and functions according to customer requirements. The annual output of organic fertilizer production process is determined by the customers themselves. The material connection in our fertilizer production line is accomplished by belt conveyor. The length and number of belt conveyor can be designed according to the actual site.