Raw material pretreatment stage

1. Raw material collection and screening:

○ Select raw materials according to the source of humic acid (such as weathered coal, peat, lignite, straw, etc.).

○ Removal of large impurities (such as stones, metals, wood chips, etc.) from the raw materials can be done by screening machines or manual sorting.

○ If the raw material has high humidity (such as fresh peat or weathered coal), it needs to be initially air-dried or mechanically dehydrated to ensure that the moisture content is below 6% required by the Raymond mill.

2. Crushing and coarse grinding (optional):

○ For large raw materials (such as weathered coal blocks), use a jaw crusher or hammer crusher to crush them into small pieces (usually ≤30mm) suitable for Raymond mill feed.

○ Reduce subsequent crushing energy consumption and improve grinding efficiency.

Core processing stage: crushing and classification

1. Raymond mill grinding:

○ Put the pre-treated raw materials into the Raymond mill main machine.

○ Start the grinding system and grind the raw materials to the target fineness (80-325 mesh, adjusted according to the application scenario) through the grinding action of the grinding roller and grinding ring.

○ Key parameter control:

■ Grinding roller pressure: Adjust according to the hardness of the raw material to ensure the crushing efficiency.

■ Feeding speed: Feed evenly to avoid overloading the equipment.

■ Classifier speed: controls the particle size of the finished product. The speed can be increased when high fineness requirements are required.

2. Powder classification and collection:

○ The crushed powder is sent to the classifier through a fan to separate the particles that meet the fineness requirements.

○ The coarse powder returns to the mill for further grinding, forming a closed loop to ensure the uniformity of the finished product.

○ Collect qualified powder and enter the next stage, or temporarily store it in the storage silo.