(1) Ore powder particle size: The particle size and size distribution of ore powder have a certain impact on the pellet strength. Appropriate particles can fully contact and bond with the binder. For briquette pellet binder and granulation molding, it is advisable to control the particle size of ore powder within the -200 mesh range at 85%-95%. However, the roller pressing process has relatively lower requirements for particle size, generally controlling particles below 3mm at 70-80%.
(2) Mixing of the mixture: The uniform mixing of ore powder and binder, which often affects the pellet strength, is frequently overlooked. Applications show that after stirring and kneading the ore powder with the binder, the material surface becomes uniformly smooth and greasy, increasing its plasticity and significantly enhancing its strength.
(3) Forming external force: Besides the performance of the binder, the strength of pellets mainly depends on the forming external force. Appropriately increasing the forming external force helps to enhance the pellet strength.
(4) Dosage of pellet binder: Selecting an appropriate amount of binder not only ensures higher quality pellets but also reduces processing costs. The dosage of dry powder pellet binder is generally 2-3%.
(5) Moisture content during pellet formation: The moisture content of ore powder directly affects the pellet formation rate, curing time, initial strength, later strength, and other quality aspects. Practice has proven that for clean coal binder, the molding moisture for both processes should be controlled between 8-15%.