Granulating Spray Dried Powders

Problem: While mixing ingredients in solution and spray drying into a fine powder creates a very uniform blend, the fine cohesive nature of many spray dried powders often creates problems in dustiness, flow-ability, and dissolution in downstream processes. In this particular situation, a powder granulation process was needed in order to improve production efficiency.

One example of a customer product requirement was:

  • Product dustless, free flowing, specified dissolution rate
  • Ability to run multiple feed stocks
  • Provide complete granulation system
  • Targeted use: specialty fertilizers

Powder granulation process considerations included:

  • Corrosive nature of material
  • Ability to operate consistently with Hygroscopic material
  • Ability to change granular product size depending on feed stock

Solution: Multiple feed materials were tested in Bepex’s Process Development center. A complete powder granulation and compaction system, with easy to change parts to best accommodate different feed stocks was developed. Compacting, milling, and screening the fine powder into a granular form solved all four of the customer’s problems. A near dustless and free-flowing granular product readily dissolved into solution without clumping like the fine powder. Additionally, the powder granulation system was able to run continuously without shutting down due to plugging issues – an issue their previous wet-agglomeration process experienced.

Benefits and Results:

  • Low utility: no addition of moisture and so no drying step
  • No constant shutdowns due to plugging of hygroscopic materials
  • Complete powder granulation industrial process system was supplied
  • Customer able to provide their clients with product significantly easier to mix into solution