Understanding and applying compaction-granulation
Using pressure to compact dry materials into a large flake [or sheet] of material that is then milled and screened to form small granules is called compaction-granulation, which is used primarily to produce fertilizers. Granulated fertilizer offers several benefits over bulk fertilizer blends, and in some cases, compaction-granulation can be a good alternative to wet granulation. This article introduces you to the compaction-granulation process, including preparing the raw materials and compacting, granulating, and finishing the materials. The last sections cover the advantages and disadvantages of compaction-granulation and controlling the process' operating variables for cost-effective operation.
Forming agglomerates can be done using wet methods [adding a liquid binder to dry ingredients to cement the particles together] or dry methods. Dry agglomeration methods require compaction -- using pressure to compact dry materials into dense, compact agglomerates. The methods include briquetting, tabletting, and compaction-granulation. Briquetting forms fine dry materials into briquettes [sticks, wafers, nuggets, or pillows], typically using a double-roll press with briquette-shaped pockets; common applications include coal, ore, flue dust, and metal powder. Tabletting compacts blended, fine dry materials into tablets using a punch-and-die press; common applications include pharmaceuticals, food products, and chemicals.