From industrial by-product to high-quality fertilizer: New thyssenkrupp process permits granulation of ammonium sulfate
Ammonium sulfate solutions are a pertinent industrial by-product. In its state-of-the-art plants thyssenkrupp has developed a process to convert ammonium sulfate solution to granules. The key advantages over liquid and crystalline solutions are improved spreading and mixing properties.
By simultaneous supplying sulfur and nitrogen, ammonium sulfate fertilizer enables strong crop growth and high yields. It guarantees long-lasting nutrient supply and promotes the availability of micronutrients in the soil, such as manganese, boron and iron.
Currently, ammonium sulfate is mostly sold in the form of crystals, which are difficult to incorporate into granulated fertilizer blends. Granulated ammonium sulfate is a high-quality fertilizer that is traded at higher prices than standard products in crystalline form.
The new patented thyssenkrupp process combines the advantages of high-value granular fertilizer with cost-efficient production. The process starts with ammonium sulfate solution, an industrial by-product occurring mainly in the production of caprolactam and in coal-burning furnaces. The ammonium sulfate solution is then processed in a fluidized bed granulator into solid granules.
This fluidized bed granulation technology is a new process that has been developed and tested on a laboratory scale and is currently operating in a 12 mtpd pilot plant. Based on this experience, plant sizes of commercially relevant size, i.e. several hundred tons per day can be planned and realized.