Potash pelletization is a reliable and beneficial method of processing potash. In fact, it is gaining popularity with fertilizer manufacturers looking for a premium, refined product that delivers nutrients quickly. However, a lot of work is required in order to produce an optimal potash pellet. Whether it’s pre-conditioning, pelletizing, or drying, every step plays an important role in the potash pelletizing system.
Potash Pelletizer Plant Overview
The following is an overview of a typical potash pelletizer plant. Click image to view larger.
Potash Pre-Conditioning
First, finely crushed potash enters the pelletizing process through a raw material feed bin.
Next, the potash travels to the Pin Mixer. The intense spinning action of the mixer and the addition of a binder work to pre-condition the material. This process reduces the air and water volume between potash particles as it creates densification within the material.
Potash Pelletization
After conditioning, the potash material is fed onto the disc pelletizer (pan granulator). Using tumble growth agglomeration (also known as wet granulation or agitation agglomeration), the potash material gradually rolls and builds against itself while rotating on the disc. Material is fed at a controlled rate and water is added to assist in binding the material. The result is a round, uniform pellet. The operational flexibility of FEECO’s disc pelletizers allows users to control the pellet size using variables such as disc speed and angle. Once the potash pellets reach the desired size, they are discharged from the disc pelletizer.
Potash Product Finalization
Because moisture is added during pelletizing, drying is necessary. In order to handle the corrosive nature of potash while also accepting a wide range of feedstock, potash pellets are most often dried using a potash dryer. A rotary potash dryer uses flights to lift and cascade material as it travels through a rotating drum. This process efficiently dries material, prevents clumps, and easily handles a high volume of potash.
Note: Fluid bed dryers are also an option for smaller processing facilities. This equipment suspends material in a fluidized state, exposing the potash pellet surface to air.
In addition to drying, potash pellets are often cooled using a potash cooler. Similar to rotary potash dryers, rotary coolers are a preferred industrial cooling method due to their robust, heavy-duty construction. Rotary coolers also use a cascading motion to shower potash material through a cool air stream in the drum. Additionally, they use a counter-current air stream to cool material and efficiently eliminate the heat of the potash.
Note: Fluid bed coolers are another cooling equipment option. The fluidized state produced by this cooler is gentle on potash, avoiding attrition-related material issues.
Finally, the potash material is screened to ensure only optimally sized pellets exit the process. Both the larger pellets (overs) and smaller pellets (unders) are recycled back into the pelletizing process, while properly sized potash pellets are bagged and/or stored.
Advantages to Potash Pelletizing
Pelletized potash offers a lot of advantages in terms of processing solutions and product benefits. Because the process is a non-pressure technique, a potash pellet is an ideal solution for fertilization. In certain occurrences, pelletization is the only solution for processing specific potash derivatives. The round, uniform pellet shape is less dense than that of more traditional compacted potash granules, allowing the pellet to deliver nutrients faster. Fixed formulations especially benefit from this quick break down ability. Moreover, the rounded shape of pelletized potash reduces occurrences of potash fines and is very easy to handle.
The easiest way to determine the best processing solution for any type of potash is to work with experienced solution providers. FEECO has delivered custom equipment and processing solutions to the potash industry for decades, garnering praise and repeat customers from a wide range of potash manufacturers. For more information on FEECO’s potash pelletizing experience, contact us today.