Prill

A prill is a small aggregate or globule of a material, most often a dry sphere, formed from a melted liquid through spray crystallization.^[1]

For other uses, see Prill (surname) and Prill School.

Prilled is a term used in mining and manufacturing to refer to a product that has been pelletized. ANFO explosive typically comprises ammonium nitrate prills mixed with #2 fuel oil.^[2] The pellets are a neater, simpler form for handling, with reduced dust.

The material to be prilled must be in a solid state at room temperature and a low-viscosity liquid when melted. Prills are formed by allowing drops of the melted prill substance to congeal or freeze in mid-air after being dripped from the top of a tall prilling tower. Certain agrochemicals such as urea are often supplied in prilled form. Fertilizers (ammonium nitrate, urea, NPK fertilizer) and some detergent powders are commonly manufactured as prills.^[3] However prilling of ammonium nitrate and urea has in recent years been replaced by fluid bed granulation as this gives strong and more abrasion-resistant granules.^[1]

Melted material may also be atomized and then allowed to form smaller prills that are useful in cosmetics, food, and animal feed.

See also

• Shot (pellet)

References

1. Van'T Land, C.M. (2004). Industrial Crystallization of Melts. Taylor & Francis. p. 117. ISBN 9780203021132. Retrieved 10 October 2022.
2. Jimino, C. Lopez; Jimino, E. Lopez; Carcedo, Ayala (1995). Drilling and Blasting of Rocks. Taylor & Francis. p. 113. ISBN 9789054101994. Retrieved 10 October 2022.
3. Vasant Gowariker, V. N. Krishnamurthy, Sudha Gowariker, Manik Dhanorkar, Kalyani Paranjape (2009). The Fertilizer Encyclopedia. John Wiley & Sons. ISBN 9780470410349. doi:10.1002/9780470431771.