Editing Unit operation (section)

{{Short description|Basic step in a process}}
[[Image:LOC MI0086 QuincyMine TIF 00027aS.png|right|thumb|400px|An ore extraction process broken into its constituent unit operations ([[Quincy Mine]], [[Hancock, MI]] ca. 1900)]]
In [[chemical engineering]] and related fields, a '''unit operation''' is a basic step in a [[process (engineering)|process]]. Unit operations involve a physical change or chemical transformation such as separation, crystallization, evaporation, filtration, polymerization, isomerization, and other reactions. For example, in milk processing, the following unit operations are involved: [[Homogenization (chemistry)|homogenization]], [[pasteurization]], and [[packaging]]. These unit operations are connected to create the overall process. A process may require many unit operations to obtain the desired product from the starting materials, or feedstocks.