Grinding Mills. Grinding is the required powdering or pulverizing process when customers have a strict demand on final size. ZENITH can provide proper grinding equipment and solutions for different applications, such as XZM Series Ultrafine Grinding Mill whose output size can reach 2500mesh ... MRN Pendulum Roller.
The Work Index is found from the first stage of the wet open circuit grinding tests by multiplying the grinding index Iw by 0.0082, and from the first stage of the dry open circuit grinding tests by multiplying the dry grinding index Id by 0.00546. How to Find Work Index From Open Circuit Grindability Tests
The test determines the Bond Impact Work Index which is used with Bonds Third Theory of Comminution to calculate net power requirements when sizing crushers*. It is also used to determine the required open side settings or closed side settings for a given product size.
The paper by Angove amp; Dunne reports a standard deviation in crushing work index tests across laboratories as 4.5. The laboratory CWi value of 27.4 is almost within 4.5 units of the 22.4 value I calculated, so what you are observing is probably the natural variation in the crushing test.