Petroleum coke grinding with the vertical airswept pendulum mill

Abstract

The vertical pendulum mill has been used in the nonmetallic mineral industry for over one hundred years to grind natural minerals such as limestone, gypsum, barite and bentonite. Petroleum coke is ideally suited to be ground in this type of grinding mill. Before investigating this application, the author describes what this mill is, how it works, and what that makes it capable of grinding this wide array of minerals. The vertical pendulum mill gets its name from the fact that the grinding rolls are suspended from a horizontal plate that rotates about a central vertical shaft arrangement. Centrifugal force causes the journal to pivot at the attachment point to the horizontal plate. This action resembles the motion of a pendulum, hence the name vertical pendulum mill (in the industrial minerals field, this mill is also known as a roller mill). The grinding action of the pendulum is considered true rolling grinding because material is forced between a stationary ring and a rotating grinding roll.