Estimation, by use of a Conductivity Bolt, of the Charge Volume and Other Milling Parameters in an Operating Mill

Abstract Physical information on the conditions inside an operating mill can be obtained continuously if the bolts that are used to clamp the liners and lifter bars to the shell of the mill are equipped with suitable sensors. The information can be transmitted telemetrically to a conveniently located receiving station. The signals from a bolt that is equipped with an insulated electrode can be used to obtain a measure of the volume of the charge in a mill, and can also be related to the pulp density. Some of the problems associated with the use of this type of bolt are discussed.