In all ore dressing and milling Operations, including flotation, cyanidation, gravity concentration, and amalgamation, the Working Principle is to crush and grind, often with rob mill & ball mills, the ore in order to liberate the minerals. In the chemical and process industries, grinding is an important
Nowadays grinding mills are almost extensively used for comminution of materials ranging from 5 mm to 40 mm (3/16″—1 5/8″) down to varying product sizes. They have vast applications within different branches of industry such as for example the ore dressing, cement, lime
Two general classifications of gearing are used for ball Mill drives. These are the spur gear and the helical gear. Helical gearing may be either of the single helical or double helical (Herringbone) design.
These are generally furnished on the smaller diameter mills using V-belt drives or reducer drives. Spur gears and pinions are
Several types of ball mill drives can be furnished, made up of various combinations of gearing, motors and transmission equipment. The correct combination to be selected takes into consideration power requirements, gear ratings, floor space, interference from other plant equipment and motor characteristics. The main types are described
Each application dictates the selection of proper feeding arrangement. This depends upon whether the grinding will be open circuit or closed circuit, and dry grinding or wet grinding. The size of feed and tonnage rates are also important factors.
Speed of scoop lip is important. Listed below for your convenience is a table showing critical speeds
Essentially tube mills and pebble mills may be considered as ball mills, the basic difference being that the ratio of length to diameter is greater. Usually the shell length is between 2 and 5 times the diameter. These mills are primarily used to grind various materials to 100 mesh and finer. The Tube Mill uses iron or steel balls
The principle of Grate Discharge grinding is nearly universally adapted in the cement grinding industry. Grate Discharge Ball Mills are the rule rather than the exception. Rod Mills for raw and finish grinding begin to enter the picture. Larger and larger diameter mills become common. Lengths tend to shorten. Cement grinding
This page is devoted to the subject “From the Comminution Theory to Practice by selection of the correct Process Equipment” by taking you step by step through some of the variables encountered in the specific part of Comminution called grinding and how each of these affect your operations. Should
The subject of grinding media is still controversial. The following information is general and based upon facts gathered from many operations.
General statements can be made and are worthy of consideration when selecting grinding media. For the best results it has been found that the smallest diameter ball or rod which will break down the particular