Comminution methods of Ball mills

Ball mills application

In almost all the metallurgical processes, crushing/grinding is considered to be an inseparable unit operation which is adopted at the very first stage of a series of other unit operations and/or unit processes. Size reduction of solids is done almost invariably. Ball mill finds its application in many industries like abrasives, animal products, brewing industry, chemical, confectionery, food processing, fuel preparation, metal powder, mineral preparation, paint preparation, paper, pigments for color industry, abrasives for grinding, plastics, printing ink, rubber, textiles, sintering, cement and limestone, powders for the detergent industry, pulverized coal for power generation, refractory materials for investment casting, dry powder opacifiers for ceramics industry, pharmaceuticals, mineral preparation, refractory materials for investment casting, tungsten powder and dry lubricants, carbon black for rubber, charcoal for briquetting and others.

Mainly because of their simple construction and application ball milling is a wide spread milling technology, particularly in mining. Various parameters viz. particle size, number of balls, time of grinding, particle density and speed of the Ball mill (rpm) have been considered for the present work to determine the performance of the ball mill.

Ball mills

Ball mills are cylindrical or conical shell rotating about a horizontal axis, partially filled with a grinding medium such as natural flint pebbles, ceramic pellets or metallic balls. The common classification of Ball mill is any type of mill in which mild steel or iron balls are used. In most cases the cylinder of such mill is made of alloy steel or some special type of lining. The material to be ground is added so that it is slightly more than fills of the voids between the balls (with a maximum limit of number of balls not exceeding 50% of the mill capacity for proper grinding). The shell is rotated at a speed, which will cause the pellets to cascade, thus reducing particle sizes by impact. It has been proposed that in the plastics industry the term Ball mill be reserved for metallic grinding media, and the term pebble mill for non-metallic grinding media.

There are two different methods of comminution:

Autogeneous comminution where the material is pure and heterogeneous comminution where the material is mixed with heavy spheres from steel of typical diameter of several centimeters to increase efficiency. There exists much experimental knowledge on the operation mechanism of ball mills and on the comminution of granular matter in these mills. To increase efficiency of the mill one would have to tune the rotation velocity so that the average collision velocity becomes maximum. In this context attempt has been made for a meticulous study of the effect of the various system parameters on the performance of ball mills.

Relative Solutions

• Stone Production Line
• Single Roll Crusher
• Talc Ore Crusher