Influence Factors of the Ball Mill in the Process of Grinding

Beneficiation ball mill has three influence  factors in the grinding process with medium, including the ore properties, the  structure of and the operation conditions of the machines.

1.The Ore Properties

(1) the grindability of the ore. The harder  of the ore, the smaller of the grindability, thus lower the productivities of  the machine.

(2) the granularity of the feeding ore and  the product. The Coarser the granularity of the feeding ore, the longer time  will be the machine take to grind the ore to specified fineness, thus lower the  productivities of the machine.

2.the Structure of the Ball Mill

(1) The type of the machine. The grid ball  mill has heavy productivity, and lighter over-crushing, while coarse  granularity of the ore, thus is not fittable to fine grinding. The productivity  of the overflow ball mill lower about 10 to 15 percent of the grid ball mill of  same type . But over-crushing problem is serious to the overflow machine, while  the granularity is small .

(2) The size of the machine. The size of  the machine means the diameter and the length of the cylinder. The length of  the cylinder decides the remain time of the ore in the cylinder. Longer of the  cylinder, more serious of the grinding. While if the length is not enough,  target fineness maybe not being reached. The diameter property of the ball  mill usually get 1-1.5.

3.Operating Conditions of the Ball Mill

(1) the rate of the rotate and the filling.  When the filling rate is 30% to 50%, and the rotate rate is 40% to 80%, the  useful rate of the machine will increase with the increase of the rotate rate.  Thus when the rotate rate gets to a proper number, the productivity of the ball  mill will get the top rate as well as the filling rate reaching 40% to 50%.

(2)the shape and size of the ball mill.  Except steel ball and steel bar, the shape of the grinding medium also includes  steel short column and steel column ball,which have more effect than the steel  ball and bar. Thus some iron dressing plant have adopted abnormity grinding  medium instead of steel ball in the second section of milling operation.

(3) the density of the pulp and the speed  of the feeding ore. Pulp density has its best range. The feeding speed should  be equality and continuity. If not, such as too little feeding ore, which will  excess the wear of the machine. On the contrary, bulging belly will  happens and stop production when necessary.

(4) Cyclic load. Typically,the appropriate  value of the cyclic load id 150% to 600%.