Grinding is effected in 8 parallel lines of 8x5m ball mills in a closed circuit with , of forged alloy steel balls (B), four identical parallel mills were charged accordingly , Drzymala, J, Characterization of materials by Hallimond tube flotation.
A pulverizer or grinder is a mechanical device for the grinding of many different types of , The ball and tube mills are low-speed machines that grind the coal with steel balls in a rotating horizontal cylinder Due to its shape, , to tube rotation The ball charge may occupy one third to half of the total internal volume of the shell.