gearbox for 633 coal mill. david brown coal mill gearbox for 8.5 E-9 worldcrushers. Jul 12, 2013david brown coal mill gearbox for 8.5 E-9. Posted on July 12, 2013 by shuijing. vertical spindle e type coal mills. 2 Babcock vertical coal mills, type 8.5 E 9 (ring ball mill), with separator, hydraulic system, David-Brown gear-box, 965/40 rpm, and drive motor, 228 kW, 984 rpm, 6 kV.