... hardness below 7 and moisture content below 6%, such as barite, calcite, feldspar, talcum, pencil stone, marble, coke, powdered- ... vibrating feeder evenly and continuously into the grinding chamber for powder-processing. The rollers oscillate outward to press the ... just for reference, any change is subject to the Professional 4R Raymond Mill products. Professional 4R Raymond Mill for barite,glass, ...