Conical mixers and dryers offer high mixing accuracy and low shear force to the products being mixed, while requiring low energy consumption, and the ability for variable volume filling down to 20% of overall volume design on powders, pastes and slurries. Units allows many different processing tasks to be carried out simultaneously to include blending, drying, mixing, heating/cooling, crystallization, granulation, agglomeration and the injection of liquids or gases directly into the batch during processing in a totally enclosed safe environment. Design features include belt driven orbit arm, heated internal cone, three dimensional mixing zone for very precise mixing accuracy, low energy consumption, un-supported cantilevered mixing screw, gentle low shear mixing action, full bore and complete discharge, heated mixing screw, fully automated CIP systems, variable volume filling capability down to 20% without changing process characteristics, and fixed connections for loading and discharging. Units range in size from 3 to 20,000 gallons.