Microwave Reactor with Combined Rigid and Flexible Stirring Paddles for Improving Fluid Heating Uniformity in Soft Manganese Ore Leaching Processes

[Image: see text] In order to overcome the apparent limitations of the inhomogeneous nature of large-scale microwave heating of fluids, a microwave reactor with a rigid–flexible combined stirring paddle is used to heat fluids, destabilizing the hot spots present in the microwave heating of fluids process. An integrated multiphysics field simulation model for calculating the microwave heating process with fluid was created for the purpose of clarifying the temperature field dispersion and fluid flow patterns in the reactor. By using the proposed model, the rigid–flexible combined stirring paddle is compared with the conventional single- and double-layer stirring paddle to highlight the benefits of the rigid–flexible combined stirring paddle in improving fluid heating uniformity. It was found experimentally that the leaching rate of soft manganese ore was increased by 7.08 and 5.22% compared to conventional single and double stirred paddles, respectively. In addition, the optimal stirrer parameters were investigated by the response surface method.