Column flotation is an efficient method commonly used in the mineral industry to separate useful minerals from ores of low grade and complex mineral composition. Its main purpose is to achieve maximum recovery while ensuring desired product grade. This work addresses a model predictive control design for a mineral column flotation process modeled by a set of nonlinear coupled heterodirectional hyperbolic partial differential equations (PDEs) and ordinary differential equations (ODEs), which accounts for the interconnection of well-stirred regions represented by continuous stirred tank reactors (CSTRs) and transport systems given by heterodirectional hyperbolic PDEs, with these two regions combined through the PDEs' boundaries. The model predictive control considers both optimality of the process operations and naturally present input and state/output constraints. For the discrete controller design, spatially varying steady-state profiles are obtained by linearizing the coupled ODE-PDE model, and then the discrete system is obtained by using the Cayley-Tustin time discretization transformation without any spatial discretization and/or without model reduction. The model predictive controller is designed by solving an optimization problem with input and state/output constraints as well as input disturbance to minimize the objective function, which leads to an online-solvable finite constrained quadratic regulator problem. Finally, the controller performance to keep the output at the steady state within the constraint range is demonstrated by simulation studies, and it is concluded that the optimal control scheme presented in this work makes this flotation process more efficient.Mathematics 2018, 6, 100 2 of 17 sub-processes, such as particle-bubble attachment, detachment, and bubble coalescence, making the process more complex and difficult to predict. After several decades of research and development, the process is still not fully understood; the process control of column flotation has proven to be a great challenge and remains a very important topic for the research community.The process control for column flotation consists of three to four interconnected levels [6-8], but according to the control effects, it can be divided into stability control and optimal control [9,10]. At present, most flotation control systems are based on stability control, and the traditional control method uses PID control to achieve automatic control of the froth depth as well as other easily measurable variables to keep the flotation process as close as possible to the steady state [11,12]. A growing number of scholars have begun to apply advanced control methods, such as model predictive control, fuzzy control, expert systems, and neural network control, to regulate the column flotation process and/or combine these novel control methods to achieve better flotation column regulation [13][14][15][16].Model predictive control is the most widely used multivariable control algorithm in current industrial practice. One of its major advanta...