The control objective of the forced-circulation evaporation process of alumina production is not only to avoid large fluctuations of the level

but also to ensure the product density to track its setpoint quickly. Due to the existence of strong coupling between the level loop and the product density loop

and high nonlinearities in the process

the conventional control strategy cannot achieve satisfactory control performance

and thus the production demand cannot bemet. In this paper

an intelligent decoupling PID controller including conventional PID controllers

a decoupling compensator and a neural feedforward compensator is proposed. The parameters of such controller are determined by generalized predictive control law. Real-time experiment results show that the proposed method can decouple the loops effectively and thus improve the evaporation efficiency.