Due to the instability of mine sources and the uncertainty of the composition of returned lye and waste liquid, there exists a significant fluctuation of raw slurry quality in the blending process of starting materials for sintering. The expected slurry was obtained through the mixing of starting materials in full-filled tanks. In this article, an optimal scheduling model of full-filled tanks is developed based on material balance principle and expert experiences subject to technological requirements. To solve such optimization problem, an improved genetic algorithm (IGA) is proposed, in which the intervention strategy is introduced into the random process of population initialization to obtain the well-proportioned initial population and the probabilities of crossover and mutation are changed according to the difference between the fitness value of the best solution and the average fitness value of the better solutions as well as the difference between the fitness value of the best solution and the average fitness value of the current population to prevent premature convergence. The IGA-based optimization system was applied to the processing of raw slurry for alumina production and the actual running results show that the composition fluctuation in mixed raw slurry decreased significantly, effectively improving the eligibility rate of the mixed raw slurry and contributing to the stabilization of the subsequent process of alumina production.