Research On Optimal Control Methods For The Overall Process Of Hydrometallurgy And Their Implementation

The problem of resources has already become a fundamental problem for sustainable development of our country. Being able to deal with complex ore and low-grade ore with little environmental pollution, many new technologies of hydrometallurgy have been developed and used widely. However, hydrometallurgy optimal control technology develops slowly in our country, which makes it difficult for us to use mineral resources effectively with low energy consumption. This thesis aims to solve such a problem, taking high sulfur overall process of one gold refinery as the background, and comprehensive and systematic research is made on mechanism modeling and optimal control methods in high sulfur overall process. Furthermore, optimal control system and simulation platform are designed in this thesis. The main work is summarized as follows:(1) After deep analysis of the characteristics and mechanism for high sulfur overall process, the main factors of the process are discussed and the mechanistic model of high sulfur overall process is established, which is based on mechanism models of sub procedures according to production process association and material conservation principles. Furthermore, based on the overall process mechanism model, considering the influence of raw material costs, material consumptions, energy consumption, environmental costs, value-added of silver and copper and profit of the cyanide slag on the total economic benefits of the overall process, the overall process optimization model with objective function of maximizing the economic benefits is established, which is solved directly with two-order oscillating particle swarm optimization algorithm. However, the conventional optimization algorithm is complex and results in waste of time. To solve this problem, hierarchical optimization method is put forward by our research team, and we realize hierarchical optimization control of the overall process, and the simulations demonstrate the effectiveness of the proposed method.(2) On the basis of high sulfur overall process modeling and optimization study, optimal control system is designed. Hardware structure and data flow of the system are given and main function modules are analyzed emphatically. The system is realized by hybrid programming, combining merits of C# in interface design, strong data access ability of SQL and powerful computation and simulation function of Matlab. For the convenience of studying the high sulfur overall process intensively in the laboratory, the simulation platform is designed and developed.Finally, future directions for research on modeling and optimization of overall process of hydrometallurgy are discussed after summarizing the whole work in this thesis. Issues which need to be further improved and intensively studied are proposed.