Research And Application Of The Advanced Control For Extracting Gold From Gold Concentrate With Three-phase Circulating Fluidized Bed

As a new process for oxidation of gold concentrate, the technology of Three-phase Circulating Fluidized Bed (TCFB) can effectively overcome many shortcomings of the process for oxidation of gold concentrate in the current industry, for example, the efficiency of extracting gold from gold concentrate is low, the investment is large, the period is long, be easy to cause environmental pollution and so on. It enables gas-solid-liquid mixture of reactants through the cycle and enables the full recycling of harmful gases, for this, the efficiency of extracting gold from gold concentrate is improved, the environment is protected and the economic efficiency is improved at the same time, so it has a good market prospects. But to put it in the widely applied in industry, make the process of extracting gold with TCFB to achieve a smooth and efficient automatic monitoring operation system is absolutely necessary. Currently, the mature research in this area is more for the gas-solid circulating fluidized bed boiler of the coal-fired power plants, and most of the research used the traditional PID control method. But the research for the process of extracting gold with TCFB is a little and the theory is not mature. So make the research of model and control for the system of TCFB is an important direction in this area.Because the system of extracting gold from gold concentrate with TCFB has nonlinearity, delay, many variables and other characteristics, so modeling and control for it must face a variety of complex problems. The use of advanced modeling theory and intelligent control strategy can effectively to modeling and control the system of TCFB, from this it can improve the reaction efficiency and the economical efficiency of industrial production. Firstly, this paper studies the characteristics of the system of extracting gold from gold concentrate with TCFB, and the main factors and the secondary factors which affect the size of the stratified pressure have been determined by experiments, then, taking the advantage of BP neural network based on its strong non-linear dynamics feature and self-learning feature, the neural network model is established. Secondly, the algorithm of dynamic matrix control based on neural network model was proposed, then, designed the controller in the MATLAB environment and the system is simulated. Finally, integrated the actual system according to the research of the theory and make the system run automatically, then, verify by experiment. The main contents are as follows:(1) A deep research about the technology features of gold extraction process with TCFB, and got that the stratified pressure is the main parameter which affects the efficiency of extracting gold from gold concentrate and the process safety. Then rate of the flowing gas and solid holdup which are the main factors affect the size of the stratified pressure had determined by experiments, and particle size is the secondary factors. The set point of the controlled object had also determined. Finally, make some assumptions on the conditions of gold extraction process with TCFB to prepare for the neural network modeling.(2) The stratified pressure of TCFB in extracting gold from gold concentrate process was experimentally investigated and the experimental data was got for modeling. Then select the rate of the flowing gas and solid holdup as input, the four stratified pressure as output. And taking advantage of BP neural network based on LM algorithm, the neural network model is established and verified. The result showed that the model has better generalization ability higher precision than the second-order model which established by the traditional respond method.(3) Aimed at the problem which is that the high pressure source of air compressor is instability which caused the stratified pressure of TCFB fluctuation, the dynamic matrix control algorithm based on the BP neural network model was proposed. Realize the optimal control of the stratified pressure of TCFB. Simulation results show that the controller design presented in this paper can obtain good control effect, the system has good dynamic performance, strong anti-interference ability, high control precision, robustness, etc., and this can meet the actual need for the control system of the stratified pressure of TCFB.(4) Designed and integrated the hardware and software of the control system. Established the project points, configuration screen, connections and preparation of the relevant control algorithm base on the platform of the REALINFO configuration and monitoring software. Then make the system run automatically, and take test experimental data compare with the data of artificial operation condition. The results showed that the design control system makes gold exaction and the number of iron per unit volume increased by 8.39% and 10.6%. For this, the economical efficiency and security of the production process will be greatly improved by using the automatic monitoring system. This can provide a basis for the technology of TCFB be widely used in industry. v...