Research And Development Of Model Software For Countercurrent Decantation Process

Countercurrent decantation is an important hydrometallurgical process, accounts for a large cost of investment, its main task is to use the method of continuous countercurrent decantation by multi-stage thickener to separate the leaching solution containing the soluble components from the leaching slurry and discharge leaching residue after washing. The thickener is the main equipment for countercurrent decantation process, widely used in ore-dressing, chemicals, sewage treatment and other industries. For the sake of the complex technology, nonlinearity, multi-variables, large time delay, slow-time varying, strong coupling, frequent wave of the incoming slurry and other features, the accurate mathematical model of the thickener is hard to provide. Therefore achieving the automatic control of the thickener has been a difficult problem for this industrial process. According to the analysis of the technology of countercurrent decantation process, the dynamic model for countercurrent decantation process is established in this thesis, which is supported by "985Project" Process Industry Integrated Automation Technological Creativity Platform Construction. Then the model software for countercurrent decantation process is designed and developed. In the end, the experimental results of the model software are researched and analysed. The main contents are as follows:(1) The dynamic model for countercurrent decantation process is established.Based on the analysis of the technological flow and dynamic behavior of countercurrent decantation process, the dynamic model of the thickener is established according to the principle of conservation. Then the model of countercurrent decantation process is established by the material connective relation of the thickeners.(2) The model software for countercurrent decantation process is designed and developed.Considering the characteristics and the control requirements of countercurrent decantation process, the simulation experiment platform for countercurrent decantation process is designed. Based on the dynamic mechanism model, the model software for countercurrent decantation process is designed and developed, which includes the man-machine interface, the background object model program and the communication. Firstly, the man-machine interface program of the model software is developed by WinCC to realize the initial display, the parameter setting display, the technical flow display, the trend display and so on; Secondly, the background object model program is developed by MATLAB to complete the real-time operation of the background model; Finally, the communication is developed by OPC.(3) The model software for countercurrent decantation process is validated.Based on the model software for countercurrent decantation process, the relevant conditions are changed to prove the validity of the model. Then the changes of the material properties are simulated by changing the feeding flow, the frequency of the underflow pump and the frequency of the flocculant pump.