Study On Automatic Control System Of Yunnan Lead - Zinc Mine Wastewater Treatment

With the development of economy and the strengthening of environmental protection, it is necessary for concentrators to reduce the pollution and develop the recycling process. Main drainage of Zinc-Lead Concentrator is flotation wastewater. Zinc-Lead wastewater have characteristics of high PH, high suspension, high metal-ion content, and high COD. There is a great influence on the selection index and the stability of flotation separation in which Zinc-Lead wastewater without treatment or treated recycle to the flotation process. Therefore, the final choice is that flotation wastewater are discharged after treatment.Firstly, according to the domestic and foreign research data of industrial wastewater treatment and years of experience summed up by our predecessors in the Zinc-Lead beneficiation wastewater treatment, this paper adopts a technology of removing coarse particulate matter by fine grid and grit chamber, aeration, neutralization precipitation, coagulation precipitation. Then the paper focuses on the design of automatic control system of Lanping Zinc-Lead wastewater treatment.PC monitoring level adopts industrial control computer by Beijing Asiacontrol Kingview as the monitoring software in this automatic control system, the realization of system configuration, monitoring, remote control, alarm prompt, data processing and other functions, lower machine control level uses PLC controller of SIMATIC S7-200 and S7-300 series to collect and monitor PH value, turbidity SS, concentration, heavy metal-ion content, liquid level, operating current value of equipments and other process parameter, as well as it can collect and control analog signal/digital signal of actuators on-line, such as pump, valve, and so on.In addition, the control program programming of technology process requires different programming software, PLC control program of S7-200 series are written by STEP 7-Micro/WIN V4.0, and PLC control program of S7-300 series make use of STEP 7 V5.5 CN (Chinese version), programming language mainly uses ladder diagram (LAD) and statement table (STL).The research and design of automatic control system of Zinc-Lead wastewater treatment not only improves the labor productivity, but also reduces the operation cost, at the same time it also can effectively solve the tailing drainage problems, avoiding the water pollution of Bijiang river caused by artificial misoperation or out of control.