Design And Application Of Multivariable Control System For Flotation Column

In recent years, flotation column has become more useful in the colored and the ferrous metal mineral,the coal and the chemical mineral separation domain. However, automation technology of flotation column has developed slowly. At present, the operators, according to the experience, regulate the operating parameters by hand, for example froth depth, the aeration rate and so on. It is very difficult for manual operation of flotation column to make flotation column run in a stable state. It is also disadvantageous for improving the final flotation target. So, strenthening automatic detection and control for parameters of the flotation column, it is very important to make concentrate quality stable and increase the concentrate yield.This article systematically summarized history and current situation of application and research. The control request and principle of flotation column were analyzed and elaborated. Adopting method of the multivariate inputs/multivariate outputs, the automatic detection and control system of flotation column is designed. The working condition of flotation column is monitored through the digital cameras. The froth depth is detected by means of the float ball and the ultrasonic position-transmitting instrument. Froth depth is controlled by the way of the combination of fuzzy logic of self-adjustment parameter on line, PID and aeration rate. Aeration rate is detected by metal rotator flowmeter and cascade control is adopted. Water flow is detected by the metal rotator flowmeter, and operator adopts manual control according to the real-time condition of flotation column.For the requirement of control system of flotation column, we choose the Contro2000 configuration software and S7-300 PLC as the development tool, which has many functions, such as real-time data acquisition, storage, printing and scaling and so on. The control system is used inφ300×3000mm horizontal baffled flotation column and debugged. A comparative study of horizontal baffled column flotation and flotation cell was performed to recovery fine scheelite in Tungsten Mine. Theφ600×6000mm horizontal baffled flotation column was used in full-scale test. The test results show that the concentrate grade is 12%-18% with the recovery of 32%-36%. Industrial application results show:①Flotation cell in laboratory can not effectively recover fine scheelite particles from the tailings of cleaner circuit.②Fine scheelite particles could be recovered by the horizontal baffled flotation column.③Control system is reliable and stable.④The quality of concentrate product can meet the requirement. So, automatic control system can realize the stable control of process and product quality of flotation column.