A Multivariable Sensor to Measure Gas and Solid Holdup in Flotation Machines

摘要

This paper describes the development of a multivariable submersible sensor to measure in real-time both the concentration of gas and solids in the collection zone of flotation machines. The device comprises a gas exclusion cell and a single straight-titanium tube Coriolis mass flowmeter. The gas exclusion cell is a tube with its both ends opened and having a gradual contraction in its cross sectional area. The Coriolis mass flowmeter is installed at the reduced end of the gas exclusion cell. When the sensor device is vertically immersed in the aerated pulp a continuous descendent flow of pulp without bubbles is induced through the sensor. The Coriolis mass flowmeter independently measures density and flow velocity. The inherent accuracy of the Coriolis meter was assessed in a in a flow loop for suspensions of fine mineral particles having different specific gravity and particle size distribution. In addition, the sensor was immersed in an aerated solution of sodium chloride at different ionic concentrations to assess the accuracy of gas holdup and the density of the solution. Experimental results demonstrate the sensor potential to provide important information in the collection zone of flotation machines.