Measurement of Solids Concentration in Slurries Using Electrical Impedance Spectroscopy Technique (Keynote)

In this research work, an electrical impedance spectroscopy technique has been developed to measure the solids concentration of slurry mixtures. This new measurement technique is based on the fact that the AC frequency responses of solids are distinct from those for the liquid phase. In this technique, the electrical impedance spectrum of slurry mixtures is measured over the frequency range of 0.1 Hz to 1 MHz. Changes in the frequency response at different excitation signal amplitudes reflect changes in the slurry composition and the electrical conductivity of the liquid phase, and by analyzing the spectra using artificial intelligence data analysis techniques, such as Multiplayer Perceptron Artificial Neural Network, one can determine the volumetric fraction of the solids phase. The technique has been successfully tested for various slurries under different conductivities of liquid phase and temperatures. In contrast with previous techniques based on conductivity or capacitance, this new technique can be used for on-line measurement of solids concentration in slurry streams even when the conductivity of the liquid phase changes substantially with time.