Identification of electrode short circuits during the electrolytic refining of copper based on heat radiation

Abstract

This study is aimed at improving the efficiency of monitoring and automated control over the technological state of electrolytic cells during copper refining using the recognition and identification of short circuits between the electrodes. Experimental works were performed on a laboratory bench consisting of two cells connected in series to the electrical circuit. The method of detecting short circuits is based on measuring infrared radiation using a scanning thermal imager (Оptris PI 400i / PI 450i) for determining areas with elevated temperatures of electrode and electrolyte surfaces. A short-circuit detection algorithm was developed and tested in MATLAB environment using the Image Processing Toolbox MATLAB functions. The proposed method for recognizing and identifying short circuits between the electrodes of an electrolytic cell is based on using a scanning digital thermal imager. This method allows a comprehensive assessment of the contact area, determination of both the start time of a short circuit and the degree of electrode heating in the short-circuit zone, as well as establishment of temperature values in all areas, including the electrolyte temperature in the entire volume of the cell. An algorithm for searching for short-circuit locations in an electrolytic cell is proposed. This algorithm involves the collection of data and its comparison for adjusting the inter-electrode distance, ensuring a stable energy mode for the entire electrolytic line, and determining the exact position of each cathode in the cell using the threshold processing of infrared images obtained by a thermal imager. It was established that timely identification of short circuit locations in the electrolytic bath (since the onset of a contact between the electrodes), as well as recording of the growth rates of a dendritic coalescence area and electrolyte temperature, ensure timely elimination of technological disturbances during the operation of electrolytic baths. Thus, the developed method of short circuit identification for comprehensive determination and recognition of the technological state of an electrolytic cell during the electrolytic refining of copper can be used to reach a stable energy mode with minimum deviations in the process temperature.