Use of titanium cassettes as a cathode on electrolytic cells of direct-flow type

Abstract

Since the main method of obtaining gold from thiourea solutions for gold mining plants operating on sorption technology is electrolysis with insoluble anodes, it is essential to ensure continuous operation of cells and reduce the number of unscheduled downtime associated with maintenance, cathode failure or troubleshooting. Electrolyzers with a developed surface are inferior in performance to direct-flow models due to the fact that for the former this figure decreases as the cathode deposit accumulates. However, during the operation of direct-flow electrolyzers, unplanned stops occur due to the dissolution of cathodes made of stainless steel mesh in thiourea solutions. In this case, the consumption and costs of purchasing the relevant elements are quite large. Therefore, it is necessary to replace the stainless steel cathode mesh with another material that can withstand the effects of acidic environment, high temperature and direct current for a long time not compromising reducing the performance of the cell. In addition, the cost should not exceed the stainless steel mesh from which the cathode is made, and the service life of such a cathode should be many times longer than the service life of cathodes made of mesh. It is shown that such material can be titanium of VT-1-0 grade made in the form of a perforated corrugated cassette. The operating parameters of the cell with a mesh cathode and using a corrugated perforated titanium cassette are given. The chemical compositions of commodity regenerates before electrolysis and solutions at the outlet of the process at the mesh cathode are shown. The description and drawing of the corrugated perforated titanium cassette are presented. The economic calculation and substantiation of the replacement of the cathode from the stainless steel mesh with the corrugated perforated titanium cassette are performed. The cost of the stainless steel mesh used for the fabrication of the mesh cathode and the titanium sheet for the perforated cassette were analyzed. The use of corrugated perforated titanium cassette on the direct-flow cell allowed to ensure its continuous operation, increase the amount of deposited cathode sludge due to the lack of unscheduled shutdowns to replace the dissolved cathodes.