Determining basic technological parameters for the process of electrochemical extraction of copper from acid sulfate concentrated technological solutions

This study investigates concentrated model solutions, acid sulfate spent technological solutions (STSs) from surface preparation and coating operations by a number of enterprises, in order to devise unified technologies and to design relevant equipment. To substantiate the basic parameters for an electrolysis system within the framework of the system approach (Quality Function Deployment), it is shown that regardless of the concept and mechanism of electrochemical transformations, one of the main elements is redox reactions that occur both at the electrode-solution interface and in the solution volume. This paper reports experimental studies on electrochemical cathodic extraction of copper from acid sulfate concentrated technological solutions under conditions of non-stationary composition and changes in the properties of STSs. The basic technological parameters of the electrolysis process have been defined; a cathodic extraction installation of metal (copper) has been designed. To adapt the installation to changes in technological parameters and to avoid the formation of by-products together with the main product (copper), installation and dismantling of cathodes and diaphragms are implied. To eliminate secondary contamination of STS, it is proposed to abandon the use of reagents in local cycles at all stages of STS purification in favor of electrochemical technology. The kinetic data reported here (current density, current consumption/1 mol, deposition rate) make it possible to define the basic principles of control and regulation of the electrolysis process. The pH and Eh values make it possible to adjust the type of precipitate (foil, precipitate containing foreign substances), as well as determine the purpose of the technological process (regeneration, disposal). It is recommended to use diaphragm-free electrolysis in local regeneration cycles and diaphragm electrolysis in local disposal cycles