Method for optimizing the yield of electroextraction of heavy metals in aqueous solution with a high salt concentration, and device for the implementation thereof

Abstract

The invention relates to technical conditions of composition and use applied to the existing method and device for extracting heavy metals from an aqueous solution with a high salt concentration, with the single aim of adapting said method to technical, technological and ecological developments that have taken place since the protection thereof, and substantially optimising the results. To this end, the invention of the present patent application adds, to the device of the initial patent, an electronic control means (MC) that can manage three new actions. Disclosed are also modifications in the quality, function, destination and operation of certain elements of the device as well as the addition of a filter at the end of the electroplating operation, the purpose of which is to optimise the quality of the rejected effluent.

1 . A method of optimizing the yield of the electroextraction of heavy metals in an aqueous solution with a high salt concentration, wherein the method comprises:
 managing, controlling, and regulating operations linked to the extraction of heavy metals via electrolysis in an aqueous solution with a high salt concentration;   adding one or more sensitive probes (SP) in order to be introduced into the solution to be treated between pairs of electrodes ( 6 )( 7 ), ( 8 )( 9 ) and ( 10 )( 11 ), and   filtering the treated aqueous solution with a high salt concentration using an additional filter (EFF).   
     
     
         2 . The method of optimizing the yield of the electroextraction of heavy metals in an aqueous solution with a high salt concentration according to  claim 1 , wherein electronic control means (CM) in charge of providing for the management, control and regulation of the operations, control the interruption of the electrical power supply (PC) of the electrolysis device for successive limited durations and a periodicity determined according to the chemical composition of the solution to be treated and the texture of the electrodes used. 
     
     
         3 . The method of optimizing the yield of the electroextraction of heavy metals in an aqueous solution with a high salt concentration according to  claim 1 , wherein electronic control means (CM) in charge of providing for the management, control and regulation of the operations, control independently of the supply of the electrodes ( 6 ) to ( 11 ) of the device, the decoupling of the ground electrode for successive durations and a periodicity determined according to the different factors linked to the method. 
     
     
         4 . The method of optimizing the yield of the electroextraction of heavy metals in an aqueous solution with a high salt concentration as claimed in  claim 1 , wherein electronic control means (CM) in charge of providing for the management, control and regulation of the operations, control the control and the regulation of the optimum and constant voltage present in solution to be treated, throughout a entire electroplating operation and on information from the sensitive probes (SP) introduced into the solution to be treated, between the pairs of electrodes ( 6 )( 7 ), ( 8 )( 9 ) and ( 10 )( 11 ). 
     
     
         5 . The method of optimizing the yield of the electroextraction of heavy metals in an aqueous solution with a high salt concentration as claimed in  claim 1 , wherein the electrodes ( 6 )( 9 )( 10 ) ( 7 )( 8 )( 11 ) are confined when fixed polluting elements are of a radioactive nature and/or are eliminated by means adapted to fixed polluting elements and to the level of polluting effect thereof. 
     
     
         6 . The method of optimizing the yield of the electroextraction of heavy metals in an aqueous solution with a high salt concentration according to  claim 1 , wherein the operation can be carried out by alternating successive cycles or continuously, in this latter case, the supply of the solution to be treated is carried out through the bottom of the electrolysis tank and at slow speed and determined according to the chemical composition of the solution to be treated and the texture of the electrodes ( 6 ) to ( 11 ) of the device, with the evacuation of the treated solution being carried out in the top portion of the electroplating tank by a duct provided for this purpose. 
     
     
         7 . Device for the implementation of the method according to  claim 1 , wherein the device comprises:
 a) electronic control means (CM) for the management, control and regulation of the operations linked to the extraction of the heavy metals via electrolysis in an aqueous solution with a high salt concentration;   b) immersed electrodes ( 6 ) to ( 11 ) constituted of anodes ( 6 ) ( 9 ) ( 10 ) and of cathodes ( 7 ) ( 8 ) ( 11 );   c) a ground electrode in order to be introduced into the solution to be treated and increase the rapidity of the ionic degreasing of the electrodes ( 6 ) to ( 11 );   d) sensitive probes (SP) in order to be introduced into the solution to be treated between the pairs of electrodes ( 6 )( 7 ), ( 8 )( 9 ) and ( 10 )( 11 ); and   e) at least one electrofiltration filter (EFF) in order to fix the residual elements with a weak electromotive force that are still present in the solution after the differential electroplating operation.   
     
     
         8 . The device for the implementation of the method according to  claim 7 , wherein the immersed anode electrodes ( 6 ) ( 9 ) ( 10 ) are of a material and texture that are different from those of the immersed cathode electrodes ( 7 ) ( 8 ) ( 11 ), according to the chemical and radiochemical composition of the solution to be treated. 
     
     
         9 . The device for the implementation of the method according to  claim 7 , wherein the ground electrode introduced into the solution to be treated inside an insulating tube in order to prevent an electronic distortion and connected to the ground (G) of the electric generator, is of a material and texture that are different from those of the other electrodes. 
     
     
         10 . The device for the implementation of the method according to  claim 7 , wherein the sensitive probes (SP) introduced into the solution to be treated, between the pairs of electrodes ( 6 ) ( 7 ), ( 8 ) ( 9 ) and ( 10 ) ( 11 ), are of a chemically neutral texture and for example made of glass. 
     
     
         11 . The device for the implementation of the method according to  claim 7 , wherein the electrofiltration filter (EFF) that is independent and associated with the electrolysis tank in order to fix the residual elements with a weak electromotive force that are still present in the solution after the differential electroplating operation, is mainly consisted of a cylindrical container (C) containing a neutral filtering material (FM) wherein are plunged two electrodes (EC), of which one is thrust on the inside peripheral plane of the container (C) and the other is thrust on an axial support tube (ST) located at the center of the inner surface of the lower plane of the container (C), with the electric current passing through the filtering material (FM) being regulated according to the chemical composition of the solution exiting from the electrolytic treatment container and adapted to the resistivity of the whole knowing that the conductivity of the filtering material (FM) varies according to the more or less aqueous liquid that it contains, with the solution filtered by its passing through the electrofiltration filter (EFF) then having an optimum quality allowing for the discharge thereof into the environment or for example the reuse thereof in another method of manufacturing. 
     
     
         12 . The device for the implementation of the method according to  claim 7 , wherein the immersed anode electrodes ( 6 ) ( 9 ) ( 10 ) are of a material and texture that are different from those of the immersed cathode electrodes ( 7 ) ( 8 ) ( 11 ), according to the chemical and radiochemical composition of the solution to be treated and are constituted in the form of plates, of a composition, material, configuration and arrangement that are compatible with the operation and the performance of the device.