Method for removing ferric ions from sulfate-based iron electroplating solution

Abstract

A method for removing ferric ions contained in a sulfate-based iron electroplating solution comprises a step of regeneration for reduction of the ferric ions by circulating a ferric ion-containing sulfate-based iron electroplating solution in a solution bath containing ferrous metal charged therein, wherein the ferrous metal is charged in an amount that satisfies the following formula (1): S≥0.01 Iconv/Cmax (1). In formula (1), S indicates a total surface (m2) of ferrous metal, Cmax indicates a maximum permissible ion concentration level (g/L) of the ferric ions in the solution, and Iconv indicates, as represented by the following formula (2), converted current (A) obtained by dividing the sum of current (I) applied to an electroplated cell during the plating time (tp, sec) by the regeneration time (tr, sec) for reduction of the ferric ions in an electrolyte.Iconv=∫Idtp∫dtr

1 . As a method for removing ferric ions from a sulfate-based iron electroplating solution, the method comprising:
 a regeneration step of reducing ferric ions by circulating a sulfate-based iron electroplating solution containing ferric ions in a solution bath containing metallic iron charged therein,   wherein the metallic iron is charged in an amount satisfying the following formula (1):
     S≥ 0.01  I   conv   /C   max    ((1),
 
   where S indicates a total surface (m 2 ) of metallic iron, C max  indicates a maximum permissible ion concentration level (g/L) of the ferric ions in the solution, and I avg  indicates, as represented by the following formula (2), converted current (A) obtained by dividing the sum of current (I) applied to an electroplated cell during a plating time (t p , sec) by a regeneration time (t r , sec) for reduction of the ferric ions in an electrolyte   
       
         
           
             
               
                 
                   
                     
                       I 
                       conv 
                     
                     = 
                     
                       
                         ∫ 
                         
                           Idt 
                           p 
                         
                       
                       
                         ∫ 
                         
                           dt 
                           r 
                         
                       
                     
                   
                 
                 
                   
                     ( 
                     2 
                     ) 
                   
                 
               
             
           
         
       
     
     
         2 . The method of  claim 1 , wherein the regeneration step is performed during a plating process. 
     
     
         3 . The method of  claim 1 , wherein a regeneration step is performed during a plating process, and the regeneration step is performed discontinuously two or more times. 
     
     
         4 . The method of  claim 1 , wherein a regeneration step is initiated during a plating process, the regeneration step is terminated in a pause in the plating process, and the regeneration step is performed continuously or discontinuously. 
     
     
         5 . The method of  claim 1 , wherein a regeneration step is initiated in a pause in the plating process, and the regeneration step is terminated in a pause during or after the plating process. 
     
     
         6 . The method of  claim 1 , wherein a regeneration step is performed during a pause in the plating process, and the regeneration step is performed continuously or discontinuously. 
     
     
         7 . The method of  claim 1 , wherein a plating process is performed discontinuously, including a pause, and a regeneration step is performed during two or more plating processes. 
     
     
         8 . The method of  claim 1 , wherein the metallic iron is ferroalloy containing at least one alloying element selected from a group consisting of Mn, Al, Mg, Li, Na and K. 
     
     
         9 . The method of  claim 8 , wherein the ferroalloy is ferroalloy containing an alloying element in an amount greater than 0% by weight and less than or equal to 3% by weight. 
     
     
         10 . The method of  claim 1 , wherein the metallic iron particles are at least one of particles, spiral chips, plates, and strips. 
     
     
         11 . The method of  claim 1 , wherein the sulfate-based iron electroplating solution further comprises a complexing agent. 
     
     
         12 . The method of  claim 11 , wherein the complexing agent is at least one amino add selected from glycine, glutamic acid and glutamine, and at least one compound selected from a group consisting of formic acid, acetic acid, lactic acid, gluconic acid, and oxalic acid, citric acid, nitrilotriacetic acid (NTA), ethylenediamine-N, N, N′, N′-tetraacetic acid (EDTA). 
     
     
         13 . The method of  claim 1 , wherein the sulfate-based iron electroplating solution has a temperature of 80° C. or lower and a pH of 1.0 to 4.0. 
     
     
         14 . In  claim 1 , wherein the method comprises
 an electroplated cell in which electroplating is performed by applying a current;   a circulation bath for circulating the electroplated cell and an electroplating solution;   a dissolution bath for circulating the circulation bath and the electroplating solution containing the metallic iron charged therein, and dissolving metallic iron to remove ferric ions from the electroplating solution,   wherein the method is performed by an iron-based electroplating apparatus having a pump for supplying the electroplating solution in the circulation bath to the dissolution bath and a filter for preventing metallic iron in the dissolution bath from entering the circulation bath.