Electro-Chemical Method In An Enrichment Process

Abstract

The invention relates to a method that inhibits the formation of a deposition layer on metal surfaces in liquid submersion in a process susceptible to deposition, e.g. in an enrichment process. In the method, anodic current is supplied to the metal surface ( 11 ) to be protected against deposition via an external power source ( 100 ) and a cathode ( 12 ) immersed in the liquid, producing in the composition of the deposition adhering to the metal surface a change causing the adherence of the deposition to the surface ( 11 ) to be substantially weakened or the formation of deposition on a clean surface ( 11 ) to be substantially retarded.

1 . Method in ore enrichment processes taking place in water solutions, in which processes undesirable depositions ( 12 ) are formed in process containers, piping and equipment, characterized in that the surface ( 11 ) of an object to be protected in a process susceptible to deposition is polarized in the anodic direction by using an external power source ( 100 ) and a current supply electrode ( 12 ) placed in the solution so that the electro-chemical reaction products thus produced alter the structure of the deposition ( 20 ) present on the surface ( 11 ) of the object ( 11 ) to be protected or accumulating on said surface ( 11 ) in such a way that the adherence of said deposition ( 20 ) to said surface ( 11 ) is substantially weakened. 
   
   
       2 . Method in ore enrichment processes taking place in water solutions, in which processes undesirable depositions ( 12 ) are formed in process containers, piping and equipment, characterized in that the surface ( 11 ) of an object to be protected in a process susceptible to deposition is polarized in the anodic direction by using an external power source ( 100 ) and a current supply electrode ( 12 ) placed in the solution so that the potential of the said surface ( 11 ) of the said object to be protected is brought to a range in which the electro-chemical reaction products formed inhibit the formation of deposition or substantially retard the formation of deposition on said surface ( 11 ). 
   
   
       3 . Method according to  claim 1 , characterized in that the change in the potential of the said surface ( 11 ) of the said object to be protected resulting from the aforesaid anodic polarization is caused to be such that the said surface ( 11 ) does not undergo any substantial corrosion damage due to the raised potential. 
   
   
       4 . Method according to  claim 1 , characterized in that anodic direct current is used in the method. 
   
   
       5 . Method according to  claim 1 , characterized in that pulsed anodic direct current is used in the method. 
   
   
       6 . Method according to  claim 1  characterized in that a combination of an alternating-current component and an anodic direct-current component is used in the method to accomplish the desired electro-chemical reactions. 
   
   
       7 . Method according to  claim 1 , characterized in that a current density value in the range of 0.5-20 A/m 2  is chosen. 
   
   
       8 . Method according to  claim 1 , characterized in that the current/voltage supplied by the said power source ( 100 ) is controlled on the basis of an external measurement signal ( 104 ) and/or an internal measurement signal ( 105 ). 
   
   
       9 . Method according to  claim 1  characterized in that the current/voltage supplied by the said power source ( 100 ) is controlled on the basis of a control signal ( 108 ) obtained from a data file ( 107 ). 
   
   
       10 . Method according to  claim 1  characterized in that the current/voltage produced by the said power source ( 100 ) is controlled by means of a timed control signal by changing the current/voltage at desired time intervals t 1 , t 2 , . . . , t, to a predesired magnitude. 
   
   
       11 . Method according to  claim 1  characterized in that the said surface ( 11 ) of the said object to be protected is selected from the group of: precipitators, clarifiers, crystallizers or inner walls of a reactor, heat exchangers, overflow chutes, process pipes and valves used in a process. 
   
   
       12 . Method according to  claim 1  characterized in that reference electrodes ( 13 ) monitoring the intensity of the anodic polarization are mounted near the surface ( 11 ) to be protected so that they are in contact with the electrolyte and galvanically isolated from the objects to be protected. 
   
   
       13 . Method according to  claim 12 , characterized in that the material of the aforesaid reference electrode ( 13 ) is selected from metals that withstand the conditions prevailing in the process and retain their characteristic potential at a level sufficiently constant in respect of reliability of the potential measurement.