Method for removing iron ions from galvanizing flux solution

Abstract

A method for removing iron ions from galvanizing flux solution includes adding zinc chloride and ammonium chloride to a solvent in a preparing tank to prepare a first galvanizing flux solution which is transferred to a treatment tank, immersing an iron/steel piece in the first galvanizing flux solution to dissolve part of the surface to form iron ions, adding oxygen-rich gas to the first galvanizing flux solution to oxidize the iron ions to form a second galvanizing flux solution containing iron oxide precipitation, filtering the second galvanizing flux solution by a multilayer filter to form a third galvanizing flux solution without iron oxide or with low content of iron oxide, transferring the third galvanizing flux solution back to the treatment tank, and repeating the above steps by immersing another iron/steel piece in the first galvanizing flux solution so as to continuously remove iron ions generated.

What is claimed is: 
     
         1 . A method for removing iron ions from galvanizing flux solution, comprising:
 adding zinc chloride and ammonium chloride to a solvent in a preparing tank to prepare a first galvanizing flux solution, which is then transferred to a treatment tank;   immersing at least one iron/steel piece in the first galvanizing flux solution such that part of a surface of the iron/steel piece is dissolved in the first galvanizing flux solution to generate iron ions so as to wet the surface of the iron/steel piece;   adding oxygen-rich gas to the first galvanizing flux solution to oxidize the iron ions to form a second galvanizing flux solution containing iron oxide precipitation;   filtering the second galvanizing flux solution by a multilayer filter to separate iron oxide and form a third galvanizing flux solution without iron oxide or with low content of iron oxide;   transferring the third galvanizing flux solution back to the treatment tank; and   repeating the above steps by immersing another iron/steel piece in the first galvanizing flux solution so as to continuously remove iron ions generated.   
     
     
         2 . The method as claimed in  claim 1 , wherein a weight ratio of zinc chloride to ammonium chloride in the first galvanizing flux solution is within 1:1.05 and 1:1.55, and the solvent is deionized water or pure water. 
     
     
         3 . The method as claimed in  claim 1 , wherein the preparing tank serves as the treatment tank. 
     
     
         4 . The method as claimed in  claim 1 , wherein the oxygen-rich gas comprises at least one of nitrogen oxide, high purified oxygen gas and ozone, and the high purified oxygen gas contains more than 50% oxygen.