Method for comprehensive treatment of ferrous ions in hot galvanizing assistant liquid

Abstract

The invention provides a method for comprehensive treatment of ferrous ions in a hot galvanizing assistant liquid, which relates to a method for removal and treatment of ferrous ions in a hot galvanizing assistant liquid during batch production of galvanization products. The method comprises the following steps: (1) preparing raw materials consisting of hydrogen peroxide and potassium permanganate according to a ratio, oxidizing iron ions and combinedly adding hydrogen peroxide and potassium permanganate; (2) changing a hydrogen peroxide hot galvanizing assistant liquid liquid-level feeding manner into a hot galvanizing assistant liquid tank-bottom feeding manner, namely, pumping hydrogen peroxide into the bottom of a plating assistant tank with a water pump so as to reduce decomposition of hydrogen peroxide and release of oxygen; (3) starting an aeration pipe to stir the hot galvanizing assistant liquid, then adding potassium permanganate and carrying out a secondary reaction; (4) measuring a pH value after completion of the reaction, adding corresponding ammonia water according to obtained data and carrying out full adjusting and stirring so as to allow the pH value to be 5 to 6; and (5) adding a flocculating agent to accelerate precipitation when the pH value is 5 to 6, pumping out a supernatant, i.e., the treated hot galvanizing assistant liquid, in the plating assistant tank, carrying out recovering, pumping a precipitate into a filter press for press filtration and recovering a filtrate to the plating assistant tank.

Description

technical field [0001] The invention relates to a method for comprehensively treating ferrous ions in a hot-dip galvanizing flux solution, and relates to a method for removing ferrous ions in a hot-dip galvanizing flux solution when galvanized products are produced in batches. Background technique [0002] Hot-dip galvanized workpieces are required to be galvanized before galvanizing, that is, the workpieces washed with degreasing and derusting water are immersed in a mixed solution of zinc chloride and ammonium chloride to cover a layer of zinc chloride ammonium salt film on the surface of the workpieces. This layer of salt film can purify the remaining iron oxide scale on the surface of steel and the newly formed rust after washing, and this layer of zinc chloride ammonium salt film can also play an activation role, thereby improving the ability of zinc liquid to infiltrate the iron matrix, making the steel matrix The metal and the galvanized layer can be well combined to ...

AI Technical Summary

Problems solved by technology

Although potassium permanganate can completely remove ferrous ions, it needs multiple treatments to control the ferrous ions to less than 2g / L for the fluxing solution with high content of iron salts, but the price is much higher than hydrogen peroxide. not economical

Therefore, using this method to treat the plating flux, the iron salt cannot be controlled in a lower range at one time, and the pH value should be adjusted before the oxidation reaction, and the pH value cannot be controlled at 5-6. The oxidized iron salt cannot be oxidized Completely precipitated and press-filtered, which again affected the treatment effect