On-line circulation process for hot galvanizing process quickening liquid

Abstract

The invention relates to an on-line circulation process for hot galvanizing process quickening liquid, which is carried out according to the following steps: (1) after a solvent is introduced into a neutralization reaction tank, an ammonium hydroxide solution is added, the pH value of the solvent is regulated to 5.0-5.5, and then, hydrogen peroxide is added to convert ferrous iron into ferric iron; (2) polyacrylamide is added to the solvent according to the proportion of 0.05-0.1 percent; (3) the water which flows out of the neutralization reaction tank is introduced into air-entraining air floating equipment to be separated, the chemical sludge generated by air floating enters a sludge storing pot, and the clear solution directly returns to the solvent tank; and (4) the chemical sludge in the sludge storing pot is dehydrated through a plate and frame filter press, the dehydrated sludge residues (iron hydroxide) are used as other industrial raw materials, and the filtered solution returns to the solvent tank. The invention has the advantages of simple and easy whole processes, saves a large amount of energy resources, has no environment pollution, improves the galvanizing quality and saves the galvanizing cost.

Description

Technical field: [0001] The invention belongs to a hot-dip galvanizing process, in particular to an on-line circulation process of a plating aid solution in the hot-dip galvanizing process. Background technique: [0002] At present, my country's hot-dip galvanizing enterprises still use the old process, which has the following defects: 1. Before hot-dip galvanizing, it is necessary to carry out acid treatment on the metal surface, and then use a large amount of water to wash off the residual acid and chlorine salt on the metal surface, and then clean it. The workpiece is then impregnated with solvent. The solvent (also known as the plating flux) is a double salt solution of zinc chloride and ammonium chloride. Since it is impossible to completely clean the hydrochloric acid and chloride salt on the metal surface during the washing process, some of them will be brought into the solvent tank, and over time the The solvent becomes sour, the concentration of ferric salt and ferr...

AI Technical Summary

Problems solved by technology

[0002] At present, my country's hot-dip galvanizing enterprises still use the old process, which has the following defects: 1. Before hot-dip galvanizing, it is necessary to carry out acid treatment on the metal surface, and then use a large amount of water to wash off the residual acid and chlorine salt on the metal surface, and then clean it. The workpiece is impregnated with solvent

The solvent (also known as the plating flux) is a double salt solution of zinc chloride and ammonium chloride. Since it is impossible to completely clean the hydrochloric acid and chloride salt on the metal surface during the washing process, some of them will be brought into the solvent tank, and over time the The solvent becomes sour, the concentration of ferric salt and ferrous salt increases, and the highest value can reach more than 60g / L (the normal value must be controlled within 13g / L), thereby reducing the quality of the solvent, affecting the quality of galvanizing, and increasing the cost of galvanizing

2. Generally, iron is removed once a quarter. Every time iron removal needs to stop production, which affects the production progress, and the annual cleaning cost needs to be 3536 yuan

3. After removing iron, pour the semi-fluid iron sludge into the environment. The semi-fluid iron sludge contains 50-60% liquid components, and these liquid components are all useful solvent components (ammonium chloride, zinc chloride) , not only waste resources, but also pollute the environment

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