Solvent method batch hot-dip galvanizing water-cooling chromium-free passivating agent and its preparation and use method

Abstract

A chromium-free passivator for water cooling of solvent-based batch hot-dip galvanizing and its preparation and use method belongs to the field of solvent-based batch hot-dip galvanizing. The components of the chromium-free passivator for water cooling of batch hot-dip galvanizing by solvent method include: film-forming agent 1% to 10%, accelerator 0.5% to 5%, chelating agent 0.1% to 1%, sealing agent 0.2% to 2.5% , wetting agent 0.1% ~ 0.4%, the balance is water. The preparation method is as follows: add film-forming agent and accelerator to water, stir, add chelating agent and sealing agent, stir, add wetting agent, and stir evenly. Its usage method is: add it to the water-cooling tank and stir; immerse the galvanized workpiece in the water-cooling liquid for passivation treatment, lift it out and drain it. This method is used to treat galvanized workpieces, which has good passivation effect and original color. The product quality complies with industry production standards and has good corrosion resistance. The chromium-free passivation agent is non-toxic, harmless, low-cost, easy to operate, and has strong industrial promotion value.

Description

technical field [0001] The invention relates to the field of batch hot-dip galvanizing by solvent method, in particular to a chromium-free passivator for water cooling of batch hot-dip galvanizing by solvent method and its preparation and use method. Background technique [0002] Solvent method batch hot-dip galvanizing products are widely used in guardrails in the fields of electric power, construction, transportation, communication, etc., welded steel structures, light poles, plumbing equipment, line fittings, iron tower components, etc. Due to the high temperature and high humidity of the water cooling process and the high salt spray atmosphere in the coastal areas, the solvent method batch hot-dip galvanizing enterprises all adopt hexavalent chromium passivation (adding 0.2% to 0.3% chromic anhydride in the water cooling tank) to prevent the production process of workpieces. rust. This passivation method will produce a large amount of chromic acid mist and chromium-cont...

AI Technical Summary

Problems solved by technology

This passivation method will produce a large amount of chromic acid mist and chromium-containing wastewater, which will seriously endanger the health of workers, and will also pollute the environment, causing huge harm

Due to the particularity of the working conditions of the water-cooling process (requiring high-temperature stability of the passivation solution, no corrosion to the workpiece, high tolerance of the passivation solution to zinc ions, etc.), related research has hardly been reported.