Trivalent chromic rainbow color passivating agent for galvanizing and its production

Abstract

A trivalent chromic ion iridescent passivating agent for galvanizing and its preparing method are disclosed. It consists of trivalent chromic salt, chelating agent, oxidant, the mol ration is 1:1:2.5-1:2:5.5, the trivalent chromic ion concentration in passivating groove liquid is 2.5-25g / L. It is prepared by adding the components into reactor, heating, mixing and chelating reacting, boiling and back-flowing to remove nitrogen dioxide after reacting, adding water and adjusting to obtain passivating agent concentrate with Cr3+ ionic concentration 30-80g / l after discharging. It achieves no pollution and wide range.

Description

technical field

[0001] The invention relates to a passivating agent for treating galvanized surfaces and a manufacturing method thereof, in particular to a trivalent chromium iridescent passivating agent and a manufacturing method thereof. Background technique

[0002] In order to improve the aesthetics and corrosion resistance of the galvanized surface, people have been using Cr 6+ It is treated with chromate passivation. This kind of treatment is divided into white zinc, blue white zinc, rainbow zinc, army green zinc, black zinc, etc. due to its different formulas. Among them, rainbow zinc has the most comprehensive comprehensive performance, so it accounts for the largest proportion.

[0003] As we all know, hexavalent chromium is a substance that seriously pollutes the environment. Long-term exposure will lead to chromium ulcers, erosive rhinitis, and perforation of the nasal septum. It is particularly noteworthy that in recent years, a large number of studies have con...