Fluorine-free and ammonium-free four-in-one sand pretreatment agent and its use

Abstract

The invention provides a fluoride-free and ammonium-free four-in-one sand finishing pretreatment agent and a use method and an agent recycling system thereof. The fluoride-free and ammonium-free four-in-one sand finishing pretreatment agent comprises the following components: 30-50 g / L sodium hydroxide, 100-200 g / L sodium chloride, 1.5-3.5 g / L sodium thiosulfate, a 1.5-3.5 g / L surfactant, 1.5-3.5 g / L sorbitol, 1.5-3.5 g / L sodium gluconate and the balance of water. The agent recycling system comprises a four-in-one bath and an immobile water washing bath subsystem which is in series-opposing connection on the whole, a water replenishing opening is formed in the starting end of the immobile water washing bath subsystem in the water flowing direction, and a water outlet in the finishing end of the immobile water washing bath subsystem is connected with the four-in-one bath. The fluoride-free and ammonium-free four-in-one sand finishing pretreatment agent provided by the invention has the functions of grease removal, acid etching, alkali etching and four-bath neutralizing, and effectively avoids fluoride and ammonium pollution caused by aluminum alloy anode oxidation pretreatment. In addition, the invention provides the agent recycling system employing the fluoride-free and ammonium-free four-in-one sand finishing pretreatment agent, and through limited application and recycling of the agent, the pollution control quantity of enterprises is greatly reduced, the production cost is lowered and the effect is improved.

Description

technical field [0001] The invention relates to the technical field of aluminum material surface treatment, in particular to a fluorine-free and ammonium-free four-in-one sand surface treatment agent and its use. Background technique [0002] Aluminum alloy sand surface treatment processes are mainly divided into three categories: alkali etching, acid etching and mechanical sandblasting. [0003] The traditional mechanical sandblasting process has been used on a large scale for more than 20 years. Although it has the advantages of low aluminum consumption and low chemical consumption, it needs to be equipped with a special sandblasting workshop, and then transferred to the oxidation workshop after sandblasting. scrap. Limited by the shape of the aluminum material, the sandblasting surface is difficult to be uniform, and the unevenness is enlarged after coloring, and the scrap rate rises linearly. [0004] The applicant's prior application (200510101420.X) for aluminum allo...

AI Technical Summary

Problems solved by technology

These fluorides are now strictly banned

[0015] 2. Chromium-containing anhydride: 7# tank contains CrO 3 35g / l, it is not allowed to use like this

[0045] (2) Sand surface agent Na 3 PO 4 Improper selection, insufficient sanding ability

[0047] (4) Improper selection of sodium dodecyl sulfonate, the liquid level rises too fast

[0048] 2. The slag extraction system is too complicated, and the production line workers are not suitable for complex operations

However, in actual production, due to the insufficient capacity of the complexing agent in the 1# four-in-one tank, the chemicals brought out decompose too quickly in the 2#, 3#, 4#, and 5# tanks, and the walls of each tank are fouled. When cleaning the bottom very troublesome

[0050] 4. The water circulation purification treatment system has a good idea and online purification, but the production line workers are not suitable for complex operations

For traditional alkali etching (such as image 3 shown), acid etching (such as Figure 4 shown) and the sandblasting process is complex, too many working tanks and washing tanks, low work efficiency, large amount of chemicals, large waste water discharge, high cost of treating fluorine, COD and ammonia nitrogen, low sandblasting efficiency, and high scrap rate Disadvantages, taking into account the advantages and disadvantages of Chinese patent 200510101420.X aluminum alloy bright acid etching technology and Chinese invention patent 201010515738 aluminum alloy four-in-one chemical recovery and zero-discharge surface pretreatment system for waste water, a specially designed set of drug-saving and water-saving equipment The aluminum alloy sand surface treatment process also plays the most fundamental purpose: saving medicine and water

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