Fluorine-free and ammonium-free four-in-one sand surface treatment process for aluminum alloy

Abstract

A fluoride-free ammonium-free four-in-one aluminum alloy sand face pretreatment process comprises a chemical recycling system and a series-opposing water saving system. The chemical recycling system comprises a four-in-one tank and an immobilization washing tank sub-system. The whole immobilization washing tank sub-system is in series-opposing arrangement, the starting end of the water flowing direction of the immobilization washing tank sub-system is provided with a first water replenishing port, and the water outlet at the terminating end of the immobilization washing tank sub-system is serially connected to the four-in-one tank. The series-opposing water saving system comprises a functional tank sub-system and a flowing washing tank sub-system arranged among functional tanks. The functional tanks are respectively arranged among flowing washing tanks. The upstream functional tanks, along the washing water flowing direction, of the functional tank sub-system are compatible with downstream functional tanks. The whole flowing washing tank sub-system is in series-opposing arrangement. The fluoride-free ammonium-free four-in-one aluminum alloy sand face pretreatment process has the advantages that the fluoride and ammonium pollution of aluminum alloy anode oxidation pretreatment are solved effectively, great water saving of an anode oxidation line is achieved, enterprise pollution treatment quantity is reduced greatly, production efficiency is lowered, and efficiency is increased.

Description

technical field [0001] The invention relates to the technical field of surface treatment of aluminum materials, in particular to a fluorine-free and ammonium-free four-in-one sand front treatment process for aluminum alloys. 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 alkaline etching process of aluminum profiles has been used for more than 100 years. Alkali etching has the disadvantages of high aluminum consumption, high alkali consumption, more alkali slag, difficult process control, many defects, high production cost, COD content, and large environmental pollution, which has long been recognized by the industry. Standard alkali etching slot arrangement figure 2 As shown, 1# oil removal tank, 4# alkali corrosion tank, 7# neutralization tank, 11# oxidation tank and 14# sealing tank are working tanks, and each workin...

AI Technical Summary

Problems solved by technology

[0023] 1. The process is more complicated and the slots are more

There are a total of 13 slots in front of the oxidation tank, 4 working tanks, and 9 washing tanks, which are more complicated;

[0024] 2. The efficacy is too low

The time is too long, which seriously restricts the production capacity of the oxidation line;

[0025] 3. There are too many working tanks, and the consumption of chemicals is too large

In addition to the cost of water, the treatment and discharge of these wastewater containing fluorine, ammonia nitrogen and COD will cost extra;

[0027] 5. The fluoride ion content of 1# tank is 5-10g / L, and the fluoride ion content of 4# tank is 30-50g / L. The HF gas released during production endangers the health of workers, corrodes equipment and pollutes the atmosphere

Wastewater contains high concentration of fluoride ions, which need to be specially treated, and the waste water cannot be reused;

[0028] 6. Tanks 1#, 4# and 10# contain ammonia nitrogen, and 7# contains COD, making wastewater treatment even worse

These fluorides are now strictly banned

[0041] 2. Chromium-containing anhydride: 7# tank contains CrO 3 35g / l, it is not allowed to use like this

[0071] (2) Sand surface agent Na 3 PO 4 Improper selection, insufficient sanding ability

[0073] (4) Improper selection of sodium dodecyl sulfonate, the liquid level rises too fast

[0074] 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

[0076] 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 the traditional alkali etching, acid etching and sandblasting process 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, and low sandblasting efficiency, The disadvantages of high scrap rate, taking into account the advantages and disadvantages of the Chinese patent 200510101420. The aluminum alloy sand surface treatment process of saving medicine and water also plays the most fundamental purpose: saving medicine and water

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