Aluminum pretreatment alkaline three-in-one, alkaline liquor regeneration and aluminum hydroxide online recycling process

Abstract

The invention provides an aluminum pretreatment alkaline three-in-one, alkaline liquor regeneration and aluminum hydroxide online recycling process. A medicament recycling system and two flowing washing tanks are included. The medicament recycling system comprises an alkaline three-in-one grinding tank and a non-flowing washing tank sub system; the a non-flowing washing tank sub system is arranged to be in reverse series-connection with the alkaline three-in-one grinding tank through a first valve; the non-flowing washing tank sub system comprises a first non-flowing washing tank body and a second non-flowing washing tank body which are arranged to be in reverse series-connection with each other, and the start end of the second non-flowing washing tank body is furthermore provided with a water supplementing opening and a third valve in the water flowing direction; and the two flowing washing tanks are arranged to be in reverse series-connection, the start end is provided with a water inlet in the water flowing direction, and a water outlet in the final end is connected with the water supplementing opening of the second non-flowing washing tank body. The aluminum pretreatment alkaline three-in-one, alkaline liquor regeneration and aluminum hydroxide online recycling process proposed by the invention has the advantages that zero discharging of waste water is achieved, waste slag is reduced, chemical consumption is low, water is saved, blocking caused by scaling is avoided, and online recycling of alkaline liquor and aluminum hydroxide is achieved.

Description

Technical field [0001] The invention relates to the technical field of aluminum alloy anodic oxidation surface pretreatment technology, in particular to the process of aluminum pretreatment alkaline three-in-one, lye regeneration and aluminum hydroxide online recovery. Background technique [0002] The traditional alkaline etching process of aluminum alloy has been used for more than 100 years. Alkaline etching has disadvantages such as high aluminum consumption, high alkali consumption, excessive alkali slag, difficult process control, many defects, high production cost, and large environmental pollution, and has long been recognized by the industry. Existing standard alkali corrosion oxidation line slot layout image 3 As shown, 4#, 7#, 10#, 13# and 16# tanks are working tanks. Each working tank is equipped with two flowing water washing tanks. The pre-oxidation treatment requires 9 tank positions. The 4# alkali etching tank is Main working tank for surface pretreatment. The f...

AI Technical Summary

Problems solved by technology

There are the following deficiencies: 1. For aluminum materials that have been stored for a long time, the oil removal is not good, the natural oxide film cannot be removed completely, the alkali corrosion is uneven, the surface of the aluminum material appears different luster, and the oxidation coloring is uneven; 2. The oil removal tank contains 150- 200g / L sulfuric acid is easy to bring into the alkali corrosion tank to neutralize caustic soda; in order to strengthen the degreasing ability, some manufacturers add about 5-15g / L ammonium bifluoride in the degreasing tank to completely eliminate the hidden danger of degreasing, but increase the treatment Fluorine and ammonia nitrogen wastewater pressure

[0041] 2. The process is complicated and there are many slots

There are a total of 9 slots in front of the oxidation tank, 3 working tanks, and 6 washing tanks, which are too complicated;

[0042] 3. Low efficacy

It takes a long time, which seriously restricts the production capacity of the oxidation line;

[0043] 4. There are many working slots, and the consumption of chemicals is large

1#, 4#, and 7# are working tanks, and the total chemical consumption is 60-80 kg / ton of material. In order to treat the wastewater containing these chemical agents, the aluminum material factory will spend more cost;

[0044] 5. There are many washing tanks and large water consumption

In addition to water costs, the treatment and discharge of these waste waters require additional environmental protection costs;

[0045] 6. The 1# tank contains fluorine, which hinders the reuse of wastewater;

[0046] 7. Tanks 1# and 7# contain ammonia nitrogen, making wastewater treatment even worse

Adding complexing agent to the alkaline etching tank, the aluminum ions are separated and separated, and the dissolution and carry-out of aluminum can achieve a dynamic balance. In addition to meeting the requirements for the appearance quality of aluminum materials, the bath management is very simple, but a fatal defect is ignored, that is, high Alkaline etching solution with high aluminum ion concentration and high viscosity is brought into 5# and 6# mobile washing tanks, and enters the waste water center to form industrial waste residue, which not only wastes aluminum resources, but also brings huge environmental protection treatment pressure

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