A kind of treatment method of alkaline etching waste liquid

Abstract

The invention discloses a treatment method for alkaline etching waste liquid, (1) adding excess calcium oxide to the alkaline etching waste liquid, and introducing it into an ammonia distillation tower, and separating the solid and liquid to obtain a blue-white precipitation mixture; (2) ammonia gas Absorbed by the absorption tower to prepare a 20%-40% ammonia solution; (3) add sulfuric acid to the blue-white precipitate mixture until the blue precipitate is dissolved, and separate the solid and liquid to obtain the Bordeaux mixture stock solution; the present invention introduces calcium oxide as an alkali source to produce Bordeaux liquid, and no new pollutants are introduced, avoiding a large amount of salinization of fresh water, resulting in waste of fresh water resources, and high recovery value.

Description

technical field

[0001] The invention relates to the technical field of etching liquid waste treatment, in particular to a treatment method for alkaline etching waste liquid. Background technique

[0002] Etching waste liquid is an important pollutant produced by the printed circuit board industry. Etching waste liquid contains a large amount of copper. If it is not handled properly, it will not only pollute the environment, but also cause a serious waste of resources. Common etching liquids are mainly alkaline There are several kinds of etching solution, acid etching solution, and traditional ferric chloride etching solution. The corresponding etching waste liquid mainly includes acid etching waste liquid, alkaline etching waste liquid, ferric chloride etching waste liquid, alkaline etching The main component is a solution containing copper ammonium ions, and the main components include copper chloride, ammonia water, ammonium chloride, etc. When etching circuit boards, alk...

Examples

Embodiment 1

[0022] The water quality of an alkaline etching waste liquid is: nitrogen ammonia concentration 40000 mg / L, copper ion concentration 50000 mg / L, pH value 8.3, and a total volume of 100L. The specific process is as follows:

[0023] 1) Add excessive CaO solids to the raw material waste until the pH value is 12.0, so that the ammonium ions in the wastewater are converted into ammonia molecules, including ammonia gas and ammonia molecules dissolved in the waste liquid. In order to fully precipitate, the waste liquid is introduced into the ammonia distillation tower to Ammonia evaporates, and there are excess hydroxide ions, generating Cu(OH) 2 Precipitation, excess CaO converted to white precipitate Ca(OH) 2 , with Cu(OH) 2 Blending into a blue-white precipitate, and the remaining waste liquid contains calcium chloride;

[0024] 2) The overflowing ammonia gas is absorbed by the absorption tower and converted into a 30% ammonia solution. The ammonia gas absorption tower mainly u...

Embodiment 2

[0029] The water quality of an alkaline etching waste liquid is: nitrogen ammonia concentration 50000 mg / L, copper ion concentration 60000 mg / L, pH value 8.0, and a total volume of 200L. The specific process is as follows:

[0030] 1) Add excessive CaO solids to the raw material waste until the pH value is 12.0, so that the ammonium ions in the wastewater are converted into ammonia molecules, including ammonia gas and ammonia molecules dissolved in the waste liquid. In order to fully precipitate, the waste liquid is introduced into the ammonia distillation tower to Ammonia evaporates, and there are excess hydroxide ions, generating Cu(OH) 2 Precipitation, excess CaO converted to white precipitate Ca(OH) 2 , with Cu(OH) 2 Blending into a blue-white precipitate, and the remaining waste liquid contains calcium chloride;

[0031] 2) The overflowing ammonia gas is absorbed by the absorption tower and converted into a 30% ammonia solution. The ammonia gas absorption tower mainly u...

technical field

[0001] The invention relates to the technical field of etching liquid waste treatment, in particular to a treatment method for alkaline etching waste liquid. Background technique

[0002] Etching waste liquid is an important pollutant produced by the printed circuit board industry. Etching waste liquid contains a large amount of copper. If it is not handled properly, it will not only pollute the environment, but also cause a serious waste of resources. Common etching liquids are mainly alkaline There are several kinds of etching solution, acid etching solution, and traditional ferric chloride etching solution. The corresponding etching waste liquid mainly includes acid etching waste liquid, alkaline etching waste liquid, ferric chloride etching waste liquid, alkaline etching The main component is a solution containing copper ammonium ions, and the main components include copper chloride, ammonia water, ammonium chloride, etc. When etching circuit boards, alk...

Examples

Embodiment 1

[0022] The water quality of an alkaline etching waste liquid is: nitrogen ammonia concentration 40000 mg / L, copper ion concentration 50000 mg / L, pH value 8.3, and a total volume of 100L. The specific process is as follows:

[0023] 1) Add excessive CaO solids to the raw material waste until the pH value is 12.0, so that the ammonium ions in the wastewater are converted into ammonia molecules, including ammonia gas and ammonia molecules dissolved in the waste liquid. In order to fully precipitate, the waste liquid is introduced into the ammonia distillation tower to Ammonia evaporates, and there are excess hydroxide ions, generating Cu(OH) 2 Precipitation, excess CaO converted to white precipitate Ca(OH) 2 , with Cu(OH) 2 Blending into a blue-white precipitate, and the remaining waste liquid contains calcium chloride;

[0024] 2) The overflowing ammonia gas is absorbed by the absorption tower and converted into a 30% ammonia solution. The ammonia gas absorption tower mainly u...

Embodiment 2

[0029] The water quality of an alkaline etching waste liquid is: nitrogen ammonia concentration 50000 mg / L, copper ion concentration 60000 mg / L, pH value 8.0, and a total volume of 200L. The specific process is as follows:

[0030] 1) Add excessive CaO solids to the raw material waste until the pH value is 12.0, so that the ammonium ions in the wastewater are converted into ammonia molecules, including ammonia gas and ammonia molecules dissolved in the waste liquid. In order to fully precipitate, the waste liquid is introduced into the ammonia distillation tower to Ammonia evaporates, and there are excess hydroxide ions, generating Cu(OH) 2 Precipitation, excess CaO converted to white precipitate Ca(OH) 2 , with Cu(OH) 2 Blending into a blue-white precipitate, and the remaining waste liquid contains calcium chloride;

[0031] 2) The overflowing ammonia gas is absorbed by the absorption tower and converted into a 30% ammonia solution. The ammonia gas absorption tower mainly u...

Images