Resourceful treatment and cyclic utilization method of PCB circuit board waste etching liquid

A technology for PCB circuit board and etching waste liquid, which is applied in the field of resource treatment and recycling of PCB circuit board etching waste liquid, can solve the problems that the ammonia nitrogen content is not easy to reach the standard, the operation steps are cumbersome, the steam consumption is large, etc. The effect of energy consumption, simple process and high purity

Active Publication Date: 2014-02-26
INST OF PROCESS ENG CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The main disadvantage of this process is that the steam consumption is large, the product is ammonia water and cannot be directly reused in the etching process, the operation steps are cumbersome,

Method used

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  • Resourceful treatment and cyclic utilization method of PCB circuit board waste etching liquid

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0043] The water quality of a circuit board etching waste liquid is: ammonia nitrogen concentration 50000mg / L, copper ion concentration 50000mg / L, pH value 9.4. During treatment, adjust the pH of the raw wastewater to 11.5 with 45% sodium hydroxide and then transport it to a reaction deamination tower with 6 theoretical plates. The temperature at the bottom of the tower is 70°C, the temperature at the top of the tower is 70°C, and the gauge pressure is -0.9 Deamination treatment is carried out under 1 atmospheric pressure. The ammonia content (volume percentage of ammonia) in the separated ammonia vapor is 70%. After the ammonia vapor enters the ammonia absorption tower, it is absorbed by concentrated hydrochloric acid into ammonium chloride solution. The reaction of the absorption process The temperature is 150°C, 85% of the generated ammonium chloride is refluxed, and the remaining 15% is collected as a product. After deamination, the high-temperature deamination water is ex...

Embodiment 2

[0045] The water quality of a circuit board etching waste liquid is: ammonia nitrogen concentration 100000mg / L, copper ion concentration 110000mg / L, pH value 9.6. During treatment, adjust the pH of the raw wastewater to 11.5 with 45% sodium hydroxide, and then transport it to a reaction deamination tower with 6 theoretical plates. The temperature at the bottom of the tower is 90°C, the temperature at the top of the tower is 90°C, and the gauge pressure is 0.1 Deamination treatment is carried out under atmospheric pressure. The ammonia content (volume percentage of ammonia) in the separated ammonia vapor is 70%. After entering the ammonia absorption tower, the ammonia vapor is absorbed by concentrated hydrochloric acid into ammonium chloride solution. The reaction temperature of the absorption process is At 175°C, 85% of the generated ammonium chloride was refluxed, and the remaining 15% was collected as a product. After deamination, the high-temperature deamination water is ex...

Embodiment 3

[0047] The water quality of a circuit board etching waste liquid is: ammonia nitrogen concentration 150000mg / L, copper ion concentration 130000mg / L, pH value 9.7. During treatment, adjust the pH of the raw wastewater to 12 with 45% sodium hydroxide and transport it to a reaction deamination tower with 16 theoretical plates. The temperature at the bottom of the tower is 110°C, the temperature at the top of the tower is 100°C, and the gauge pressure is 7 Deamination treatment is carried out under atmospheric pressure. The ammonia content (volume percentage of ammonia) in the separated ammonia vapor is 50%. After the ammonia vapor enters the ammonia absorption tower, it is absorbed by concentrated hydrochloric acid into ammonium chloride solution. The reaction temperature of the absorption process is At 190°C, 75% of the generated ammonium chloride was refluxed, and the remaining 25% was collected as a product. After deamination, the high-temperature deamination water is exchange...

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Abstract

The invention relates to a resourceful treatment and cyclic utilization method of PCB circuit board waste etching liquid. The resourceful treatment and cyclic utilization method comprises following steps: an alkali source is added into the waste etching liquid so as to promote decomposition of cuprammouium complex ions in the waste etching liquid, and transfer free ammonium ions into molecular state ammonia; waste water generated by the hybrid reaction is delivered into a deamination reaction tower, further decomposition of cuprammouium complex ions is realized in the deamination reaction tower, and free ammonia molecules in the waste water is exhausted via the top of the deamination reaction tower in gaseous state, is delivered into an ammonia absorption tower, is absorbed by concentrated hydrochloric acid, and is transferred into ammonium chloride solution so as to realize ammonium/ammonia resource recovery; and copper ions in the waste water is transferred into copper compounds to precipitate and realize recovery. According to the resourceful treatment and cyclic utilization method of PCB circuit board waste etching liquid, ammonia-nitrogen removal rate and ammonia recovery rate are both above 99.9%; copper recovery rate is more than 95%; coupling of ammonia recovery process and ammonium chloride synthetic process is realized; recoveries of ammonia/ammonium and copper are realized respectively; the ammonium chloride solution prepared by recycling can be recycled as a new etching solution after supplement of additives and deionized water; and all-component resourceful utilization of circuit board etching ammonia-nitrogen wastewater is realized.

Description

technical field [0001] The invention relates to a method for treating ammonia- and copper-containing etching waste liquid generated during circuit board processing, in particular to a method for separating the circuit board etching waste liquid from ammonia and then absorbing it with concentrated hydrochloric acid to generate ammonium chloride. Background technique [0002] With the rapid development of the modern electronic information industry, the printed circuit board (PCB) industry has developed extremely rapidly. At present, China has become the world's number one manufacturer of printed circuit boards. Among them, the etching process is the most important part of the PCB production process. When the copper ion in the etching solution reaches a certain concentration, it is discharged as waste liquid. There are two types of etching solutions, alkaline and acidic. There is a large amount of copper in the alkaline etching waste liquid, which is mainly based on [Cu(NH 3...

Claims

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Application Information

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IPC IPC(8): C23F1/46
Inventor 林晓高明曹宏斌
Owner INST OF PROCESS ENG CHINESE ACAD OF SCI
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