Hierarchically recycling method of waste aluminum etching liquid

An aluminum etching, liquid technology, applied in chemical instruments and methods, separation/purification of carboxylic acid compounds, inorganic chemistry, etc., can solve the problems of ineffective utilization of acetic acid and nitric acid, time-consuming, waste of resources, etc., to reduce decomposition effect of risk

Pending Publication Date: 2019-11-22
湖北兴福电子材料股份有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] At present, the treatment method for waste aluminum etching solution is acid-base method, which consumes a lot of energy, and the phosphoric acid, acetic acid and nitric acid in it have not been effectively used, and the waste of resources is serious.
Extraction method, this treatment method needs to consume a large amount of extractant, and the treat

Method used

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  • Hierarchically recycling method of waste aluminum etching liquid
  • Hierarchically recycling method of waste aluminum etching liquid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] Get a certain TFT-LCD factory waste aluminum etching solution, its chemical composition is as follows:

[0033] chemical composition h 3 PO 4

HNO 3

CH 3 COOH

h 2 o

Al Content (mass fraction) 57～71％ 3～6％ 7～10％ 15～25％ 7000~9000ppm

[0034] According to the following steps, the waste aluminum etching solution is graded and recovered:

[0035] (1) Add 300mL of waste aluminum etching solution into a distillation flask, add a magnetic stirrer, and conduct vacuum distillation with a continuous water replenishment rate of 1mL / min and a distillation temperature of 90°C. Condensate and recover the mixture of nitric acid and acetic acid in the distillate, and keep the solution in the distillation bottle.

[0036] (2) When phosphoric acid is cooled to below 15°C, 5% mass fraction of phosphoric acid seed crystals are added to slowly crystallize, so as to prevent metal ions from being difficult to remove due to too fast crystalliza...

Embodiment 2

[0040] Get a certain TFT-LCD factory waste aluminum etching solution, its chemical composition is as follows:

[0041] chemical composition h 3 PO 4

HNO 3

CH 3 COOH

h 2 o

Al Content (mass fraction) 57～71％ 3～6％ 7～10％ 15～25％ 7000~9000ppm

[0042] According to the following steps, the waste aluminum etching solution is graded and recovered:

[0043] (1) Add 300mL waste aluminum etching solution into a distillation bottle, add a magnetic stirrer, and conduct vacuum distillation with a continuous water replenishment rate of 1.5mL / min and a distillation temperature of 80°C. Condensate and recover the mixture of nitric acid and acetic acid in the distillate, and keep the solution in the distillation bottle.

[0044] (2) When phosphoric acid is cooled to below 15°C, add perfluorosulfonic acid, the amount of perfluorosulfonic acid accounts for 5.6% of the mass fraction of phosphoric acid solution collected, add 3% mass fraction of ph...

Embodiment 3

[0048] Get a certain TFT-LCD factory waste aluminum etching solution, its chemical composition is as follows:

[0049] chemical composition h 3 PO 4

HNO 3

CH 3 COOH

h 2 o

Al Content (mass fraction) 57～71％ 3～6％ 7～10％ 15～25％ 7000~9000ppm

[0050] According to the following steps, the waste aluminum etching solution is graded and recovered:

[0051] (1) Add 300mL of waste aluminum etching solution into a distillation flask, add a magnetic stirrer, and conduct vacuum distillation with a continuous water replenishment rate of 0.5mL / min and a distillation temperature of 100°C. Condensate and recover the mixture of nitric acid and acetic acid in the distillate, and keep the solution in the distillation bottle.

[0052] (2) When phosphoric acid is cooled to below 15°C, add fluosilicic acid, the amount of fluosilicic acid added accounts for 5.6% of the mass fraction of the phosphoric acid solution collected, and 4% mass fraction of p...

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Abstract

The invention discloses a method for hierarchically recycling phosphoric acid, acetic acid and nitric acid from an aluminum scrap etching solution, which comprises the following steps of volatilizingthe acetic acid and nitric acid in the aluminum etching solution by reduced pressure distillation, and recycling by condensation; adding an additive into the residual phosphoric acid solution, crystallizing, washing, dissolving and the like to obtain the high-purity phosphoric acid; adding the sodium acetate into the collected distillate containing the acetic acid and nitric acid, and distilling to collect the acetic acid; and carrying out vacuum concentration, crystallization, filtration and drying on the acetic acid distilled liquid to obtain a sodium nitrate finished product. The reusable high-purity phosphoric acid is obtained by methods of distillation, concentration, recrystallization and the like, the acetic acid is recycled, and the nitric acid is converted into the available sodium nitrate, so that the useful components in the aluminum etching solution are reasonably and effectively utilized, and the resource waste and the environmental pollution are avoided. The method is high in recycling rate and high in operability, can meet the large-scale production, realizes the resource cyclic utilization to the maximum extent, and avoids the direct emission of the aluminum etchingsolution.

Description

technical field [0001] The invention relates to a separation and recycling method of ternary component waste acid etching solution, in particular to a classification recycling method of waste aluminum etching solution. Background technique [0002] With the rapid development of thin film transistor liquid crystal display, my country has grown into the world's largest display production base. The etching process is an indispensable key step in the preparation of liquid crystal displays. The etching solution used is mainly strong acid waste liquid. Under the severe environmental protection situation today, if these waste liquids cannot be treated by effective methods It poses a great challenge to the survival of enterprises. Therefore, it is imperative to effectively recycle these resources. [0003] The waste aluminum etchant is the waste liquid produced by wet etching of TFT-LCD to make aluminum wires, and mainly contains phosphoric acid, nitric acid, acetic acid and a sma...

Claims

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Application Information

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IPC IPC(8): C01D9/04C01B25/234C07C51/02C07C51/44C07C51/46C07C53/08
CPCC01B25/234C01D9/04C07C51/02C07C51/44C07C51/46C07C53/08
Inventor 李少平王书萍杨着贺兆波张庭蔡步林张演哲冯凯尹印万杨阳
Owner 湖北兴福电子材料股份有限公司
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