Method for preparing sodium stannate using circuit board tin-stripping wastewater

A technology of tin stripping wastewater and sodium stannate, applied in chemical instruments and methods, tin compounds, water/sewage multi-stage treatment, etc., can solve the problems of low recycling rate of valuable metals, difficult treatment, environmental hazards, etc. Achieve resource utilization, reduce production costs, and achieve significant economic benefits

Active Publication Date: 2009-08-05
江西东江环保技术有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The wastewater produced by this treatment method has a high pollution index and is difficult to treat. Most of it is directly discharged without effective treatment, causing great harm to the environment.
It can be seen that the current method has serious disadvantages. On the one hand, the precipitated alkali slag is used as a raw material for pyrometallurgy, and the recycling rate of valuable metals is low, resulting in serious waste. On the other hand, there is serious secondary pollution.

Method used

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  • Method for preparing sodium stannate using circuit board tin-stripping wastewater
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  • Method for preparing sodium stannate using circuit board tin-stripping wastewater

Examples

Experimental program
Comparison scheme
Effect test

example 1-3

[0050] The tin stripping wastewater from three manufacturers of circuit board factory A, B, and C is the second type of tin stripping wastewater introduced in the technical background of the present invention, and its composition analysis is shown in Table-3.

[0051] Table-3 Main components of tin stripping wastewater

[0052] Composition and content

(g / L) sn

Cu

Pb

Fe

Example 1 (A) 107.00 45.75 40.50 27.55 Example 2 (B) 80.50 30.80 40.20 15.00 Example 3 (C) 120.60 48.60 50.30 35.20

[0053] Add ammonium carbonate to the three kinds of tin stripping wastewater A, B, and C respectively for neutralization and precipitation, the pH value is controlled between 7.0 and 8.5, and the above neutralized waste liquid is subjected to pressure filtration to obtain a filter cake (i.e., tin sludge ); the filtrate enters the wastewater treatment system for further treatment and then discharges up to standard.

[0054] After testing...

example 4

[0063] Originated from the circuit board factory D, belongs to the first kind of tin stripping wastewater introduced in the technical background of the present invention and the third kind of tin stripping wastewater derived from the circuit board factory E and the second one from the circuit board factory A described in Example 1 The tin stripping wastewater is mixed and the water quality is balanced.

[0064] Add 18% industrial ammonia water to this kind of tin stripping wastewater for neutralization and precipitation, the pH value is controlled between 7.5 and 8.5, and the above-mentioned neutralized waste liquid is subjected to pressure filtration to obtain a filter cake (i.e. tin sludge); filtrate After entering the wastewater treatment system for further treatment, it will be discharged up to standard.

[0065] Add sodium hydroxide solution to the filter cake, beat it, roast it at 950°C for 4.5 hours, take the roasted dry material, and carry out two-stage countercurrent ...

example 5

[0071] The applicant of the present invention is an environmental protection enterprise specializing in the treatment and disposal of hazardous waste including circuit board waste. Using the technology provided by the present invention, it has built a production line for treating 5,000 tons of tin stripping wastewater per year.

[0072] The treatment process is as follows: add ammonium bicarbonate to the collected tin stripping wastewater (mainly the second type, and occasionally collect the first or third type and then merge them into the second tin stripping wastewater). and precipitation to obtain tin mud, with an annual output of about 1,500 tons, and the average tin content in the tin mud is 16%.

[0073] Add sodium hydroxide solution to the obtained tin mud, beat it, and roast it at 900°C for 4 hours, take the roasted dry material, and perform three-stage countercurrent leaching on it with water, the ratio of solid to liquid is 1:3, the leaching temperature is 92°C, and t...

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Abstract

The invention relates to a method for preparing sodium stannate by utilizing tin-stripping wastewater of a circuit board. Collected tin-stripping wastewater is neutralized and precipitated by adding alkali to obtain tin sludge with higher tin content; the tin sludge is beat by adding the alkali, and is subjected to high-temperature roasting and countercurrent leaching; then a leachate is subjected to filter pressing; a filtrate is subjected to evaporation, concentration and centrifugal separation after impurity removal; and 10 to 15 percent sodium hydroxide solution is used to wash the obtained product, and thus a crude sodium stannate product can be obtained and then is vacuum dried at a temperature of between 100 and 110 DEG C for 2 to 3.0 hours to obtain a sodium stannate product. The method ensures that the separation rate of tin in the tin-stripping wastewater can reach more than 99 percent, finds a novel treatment way for the tin-stripping wastewater which is produced by printed circuit board industry and is extremely difficult to treat, gives a reasonable fate for all pollutants in the tin-stripping wastewater, and realizes the resource utilization of useful components of the tin-stripping wastewater to the utmost extent when realizing the innoxious treatment of the tin-stripping wastewater.

Description

technical field [0001] The invention relates to a treatment method for circuit board tin stripping wastewater, in particular to a method for preparing sodium stannate by recycling its valuable metal tin. Background technique [0002] In the circuit board processing process, the etching operation of the circuit board is an important part of the circuit board processing, and the circuit needs to be effectively protected before etching. The etching of the circuit board is divided into two processes: acid etching and alkaline etching. The acid etching is protected by ink, and the alkaline etching is protected by a tin layer. After the alkaline etching of the circuit board, the protective tin layer needs to be removed. The general tin stripping solution is nitric acid solution, equipped with ferric nitrate, nitric acid stabilizer and copper corrosion inhibitor. When the amount of tin in the tin stripping solution reaches a certain concentration, the tin stripping ability decrea...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01G19/00C02F9/04
Inventor 刘富强朱兆华王治军胡春林邓华利
Owner 江西东江环保技术有限公司
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