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Method for recovering simple substance tin by nitric acid type tin-stripping waste liquid

A technology of waste liquid recovery and elemental tin, applied in the direction of improving process efficiency, can solve the problems of high energy consumption, large consumption of alkali and other materials, low resource utilization rate, etc., and achieve low energy consumption, easy operation, and process conditions. Not harsh effect

Inactive Publication Date: 2014-07-09
GUANGDONG UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, its disadvantages are also obvious: the consumption of alkali and other materials is large, it is difficult to discharge waste water up to the standard, the separation and treatment of the filter residue obtained by neutralization is heavy, the cost is high, and the resource utilization rate is low.
2. Recycling and recycling of resources by distillation is based on the reuse of resources. Typical examples include Tang Mingkun and others who recover tin from PCB tin stripping or tin-lead waste liquid. First, the waste liquid is recovered by vacuum distillation to recover nitric acid. For the reproduction of the tin stripping roll, the concentrated solution is neutralized with alkali until the pH value is 6-10, so that tin and iron are precipitated, and the obtained precipitate is added with alkali and heated to 100°C-300°C until it is completely dissolved and then hot-dipped; then Cool and centrifuge to convert tin into tin chemical products, and iron into iron red or ferric nitrate. Among them, ferric nitrate is an important raw material for the production of tin stripping liquid, which is directly used for the production of tin stripping liquid, but its disadvantage is that it needs The alkaline substance is relatively large, the energy consumption is relatively large, and the process is relatively complicated
3, produce the product of tin, typically have its patent such as Liao Weifeng to describe and utilize the tin in the tin stripping waste liquid to prepare barium stannate product, but its shortcoming is that this method also contains a large amount of acid and Other metals have not been utilized as resources, and a large amount of waste liquid and sludge are produced in the process of preparing barium stannate trihydrate. How to deal with these waste liquids and sludge is also a problem that needs to be solved

Method used

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  • Method for recovering simple substance tin by nitric acid type tin-stripping waste liquid

Examples

Experimental program
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Effect test

example 1

[0017] Take the tin stripping waste liquid of No. 1 multi-panel production line of a certain circuit board manufacturing plant. Take 50 ml (about 67 grams) from it, add 50 ml of polyacrylamide with a mass concentration of 0.1%, stir manually, stop stirring and let it stand for 30 minutes, recover the wet mud after filtration, and the filtrate can be returned to the production line for use;

[0018] Put the recovered wet mud into a three-necked bottle, add 20 grams of hydrochloric acid into the three-necked bottle, control the reaction constant temperature at 60°C, and react to form tin chloride or stannous chloride. The reaction time is 120 minutes, and the stirring rate is 100 rpm After the reaction, room temperature was cooled, and the solution obtained at this time was referred to as A solution.

[0019] Preparation of reducing solution B, B solution contains 0.67 grams of sodium borohydride, 3.35 grams of sodium hydroxide, mixed and stirred until all solid substances are d...

example 2

[0022] Take the tin stripping waste liquid of No. 1 multi-panel production line of a certain circuit board manufacturing plant. Take 50 ml (about 67 grams) from it, add 50 ml of methacrylic acid with a mass concentration of 2%, stir manually, stop stirring and let it stand for 60 minutes, recover the wet mud after filtration, and the filtrate can be returned to the production line for use;

[0023] Put the recovered wet mud into a three-necked bottle, add 20 grams of hydrochloric acid into the three-necked bottle, control the reaction constant temperature at 85°C, the reaction time is 80 minutes, and the stirring rate is 200 rpm. After the reaction, cool the room temperature and obtain solution as A solution.

[0024] Prepare reducing solution B, B solution contains 1.5 grams of hydrazine hydrate, 3.35 grams of sodium ethoxide, mix and stir until the solid matter is completely dissolved.

[0025] Add solution B dropwise to solution A after cooling, the rate of addition is 15 ...

example 3

[0027] Take the tin stripping waste liquid of No. 2 multi-panel production line of a circuit board manufacturing plant. Take 100 ml (about 134 grams) from it, add 150 ml of polyaluminum sulfate solution with a mass concentration of 2%, stir manually, stop stirring and let it stand for 30 minutes, recover the wet mud after filtration, and the filtrate can be returned to the production line for use ;

[0028] Put the recovered wet mud into a three-necked bottle, add 67 grams of hydrochloric acid into the three-necked bottle, control the reaction constant temperature at 90°C, the reaction time is 120 minutes, and the stirring rate is 500 rpm. After the reaction, cool the room temperature and obtain solution as A solution.

[0029] Preparation of reducing solution B, B solution contains 5 grams of hydrazine hydrate, 6.7 grams of potassium hydroxide, mixed and stirred until the solid matter is completely dissolved.

[0030] Add solution B dropwise to solution A after cooling, the...

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Abstract

The invention discloses a method for recovering a simple substance tin by nitric acid type tin-stripping waste liquid, the method is characterized in that tin-stripping waste water which is difficult to process is used for recovering metallic tin by a novel process with simplicity and environmental protection. The method comprises the following steps: alpha type stannic acid or beta type stannic acid in the nitric acid type tin-stripping waste liquid is flocculated by a flocculating agent, then reacted with concentrated hydrochloric acid under certain temperature for conversing to stannic chloride, a reducing agent is used for reducing to the simple substance tin. The method of the invention has the characteristic that problem for processing the tin-stripping waste liquid of a printed circuit board factory can be overcome and solved, and the simple substance tin with better economic benefit can be prepared, and the purposes of eliminating pollution, reducing energy consumption, minimizing discharge of waste water and recycling the resource can be realized.

Description

technical field [0001] The invention relates to a method for extracting useful substances from waste liquid discharged from factories, in particular to recovering elemental tin from waste liquid of nitric acid type tin stripping in printed circuit boards. Background technique [0002] In the double-sided or multi-layer board manufacturing process, stripping tin is an essential process. With the continuous progress of tin stripping, the concentration of tin in the system will inevitably continue to rise. When the concentration of tin reaches a certain concentration, if no treatment is performed, the effect of tin stripping will be affected. However, for the vast majority of companies, they are discharged or sold to wastewater treatment companies after simple treatment, which wastes a lot of precious resources and reduces economic benefits for the company itself. The main components of nitric acid type tin stripping waste liquid are stannic acid, nitric acid, iron nitrate and...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22B25/06
CPCY02P10/20
Inventor 肖应东张俊峰陈世荣罗小虎高品华
Owner GUANGDONG UNIV OF TECH