Recovery of tin from waste liquid of tin and lead

A waste liquid and tin-lead technology, applied in the field of tin recycling, can solve the problems of waste of limited resources, secondary environmental pollution, heavy metal transfer, etc., achieve significant economic benefits, and solve the effect of secondary pollution of heavy metals

Inactive Publication Date: 2004-09-22
GAOQI INDAL HUNAN PROV
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  • Abstract
  • Description
  • Claims
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Problems solved by technology

Such a treatment method will cause the transfer of heavy metals, cause secondary e

Method used

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  • Recovery of tin from waste liquid of tin and lead
  • Recovery of tin from waste liquid of tin and lead
  • Recovery of tin from waste liquid of tin and lead

Examples

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Example Embodiment

[0044] An implementation process step of the present invention is:

[0045] (1) Distill under reduced pressure on the printed circuit board tin stripping waste liquid to two-thirds of the volume of the original liquid, temperature 75℃, pressure 0.5×1.03×10 5 Pa;

[0046] (2) Add NaOH to the waste liquid after distillation for neutralization, and control the pH value of the neutralization solution to 6-8;

[0047] (3) Filter the aforementioned neutralized waste liquid in a conventional manner to obtain a filter cake;

[0048] (4) Add NaOH to the resulting filter cake and heat it to 120°C for alkali dissolution until it is completely dissolved;

[0049] (5) Hot-dip the alkali solution for 4 hours, temperature 95°C, alkali (NaOH) concentration 200g / L, and the liquid-solid ratio of water to filter cake by weight is 6;

[0050] (6) The hot immersion liquid is routinely filtered, and the corresponding amount of Na is added to the filtrate 2 S in addition to impurities;

[0051] (7) Afte...

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Abstract

A process for recovering the tin from the waste solution of tin or tin-lead generated by detinning PCB or preparing PCB includes such steps as distilling, adding KOH, NaOH, Na2CO3 or K2SO4 to regulate pH-6-10, filtering to obtain cake, adding to alkali solution, heating to 100-300 deg.C until it is fully dissolved, thermal immersing at 70-100 deg.C for 2-5 hr, cooling and centrifugal separating.

Description

technical field [0001] The invention relates to a technical method for recovering tin from the waste liquid produced in the process of stripping tin or tin-lead in the production process of printed circuit boards. Background technique [0002] In the manufacturing process of printed circuit boards, tin-lead or tin (Sn / Pb, Sn) plating should be plated on the thickened copper-plated patterns (lines, holes and pads, etc.) after pattern plating to protect the patterns. Not damaged by corrosion during etching. When the pattern etching is completed, the coating (Sn / Pb, Sn) of the protective pattern needs to be removed; the function of stripping tin lead or tin (Sn / Pb, Sn) liquid is to remove the Sn / Pb, Sn coating of the protective pattern. During this process, a large amount of waste tin-lead or tin (Sn / Pb, Sn) liquid will be produced. The main components of waste liquid: [0003] HNO 3 : 200±20g / L, Fe: 25~40g / L, [0004] Sn: 60~80g / L, Cu: 5~10g / L, [0005] Pb: 35~48g / L, ...

Claims

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Application Information

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IPC IPC(8): C23F1/46
Inventor 汤明坤谭丽霞罗新辉
Owner GAOQI INDAL HUNAN PROV
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