Method for recycling of obsolete printed circuit boards
US-2016095230-A1 · Mar 31, 2016 · US
Simplified method of gold recovery from electronic waste
US2022235433A1 · US · A1
| Field | Value |
|---|---|
| Publication number | US-2022235433-A1 |
| Application number | US-202217583385-A |
| Country | US |
| Kind code | A1 |
| Filing date | Jan 25, 2022 |
| Priority date | Jan 25, 2021 |
| Publication date | Jul 28, 2022 |
| Grant date | — |
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- Title
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Abstract
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The present invention related to generally to a process to recover metals from waste electronics, and more particularly a process to recover gold from waste electronics. The gold is first delaminated in a first step using a solution containing a weak acid in combination with an oxidizer. The second step isolates and purifies the delaminated gold from the chip debris using solvents, water and a wetting agent/surfactant. The proposed two step method of gold recovery from electronic waste is effective without the need for strong or costly chemicals or leaching.
First claim
Opening claim text (preview).
What is claimed is: 1 . A method of gold recovery from electronic waste, the method comprising the steps of: (i) Contacting electronic waste containing printed circuit boards having gold electroplated on top of copper electrical contacts with a solution containing a weak acid in combination with an oxidizer, wherein the gold electroplated on top of copper electrical contacts becomes delaminated from the electrical contacts to form gold leaf and wherein the solution then contains a mixture of the delaminated gold leaf and chip debris; and (ii) Isolating the delaminated gold leaf from the chip debris mixed in the solution by: a. First adding a solvent and water to the solution containing the delaminated gold leaf mixed with chip debris; and b. Second adding a surfactant to the solution containing the delaminated gold leaf mixed with the chip debris, solvent and water, wherein the delaminated gold leaf floats upward in the solution and purified gold is obtained. 2 . The method of gold recovery from electronic waste from claim 1 , wherein the weak acid is acetic acid. 3 . The method of gold recovery from electronic waste from claim 1 , wherein the oxidizer is hydrogen peroxide. 4 . The method of gold recovery from electronic waste from claim 1 , wherein the solvent is a hexane, a heptane or an octane. 5 . The method of gold recovery from electronic waste from claim 1 , wherein the surfactant is polyether siloxane copolymer.
Assignees
Inventors
Classifications
- C22B11/046Primary
from manufactured products, e.g. from printed circuit boards, from photographic films, paper or baths · CPC title
by acid leaching · CPC title
Recycling · CPC title
Recovery of noble metals from waste materials · CPC title
- C22B7/006Primary
Wet processes · CPC title
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- What does patent US2022235433A1 cover?
- The present invention related to generally to a process to recover metals from waste electronics, and more particularly a process to recover gold from waste electronics. The gold is first delaminated in a first step using a solution containing a weak acid in combination with an oxidizer. The second step isolates and purifies the delaminated gold from the chip debris using solvents, water and a …
- Who is the assignee on this patent?
- Lexmark Int Inc
- What technology area does this patent fall under?
- Primary CPC classification C22B11/046. Mapped technology areas include Chemistry & Metallurgy.
- When was this patent published?
- Publication date Thu Jul 28 2022 00:00:00 GMT+0000 (Coordinated Universal Time) (A1). Legal status and post-grant events are not shown on this page.
- What related patents are in patentsdb?
- We list 1 related publication on this page (citations in our corpus or others sharing the same primary CPC).