Recovering gold from circuit boards with out resorting to harsh chemical compounds is an environmentally acutely aware and cost-effective strategy. In contrast to typical strategies that make use of poisonous solvents and acids, this modern method affords a safer and extra sustainable different, minimizing environmental influence whereas maximizing gold yield.
The method begins with bodily extracting the gold-plated parts from the circuit boards. These parts sometimes embrace connectors, capacitors, and transistors. As soon as eliminated, they’re meticulously sorted and grouped based mostly on their gold content material. Subsequently, a specialised machine, generally known as a gold restoration mill, is employed to mechanically abrade the gold plating from the parts. This light course of successfully separates the gold from the bottom metallic, leading to a positive gold powder.
The gold powder obtained from the milling course of is additional refined to take away any impurities. This includes treating the powder with a gentle acid resolution, which dissolves the impurities whereas leaving the gold intact. The ensuing gold resolution is then subjected to electrolysis, the place an electrical present is utilized to extract pure gold from the answer. The top result’s a extremely concentrated and pure gold product, prepared to be used in numerous purposes.
Collect Obligatory Instruments
To efficiently take away gold from circuit boards with out utilizing harsh chemical compounds, it’s essential to have the suitable instruments at hand. These instruments will allow you to extract the dear metallic with out damaging the board or releasing dangerous fumes.
Important Instruments:
| Software | Objective |
|---|---|
| High-quality-tip tweezers | Deal with and manipulate small gold parts |
| Precision screwdriver set | Take away screws and fasteners holding circuit boards in place |
| Magnifying glass or jeweler’s loupe | Examine circuit boards for gold parts and establish positive particulars |
| Warmth gun | Gently warmth gold parts to loosen their bonds with out damaging the board |
| High-quality-grit sandpaper (e.g., 400-grit) | Sand off gold parts or uncovered gold plating |
| Comfortable fabric or brush | Take away any particles or mud from the circuit board after gold extraction |
| Container for collected gold | Retailer the extracted gold for future refining or storage |
Along with these instruments, it’s advisable to put on security glasses and gloves to guard your self from any potential hazards whereas dealing with circuit boards.
Determine Gold-Bearing Elements
### Gold-Plated Connectors
Gold plating is often used on connectors to enhance electrical conductivity and forestall corrosion. Gold-plated connectors may be simply recognized by their distinctive yellow coloration.
### Gold-Stuffed Contacts
Gold-filled contacts are a mixture of gold and one other metallic, resembling copper or silver. They’re sometimes present in switches and relays. Gold-filled contacts have a decrease gold content material than gold-plated connectors, however they’re nonetheless worthwhile to scrap.
### Gold-Plated Traces
Gold-plated traces are discovered on printed circuit boards (PCBs). They’re the conductive strains that join the varied parts on the board. Gold-plated traces may be recognized by their shiny, metallic look.
### Different Gold-Bearing Elements
Along with the parts listed above, gold will also be present in:
| Element | Description |
|—|—|
| Gold-plated capacitors | Capacitors with a gold-plated coating on their terminals |
| Gold-plated inductors | Inductors with a gold-plated coating on their terminals |
| Gold-plated resistors | Resistors with a gold-plated coating on their terminals |
| Gold-plated shields | Shields which might be coated with gold to stop electromagnetic interference |
Use Mechanical Extraction Strategies
Mechanical extraction strategies for eradicating gold from circuit boards are bodily methods that don’t contain using chemical compounds. These strategies are usually protected, environmentally pleasant, and may be carried out with primary tools.
Hand Extraction
Hand extraction includes manually eradicating the gold-plated parts from the circuit board utilizing instruments resembling tweezers, pliers, and a magnifying glass. This methodology is appropriate for small-scale operations and permits for exact collection of the parts to be eliminated. Nonetheless, it may be time-consuming and will not be possible for large-scale operations.
Thermal Extraction
Thermal extraction makes use of warmth to separate the gold-plated parts from the circuit board. The board is heated to a temperature the place the solder holding the parts melts, permitting them to be simply eliminated. This methodology is extra environment friendly than hand extraction and may be utilized to bigger boards. Nonetheless, it requires specialised tools, resembling a reflow oven or sizzling air gun, and may harm the board if not fastidiously managed.
Mechanical Extraction
Mechanical extraction employs automated equipment to bodily take away the gold-plated parts from the circuit board. This methodology makes use of a mixture of chopping, grinding, and sorting mechanisms to extract the gold. It’s extremely environment friendly and may deal with giant volumes of boards. Nonetheless, mechanical extraction requires specialised tools, may be costly to implement, and should end in some gold loss throughout processing.
| Methodology | Benefits | Disadvantages |
|—|—|—|
| Hand Extraction | Exact, no chemical compounds | Time-consuming, small-scale |
| Thermal Extraction | Environment friendly, bigger boards | Requires specialised tools, potential board harm |
| Mechanical Extraction | Extremely environment friendly, large-scale | Costly, potential gold loss |
Apply Abrasive Strategies
Abrasive methods contain utilizing supplies or instruments with tough surfaces to scrape or grind away gold from circuit boards. These methods are usually extra labor-intensive than chemical leaching, however they are often efficient for eradicating gold from delicate or fragile parts.
There are a number of completely different abrasive methods that can be utilized:
Sanding
Sanding is a standard abrasive method that includes utilizing sandpaper or different abrasive supplies to rub away gold from the floor of a circuit board. This methodology is comparatively easy and cheap, however it may be time-consuming and should harm the circuit board if not executed fastidiously.
Wire Brushing
Wire brushing is one other abrasive method that includes utilizing a wire brush to wash away gold from the floor of a circuit board. This methodology is extra aggressive than sanding and can be utilized to take away thicker layers of gold. Nonetheless, it is usually extra prone to harm the circuit board, so it must be used with warning.
Blasting
Blasting is an abrasive method that includes utilizing a high-pressure stream of abrasive particles to blast away gold from the floor of a circuit board. This methodology could be very efficient at eradicating gold from giant areas, nevertheless it will also be very damaging to the circuit board. Subsequently, it’s only advisable to be used on very sturdy parts.
The desk under summarizes the completely different abrasive methods for eradicating gold from circuit boards:
| Abrasive Method | Professionals | Cons |
|---|---|---|
| Sanding | Easy and cheap | Time-consuming and should harm circuit board |
| Wire Brushing | Extra aggressive than sanding | Extra prone to harm circuit board |
| Blasting | Very efficient at eradicating gold from giant areas | Very damaging to circuit board |
Make the most of Warmth Dissipation
Warmth dissipation is an important method in eradicating gold from circuit boards with out using chemical compounds. Warmth causes the gold to soften and separate from the board, making it simpler to gather.
Supplies Required:
- Warmth gun
- Tweezers
- Warmth-resistant gloves
- Glass or metallic container
Process:
- Put on heat-resistant gloves to guard your arms.
- Place the circuit board in a glass or metallic container to guard it from flying sparks.
- Set the warmth gun to a low temperature (round 300-350°C) and direct it on the gold-bearing areas of the board.
- Warmth the board till the gold begins to soften and stream. Use tweezers to information and accumulate the molten gold.
- Proceed heating and accumulating the gold till all the specified areas have been processed.
Security Precautions:
When working with warmth, it is important to train warning to stop burns or accidents. Guarantee enough air flow within the work space to attenuate the chance of inhalation of fumes.
The desk under summarizes the steps concerned in warmth dissipation:
| Step | Motion |
|---|---|
| 1 | Put on heat-resistant gloves. |
| 2 | Place the circuit board in a heat-resistant container. |
| 3 | Warmth the gold-bearing areas with a warmth gun. |
| 4 | Accumulate the molten gold with tweezers. |
| 5 | Proceed heating and accumulating till all gold is eliminated. |
Make use of Ultrasonic Cleansing
Ultrasonic cleansing is a extremely efficient method for eradicating gold from circuit boards with out utilizing chemical compounds. This methodology includes submerging the circuit board in a cleansing resolution whereas producing high-frequency ultrasonic waves. The ultrasonic waves create tiny cavitation bubbles, which collapse on the floor of the circuit board, dislodging the gold particles.
Here’s a detailed rationalization of the ultrasonic cleansing course of:
- Put together the cleansing resolution: The cleansing resolution sometimes consists of water and a surfactant (wetting agent). The surfactant helps cut back the floor pressure of the liquid, permitting it to penetrate the small crevices on the circuit board.
- Submerge the circuit board: Place the circuit board in an ultrasonic cleaner and submerge it fully within the cleansing resolution.
- Set the ultrasonic parameters: Regulate the frequency and energy of the ultrasonic waves in accordance with the dimensions and complexity of the circuit board. Larger frequencies and energy ranges will end in extra aggressive cleansing.
- Cleansing time: The cleansing time can fluctuate relying on the quantity of gold current and the specified stage of cleanliness. Sometimes, a cleansing time of 30-60 minutes is adequate.
- Put up-cleaning: After ultrasonic cleansing, rinse the circuit board completely with clear water to take away any remaining cleansing resolution.
- Drying: Dry the circuit board fully by inserting it in a drying oven or utilizing compressed air.
Here’s a desk summarizing the advantages of ultrasonic cleansing for gold removing:
| Advantages |
|---|
| No chemical compounds required |
| Exact and managed course of |
| Efficient for complicated geometries |
| Environmentally pleasant |
| Price-effective |
Laser Ablation
Laser ablation is a method that makes use of a targeted laser beam to vaporize and take away gold from circuit boards. This course of is carried out in a managed setting, guaranteeing minimal harm to the board. The laser beam is exactly directed onto the gold areas, and the vaporized gold is collected for restoration.
The laser ablation methodology affords a number of benefits over chemical removing. It’s a non-contact course of, eliminating the necessity for harsh chemical compounds and the chance of board harm. Furthermore, laser ablation permits for exact removing of gold, concentrating on particular areas with out affecting different parts on the board.
The desk under summarizes the benefits and downsides of laser ablation for gold removing from circuit boards:
| Benefits | Disadvantages |
|---|---|
| Non-contact, no harm to board | Requires specialised tools |
| Exact removing of gold | Is probably not appropriate for large-scale operations |
| No chemical waste | Will be time-consuming |
For enterprises searching for a precision and environmentally pleasant gold removing method, laser ablation proves to be a viable resolution. Nonetheless, it is important to think about the constraints concerning tools availability and potential time constraints for large-scale purposes.
Bioleaching
Bioleaching is a course of that makes use of microorganisms to extract metals from ores or different supplies. This course of can be utilized to take away gold from circuit boards with out using chemical compounds.
The microorganisms utilized in bioleaching produce acids that dissolve the gold on the circuit board. The gold is then launched into resolution and may be recovered utilizing quite a lot of strategies.
Bioleaching is a comparatively gradual course of, however it’s environmentally pleasant and doesn’t require using harsh chemical compounds.
Microorganisms Utilized in Bioleaching
The microorganisms utilized in bioleaching are sometimes micro organism or fungi.
A few of the commonest micro organism utilized in bioleaching embrace:
| Micro organism | Description |
|---|---|
| Acidithiobacillus ferrooxidans | A bacterium that oxidizes iron and sulfur compounds |
| Acidithiobacillus thiooxidans | A bacterium that oxidizes sulfur compounds |
| Leptospirillum ferriphilum | A bacterium that oxidizes iron compounds |
A few of the commonest fungi utilized in bioleaching embrace:
| Fungus | Description |
|---|---|
| Aspergillus niger | A fungus that produces natural acids |
| Penicillium chrysogenum | A fungus that produces penicillin and different natural acids |
| Trichoderma reesei | A fungus that produces cellulase and different enzymes |
Mercury Amalgamation
Mercury amalgamation is a standard methodology of extracting gold from circuit boards that includes utilizing elemental mercury to dissolve the gold. This course of was traditionally prevalent, however its use has declined resulting from issues about environmental air pollution and well being dangers related to dealing with mercury.
Course of
This is an in depth rationalization of the mercury amalgamation course of:
- Crushing and Grinding: Circuit boards are damaged down into smaller items utilizing a crusher or grinder.
- Roasting: The bottom materials is heated in a furnace to vaporize natural matter and take away impurities.
- Mixing with Mercury: The roasted powder is combined with elemental mercury in a pitcher or ball mill. The mercury selectively types an amalgam with the gold particles.
- Filtration: The amalgam is separated from the remaining materials by filtration.
- Retorting: The amalgam is heated in a retort to vaporize the mercury, abandoning the gold.
- Condensing: The vaporized mercury is condensed and recovered for reuse.
- Refining: The recovered gold is additional refined to take away impurities and attain the specified purity.
Benefits and Disadvantages
Benefits:
- Comparatively easy and cost-effective
- Excessive restoration charges
Disadvantages:
- Environmental issues resulting from mercury air pollution
- Well being dangers related to dealing with mercury
- Requires specialised tools and coaching
Well being and Security Concerns
Dealing with mercury requires correct security precautions to attenuate well being dangers. These embrace:
- Satisfactory air flow
- Use of respirators and protecting gear
- Correct disposal of mercury and amalgam waste
- Monitoring of mercury ranges within the office and setting
Supplies Required
- Scrap circuit boards
- Container (glass or plastic)
- Distilled water
- Graphite rod or different conductive materials
- Energy provide (9-12 volts)
- Metal wool or sandpaper
- Nitric acid (non-compulsory)
1. Preparation of Scrap Boards
Clear the circuit boards to take away any particles or solder. Reduce them into smaller items for simpler dealing with.
2. Container Setup
Fill the container with distilled water. The water must be deep sufficient to cowl the circuit boards fully.
3. Graphite Rod Preparation
Sharpen one finish of the graphite rod to create a pointed tip.
4. Connection of Energy Provide
Join the constructive terminal of the ability provide to the graphite rod and the unfavourable terminal to the circuit boards.
5. Electrolytic Course of
Submerge the circuit boards and graphite rod within the water. Activate the ability provide and alter the voltage to 9-12 volts.
6. Formation of Gold Movie
As the present flows by the answer, the gold current on the circuit boards will dissolve and type a gold movie on the graphite rod.
7. Monitoring the Course of
The electrolytic course of might take a number of hours and even days, relying on the quantity of gold current on the circuit boards.
8. Removing of Gold Movie
As soon as the gold movie has fashioned, flip off the ability provide and thoroughly take away the graphite rod from the water. The gold movie must be connected to the rod.
9. Cleansing the Gold Movie
Use metal wool or sandpaper to softly rub off the gold movie from the graphite rod.
10. Purification of Gold (Non-compulsory)
If desired, the gold movie may be additional purified by dissolving it in nitric acid and precipitating it with a lowering agent.
How To Take away Gold From Circuit Boards With out Chemical substances
Gold is a worthwhile metallic that’s typically utilized in digital circuit boards. Nonetheless, over time, gold can develop into tarnished or broken, which may have an effect on the efficiency of the circuit board. If it’s essential to take away gold from a circuit board, there are just a few completely different strategies you should use that don’t require using chemical compounds.
One methodology is to make use of a gold stripper. Gold strippers can be found in each liquid and gel type, and so they work by dissolving the gold on the circuit board. To make use of a gold stripper, apply it to the circuit board and let it sit for the period of time specified by the producer. As soon as the gold has dissolved, rinse the circuit board with water and dry it completely.
One other methodology for eradicating gold from a circuit board is to make use of a laser. Lasers can be utilized to vaporize the gold on the circuit board, abandoning a clear floor. This methodology is costlier than utilizing a gold stripper, however it is usually extra exact.
Lastly, you may also take away gold from a circuit board by utilizing a mechanical methodology. This includes utilizing a instrument resembling a scraper or a wire brush to bodily take away the gold from the circuit board. This methodology is much less exact than utilizing a gold stripper or a laser, however it is usually inexpensive.
Individuals additionally ask
How do you take away gold from a circuit board with baking soda?
Baking soda will not be an efficient methodology for eradicating gold from a circuit board.
How do you take away gold from a circuit board with vinegar?
Vinegar will not be an efficient methodology for eradicating gold from a circuit board.
How do you take away gold from a circuit board with electrolysis?
Electrolysis is a technique for eradicating gold from a circuit board utilizing an electrical present. To make use of this methodology, you will have an influence provide, a cathode, and an anode. The cathode is the thing that you simply need to take away the gold from, and the anode is a bit of metallic that might be used to dissolve the gold. Join the ability provide to the cathode and the anode, after which immerse the circuit board in an answer of water and baking soda. The electrical present will trigger the gold to dissolve from the circuit board and deposit on the anode.
