Q1.Why do we use SnST-550A Tin stripper to remove Sn solder from the motherboards?

The advantages of SnST-550A technology are not only the recycling value of Sn itself, but also provide easy way to collect the components (IC chips, CPU) from motherboard. There are many precious metals inside the IC chips and CPU.
UW-860G Gold stripper can be used to recycle Au from these electronic components.

Q2.What is the difference between UW-700 electrolyte gold stripper and UW-860 chemical gold stripper?

UW-700 is suitable for thegold plating layer on the whole metal substrate (connectors or gold pins).
UW-860is suitable for PCB, CPU, and RAM, which gold plating layer on the ceramic, silicon, plastic that not easy to conduct.

Q3.Should I worry about Customs clearance of your products after I release the order?

Our products have been exported worldwide, including North America, South America, Europe, and Asia.There is no any problem occurs at all. Or you could check HS code of our chemical products, 3810.10.10, with your country’s Customs office first.

Q4.Could UWin’s stripper remove Au or Ag layer from Aluminum substrate without damaging it?

UW-700 could remove Au layer perfectly without damaging any substrate, including Copper, Nickel, and Aluminum material. This is also an advantage compared with Cyanide or Aqua regia system.

On the other hand, AgST-350 is frequently used to recover Ag from surface of telecommunication server. No damage to Aluminum at all.

Q5.How to collect valuable components from PCB mother board without burning?

SnST-550 Tin stripper can strip the tin from the mother board, without burning or grinding them.We can recycle valuable metal in those ICs, capacitors and others by different chemical stripping method.

Q6.What equipment I need for a pilot testing?

UWin has developed portable machines for metal strippers:

  • ● Catcher One : UW-700 electrolyte gold stripper
  • ● Rolling One : UW-860 chemical gold stripper
  • ● Spray One : SnST-550A Tin stripper


The advantages of Portable machines are :

  • ● Easy to carry to everywhere.  
  • ● Easy to estimate the Gold content of small amount E-waste.
  • ● Lab demonstration for training.
  • ● Trial run for mass production.
  • ● Easy to collect precious slurry.
  • ● School education

Q7.How to recovery platinum or palladium?

Choosing the UW-195 platinum stripper can strip the Pt and Pd metal from the e-waste, and using the different reduction agent to separate these two kinds of precious metals.

Q8.What kind of Eco-friendly stripping machine for mass production?

We suggest you can test your e-waste by portable machine first.

  • ● Iron One : Suitable for whole metal substrate and easy to electrical conduct by using UW-700 electrolyte gold stripper, UW-602 electrolyte silver stripper, and UW-400 electrolyte palladium stripper.
  • ● Fortune One : Suitable for PCB without any components on its surface by using UW-860G chemical gold stripper.
● Rolling One : Suitable for mother board and loose piece components by using SnST-550A Tin stripper, and UW-860G chemical gold stripper.

Q9.What kind of recycling is needed for the gold taking fluid after it has reached the maximum level of effectiveness and we need to through it away?
  • ● UW-700 electrolyte gold stripper:

One bottle of UW-700 is 600 grams powder, and can be dissolved in 10 liter of water. The saturation is 70 grams of gold in 10 liter solution. UW-700 stripping solution can be reuse, so it doesn't have any waste water. You can use the specific weight to measure the saturation.

  • ● UW-860G chemical gold stripper:

One liter of eco-friendly chemical gold stripping solution is ==> 68% HNO3 500ml/L + UW-860G stripper 500 ml/L
One liter gold stripping solution can dissolve 7.5g/L of pure gold, but if your e-waste has a lot of copper and nickel metal, the saturation of gold is near 0.5~2 g/L. So, it's why we need to design the automatic machine to control the stripping reaction conditions (time and temp.)
If UW-860G stripping solution can't dissolve the gold, you need to through it away to reduction the gold by using K2S or Zn powder or Sodium Hydrosulphite.

Q10.Is it a dangerous substance, for example heavy metals are left inside?
  • ● UW-700 electrolyte gold stripper has highly selectivity. Just strip the gold plating layer.
  • ● UW-860G chemical gold stripping solution doesn't damage the plastic, ceramic, silicon, stainless steel, and Ti.
  • ● After gold reduction, you need to use dilute Nitric acid to remove the metals (Cu, Ni, Sn) to purify the gold.
● Other waste water solution can be treat, and compliance with environmental regulations.

Q11.This is necessary to know in order to prepare the used water recycling technologies.

Metal sludge sedimentation and pH adjustion (pH 5-10, COD < 100)

Q12.This would be good to know with both types of recycling (chemical as well as electro type).

Both of them are needed.
UW-700 electrolyte gold stripper can strip the gold from the whole metal (easy to conductive)
UW-860G chemical gold stripper can strip the gold from the plastic, silicon, ceramic (non-conductivity)

Q13.What kind of products can use UW-860 solution to strip gold?

Gold finger, PCB, Flip Chip, IC, Wafer, CPU and so on.

Q14.How long does the lifetime of UW-700 electrolyte gold stripper?

It can be re-used for a long time. If the stripping rate became slowly, you just added the UW-700 electrolyte gold stripper into the solution.

Q15.How do you measure the gold content in the stripping solution?

You can use UW-860G chemical gold stripper to dissolve the gold from e-waste first, and use the ICP instrument to analyze the gold concentration in the solution.

Q16.What’s the difference between traditional method and eco-friendly ’s treatment?

Traditional methods are pyrometallurgy, cyanidation and Aqua Regia. UWin’s eco-friendly treatment is a reverse engineering to PCBA. SnST-550 can desolder the tin,and you can collect all components from the PCBA, then leach the precious metals from different components by UW-860 and UW-700. Without shredding process, cyanidation and Aqua Regia, it is an eco-friendly hydrometallurgy.

Q17.What is the first step I should take in order to understand your technologies more?

The first step we suggest for you is to send 1 kg of your e-waste or mine to us for the precious metal analysis paid testing. UWin will send you the test report.

Q18.What is your mass production system for e-waste looks like? Would you provide me a brief concept first?

Although we still need to discuss about the size and other details, all equipment you need is in this video. https://www.youtube.com/watch?v=yPp88YiPvTM&t=31s

Q19.Why do we need to separate electronic components form PCB before recycling precious metals?

It’s a concentrate process. IC has high gold content inside.

Q20.What to do when the UW-700 gold stripping decay?

It is not necessary to change the whole liquid. Just replenish UW-700 powder to the liquid and make sure it’s all dissolved in the liquid.

Q21.Is there a recycling process for palladium-containing waste?

UW-400 electrolyte Pd stripper and UW-195 Pd/Pt stripper are your good choice.

Q22.How to strip Ti coating layer on the wafer?

TiST-800 Ti stripper is an eco-friendly solution, without HF and Cyanide.

Q23.How to solve the problem of NOx when using Nitric acid to strip copper?

UW-480 copper stripper is suitable, which has the following advantages:
1. The reaction is mild and does not produce NOx.
2. High selectivity, no damage the substrate.
3. Simple wastewater treatment.

Q24.What’s LCO, NMC and NCA batteries?

It means different kind of cathode material of battery.
LCO: lithium cobalt oxide.
NMC: lithium nickel manganese cobalt oxide.
NCA: lithium nickel cobalt aluminum oxide.

Q25.Why lithium ion battery needs “cobalt”?

LCO, NMC and NCA batteries with cobalt inside have much higher operating voltage, higher energy density and more eco-friendly than nickel-cadmium battery.

Q26.I am a gold miner. I used to use cyanide and mercury to extract gold. If I change to the UWin process, will it be difficult to execute?

Definitely not. Cyanide and mercury are very toxic and harmful to humans and the environment. Therefore, we strongly recommend that you replace with the more environmentally friendly process. We can provide you the best plan best suit your needs.

Q27.How do I learn UWin's technology?

We provide a series of professional training courses for our clients to apply our technology in your business. The courses take about 2 to 4 days.