🔎 What’s going on?
New Zealand startup, Mint Innovation, aims to open a biological refinery for extracting precious metals from electronic waste. UK to build the world’s first commercial biological refinery of the future.
✅ How does it work?
- Any incoming feedstock must be ground into a fine sand-like powder to allow the chemical process to work efficiently.
- Once ground, it’s transferred into the first reaction vessel - where base metals (copper, iron and tin) are removed.
- A proprietary chemical leachate is added to the solids and stirred drawing the base metals into the solution. This completes the first leaching process (within just hours).
- The solids can be separated from the base metal-rich liquid using the filtration method.
- Only precious metals are now left in the solid fraction. Any valuable metals contained in the leachate such as copper can then be removed using electrolysis and other techniques.
- Extractive metals can then be returned into the economy to make new manufactured goods.
- The solids are then moved to the second leach to recover the remaining precious metals which are more difficult to recover than the base metals. This is where Mint’s technology stands alone and its ability to recover precious metals at higher concentrations than existing methods.
- Once the metals are dissolved, Mint adds its special microbes into the reactor to absorb the metal ions, thus known as BIOS option
- The microbes gain weight as they absorb these precious metals allowing them to be easily separated using a centrifuge.
- The gold is separated from the biomass (bacteria) using the gnashing and refining process.
- The various precious metals can then be extracted using established processes to produce high purity metals for use in industry.
- Minerals recycled in this way have a lower carbon footprint as well as reducing the environmental degradation associated with mining and other forms of extraction.
*Source: Please note, this step by step is taken directly from Mint Innovation’s website and social.
📱 Cool, what does it mean?
In a nutshell, the process has been optimised to maximise metal recovery whilst also minimising waste. That's really important because that's how the circular economy principles are embedded in the process itself.
There are three processes at play here:
- The leaching process just describes how liquids drain through solids such as soil or similar material. Leachate is simply the liquid after it has percolated through the solid.
- The filtration process separates particles from each other. Depending on the particles you want to separate.
- The electrolysis process uses electricity to separate liquids from solids.
Any combination of these three processes can be applied to any contaminant (or pollutant).
❓ Why should I care?
Electronic waste (or e-waste) is the world’s fastest-growing domestic waste stream. E-waste, in this case, refers to any discarded product with a battery or plug. According to the UN’s Global e-waste monitor 2020 report, $10 billion worth of precious metals is dumped or burned every single year from electronic waste. In 2019, only 17.4% of e-waste was actually collected and recycled. This means that precious metals (gold, silver, copper, platinum) worth at least $57 billion is wasted every single year. A huge opportunity.
In their current form, e-waste is a health and environmental hazard because they contain toxic additives or hazardous substances such as mercury. This damages the human brain and our nervous systems.
🚦 Where do we need to be?
We need to implement a circular economy and implement proper, biological e-waste management. With minimal or no chemical processing where possible. All governments should adopt a robust national e-waste policy and regulation to illicit accountability from businesses.
👤 What can I do about it?
As an individual, follow the simple motto of ‘Reduce, Re-use, Recycle and Repair’ with all of your personal and work electronic products.
As a business, implement systems within your businesses to first collect and segregate all your e-waste, then partner with a technology startup such as Mint Innovation to recycle your e-waste. The goal is zero waste.