Industry: Semiconductor
Process: Copper recovery from concentrated wastewater streams for discharge compliance
Benefits:
- Eliminate associated hazardous waste hauling risk & cost
- Reduce CO₂ emissions from inbound & outbound heavy trucks
- Operating revenue from recovered copper
Background
The semiconductor industry is undergoing a surge of unprecedented growth fueled by the demand for electrification of our society. From electric vehicles to renewable energy solutions, the thirst for chips is unquenchable. However, behind the curtain of this remarkable expansion, there’s a challenge that often goes unnoticed: the management of hazardous waste, specifically, concentrated acidic copper waste. The wafer manufacturing processes in the semiconductor industry result in a high volume of hazardous waste containing high levels of copper, peroxide, organics, and other contaminants. Due to the complex nature of this wastewater, the solution has been to ship it offsite for 3rd party processing and disposal.
Challenges
A semiconductor facility produces ~4,000 gallons daily of acidic, concentrated copper wastewater that is collected and hauled off-site for disposal. Any delay in the trucking could result in a shutdown due to fixed storage capacity, which is unacceptable. Additionally, the annual cost of hauling & landfill fees exceeded g was expensive at $3/gallon and unrealized recovery of 25 tons of copper per year. Seasonal, adverse weather presents high risks to trucking fulfillment of the concentrated waste.
Challenge
Upstream operations are reliant on storage volume and removal
Complex water matrix makes traditional treatment expensive or impossible
Expensive current solution creating budget strain as regulations tighten
Solution
Cost-efficient recovery of copper from concentrate stream
Fast, reliable, and automated on-site copper extraction & recovery
Robust electrochemical solution for complicated wastewater mixtures
Impact
>50% reduction in operating costs for fab
Significant reduction in CO₂ emissions
$378,000 in copper revenues from recovered pure metal
Proven Results | Case Study
The wastewater streams generated from wafer manufacturing at a semiconductor plant contained 8,000 – 10,000 ppm copper. The site permit allowed for 2.07 ppm in effluent discharge. Due to the complex nature of the wastewater stream, traditional treatment solutions were prohibitively expensive. Instead of treating the wastewater onsite, the facility was trucking the hazardous waste off site for 3rd party disposal at a cost of $3/gallon. The facility produced ~4,000 gallons of copper/peroxide wastewater daily with an annual disposal cost over $1.2MM
ElectraMet’s automated solution was implemented to:
- Replace trucking for off-site disposal with onsite treatment
- Optimize copper recovery for waste valorization
Site expectations were realized through the removal of copper in the concentrated wastewater stream to <1 ppm and recovery of all the copper tubes.
ElectraMet’s automated electrochemical process selectively removes and recovers Cu from complex process water or wastewater streams. The system is modular and can scale as production grows. The system consumes very little power of <0.5 kWh/m³ treated. With its capture and recycling technology, ElectraMet’s chemical-free process presents a circular and economical solution for handling copper in process/waste streams. This economic and environmental solution is a winning combination, benefiting the plant, its employees, and the surrounding community.
Observed Benefits:
- risk of adverse weather events dropped to near 0%,
- automation and elimination of truck supervision significantly reduced operator hours,
- clean removal of peroxide and metal from concentrated waste enabled possible recycling of acid for resale,
- condition-based monitoring and analytics maximized uptime at 100%, and
- increased personnel time spent on preventative maintenance for other systems.
