The amount of platinum, palladium and rhodium used in the catalytic converter of a typical car is small—a little more than a tenth of a gram in the case of rhodium.
But these metals are so valuable—rhodium can fetch up to $17,000 per ounce—that a spent catalytic converter from a car that has been sent to the scrapyard can contain more than $300 worth of platinum-group metals.
The challenge is separating those valuable metals from the other metals and materials in discarded, ground up catalytic converters, diesel particulate filters and industrial catalysts used in petrochemical and pharmaceutical plants.
Currently, the most common method for recovering these metals involves smelting, which is highly energy intensive and costly.
A B.C. startup called pH7 Technologies has been gaining a lot of attention lately for a solvent-based process—called solvometallurgy—that it has developed as an alternative way of extracting platinum-group metals from industrial and auto waste.
“We are an alternative for smelting,” explained pH7 founder and CEO Mohammad Doostmohammadi.
The solvometallurgy process pH7 developed uses organic and inorganic chemicals and an electro-chemical process that can extract valuable metals from waste without generating emissions or wastewater. The process is described as a “closed loop,” because the chemicals used in the process are regenerated and reused.
“It’s way more energy efficient, way cheaper,” Doostmohammadi said.
Last year, the company raised $22 million in Series A financing, and was one of 13 Canadian companies to make the international Cleantech 100 list earlier this year.
More recently, the B.C. Centre for Innovation and Clean Energy (CICE) approved $1 million in funding to help pH7 develop an electrolyzer that will be used in the process for extracting copper from mine waste.
“This process not only increases copper extraction by up to 50 per cent, but also produces green hydrogen through its patent-pending organo-acidic electrolyzers,” CICE noted.
“When pH7’s process is adopted in Canada, it could potentially add over 80,000 tonnes to the country’s current copper capacity and generate over a billion dollars in revenue.”
Originally from Iran, Doostmohammadi, who has master’s degree in chemical engineering, worked as an engineer for a gold-mining company in Iran for several years before moving to Canada to get an MBA from Simon Fraser University.
Processing and storing ore from mining operations can consume a lot of water, and in regions that have arid climates—such as Iran and Chile—that can be a real obstacle.
Water use in mining was one of the things Doostmohammadi wanted to address through pH7 Technologies, which he founded in 2020 based on a proprietary closed-loop critical metals extraction process he developed. The company initially focused on platinum-group metals (PGM).
“We are adding more metals to our metal portfolio,” Doostmohammadi said. “We started with PGM.… Now we are adding copper, tin, gold, silver.”
The company is currently building and commissioning a new demonstration plant in Burnaby that will process up to five tonnes of waste per day.
The waste comes from spent catalysts and catalytic converters, mostly from the U.S. The waste comes to pH7 already ground up into a powder, and pH7 then extracts valuable metals from that waste. The company currently employs 40 people.
“The hope is, after this plant being commissioned and processing materials for our partners, we’ll build commercial plants—larger scale than this—around the world,” Doostmohammadi said.
One of the pH7’s current customers is Mitsubishi Corp. (TYO:8058).
Doostmohammadi said he thinks one of the biggest markets for pH7’s solvometallurgy technology is copper.
Anywhere from 0.1 per cent to one per cent of the material in mine tailings is copper. Current mine processing methods make it prohibitive to try to recover such small amounts of the metal, which is used in renewable energy technologies, construction, electronics and elsewhere.
“The market is huge,” Doostmohammadi said. “We are targeting billions of dollars of copper that are sitting on the ground. We are designing pilots right now to be able to extract those materials from old mines and even the mines that are operating right now.”
What makes pH7’s process a closed loop is the fact that the chemicals used in the solvometallurgy process are regenerated using an electrolyzer that pH7 designed. This process happens to produce hydrogen as a byproduct.
Doostmohammadi said his company is working with several large mining companies interested in having pH7 extraction plants built at their mine sites to produce both copper and hydrogen.
“With a significant copper shortage on the horizon, responsibly optimizing mine output is crucial for accelerating the transition to a clean energy future,” said CICE CEO Sarah Goodman.
“PH7’s heap-leaching closed-loop process, which enables on-site copper extraction and hydrogen production, stands out as a game-changer. We are proud to support pH7’s efforts to enhance the global copper supply while also generating clean hydrogen directly at the mine site, addressing the infrastructure challenges of hydrogen supply at remote location,” she said.
