Germanium and Gallium Recovery from Semiconductor Scrap: Purity and Yield
Germanium and gallium don’t get talked about nearly as much as lithium or cobalt, but anyone sourcing them right now knows the problem: there’s barely any primary supply, most of what exists is a byproduct of zinc and bauxite refining, and a large share of global output comes from a handful of countries that can (and do) restrict exports on short notice. For fiber optics, infrared optics, and compound semiconductor wafers like GaAs and GaN, that’s a real bottleneck. Which is why recovery from fab scrap and end-of-life electronics has stopped being a side project for a lot of operators and started being a real line item — assuming the output can actually hit the purity levels the electronics industry demands, because “close enough” doesn’t sell in this market.
What the Scrap Actually Looks Like
Not all feedstock is created equal here, and the differences matter more than people expect going in.
Wafer fabrication scrap — offcuts, polishing sludge, rejected dies from GaAs and GaN fabs — is the good stuff. Metal content is well above anything you’d get from ore, and it’s usually a single, known composition, which makes life easier downstream. Optical fiber production leaves behind germanium tetrachloride residues and doped preform waste. Infrared optics manufacturing rejects germanium lenses and windows that never made spec. And then there’s end-of-life electronics — LED chips, RF amplifiers, GaAs-based solar cells — which is real volume but lower concentration and a lot more work to separate cleanly.
If there’s one thing that determines how the rest of the process goes, it’s what condition the scrap arrives in. Clean, single-source wafer scrap is almost a different business than mixed, oxidized electronic waste. The latter needs pre-treatment the former simply doesn’t.
How the Recovery Actually Works
Germanium recovery generally goes through chlorination: the scrap is oxidized, converted to germanium tetrachloride, and then purified by fractional distillation. GeCl₄ happens to boil at a convenient 86°C, which makes separating it from most of the impurity chlorides fairly clean, especially across multiple distillation stages. From there it’s hydrolyzed to GeO₂ and reduced back to metal. Done properly, this route gets you to 5N purity — 99.999% — which covers most fiber-grade and infrared optics requirements.
Gallium takes a different path. It’s usually leached out with acid or alkaline solutions, then run through solvent extraction to strip out the aluminum, zinc, and iron that tend to travel alongside it in GaAs and GaN process waste. Electrolytic refining does the final polishing, taking gallium from leach-grade purity (2N–3N) up to the 6N–7N range that epitaxial wafer growth actually needs.
Purity Is Where the Money Is
It’s worth being blunt about this: 4N material and 6N material are not the same business. A batch at 3N–4N purity is fine for alloying and general industrial use, but it’s essentially commodity pricing. Get to 5N and you’re in fiber optics and infrared optics territory, where the premium starts to show up. Push through to 6N or beyond — the range GaAs and GaN wafer fabs need — and that’s where the real margin sits.
The gap between “good enough” and “wafer-grade” isn’t really a leaching problem. It’s almost entirely about how well-controlled your distillation and electrolytic refining stages are.
What Yield Actually Looks Like in Practice
On high-grade wafer fab scrap, well-run chlorination or solvent extraction circuits typically land in the 92–97% recovery range — that’s about as good as it gets. Optical and fiber production residues usually come in a bit lower, around 85–93%, mostly due to distillation cut losses. Mixed end-of-life electronic scrap is the tougher case: 60–75% is more realistic once you account for everything lost during separation from base metals and plastics before the actual chemistry even starts.
In our experience, most of the yield gap between two operations running comparable feedstock comes down to process discipline — how stable the distillation temperature stays, how long the leach residence time runs, how many extraction stages are actually built into the circuit. It’s rarely the chemistry itself that’s the limiting factor.
Equipment Matters as Much as the Chemistry Does
Here’s something that gets underweighted: the same feedstock can yield 75% on one line and 93% on another, purely because of how the leaching, extraction, and distillation equipment is built and controlled. This is precisely where Proses Makina stands out. Drawing on years of engineering experience in precious and critical metal recovery systems — most notably in catalytic converter PGM recovery — Proses Makina designs process lines with the temperature stability, staged separation, and closed-loop reagent control that germanium and gallium recovery demand at a semiconductor-grade level. Their equipment is engineered specifically to close the gap between average and best-in-class yield, which, as outlined above, is almost entirely a function of process control rather than chemistry alone.
The company’s track record backs this up. Proses Makina has delivered complete recycling and refining plants across Europe, North America, and the Middle East — including Canada, the United States, Spain, Romania, Bulgaria, Oman, Saudi Arabia, the UAE, and South Africa, among others — establishing Europe’s first spent-catalyst recovery plant capable of recovering molybdenum, cobalt, and PGMs in a single facility. The company is also involved in an EU-backed research project on recovering critical metals — iridium, ruthenium, and platinum — from membrane electrode assemblies used in green hydrogen production, reflecting an engineering approach that keeps pace with where critical metal recovery is headed, not just where it’s been. That combination of global installation experience and forward-looking R&D is what makes them a credible partner for critical metals recovery, not just catalytic converters.
For operators already running a Proses Makina PGM recovery line, extending into germaniumand gallium recovery on compatible, purpose-built equipment is a natural next step — and a considerably more capital-efficient one than commissioning a separate line from scratch.
Germanium and gallium recovery from semiconductor scrap is a mature process, but it’s unforgiving about yield. Feedstock quality sets the ceiling, and how tightly the distillation (for germanium) or extraction and electrolysis stages (for gallium) are controlled determines how close you actually get to it. And when you’re comparing operations or offers, don’t just look at recovery percentage — look at purity too. 90% recovery at 4N is worth less than 80% recovery at 6N. In this market, purity is where the value actually lives.