Recovering Gold from Optical Fiber Scrap with Acidless Separation
The rollout of high-speed broadband across Australia has generated an unexpected byproduct, kilometres of discarded optical fibre cable. As the National Broadband Network upgrades older sections and telecommunications carriers retire legacy infrastructure, stockpiles of fibre offcuts are building up in depots from Sydney to Perth. Much of this material carries a thin gold coating on its connector pins and end faces, a vestige of the high-conductivity contacts used to keep signal loss low. That gold is too valuable to leave in landfill and too difficult to liberate with conventional pyrometallurgical routes.
Optical fibre is essentially glass, which makes it one of the more awkward substrates in the electronics recycling stream. The glass matrix tolerates heat poorly, and any attempt to burn off insulation can fuse the precious metal into silicates that resist further treatment. Acid leaching, the workhorse of the gold refining industry for decades, gets around this problem but introduces its own headaches, particularly around worker exposure, effluent handling, and the corrosion of equipment. For operators in Australia, where workplace safety standards are enforced strictly and environmental liability sits with the producer, these headaches translate directly into compliance cost.
ALS2, the acidless separation technology developed under the Horizon 2020 framework, offers a different pathway. It is designed to recover precious metals from electronic waste without the aggressive chemistry that has historically defined the sector. Instead of dissolving metals in aqua regia or cyanide baths, the process uses mechanical and electrochemical separation to liberate gold, silver, and platinum group metals from complex substrates, including fibre-optic components, printed circuit boards, and WEEE shredder dust.
For Australian recyclers, the appeal of a closed-loop, low-emission process fits neatly with both state-level waste strategies and the federal product stewardship obligations now shaping the electronics sector. With the volume of end-of-life fibre expected to climb as 5G small-cell densification accelerates and older GPON gear is decommissioned, processors are actively looking for technologies that can keep pace without expanding their chemical footprint.
The Optical Fibre Scrap Challenge
A single optical fibre cable may contain only milligrams of gold per metre, but the cumulative figure across a national network is substantial. In a country the size of Australia, where undersea cables link Perth to Singapore and transcontinental runs cross the Nullarbor, even modest scrap streams represent meaningful recoverable value. The challenge is not the quantity but the form.
Gold on optical fibre is typically found as a plated layer on ferrule pins, on the contact surfaces of SC, LC, and ST connectors, and occasionally on the reflective coatings of specialised sensor fibres. When these connectors are stripped or cut, the gold stays bonded to ceramic or polymer housings that are difficult to dissolve selectively. Traditional smelters recover gold efficiently but require temperatures that destroy the underlying fibre glass, making the process energetically expensive and difficult to scale for low-mass, high-purity inputs.
Brisbane-based recyclers serving the carrier market have reported that optical fibre scrap tends to arrive in mixed bales, often contaminated with copper pairs, polymer jacketing, and steel strength members. Sorting alone does not solve the recovery problem. The metal has to be physically or chemically detached from a substrate that resists most conventional leaching chemistries, which is precisely the niche ALS2 was engineered to fill.
Why Acidless Separation Makes Sense for Fibre Waste
The acidless approach sidesteps several of the operational risks that come with aqua regia or cyanide-based leaching. There is no chlorine gas evolution, no aqua regia storage, and no requirement for effluent treatment plants capable of handling mixed acid-metal streams. For facilities located near residential suburbs in cities like Melbourne or Adelaide, where buffer zones around chemical operations are tightly policed, that simplification matters.
ALS2 operates at lower temperatures and avoids the corrosive fumes that typically force refiners to install scrubbers, dual containment, and continuous air monitoring. Workers handling fibre scrap do not need full chemical PPE for the separation step itself, although standard dust controls remain important. The process is also compatible with intermittent throughput, which suits Australian e-waste processors that receive fibre in irregular batches tied to major network refresh cycles rather than continuous tonnage.
Another practical benefit is water stewardship. Acid refining consumes and contaminates large volumes of process water, a particularly sensitive issue across the Murray-Darling basin and in regions where mining and processing compete with agriculture for clean water. A separation route that minimises liquid effluent reduces both the regulatory burden and the operating cost tied to water access, treatment, and disposal.
How ALS2 Works on Gold-Coated Substrates
The technology relies on a staged mechanical-electrochemical sequence. Optical fibre scrap is first shredded under controlled conditions to break connector housings and expose metal surfaces without generating the fine respirable dust associated with high-speed hammermill processing. Exposed gold-plated components are then routed through an electrolytic cell where an applied potential dissolves the underlying base metals while leaving the noble metal intact as a recoverable solid.
Because gold does not oxidise at the potentials used in the cell, it collects on the cathode or settles as a high-grade sludge that can be smelted directly without further purification. Silver and any platinum group metals present on connector pins or specialty fibres are captured in parallel streams. The glass fibre itself, now stripped of its metallic coating, becomes a clean silicate fraction that can be redirected into glass recycling or aggregate markets.
Ikoi S.p.A., the Italian engineering firm behind the development, has positioned the platform as a modular unit suitable for containerised deployment. That configuration is well suited to Australian conditions, where recyclers may need to set up temporary recovery capacity near large network operators in Sydney's Alexandria industrial precinct, Melbourne's Tottenham, or the technology parks sprouting around Macquarie Park. Operators interested in the broader technical roadmap can review deployment notes on the project's official site.
Australian Applications and Regulatory Alignment
Australia does not yet have a federal ban on e-waste landfill comparable to the European Union's WEEE Directive, but the trajectory is clear. The New South Wales Environment Protection Authority has moved to restrict certain categories of electronic waste from landfill, and Victoria's container deposit scheme has shown how product stewardship can reshape recovery behaviour at scale. Queensland is similarly tightening reporting requirements for large producers of electronic goods.
Under the existing National Television and Computer Recycling Scheme, the infrastructure for collecting and processing e-waste is already in place through organisations such as TechCollect and MobileMuster. Optical fibre scrap falls outside the scheme's current scope, but several carriers including Telstra and Optus have established internal recovery targets that exceed regulatory minimums, often tied to their own sustainability disclosures under the ASX Corporate Governance Council recommendations.
For these operators, deploying or contracting ALS2-based capacity provides measurable ESG outcomes. Reduced acid consumption, lower Scope 1 emissions from avoided smelting, and diversion of fibre glass from landfill all align with the reporting metrics now expected by institutional investors. In Western Australia, where mining heritage gives local engineers deep familiarity with metals recovery, the technology also opens a pathway for diversifying beyond iron ore and lithium into higher-value niche recycling.
Comparative Outlook for ALS2 and Acid-Based Refining
A side-by-side comparison highlights why processors handling optical fibre scrap are reassessing their choice of recovery route. The table below summarises the main operational and environmental dimensions relevant to Australian operators.
| Dimension | Acid-Based Refining | ALS2 Acidless Separation |
|---|---|---|
| Reagent profile | Aqua regia, cyanide, mixed acids | Electrolyte only, no cyanide or aqua regia |
| Operating temperature | Often elevated, with fume control | Ambient to moderate |
| Worker PPE requirement | Full chemical PPE and gas monitoring | Standard dust and electrical PPE |
| Effluent load | High-volume mixed acid wastewater | Low-volume, lower-hazard effluent |
| Throughput | High, suited to bulk doré | Moderate, suited to distributed e-waste |
| Suitable substrates | Primary ores, doré, bulk concentrates | E-waste, WEEE shredder dust, fibre scrap |
| Regulatory pressure in Australia | Increasing under state EPA frameworks | Aligned with product stewardship goals |
| Footprint and modularity | Fixed central plants | Containerised, deployable on-site |
Acid-based refining remains the dominant global route for high-throughput gold recovery and is unlikely to disappear, particularly for primary doré and mining concentrates. For distributed e-waste streams, however, its operational overhead is increasingly difficult to justify. ALS2 does not claim to match the throughput of a large central refinery, but for fibre scrap, connector bins, and small-format WEEE, it offers a more proportional footprint.
The economic case strengthens as logistics costs rise. Transporting low-density fibre scrap from regional depots in Townsville or Hobart to a central acid refinery is expensive and carries spill risk. Distributed ALS2 units, by contrast, allow preliminary separation close to the source, with only the concentrated noble metal fraction shipped onward for final refining. That model mirrors the distributed logistics strategies used in Australia's mining sector for lithium and rare earth processing.
Looking ahead, the integration of ALS2 with downstream hydrometallurgical polishing could give processors a complete non-cyanide flowsheet. Early trials reported by the Horizon 2020 consortium suggest gold recoveries above 95 percent from coated substrates, with purity levels suitable for direct sale to bullion dealers or re-entry into connector manufacturing.
If you operate an e-waste processing facility in Australia and handle fibre-optic scrap as part of your intake, the ALS2 platform is worth a closer look. Reach out to the project team through the official website to discuss deployment options, pilot studies, or partnership opportunities. Compact, modular units are available for trial installations, and the consortium is actively seeking collaboration with Australian recyclers, research institutes, and telecommunications carriers committed to closing the loop on precious metals.