Recovering platinum from discarded spark plug electrodes with ALS2
Spent spark plugs are a small but concentrated source of platinum group metals in the broader stream of electronic waste and WEEE. Because electrodes are designed to withstand extreme combustion conditions, they can contain valuable platinum alongside iridium, palladium and nickel. Recovering these metals from spark plug electrode waste turns an obsolete component into a traceable secondary resource rather than an exportable disposal cost.
For Australian workshops, used-vehicle businesses and local councils, that resource is scattered across service depots, garages and household repair bins. ALS2, an Ikoi S.p.A. project, offers an acidless separation route designed to recover precious metals from e-waste and WEEE in compact plants. Its development with support from the European Union’s Horizon 2020 programme positions it within Europe’s wider effort to substitute primary mining with safer urban-mining systems.
Why spark plug electrodes matter
Australia’s large second-hand vehicle market keeps older engines and their replacement parts in circulation for longer than in some other markets. Service depots in Sydney, Melbourne, Brisbane and Perth routinely remove spark plugs during servicing, while motorists also replace them in home garages. Those routine maintenance habits create a steady, distributed stream of plugs that is often mixed with washers, cables, insulators and general workshop scrap.
Platinum is not present in every modern plug: many use nickel electrodes, while iridium and platinum variants remain valuable when present. A used-plug stream can therefore combine almost worthless components with small concentrations of precious metal. This makes sorting and representative sampling essential. A load that appears rich at first glance may contain too few platinum electrodes to support an economic recovery, whereas a carefully separated batch can justify dedicated processing.
What ALS2 changes for metal recovery
Ikoi S.p.A. presents ALS2 as an acidless separation technology for recovering precious metals from electronic waste and WEEE. In practical terms, the value proposition is the potential to avoid mineral-acid leaching during the separation stage, along with the effluent burden associated with neutralising acid residues. That can lower chemical-handling demands, although an acidless label does not remove the need to control dust, energy use, captured residues or any process chemicals.
The project’s compact configuration is intended for precious-metals recovery plants that can operate close to collection sources rather than relying only on large, centralised refineries. Further technical reading on separation methods is available through process chemistry resources. Operators would still need clear data on mass balance, recovered-metal purity, throughput, maintenance and residue treatment before scaling any unit from a research or demonstration setting.
Building a dependable feedstock stream
A reliable Australian feedstock model should begin with the businesses that already control waste streams. Vehicle service chains, roadside-repair operators, fleet maintenance depots, motorcycle workshops and licensed scrap dealers can all separate plugs at the point where they are removed. Contracts can specify segregation, pickup frequency and chain-of-custody records. Council-run e-waste events in major cities can reach household-held components, provided collection messaging states clearly whether plugs and small automotive parts are accepted.
Contamination affects both recovery economics and worker safety. Ceramic fragments can enter the feed, while oil, grease, fuel and metal fines complicate sorting. Plugs should be drained and cleaned through approved procedures before crushing or briquetting; manual dismantling should avoid creating sharp shards and dust. Mixed loads require robust sampling, and a laboratory assay should establish the platinum-group-metal content before material is described as a refinery-grade feed.
Collection does not have to wait for a dedicated national network. In Melbourne and Sydney, scheduled collections from high-volume workshops could create dense urban-mining hubs, while regional depots could consolidate plugs into secure containers before shipment. Because Australia’s distances to processors can be substantial, tracking mass, metal content and transport emissions from the first weighbridge is important. A smaller local ALS2 installation may shorten logistics, but only if feedstock density supports stable operation.
A practical recovery pathway
A workable processing route starts with controlled dismantling, followed by size reduction to separate the electrode and conductive metal from the ceramic insulator. Screens, magnets and other physical sorting steps can enrich the relevant fraction before the ALS2 separation stage. The objective is a consistent, metal-bearing stream with minimal plastics, oils and fine ceramics, because those contaminants increase handling losses and complicate downstream assay and refining.
Process controls should cover feedstock composition, particle size, moisture, equipment load, reagent or medium use where applicable, and the destination of every solid residue. Samples taken at several points reveal whether losses arise during liberation, separation or final transfer. After recovery, the platinum-group-metal product still needs chemical analysis and may require further refining to meet the purity expected by autocatalyst, electronics or jewellery customers. ALS2 can simplify an upstream stage without eliminating the entire refining chain.
How ALS2 compares with acid refining
| Consideration | Conventional acid-based refining | ALS2-enabled recovery |
|---|---|---|
| Core chemistry | Often uses strong-acid leaching, followed by purification and precipitation. | Uses an acidless separation stage, with project materials focused on precious-metal recovery from e-waste and WEEE. |
| Feedstock fit | Can handle broad, high-volume mixed streams once the plant is designed for them. | Best evaluated on concentrated, pre-sorted fractions such as electrode-rich material. |
| Site profile | Usually a large, centralised refinery with dedicated utilities and effluent treatment. | Designed around a smaller, compact precious-metals recovery plant. |
| Chemical burden | Requires acid storage, corrosion control, neutralisation and management of liquid residues. | Avoids the acid burden of conventional leaching; other media, energy and solid outputs must still be managed. |
| Main risks | Worker exposure, corrosion, water demand and salt-bearing effluent. | Dust, mechanical hazards, process stability and residue treatment remain significant. |
| Commercial position | Long-established route with extensive refining expertise. | Emerging technology; project claims and site-specific performance need commercial validation. |
| Best fit | Large, diversified e-waste or PGM streams. | Compact urban-mining hubs and separated automotive or electronic component streams. |
Acid-based hydrometallurgical refining is mature and can process large, mixed feed streams, but it requires disciplined acid storage, corrosion-resistant equipment, controlled leaching and reliable waste treatment. Neutralisation creates additional salts and sludge, while worker exposure and water consumption remain important considerations. For a small stream of spark plug electrodes, those requirements can outweigh the value contained in the feed.
ALS2 offers a targeted alternative with less reliance on strong acids and a potentially smaller plant footprint. It appears better suited to concentrated, pre-sorted urban-mining streams than to replacing every large refinery. Comparative claims should still be verified with local feedstock and independently measured outputs, including recovery rate, product purity, energy per kilogram, residual waste and total cost per gram of recovered platinum.
Making the model work in Australia
Regulation shapes how recovered plugs and the resulting metal move through Australia. The National Environment Protection (Used Electronic Equipment) Measures 2015 is implemented by state and territory agencies, although the classification of automotive components and accepted collection routes can vary. Scrap dealers, transporters and processors should confirm local obligations, site licences and recordkeeping requirements before presenting recovered material as a circular product.
The commercial opportunity extends beyond platinum prices. Clean, traceable feed supports Australia’s critical-minerals strategy, while recovered PGMs can be returned to automotive catalyst, electronics, chemical or jewellery supply chains. Local buyers already understand ferrous and non-ferrous scrap, but a platinum-bearing material needs settlement based on assay rather than visual grade. Contracts should define sampling methods, responsible-party transfers, price adjustments and ownership of unrecovered residues.
A modular plant could serve several collection routes under one operating standard: metropolitan workshops, regional scrap yards and authorised e-waste facilities. The business case should include collection incentives, freight, assay costs, equipment servicing and residue disposal, not just the spot price of platinum. Pilot batches from Sydney and Melbourne would provide useful operating data, including traffic and contamination patterns, before equipment is placed in another city or near a larger recycling precinct.
Closing the loop with recovered platinum
The strongest case for ALS2 is a closed-loop system in which workshops separate a small, valuable material stream, a compact plant recovers the metal, and refiners return verified platinum to manufacturers. That arrangement can reduce waste volumes, retain critical material in Australia and create a traceable supply outside primary mining. It also gives consumers and regulators evidence that recovery performance is being measured rather than inferred from the word acidless.
Start with a representative batch of sorted electrodes, set agreed assay and recovery targets, and compare the full route with established refining and disposal costs. Contact Ikoi S.p.A. and the ALS2Project team to discuss a feedstock trial, technical data and a compact plant suited to Australian collection networks. One measured batch can start the route from workshop bins to verified recovered metal, with commercial terms built around transparent assay and recovery results.