ALS2 compatibility with e-waste shredding oils

Electronic waste and WEEE recycling streams often reach separation plants with residues of lubricants used by crushers, granulators and shredders. The contamination may be hydraulic oil, gearbox lubricant, cutting fluid or a vegetable-based fluid, depending on the machine and maintenance regime. For Ikoi S.p.A.’s ALS2Project, that variability is central to judging whether a feed is suitable for the acidless precious-metals recovery process.

Compatibility does not mean every oily feed can be accepted unchanged. It means the material can be handled at a stable rate, precious metals can be recovered consistently, and oil is not transferred into an unmanageable residue or used to create a new safety problem. An acidless route removes the demand for aggressive acid refining, but oil can still affect wetting, particle behaviour and downstream separation.

Australian recyclers deal with a particular mix of council collections, IT asset disposal, second-hand trade and industrial scrap. This article examines the technical issues around e-waste shredding oils, the conditions under which ALS2 can be considered compatible, and the sampling and trial work needed before a compact recovery module is installed.

Why shredding oil changes the feed

Shredding oil arrives in several forms. Free liquid can collect in hoppers or stick to large pieces, while a thinner film may coat every fragment. Metal parts can also carry oil in hollows, fasteners and connectors. Hydraulic and transmission lubricants are common in older shredding lines, synthetic and fire-resistant fluids may be used in newer plants, and some sites use biodegradable oils. Their viscosity, water content, flash point and additive packages can differ substantially.

Those differences affect processing. A greasy particle can bridge rather than fall through a screen, adhere to another particle or hide a metal surface from a sensor. Oil-wetted fines may report to a residue stream even when they still contain gold, silver, palladium or platinum. It can also complicate weighing, sampling and assay interpretation. At plant level, an oil-soaked mixture raises fire-control and housekeeping concerns, especially where hot cutting, compaction or poorly ventilated conveyors are used.

What compatibility must prove

A useful ALS2 compatibility trial measures more than whether precious-metal-bearing material enters the plant. It should establish feed acceptance, stable throughput, metal recovery, product purity and the destination of non-metallic material. Each result needs a mass balance because a small change in the weight of wet or oily fines can otherwise look like a recovery gain. A control sample without added oil is essential when comparing results from a laboratory test.

Safety and environmental performance belong in the same acceptance test. The oil profile should include water, viscosity, flash point and any known additives, while operators should track vapour, dust, fire controls, wash water and residue waste. This protects the cleaner operating case claimed for acidless separation. If a simple drain or mechanical de-oiling step removes most of the lubricant, the commercial calculation may improve; if treatment creates more waste or energy use, the feed may not suit ALS2.

How ALS2 should be matched to oily feed

ALS2 is Ikoi S.p.A.’s acidless technology for recovering precious metals from electronic waste and WEEE, developed as a compact alternative to larger acid-based refining arrangements. Support from the European Union’s Horizon 2020 research and innovation programme has supported the project’s technical development and pathway towards demonstration. Its value for an Australian recycler is not simply the removal of acid from the flow sheet. It is the possibility of recovering metal from smaller, mixed streams near the point where waste is generated.

That possibility depends on controlled feed preparation. Depending on the oil and the plant layout, options can include draining free liquid, mechanical separation, absorbent capture, de-oiling before crushing, or removing a specific troublesome fraction. Solvent washing and extra water should not be introduced without an environmental and process review. Any separated oil must also enter an approved waste-management route rather than being washed into drains. The preferred sequence is to remove avoidable oil at the shredder, accept a measured residual film only if testing demonstrates stable separation, and place any polishing step ahead of the ALS2 module.

Australian conditions that shape the decision

Many Australian households are told by councils to chuck out old televisions, computers and phones at an approved e-waste drop-off, while offices and retailers run collection campaigns or paid take-back schemes. Sydney, Melbourne, Brisbane, Perth and Adelaide each have different service arrangements, yet most household items arrive without lubricant; oil is usually added when mixed WEEE is later run through industrial shredders. The relevant sample therefore needs to come from the shredding line, not from a council bin.

Second-hand supply adds mixed provenance. Devices moving through Cash Converters, eBay, Gumtree, workplace refresh programmes and local traders can contain plastics, batteries and obsolete components that challenge a narrow feed specification. Australian operators commonly speak about getting a “clean stream” or running a “mixed load”, but those labels need measurable limits for oils, halogens and other contaminants. Contracts with IT asset disposal firms should therefore specify shredder conditions and oil carry-over, not just equipment type.

Distance, heat and regulation affect the business case. Material can travel long distances to a metro recovery plant, while a modular ALS2 unit could reduce transport by operating closer to scrap networks. Warm storage can lower oil viscosity and increase leakage; hot, dry conditions also raise the importance of fire prevention and dust control. Across state and territory waste rules, used equipment and waste transport documentation must support the chosen processing route. A plant that can show a stable assay, compliant residue and positive economics will be more credible than one selling only a theoretical metal yield.

A practical validation programme

Start with samples taken across several loads, shifts and machine conditions, including the fractions that normally report to fines, metal concentrate and residue. A hand-picked printed circuit board is not representative of shredded WEEE. Record the feed source, shredder maintenance, oil type and any recent change to lubricants. Characterise the oil for water, viscosity, flash point and additives, then have an accredited Australian laboratory assay the associated metals in both the feed and each output.

Run the candidate feed through a controlled comparison: untreated material, material with the normal residual oil load, and material given the agreed de-oiling treatment. Measure throughput, uptime, recovery, output purity, residue mass, water use and energy demand. Set acceptance limits before the trial and retain chain-of-custody records for every sample. If results support the case, repeat the exercise at increasing tonnage so that startup, feed variation and operator routines are tested rather than a narrow laboratory window.

Contact the ALS2Project team at Ikoi S.p.A. to scope a compatibility trial for an Australian WEEE stream. The useful starting package is a representative shredded sample, oil and moisture data, current throughput, and the recovery or residue target the operation needs to meet. With that information, the team can design a controlled comparison and identify any de-oiling requirement before capital is committed.

Begin with one plant, one feed type and agreed acceptance criteria. That keeps the test grounded in Australian operating conditions and provides a clear basis for scaling an ALS2 module into a compact precious-metals recovery operation.