How ALS2 recovers palladium from ceramic furnace elements
Industrial furnaces used for heat treatment, kiln work and process ovens eventually require replacement of their ceramic heating elements. For many sites, the ceramic appears to be low-value waste; specialist designs can, however, contain palladium-bearing internal conductors, electrical contacts or metallised layers. The metal may represent a small proportion of the component but a disproportionate share of its recoverable value. The challenge is locating it, liberating it from the refractory body and preventing its dilution with ordinary scrap.
Ikoi S.p.A.’s ALS2Project develops an acidless route for recovering precious metals from electronic waste and WEEE, supported by the European Union’s Horizon 2020 research and innovation programme. Applied to spent ceramic elements, ALS2 is designed to separate and concentrate the palladium-bearing fraction instead of treating the entire component as one undifferentiated refining feed. The route still requires feed-specific trials, but it offers Australian operators a way to reduce aqua-regia handling while developing a compact precious-metals recovery stream.
Why palladium ends up in spent furnace elements
Not every ceramic heating element contains palladium. Conventional elements may use nickel-chrome, iron-chrome-aluminium or other resistance alloys, with no precious-metal value to recover. Specialist elements are different: palladium-containing pastes, terminals or contact components may be integrated into an alumina or silicon-carbide assembly selected for demanding industrial temperatures.
Palladium is used in certain high-temperature electrical applications because it combines useful conductivity with resistance to oxidation. Its presence in a heating element can therefore be hidden within a ceramic-coated or encapsulated component. If maintenance staff inspect only the visible terminals, palladium-bearing material can be overlooked or discarded during dismantling.
This creates a fragmented feedstock. Used elements may sit in maintenance stores, arrive through equipment contractors or be replaced during furnace relining across different manufacturers. Their age, construction and contamination levels can vary, so every batch needs representative sampling before an economically suitable recovery route can be selected.
Preparing ceramic heating elements for recovery
The first operation is safe isolation, cooling and removal under the furnace’s maintenance procedures. Ceramic fragments should not be treated as inert waste because sharp edges, adhered coatings and entrained process residues can create handling risks. Where appropriate, larger terminals and easily separable metal fittings can be detached to reduce the burden placed on later size-reduction equipment.
The ceramic body then needs controlled liberation. Milling or crushing exposes internal conductors and contact surfaces, while screening and mechanical sorting can remove obviously non-metallic material. The aim is to create a concentrated palladium-bearing fraction without producing excessive fines that complicate subsequent separation. Equipment selection depends on element dimensions, brittleness and whether the elements contain steel supports, mineral insulation or other metals.
Representative samples should be sent for laboratory analysis before a full batch is processed. X-ray fluorescence can help screen larger, homogeneous pieces, but low palladium concentrations require appropriate laboratory methods for reliable results. Knowing the grade, metal distribution and contaminants allows ALS2 operating conditions to be tailored and helps determine whether the batch is economic as a standalone stream.
How ALS2 separates the palladium
The ALS2 treatment route begins with the liberated, size-reduced fraction. Instead of placing the entire ceramic component into an aggressive aqua-regia solution, the process focuses on separating the valuable metal-bearing portion from the refractory bulk. This distinction is important for ceramic elements because the volume of non-target material can otherwise dominate reagent consumption and downstream residue.
During the controlled separation stage, ALS2 chemistry is used to move palladium into a concentrated metal-bearing stream while excluding most ceramic material. A solid–liquid separation then creates two distinct fractions: a palladium-rich fraction for recovery and a ceramic-rich residue requiring further assessment. The palladium-bearing stream proceeds to a controlled capture and refining stage, where its composition determines the most suitable final treatment.
ALS2Project’s place within the EU’s Horizon 2020 programme connects the technology with wider European research and industrial collaboration. Additional European project background and dissemination material are available through AAE Europa.
| Consideration | Aqua-regia refining | ALS2 treatment for ceramic elements |
|---|---|---|
| Feed preparation | Mixed metal-bearing material is commonly dissolved into an aggressive acidic solution | Crushing and sorting first liberate a palladium-bearing fraction from the ceramic |
| Core separation | Broad dissolution captures several metals into one acidic solution | Selective acidless separation concentrates palladium while separating most ceramic material |
| Transport requirements | Aqua regia may require dangerous-goods documentation, permits and corrosion controls | Aqua regia is not part of the transport route, although other substances may still need classification |
| Plant footprint | Often associated with a centralised, purpose-built refining operation | Can support compact recovery equipment located closer to waste streams |
| Principal hazards | Corrosivity, toxic fumes, spills, high PPE demand and hazardous transport | Lower chemical burden, but site safety, residue testing and operational controls remain necessary |
| Remaining material | Contaminated liquid and sludge require dedicated treatment | A separated ceramic residue can be assessed for further reuse or controlled disposal |
Acidless does not mean chemical-free, impact-free or suitable for every feed. ALS2’s advantages emerge when the ceramic elements are correctly identified, liberated and characterised. A qualified trial should establish reagent demand, palladium recovery, residue quality and the operating controls needed for safe scale-up.
Why the route suits Australian operations
Australian manufacturers and resource businesses operate furnaces in automotive component plants around Melbourne and Sydney, aerospace facilities in Brisbane, food-processing equipment in Adelaide and mining operations near Kalgoorlie. Heat-treatment furnaces, kilns and process ovens can all generate spent elements in small, dispersed batches. A familiar site routine is to tag failed heaters during isolation, place them in a labelled electrical-waste area and await consolidated collection.
Waste obligations differ between states and territories. Used industrial electrical components generally fall outside household electronic-waste take-back programmes, so businesses must check the relevant environmental laws, waste documentation and transport requirements. The National Waste Policy 2019 provides national policy direction, while state and territory legislation governs the day-to-day management of industrial waste and some producer-responsibility arrangements.
Transporting aqua regia can add another layer of administration because corrosive mixtures must be classified, packaged and documented under the Australian Dangerous Goods Code, with permit requirements varying by quantity and jurisdiction. The operational difference is explained in the ALS2 material on aqua regia transport requirements. Eliminating aqua regia from the route does not remove the need to classify other chemicals or wastes correctly.
Australia is not a major primary palladium producer, and local buyers participate in the global precious-metals market. Ceramic elements alone may not provide enough volume or grade to support a dedicated refinery, so they can complement other high-grade WEEE streams. The strongest business case combines secure feedstock collection, reliable assays and a compact plant that reduces both transport exposure and handling losses.
Start a controlled palladium recovery trial
The practical starting point is a recovery audit rather than a full processing commitment. Record furnace types, element suppliers, replacement dates and storage locations; separate probable palladium-bearing assemblies from conventional resistance elements; and obtain representative laboratory results. This initial work identifies recoverable value while preventing contamination of high-grade material with bulk ceramic waste.
Ikoi S.p.A. and the ALS2Project team can use those findings to assess feed compatibility, separation requirements and the scale of a suitable demonstration. A controlled trial can then establish recovery performance, residue characteristics and realistic operating costs for Australian conditions. Commercial planning should also consider collection agreements, quality controls and the final route for palladium-rich outputs.
For furnace operators, distributors and recycling specialists, the immediate action is to identify a representative batch of spent ceramic elements and scope an assay and feasibility study. Contact ALS2Project to evaluate an acidless route from maintenance storage to a traceable palladium recovery stream and a compact Australian recovery plant.