Mechanical Sand Reclamation
Primary reclamation stage: crushing, attrition, classification and dedusting. Ideal for furan-based no-bake systems.
Thermische Sandregeneration
Thermal Sand Reclamation:
Thermal Sand Reclamation:
Fluid-Bed Calcination at 600 to 800 °C
Restore used foundry sand close to virgin specification. Axmann builds thermal sand reclamation plants for phenolic urethane, alkaline phenolic and high-reclamation no-bake systems, lifting total sand reuse into the 90 to 95% range, engineered in Germany.
What is Thermal Reclamation?
Restore Sand to Virgin Quality, Without Mining It
Thermal sand reclamation, or thermische Sandregeneration, is the process of restoring used foundry sand close to virgin specification by burning off every trace of residual organic binder in a fluid-bed calciner at 600 to 800 °C. The silica grain core is untouched; the organic binder envelope is oxidised to CO₂ and water vapour. The resulting reclaimed sand has grain-size distribution, loss on ignition (LOI) and acid demand values indistinguishable from newly-mined silica. Thermal reclamation is the way to hit the highest sand-reuse rates, 90 to 95%+, and it is essential for foundries running phenolic urethane or alkaline phenolic binder systems whose residues cannot be fully removed mechanically.
An Axmann thermal reclamation plant almost always runs as the secondary polishing stage after mechanical reclamation. The mechanical stage removes bulk binder, fines and oversize; the thermal stage polishes what remains and restores LOI values to near-virgin. A modern fluid-bed calciner with regenerative heat recovery consumes roughly 0.4 to 0.7 m³ of natural gas per tonne of sand, and 15 to 25 kWh of electricity, numbers that pay back fast against the cost of virgin silica and landfill.
How It Works
The Thermal Reclamation Process
Fluid-bed calcination, heat recovery and controlled cooling, five engineered stages.
1
Feed & Preheat
Mechanically reclaimed sand enters a preheater fed by calciner exhaust. Sand is heated to 250 to 350 °C before entering the main chamber, reducing fuel consumption by 25 to 40%.
2
Fluid-Bed Calcination
Sand grains are suspended in an upward flow of combustion gas at 600 to 800 °C in a fluid-bed calciner (Wirbelschichtofen). Organic binder residues combust completely, escaping as CO₂ and water vapour.
3
Exhaust Treatment
Exhaust gases pass through a cyclone and bag filter to capture fines, then through the regenerative heat exchanger that preheats the incoming sand and combustion air.
4
Controlled Cooling
Calcined sand is cooled in stages, first by air-to-sand heat exchangers (recovering heat back into the process), then by water-cooled coolers to reach mixer-inlet temperature.
5
Silo Return & QA
Reclaimed sand is pneumatically conveyed to the storage silo. Inline sampling and lab QA verify grain-size distribution, LOI and acid demand against the moulding specification.
Turnkey Scope
What Axmann Provides
Every component of the thermal reclamation line, engineered and integrated as one system.
Fluid-bed calciners (Wirbelschichtöfen)
Regenerative heat exchangers
Sand preheaters
Multi-stage sand coolers
Cyclones, bag filters & dedusting
Natural gas & combustion-air systems
Pneumatic conveying & silos
Process control & inline sand QA
Why Thermal?
Six Reasons to Add a Thermal Stage
90 to 95% Sand Reuse
Thermal polishing lifts total reclamation rate into the 90 to 95% range. The highest reuse achievable in chemically bonded sand operations.
Required for PU & Alphaset
Phenolic urethane and alkaline phenolic binder residues cannot be fully removed mechanically. Thermal calcination is the only way to reclaim these systems reliably.
Virgin-Quality LOI
Reclaimed sand leaves the calciner with loss-on-ignition values at or below virgin specification, crucial for premium casting quality.
Heat Recovery, Low Energy
Regenerative heat exchangers and sand preheating cut fuel consumption by 25 to 40% versus older plant designs.
Lower Total Cost per Casting
At high sand volumes, the fuel cost of thermal reclamation is far less than the combined cost of virgin sand plus landfill disposal avoided.
Carbon-Compliant
Even accounting for combustion emissions, thermal reclamation cuts embodied carbon per tonne of good casting by 50 to 70% versus using virgin sand and landfill.
Complete the Line
Related Foundry Systems
Thermal reclamation polishes mechanically reclaimed sand. These systems complete the closed-loop foundry.
Ready to Go Beyond 90%?
Your Thermal Reclamation Plant, Engineered for Energy Efficiency
Axmann sizes the calciner, heat-recovery system and coolers around your sand tonnage, binder chemistry and energy cost. Retrofits into existing mechanical reclamation plants are routine.
Get in Touch
Request a Quote
Tell us about your foundry: sand tonnage per month, binder system, existing reclamation, target reuse rate. Our engineers respond within one business day with a sized proposal.
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