The spec envelope for this duty sits between 1-15 t/h of dried, cooled, attrited and sieved grain returned to a near-original AFS 50-70 fineness number, and the choice between thermal, mechanical and pneumatic attrition equipment is driven primarily by binder chemistry rather than throughput alone [S2][S5].
Binder chemistry dictates the reclamation route
Phenolic urethane no-bake (PUNB) binder burns out cleanly at roughly 700-800 °C in a fluidised-bed or rotary thermal reclaimer, returning the grain close to its original AFS 50-70 distribution and tolerating 90-95% reclaimed-sand reuse rates on ductile iron telecom-enclosure work [S5].
Resole ester binder chemistry trades stripability and bench-life for low odour, but the organic residue does not combust as completely as PUNB at 700-800 °C, so mechanical attrition with air classification is the common paired route for plants running ester-cured moulds at 3-8 t/h [S5].
Mechanical, pneumatic and thermal trade-off
Mechanical reclamation uses a vibrating screen, magnetic separator and grinding mill to break down lump sand; it is the lowest-capex route and the default on phenolic shell lines below 10 t/day where the binder skin is friable enough to pop off without heating [S2][S4]. Pneumatic attrition in the 5-15 t/h mid-band adds an air blast and classifier to scrub binder film off individual grains, lifting AFS fineness back to 50-65 without thermal stress; the trade-off is 8-12 kWh/t of power and accelerated wear on the classifier wheel [S2].
Thermal reclamation at 700-800 °C is preferred over mechanical for PUNB lines because the organic binder burns out of the grain and the recovered sand returns to a near-original AFS fineness, with LOI (loss-on-ignition) under 0.3% achievable on a 5-10 t/h fluidised-bed unit [S5]. The same study shows that a thermal reclaimer on a phenolic-urethane enclosure line easily holds 90-95% closed-loop reuse without fresh-sand makeup above 5% per shift, and the recovered-grain AFS band of 50-70 is what lines up with the 90-120 s rotor-mixer cycle on a sand mixer downstream [S2][S5].
Capacity sizing and the t/h rule
Sizing a reclamation unit starts from the highest hourly moulding tonnage, then divides by the realistic closed-loop reuse rate; a 5-10 t/h no-bake enclosure line at 90% reuse still demands 0.5-1.0 t/h of fresh-sand makeup, and a 95% reuse line drops that to 0.25-0.50 t/h of fresh makeup plus attrition losses to fines [S2][S5]. For foundries tied to telecom-enclosure castings in the 12 g to 7 kg bracket at 2.0-3.0 mm wall thickness, the working band is a 3-8 t/h mechanical or pneumatic unit for jobbing operations and a 5-10 t/h fluidised-bed thermal unit for medium-volume PUNB [S5].
The 1.2-1.5 kW-per-kg platen heating rule used for shell core sizing does not transfer directly, but a 5 t/h thermal reclaimer typically draws 180-280 kW of burner input with 25-40 kW of vibration and conveyor drives, and the gas train must meet ATEX category 2 or IECEx zone-20 inside the fluidised bed for foundry installations handling furan fumes [S4][S5].
Sand temperature, AFS and the loop to the mixer
Reclamation output temperature is the hidden spec: thermal units discharge at 150-200 °C and need a fluidised-bed cooler or rotary drum cooler to bring the grain back below 35 °C before it reaches the sand mixer, otherwise binder activation drifts and tensile strength falls outside the 1.4-1.8 N/cm² PUNB band on the first mix [S2][S5]. Mechanical attrition discharges near ambient, which is why it pairs naturally with phenolic shell lines running 24-36 kW platen heating at 220-260 °C without an intermediate cooler [S4].
AFS fineness consistency is the next gate: a 2026 PUNB enclosure line should hold AFS 50-70 with a standard deviation under ±3 across an 8 h shift, and the test is a simple sieve-and-roto-tap per AFS 1106-00-S or equivalent foundry in-house procedure [S2][S5]. When the AFS number drifts above 70 the binder demand rises, scrap on machined faces climbs, and the hydraulic power unit on the moulding line pays for it in higher closing-force trim pressure.
Lining, dust and stack emissions
Reclamation equipment is built with the same lining discipline as a mixer: Ni-Hard cast iron at approximately 550 HBW is the default on mechanical and pneumatic units, with a 18-36 month service life in two-shift iron work, and 304/316 stainless is specified where sodium silicate or phenolic residue attacks the ferrous lining [S2]. Thermal fluidised-bed shells commonly run silicon carbide or alumina tiles in the hot zone above 600 °C, and the underbed plenum uses 304 stainless to resist sulphur-bearing fume condensation on furan lines [S5].
Stack emissions on a PUNB thermal reclaimer are dominated by VOC and CO from binder combustion; a 5 t/h unit typically needs an afterburner at 750-820 °C with 0.6-0.8 s residence time to drop VOC below 20 mg/Nm³, and on a furan line a wet scrubber on the acid-gas train is mandatory to keep SOx below the EU IED 2010/75/EU BAT-AEL envelope [S5].
Selection criteria summary
Four decision points decide the unit. Binder chemistry sets the route: PUNB to thermal at 700-800 °C; furan acid-catalysed to thermal with scrubbing or to pneumatic with restricted 80-85% reuse; resole ester or shell phenolic to mechanical attrition. Throughput sets the size: 1-3 t/h mechanical for job-shop enclosure work, 5-10 t/h pneumatic or thermal for medium-volume PUNB, 10-15 t/h thermal fluidised-bed for ductile iron enclosure cells at 100+ moulds per day. AFS recovery band of 50-70 with ±3 stability locks the unit to its downstream sand mixer cycle, and stack/emission compliance under ATEX 2014/34/EU plus EU IED 2010/75/EU gates the burner train [S2][S5].
Two signals to track next: any 2026 update to EU IED BAT-AEL on furan-line SOx limits, and Chinese-OEM thermal-reclaimer offerings below USD 120,000 at 3-5 t/h that would compress payback on a 5 t/h PUNB enclosure line from 36 to under 24 months at a fresh-sand cost of USD 90-140/t.
Background reading: Scaffolding selection for electrical installation: fibreglass, tower class, and.