Precious Metal Recovery & Refining System
— Turnkey Precious Metal Recovery & Refining Line
The precious metal recovery and refining system extract and purify valuable metals such as gold, silver, platinum, palladium, rhodium, iridium, ruthenium, and other precious metals from various waste materials, industrial waste, and secondary resources (E-waste). They are widely used in electronic waste recycling, metallurgical anode slime treatment, spent catalyst regeneration, jewelry waste treatment, and industrial precious metal waste recycling.
The system is engineered, manufactured and commissioned as one package: pre-treatment, leaching reactors, solid-liquid separation, solvent extraction and ion-exchange separation, electrowinning, melting & casting, plus complete environmental systems and PLC/DCS automation.
Product Overview
The Precious Metal Recovery & Refining System is a complete, turn-key hydrometallurgical plant for recovering and refining gold (Au), silver (Ag), platinum (Pt), palladium (Pd) and rhodium (Rh) from a broad range of feed materials — electronic waste, spent automotive catalysts, anode slime, jewelery scrap and mining concentrates.
Instead of high-temperature smelting, our system dissolves target metals into aqueous solution and separates them selectively through chemical refining. The result is a cleaner, more profitable process with three decisive advantages:
- Higher recovery — total gold recovery ≥ 99%; PGM recovery 88–96%; overall system metal loss held under 1%
- Higher purity — gold and silver up to 99.99% (four nines), platinum group metals 99.95–99.99%
- Lower cost & emissions — low-temperature aqueous processing, reduced energy use versus smelting, NOx/Cl₂ fumes scrubbed and wastewater treated to discharge standards
The system is engineered, manufactured and commissioned as one package: pre-treatment, leaching reactors, solid-liquid separation, solvent extraction and ion-exchange separation, electrowinning, melting & casting, plus complete environmental systems and PLC/DCS automation. Capacities range from pilot scale (1–5 kg/batch) to industrial scale (100+ kg/day), with gold-only lines, silver lines, PGM lines or fully integrated multi-metal plants.
Recovery Value
- Gold (Au): ~USD 4,350–4,413/oz (≈USD 140–142/g)
- Silver (Ag): ~USD 64.6–66.3/oz (≈USD 2.1/g)
- Platinum (Pt): ~USD 1,725–1,759/oz (≈USD 55–57/g)
- Palladium (Pd): ~USD 1,285–1,408/oz (≈USD 41–45/g)
- Rhodium (Rh): ~USD 8,240–8,800/oz (≈USD 265–283/g)
- Iridium (Ir): ~USD 7,830–7,850/oz;
- Ruthenium (Ru): ~USD 1,670–1,675/oz
Typical feedstock value (Aug 2026 basis)
- 1 ton of PCB / motherboard scrap — 200–300 g gold, worth roughly USD 28,000–42,000 in gold alone, plus silver, palladium and copper
- 1 ton of older-generation mobile phones — about 200 g gold, worth roughly USD 28,000
- 1 spent catalytic converter — typically several grams of Pt and Pd plus 0.2–0.8 g of Rh; intrinsic precious metal value around USD 200–250 per unit (market buying price varies with metal prices and model)
- Anode slime — 20–40% gold content, the highest-value intermediate, returned directly to the refining line
Recovery performance
- Gold (Au): recovery ≥ 99%, purity up to 99.99%
- Silver (Ag): recovery ≥ 97%, purity up to 99.99%
- Platinum (Pt) from spent catalysts: recovery 88–94%, purity 99.95–99.99%
- Palladium (Pd) from spent catalysts: recovery 88–96%, purity 99.95–99.99%
- Rhodium (Rh) from spent catalysts: recovery 84–94%, purity 99.95–99.99%
Send us your feedstock data and we will prepare a metal balance, payback analysis and ROI projection free of charge.
Applicable Raw Materials
The primary target of precious metal recycling and refining is various industrial wastes, byproducts, and post-consumer waste containing high-value extractable precious metals (such as gold, silver, platinum, palladium, rhodium, ruthenium, and iridium), encompassing multiple industrial sectors and various waste types. This system is tailored to your materials and mainly includes:
E-waste & electronics
- Waste PCB boards and motherboards (200–300 g gold per ton, plus silver, palladium and copper)
- Mobile phone boards, CPUs, memory modules and SIM cards
- Gold-plated connectors, fingers and plating scrap
- Electronic components (capacitors, relays, contacts)
Spent catalysts
- Spent automotive catalytic converters (Pt, Pd, Rh)
- Petrochemical reforming catalysts (Pt-Sn, Pt-Re)
- Chemical and hydrogenation catalysts (Pd, Pt, Rh)
Smelting intermediates
- Copper/gold electrolytic anode slime (20–40% gold)
- Smelting slag, flue dust and precious metal melting residues
Jewelery & industrial scrap
- Used jewelery and workshop sweeps
- Polishing dust and gold-bearing ash
- Gold/silver plating solutions and electroplating anode slime
- Dental alloys
Mining concentrates
- Gold ore and flotation concentrates (1–10 g/t ore grade)
- Silver-bearing concentrates
- PGM flotation concentrates
Not sure whether your material is suitable? Send us a sample — our laboratory will run fire assay / ICP analysis and recommend the optimal process flow.
Precious Metal Recovery And Refining Process Flow
Every refining line follows our proven six-step hydrometallurgical route, with clear process objectives, key parameters and quality control points at each stage. The entire line is automated by PLC/DCS for consistent, repeatable results.
Step 1: Pre-treatment — Enrichment & De-contamination
Dismantling to remove casings, batteries and plastics → two-stage crushing and screening → rotary kiln roasting (350–550°C) to remove organics → magnetic separation for iron and eddy-current separation for aluminum/copper matrices.
The goal is to multiply the precious metal grade while preventing organics from consuming reagents in leaching. Key control points: output particle size of 80–200 mesh; roasting temperature must avoid metal sintering (too hot) or incomplete organic removal (too cool).
Step 2: Leaching — Dissolving Precious Metals into Solution
The leach system is selected according to feedstock composition:
- Aqua regia system (gold, platinum, palladium): HCl:HNO₃ ≈ 3:1, 60–95°C, gold dissolves as HAuCl₄ with leaching rate ≥ 98%
- HCl + oxidant system (controlled-potential chlorination): Cl₂ or H₂O₂/NaClO₃ with real-time ORP monitoring for selective dissolution — base metals stay in the residue
- Nitric acid system (silver & base metals): dissolves silver and copper/nickel matrices while precious metals enrich in the residue
- Pressure oxidation leaching (optional): HCl + O₂ in an autoclave at 100–150°C for refractory materials and PGM concentrates
Temperature, acidity, ORP, reaction time and liquid-to-solid ratio are all automated; fumes are scrubbed under negative-pressure ventilation.
Step 3: Solid-Liquid Separation — The Value Gate
Leach slurry is filtered through plate & frame / membrane filter presses. The filtrate proceeds to separation, while the filter cake undergoes 2–3 stages of counter-current washing to recover entrained precious metal solution.
Cake moisture, wash water volume and wash liquor concentration are assayed batch by batch to hold precious metal loss below 1%; polishing filters protect downstream extraction and resin systems.
Step 4: Purification & Separation — The Core Stage
- De-contamination: base metals (Cu, Fe, Ni) removed first and metal oxidation states adjusted
- Solvent extraction (SX): metals separated one by one in mixer-settlers by multi-stage counter-current extraction in the order Gold → Platinum → Palladium → Rhodium — DBC/TBP for gold, amine extractants (e.g. Alamine 336) for platinum, oxime/amine extractants for palladium
- Ion exchange (IX): anion-exchange resins adsorb PtCl₆²⁻ and PdCl₄²⁻ complexes, ideal for polishing low-concentration solutions
- Precipitation / cementation: ammonium chloride precipitation for platinum, dimethylglyoxime precipitation for palladium, silver chloride precipitation followed by zinc/iron cementation
Rhodium separation is the most difficult; our multi-stage extraction + ion-exchange combination reaches 84–94% rhodium recovery from spent catalysts.
Step 5: Reduction / Electrowinning — Recovering Pure Metal
Gold solutions are reduced with SO₂ (the purest option), oxalic acid or sodium sulfite; gold powder is washed to neutral and dried. Electrolytic refining produces 99.99% gold and silver. Low-concentration solutions are recovered directly by electrowinning.
Reduction endpoint is verified with the stannous chloride test to avoid gold residue in the mother liquor; electrolytes are regularly assayed for acidity, metal concentration and impurities.
Step 6: Melting & Casting — Finished Product
Vacuum drying → medium-frequency induction melting (above 1,064°C) → graphite crucible casting → ingot mold forming → ingot-by-ingot QC by ICP-OES spectrometer, with a purity report issued with every shipment. Standard 1 kg / 5 kg / 12.5 kg gold ingots and custom shapes available.
Metal-specific process lines (customizable)
- Gold line: aqua regia / controlled-potential chlorination / electrolytic refining / solvent extraction — choose one or combine
- Silver line: nitric acid leaching + Möbius electrolysis, purity 99.99%
- PGM line: dissolution → solvent extraction → reduction → calcination, producing sponge platinum, sponge palladium and high-purity metal salts
- E-waste line: base-metal matrix leaching to remove impurities and enrich precious metals, then into the gold/PGM refining section
- Spent catalytic converter line: carrier crushing → sulfuric acid leaching of carrier → aqua regia / HCl+Cl₂ leaching of precious metals → solvent extraction separation of Pt, Pd, Rh
Main Equipment
Pre-treatment — jaw/hammer crushers, ball mill, rotary kiln, vibrating screen, magnetic & eddy-current separators
Leaching & reaction — glass-lined reactors (aqua regia duty), titanium reactors (nitric acid), PP-lined leach tanks, Hastelloy-lined pressure autoclaves, agitation & heating systems, chlorine gas distribution
Solid-liquid separation — plate & frame filter presses, membrane filter presses, rotary vacuum filters, centrifuges, clarifiers & polishing filters
Separation & purification — mixer-settler solvent extraction units, pulse extraction columns, ion-exchange columns, precipitation reactors, cementation tanks
Reduction & electrolysis — reduction reactors, gold/silver electrolytic cells, electrowinning cells, rectifiers
Melting & QC — medium-frequency induction furnaces, graphite crucibles, ingot molds, mold pre-heaters, ICP-OES / spark spectrometers
Environmental systems — fume scrubbers (caustic/urea absorption for NOx & Cl₂), wastewater treatment (neutralization, precipitation, ion-exchange), ventilation, PLC/DCS automation
Key Notes & Cautions
Feedstock handling
- Grade and price materials by handheld XRF screening plus fire assay / ICP arbitration — never by visual estimation
- Silver-rich feeds should go through the nitric acid / electrolysis route first: silver reacts with chloride to form AgCl passivation that encapsulates gold in aqua regia
- E-waste and spent catalysts are hazardous waste in most jurisdictions — verify supplier licenses and keep a traceability ledger
Process operation
- Aqua regia: add acid to material slowly with temperature control to prevent boil-over; prepare fresh before use; connect NOx fumes to the scrubber
- Controlled-potential chlorination: monitor ORP and acidity in real time for selective dissolution
- Counter-current washing is mandatory at solid-liquid separation; assay cake and filtrate separately
- Use SO₂ for the cleanest gold reduction; check reduction endpoint with stannous chloride; wash gold powder to neutral before drying
- Prevent emulsion in solvent extraction: clarify and de-oil the feed solution, keep agitation moderate, regenerate extractants
Safety & compliance
- NOx and Cl₂ off-gas must be scrubbed to discharge standards; install gas alarms in the working area
- Hydrazine and hydrogen used in reduction are toxic/flammable — manage as hazardous chemicals
- Hazardous waste (residues, effluents, spent carbon) must be handled under a hazardous waste operating license; complete environmental assessment and discharge permits before commissioning
- Equipment material limits: glass-lined reactors avoid hydrofluoric acid and strong alkalis; titanium avoids hydrofluoric acid and hot concentrated HCl
Business management
- Maintain a metal balance ledger: sample and assay every batch in and out, reconcile monthly, investigate any loss above 1%
- High-value asset security: vault, CCTV, dual-person dual-lock, and in/out registration
- For buyout (toll-free) models, hedge metal price exposure or keep inventory turnover fast
- Double-verify product purity with ICP and fire assay; issue quality reports with every shipment
FAQ
Q1: What purity can your recovery and refining system achieve?
Gold and silver up to 99.99%; platinum, palladium and rhodium up to 99.95–99.99%.
Q2: What materials can you process?
E-waste (PCB boards, phone boards, SIM cards), spent catalytic converters, anode slime, jewelery scrap, dental alloys and mining concentrates. Send a sample for free laboratory testing.
Q3: Is rhodium recovery included?
Yes. Multi-stage solvent extraction combined with ion exchange achieves 84–94% rhodium recovery from spent catalysts.
Q4: What is the minimum capacity?
Lines start from pilot scale (1–5 kg/batch) up to industrial scale (100+ kg/day). Tell us your feedstock volume and we will size the system.
Q5: Do you provide installation and training?
Yes — installation supervision, commissioning and full operator training are included with every line.
Q6: How do you handle environmental and hazardous waste regulations?
We design fume scrubbing and wastewater treatment to local discharge standards and advise on the hazardous waste permits required in your region.
Get services for free
Ready to start recovering value from your material? Send us your sample and target capacity — our engineers will provide a process proposal and quotation within 5 working days.
- +86 18339216321
- info@yusaipreciousmetals.com
- Zhengzhou.Henan.China
If you are interested in our equipment, please feel free to contact us!
- +86 18339216321
- info@yusaipreciousmetals.com
- zhengzhou.henan.china
