ARBOK-Tin

Overview

Tin is lost neither in the mine nor in the plating bath. It is lost in the rinse.

A part leaving a tinning bath carries out a film of bath solution — drag-out, 0.1–2 litres per square metre. At a bath concentration of 30–60 g/L Sn that is 3–120 grams of tin removed from the bath per square metre of treated surface. Drag-out is the dominant loss channel of a plating bath: to a first approximation, everything the shop tops the bath up with beyond what plated onto the part has left as drag-out. Rinsing the part then dilutes that film 500–1,000-fold, producing a rinse stream at 10–500 mg/L Sn in volumes one to three orders of magnitude greater than the bath itself.

Spent baths are regenerated, because concentration is high and volume is small. Rinse water is regenerated nowhere, because the cost of every established recovery technology scales with volume while the metal is present only in trace. It is instead precipitated with lime and caustic into a hazardous metal-hydroxide sludge. The plant pays for its tin three times: to buy it, to convert it into sludge, and to have the sludge taken away.

ARBOK-ZWD breaks the link between cost and concentration. A 0.5 mg/L stream and a 500 mg/L stream cost the same per cubic metre to process.

Applications

Solder. Roughly half of world tin demand. Every soldered joint on every board in the world. AI-server and data-centre construction is forecast to triple this demand by 2030.

Tinplate. Electrolytic tinning lines for food cans — the largest single pool of rinse-water tonnage.

Chemistry. PVC stabilisers, catalysts, tin chemicals.

Alloys. Bronze, pewter, bearing metals, lead-acid battery grids.

Operating Principle

Deep-vacuum phase separation carried out at ambient temperature. The process draws no external heat: the operating temperature simply tracks that of the incoming rinse stream and the surrounding environment, whatever the climate of the site. The process acts on the water, not on the solute: it removes the solvent and leaves everything that was dissolved in it. Consequently cost per cubic metre is fixed by the energy of phase change and is indifferent to what is dissolved or at what concentration.

Outputs from a tinning-line or PCB rinse stream:

• Clean water, 100% of input volume, returned to the rinse cascade. Discharge is zero.
• Dry ballast fractions at 10–15% residual moisture — chlorides, sulfates, methanesulfonate, base metals — handled as ordinary solids rather than as hazardous filter cake.
• A tin-bearing concentrate at a concentration the plant's existing electrowinning cell or a refiner will accept.

ARBOK does not replace the shop's metallurgy. The concentrate goes into the same electrowinning or remelt the shop already runs on its spent baths. What ARBOK removes is the volume problem that stopped that metallurgy from ever seeing the rinse water.

Key Parameters

Energy: < 1 kWh/m³ net (0.72 kWh/m³ with 98% condensation-heat recuperation). Operates under deep vacuum. Temperature: ambient — the process runs at the temperature of the incoming stream and the surrounding environment, with no external heating supplied at any site. Water return 100% by volume. Discharge 0%. Membranes, reagents, consumables: none. Salt fractions dry at 10–15% moisture. Standard module: a standard containerized unit, nominal throughput 200 m³/day = 73,000 m³/year.

Market context for the metal:

| | |

|---|---|

| Price | ~$56,000/t (August 2026), +66% year on year |

| World refined production | ~380,000 t/year |

| Balance | Deficit from 2026 — the first since 2021 (production +2–3%/yr vs demand +3.5%) |

| Mine production | China ~30%; Indonesia second and declining; DR Congo + Myanmar ~20% combined |

| Refining | China ~50% of world refined output |

| Chinese ore imports | ~60% from DR Congo and Myanmar |

| Reserve life | ~15 years — the worst of any major industrial metal |

| Demand | ~50% solder; AI-server demand forecast to triple by 2030 |

| Compliance | One of the four 3TG conflict minerals (Dodd-Frank 1502, EU Regulation 2017/821) |

Architecture and Components

A standard containerized module, nominal throughput 200 m³/day. Installed in parallel to match stream volume. Vacuum separation stage, clean-water return loop, dry-fraction extraction, tin concentrate take-off. No membrane cleaning cycle, no resin regeneration downtime, no reagent inventory. Existing precipitation plant retained but idled, so the day-one fallback is the status quo.

Advantages

Feedstock already paid for. The tin was mined, shipped, cleared and dissolved by someone else. The rinse water must be treated regardless.

Cost independent of concentration. The mechanism that kills ion exchange and solvent extraction below single-digit mg/L does not apply.

Matrix is not an interference. Acid, surfactants, brighteners, base metals and solids defeat resin capacity but report to the ballast fractions here as product.

Two liabilities removed at once. The hazardous hydroxide sludge is not treated more cheaply — it never forms. Reagent purchase and the precipitation plant's labour go with it.

Provenance. Tin recovered from a plant's own rinse water has a chain of custody one metre long. For a manufacturer under 3TG obligation it is the only tin in the supply chain whose origin is not an assertion. Currently unpriced.

Operationally. No membranes, no reagents, no consumables, full water return, containerised.

Integrations

Plug-in on the rinse return line. No process bath altered, no line chemistry changed, no production step modified. Concentrate routed to existing electrowinning or to a refiner. SCADA/PLC tie-in. Sits alongside ARBOK-GALVANIX where the whole galvanic water circuit is in scope.

Deployment & Operation

Effluent assay across the rinse cascade to establish flow and grade → module count and tie-in point → installation on the rinse return, precipitation plant retained but idled → commissioning against the plant's own water specification → concentrate to electrowinning.

TRL

TRL 8 by analogy with ARBOK-GALVANIX (galvanic effluent, same stream class) — confirm against deployment evidence.

Market Potential

Stream inventory, in order of grade and accessibility:

1. Tinning and plating line rinse waters — electrolytic tinplate, connector and leadframe plating, general metal finishing. Large continuous volumes, 10–200 mg/L Sn. The largest single pool by tonnage.
2. PCB manufacturing effluent — spent tin strippers are concentrated (tens of g/L), small in volume, and often already sold; the post-strip rinses that follow them are not, and carry 50–500 mg/L. Immersion tin and HASL lines add volume.
3. Semiconductor and advanced packaging — tin bump and pillar plating, etch and rinse. Moderate volume and grade, high water-quality spec for reuse, which favours a process returning distillate-grade water.
4. E-waste and secondary leachates — tin reports to solution alongside copper and the precious metals and is left in the raffinate.

Geographies: PCB manufacture in China, Taiwan, South Korea, Vietnam and Thailand; tinplate mills worldwide; semiconductor fabs; anyone under 3TG or EU 2017/821 due-diligence obligation.

Typical Project Economics

Basis: one ARBOK module, 200 m³/day, 73,000 m³/year, treating plating or PCB rinse water. Tin at $56,000/t.

Tin recovered (100% capture of dissolved tin):

| Grade | Tonnes/year | Value/year |

|---|---|---|

| 10 mg/L | 0.73 | $41,000 |

| 50 mg/L | 3.65 | $205,000 |

| 100 mg/L | 7.30 | $409,000 |

| 500 mg/L | 36.50 | $2,044,000 |

Water. 73,000 m³/year returned to the plant. Supply + sewer + heavy-metal surcharge at $2–5/m³ all-in = $150,000–360,000/year avoided.

Sludge. Conventional treatment generates 0.5–2 kg dry solids per m³ = 36–146 t/year dry, or 145–585 t/year as 25%-solids cake. Hazardous disposal at $150–400/t = $22,000–230,000/year avoided. Reagents (lime, caustic, flocculant) and the precipitation plant's labour are additional and not counted.

Aggregate for a typical 50 mg/L stream: approximately $500,000 per module per year — roughly 40% metal, 60% avoided cost. At the top of the grade range the metal dominates.

Scale. An average PCB plant discharges 500–2,000 m³/day = 3–10 modules. A large integrated tinplate mill exceeds this. The relationship is linear in measured flow.

Risk Factors

Assumptions requiring site-specific verification before any commercial proposal: the tin concentration of a given plant's rinse water (10–500 mg/L is the plausible envelope, not a prediction); the all-in water and discharge tariff; the local hazardous-waste disposal rate; capture efficiency, treated here as 100% of dissolved tin and in practice lower. An effluent assay resolves all four. No proposal should be built on the envelope.

Engineering ranges from the surface-finishing literature: drag-out 0.1–2 L/m², bath concentration 30–60 g/L Sn, rinse dilution factor 500–1,000, hydroxide sludge 0.5–2 kg dry solids per m³.

Price exposure. Tin is up 66% in a year on a deficit and a speculative bid. A reversion to $35,000–45,000/t cuts the metal line by 20–40%; the water and sludge lines are unaffected, which is why the "cheap metal, expensive problem" framing carries the low-grade cases.

Counterparty. Well-run shops already operate drag-out recovery tanks and counterflow rinsing, which lowers grade. That reduces the metal line but not the water or sludge lines, and those shops are the ones most likely to buy.

Related Technologies

ARBOK-GALVANIX · ARBOK-Bismuth · ARBOK-Indium · ARBOK Critical-Materials Recovery · ARBOK-Rhodium