Overview
Gold's criticality is not scarcity but recovery efficiency in the aqueous phase. Three streams lose it. Cyanide leaching, which carries ~80% of the 3,300 t of world mine output, dissolves gold as the dicyanoaurate ion [Au(CN)₂]⁻; part never loads onto the carbon and leaves in recycle and tailings solutions that still assay 1–8 g/t. Electronic waste — ~72 million t in 2026, heading for 82 million t by 2030 — yields only 10–15% of its contained gold, losing roughly 228 t/year worth ~$29 billion at 2026 prices. Copper anode slime concentrates gold with the copper and needs its own leach. ARBOK recovers gold from all three on the same platform that already pulls rhenium, molybdenum and cobalt from industrial waters, concentrating dicyanoaurate and recovering the cyanide inventory instead of destroying it.
> Core technology and architecture: see ARBOK Critical-Materials Recovery. Ore, rock and seawater feedstocks: see ARBOK-GOLD (separate technology, TRL 5). This entry covers the aqueous streams, market, and economics.
Applications
Primary use cases: gold recovery from cyanide recycle, barren and tailings solutions; from e-waste board-leaching effluent; from copper anode-slime pregnant liquors.
Outputs/uses: gold for electronics contacts, connectors and aerospace; recovered cyanide inventory; copper; clean water.
Industries and users: gold miners, e-waste recyclers, copper refineries, electronics and aerospace supply chains.
Scale: container-class module; co-sited on existing solution circuits.
Operating Principle
Per the platform: the whole aqueous stream is concentrated by deep vacuum at ambient temperature; ballast salts separate by density and are valorized rather than fouling the sorbent; water is returned at 100% by volume. Dicyanoaurate concentrates in the residual liquor and is brought to product grade by a secondary pass through the same stage. Because cyanide is concentrated with the gold rather than oxidatively destroyed, the reagent inventory is recovered for reuse instead of being consumed and then detoxified. No high temperature or pressure, no mercury, no chemicals, membranes or consumables, no CO₂, fumes or noise.
Ore/rock/seawater route: ARBOK-GOLD binds gold without mercury or cyanide, viable from 1 g per 2.2 t of rock.
(Full mechanism: see platform entry.)
Key Parameters
Platform base: deep vacuum, ambient temperature, ~0.7 kWh/m³, 100% water return by volume, ZWD.
Resource: gold ~$129,000/kg (July 2026), forecast ~$161,000/kg at end-2026; world mine output 3,300 t with ~80% via cyanidation; sodium cyanide use >1.2 million t/year at 25–50 g per gram of gold.
Feed concentration: 0.5 mg/L Au used as design basis. Barren solutions run 0.01–0.05 mg/L; loaded and recycle solutions 1–5 mg/L; e-waste and anode-slime liquors by assay.
Module example: 200 m³/day (~70,000 m³/year) at 0.5 mg/L Au → ~35 kg gold/year.
Prior-art context: cyanide tailings 1–8 g/t; barren solutions give back 60–90% of cyanide and up to 99.98% of copper; e-waste gold concentration reaches 140 g/t.
Architecture and Components
Platform vacuum separation + density valorization of ballast salts + dicyanoaurate concentration with a secondary pass + cyanide inventory recovery; copper co-recovery. Container-class. (See platform entry.)
Advantages
Technical: recovers dissolved gold that carbon adsorption leaves behind; tolerant of high-salinity, extreme-pH, multi-metal leachates that foul sorbents and membranes.
Economic: one module ~$4.75M/year — ~$4.5M gold, ~$0.07M recovered cyanide, ~$0.07M water, ~$0.11M eliminated detoxification.
Environmental: 100% water return; cyanide returned to the circuit instead of destroyed; no mercury, no combustion, no CO₂.
Strategic: opens secondary gold — e-waste and process liquors — as a domestic feedstock for electronics and aerospace contacts.
Integrations
Co-locates with CIL/CIP and heap-leach solution circuits, e-waste hydrometallurgical plants and copper electrorefineries; cascades on the platform with copper and other metal recovery; complements ARBOK-GOLD on the ore side and DirtyGold on radiological compliance.
Deployment & Operation
Steps: liquor assay → recovery and secondary-pass configuration → module sizing → install on the existing solution circuit → commissioning. Container-class, automated, ambient conditions, renewable-compatible; BOOM or purchase.
TRL
TRL 9. Built on the industrially validated recovery platform already applied to rhenium, molybdenum and cobalt in industrial waters; dicyanoaurate secondary-pass configuration defined. Documented in an ARBOK preprint (July 2026).
Market Potential
Gold at ~$129,000/kg and rising, with no substitute in high-reliability contacts. The e-waste stream alone carries ~268 t/year of gold, of which ~228 t is lost; recovering 30% of the loss is ~68 t/year, approximately $8.8 billion. On the mining side, ~80% of 3,300 t of annual output passes through cyanide circuits that must be detoxified regardless, making recovery an addition to an existing obligation rather than a new operation.
Typical Project Economics
One module (~70,000 m³/year at 0.5 mg/L Au): ~35 kg gold/year → ~$4.5M/year, plus recovered cyanide (~$0.07M/year), returned water (~$0.07M/year) and eliminated detoxification (~$0.11M/year) — total ~$4.75M/year, of which ~$4.5M is product revenue and ~$0.25M is cost elimination. Output scales approximately linearly with feed concentration; on loaded solutions at 1–5 mg/L the gold line rises accordingly. BOOM available for zero operator capital.
Risk Factors
Feed concentration spans 0.01–5 mg/L across the three streams and is set by site assay; gold price volatility; cyanide handling and permitting at host sites; offtake and grade qualification; co-located with existing leach and refining circuits.
Related Technologies
ARBOK Critical-Materials Recovery · ARBOK-GOLD · DirtyGold · ARBOK-Copper-Waters · ARBOK-Cobalt