ARBOK-Thallium (metal case)

Overview

Nobody mines thallium. There is no thallium mine anywhere and no thallium recycling anywhere. World supply is ~10,000 kg/yr, taken off flue dust from roasting copper, lead and zinc ores, produced by China, Kazakhstan and Russia. The US consumes ~25 kg/yr and imports 90% of it from Mexico. Price $9,300/kg (99.99% granules).

Those ten tonnes carry the world's radiation detection. NaI(Tl) is the scintillator in border radiation portal monitors, gamma cameras and dosimetry; Tl-201 is a cardiac tracer; thallium halides are IR optics; Tl-Ba-Ca-Cu-O carries among the highest superconducting transition temperatures. No drop-in substitute in the scintillator lattice.

The same element is odourless, tasteless and lethal at mg/kg body weight. China's lead-zinc discharge limit is <5 ug/L; the US drinking-water MCL is 2 ug/L — both tighter than selenium. Enforced by incident: 2021, a release from a zinc plant in Gansu reached the Jialing and the Yangtze, a reservoir measured 0.22 ug/L (2x the limit), the plant was shut and discharge prohibited.

The industry pays to destroy an element it cannot buy. Sulphide precipitation or oxidation + coagulation costs ~$1.1–3.9 M/yr on a 32,000 m³/day facility and produces a thallium-bearing hazardous sludge.

> Core technology: see ARBOK-VC (Vacuum Cracking) and ARBOK-VC (Vacuum Cracking).

Applications

Feedstock streams: acid water from lead-zinc smelter gas washing; copper roasting flue dust wash waters; sulphuric acid plant effluent on pyrite roasting; sulphide mine drainage.

Outputs: thallium as a dry separated fraction (refining to commercial spec is a separate step); returned water; no discharge; no sludge.

End uses: NaI(Tl) scintillators, Tl-201 radiopharmaceutical, KRS-5 IR optics, high-Tc superconductors.

Operating Principle

Phase separation under deep vacuum, in a single pass. Water leaves as condensate and returns to circulation; dissolved load leaves as dry separated fractions. No sulphide, no oxidant, no coagulant, no consumable.

Contrast with the incumbent is the argument: precipitation and coagulation do not recover anything — they move thallium from water into a sludge that must be characterised, stored and buried under licence, with the thallium still in it. Vacuum separation yields a fraction that can be refined instead of buried, and removes the outfall entirely.

Key Parameters

Thallium: $9,300/kg (99.99% granules). World output ~10,000 kg/yr. Producers: China, Kazakhstan, Russia.

US: ~25 kg/yr consumption; 90% of imports from Mexico; no domestic production; no recycling anywhere.

Limits: <5 ug/L discharge (China, GB 25466-2010 amendment, lead-zinc); 2 ug/L US drinking-water MCL.

Incumbent treatment: ~$1.1–3.9 M/yr on 32,000 m³/day, plus hazardous sludge.

Feed concentration (case basis): 0.05–1 mg/L concentrated gas washing; ~13 ug/L dilute mine drainage.

Source stream volume: ~500 m³/day per smelter gas-washing circuit.

Architecture and Components

Standard modular unit, 200 m³/day = 73,000 m³/yr. Deployment is distributed by design: several small units per source rather than one central plant — each stream differs in composition, and thallium is a poison, so hauling and interim storage of a toxic intermediate are avoided by treating in place.

Advantages

Technical: recovers instead of immobilising; no reagent chemistry to tune against a ug/L limit.

Operational: no sludge, therefore no licensed disposal chain and no custodial liability.

Regulatory: no discharge means the outfall leaves the regulated set — the 0.22 ug/L shutdown scenario ceases to exist.

Strategic: converts a three-country supply dependency into on-site domestic production.

Integrations

Lead-zinc and copper smelter gas-cleaning circuits; sulphuric acid plants; mine water systems. Connects to ARBOK-Selenium, ARBOK-Tellurium, ARBOK-Bismuth, ARBOK-Copper-Waters, ARBOK-SULPHUR, ARBOK-VC (Vacuum Cracking).

Deployment & Operation

Stream assay (Tl, Cd, Pb, Zn, As, acidity, TDS) → configuration → install on the existing gas-washing circuit. Purchase or BOOM with off-take on the thallium fraction.

TRL

ZWD platform TRL 9. Thallium-specific field reference pending. Refining of the recovered fraction to 99.99% specification is not demonstrated in-house and is costed separately.

Market Potential

Not a tonnage market — a bottleneck. Every lead-zinc smelter, copper roaster and pyrite acid plant inside a jurisdiction with a ug/L thallium limit is a candidate, and each is already paying for reagent treatment plus hazardous disposal. Buyer set for the metal is thin (scintillator crystal growers, radiopharma, IR optics) and must be secured before volume is promised.

Typical Project Economics

Basis: modules of 200 m³/day, 73,000 m³/yr.

• Dilute mine drainage at 13 ug/L: ~1 kg/yr = $9k. Not an investment case. On that stream only the avoided compliance cost pays.
• Concentrated gas washing at 0.05–1 mg/L: 3.5–73 kg/yr = $34–680k/yr per module
• One source (one smelter's gas washing, ~500 m³/day, 2–3 modules): 9–180 kg/yr = $85k–1.7 M/yr
• Avoided incumbent treatment on a large facility: up to $1.1–3.9 M/yr
• Avoided hazardous sludge disposal: additional, site-specific

National / global potential (order-of-magnitude estimate): US 0.03–1.8 t/yr; world 2–37 t/yr, i.e. from a quarter of present world output to several times it. Derived from source counts x concentration ranges — not measured. Requires plant-level assay before any commercial use.

Risk Factors

Tl concentration varies by two orders of magnitude between streams — assay per plant, never a point figure. The market is ~10 t/yr: material new supply moves the price, so the case must be led on supply security and avoided liability, not on revenue. Off-take is thin and must be secured. Acid, cadmium, lead and arsenic travel with thallium in the same stream — the separation must be specified for the whole matrix. The customer is a lead-zinc smelter, i.e. tonnage metallurgy, which sits outside the declared ARBOK target sector — the water is ours, the client is not.

Related Technologies

ARBOK-Selenium · ARBOK-Tellurium · ARBOK-Bismuth · ARBOK-Copper-Waters · ARBOK-SULPHUR · ARBOK-VC (Vacuum Cracking) · ARBOK-VC (Vacuum Cracking)