Or — who really runs your plant?
🏭 On July 13, 2026, a tonne of sulfur in Tampa cost $705. In 2024 it was 15 times less. Almost nobody mines sulfur: more than 90% of the world’s supply is a by-product of oil and gas, and half of seaborne trade goes through the Gulf. Hormuz closed — and the price did not rise, it exploded.
📊 Sulfur is sulfuric acid, the No. 1 chemical on the planet: about 260 million tonnes a year. Phosphate fertilizers take 60%. Everything else is copper, nickel, cobalt, lithium, batteries, oil refining. Whoever dissolves metal in acid is tied to the price of a tonne of sulfur in Tampa. That is the first noose.
💎 The second is pulled from the other side. In April 2025, China put 7 elements under export licence, among them yttrium, dysprosium, terbium and lutetium. US imports collapsed by 95% — from 333 tonnes to 17. A licence for a Western buyer takes 45–90 days. Yttrium in China costs about $35/kg, before April 2025 it was under $10; outside China — $80–120/kg, and one-off European lots have reached $250.
🧲 These are not just “metals”. Dysprosium is 1–6% of a magnet, and it is what keeps an electric motor running at 180 °C. Yttrium is the thermal barrier coating on turbine blades and the shield inside plasma etching chambers in chip production. No coating — no engine to ship.
⚖️ Now look at a hydrometallurgical plant. On one side it buys acid from those who hold the first noose. On the other it dumps into lime sludge the very metals on which the second noose hangs. It depends on someone else’s tap and pours out what the whole market is short of.
What does the plant throw away while it waits for someone else’s permission?
🧪 The scheme is the same for nickel, cobalt, copper, lithium. Acid is bought. It dissolves the ore or scrap. The metal goes into solution, and the waste is left with a lot of acid nobody needs any more. It is quenched with lime. Every tonne of acid gives 1.4 tonnes of gypsum and 0.45 tonnes of CO₂, plus hauling and burial of the sludge. The acid is bought, used, destroyed. Tomorrow they buy new acid.
🪨 Together with iron and aluminium, rare earths and yttrium go into the lime precipitate. Lime treatment costs $1–3 per cubic metre, and every cubic metre leaves 1–3 kg of dry sludge. For an effluent of 73,000 m³ a year that is 73 to 220 tonnes of sludge to be stored forever. The plant pays to turn expensive metals into sludge, then pays again to store the sludge.
🚫 Neutralization is the classic part of the technology — and it is the industry’s crutch: lime cost pennies while sulfur cost pennies. It is objectively time to ban that line in the budget.
🔬 Everyone knows industrial effluents contain everything we need, so why does nobody take it out? Economics, not chemistry. Sorption, ion exchange, extraction, precipitation, membranes — all of them charge per cubic metre of solution, while the revenue comes from the mass of metal in it. Concentration drops — the cost per cubic metre stays the same, the revenue per cubic metre melts. At 1 mg/L the lines crossed long ago. The best published method for pulling rare earths out of mine water costs $86–278 per gram, and its own authors write that this is 2 orders of magnitude above the market.
How do we loosen the first noose?
♻️ ARBOK technologies can fully restore spent acid by physical means, not with a long list of expensive reagents. The solution passes through deep vacuum at ordinary temperature: water evaporates and the acid returns for reuse. The acid — sulfuric, hydrochloric, nitric — does not evaporate under these conditions and concentrates as the water leaves. Dissolved metals and salts drop out as separate brines, acids or dry concentrates.
⚡ No neutralizer. No membranes. Electricity — up to 1–3 kWh/m³. Practically all the acid goes back into circulation, with almost no losses. No other technology can do this — in reverse osmosis, an acidic, salty solution of mixed metals instantly destroys both the membranes and the ion exchange. Phase separation does not care what is in the solution.
💰 The plant stops paying for 5 things: fresh acid, neutralizer, hauling and burial of the solution, lost acid, fines. Every tonne of acid returned to the cycle is also tonnes of sulfur that did not end up in sludge mountains — and no longer has to be bought from the monarchies of the Gulf.
🔄 Of course, this acid-cleaning cycle is not eternal: part of the acid is lost, and a growing plant needs new acid. The old answer was one — buy it. But sulfuric acid is sulfur, oxidized and dissolved in water: no sulfur — no acid. So “buy acid” in fact means “buy sulfur” from the very people who hold the first noose. Your own sulfur closes the question: it stays with you in sulfates from hydrogen sulfide, and arrives as ready sulfur and acid from the waste of a neighbouring refinery. Now the sulfur can be your own.
🥚 Hydrogen sulfide. The smell of rotten eggs, which industry has fought for half a century. It comes with associated water from oil and gas wells, from biogas plants, from sewers, from farms. Worldwide, about $12 billion a year goes into fighting it. Carbon, iron sponges, caustic scrubbers — $2.50 to $8 per cubic metre, and the bigger the flow, the bigger the bill. Pure waste, no product.
🛢️ ARBOK-HS takes water with hydrogen sulfide and works in the same mode — in vacuum, with no heating, catalysts or filters. Capture — 95–98% of the gas. Energy — 1 kWh per tonne against 50–150 for conventional methods. Cost about $0.54/m³. The output is clean water with 99.99% recovery, sulfur fixed in solid sulfates, and a dry organic substrate as fuel. Hydrogen sulfide stops being waste with fines and becomes raw material on your site.
🏗️ A refinery often stands next to the plant. ARBOK-SULPHUR extracts elemental sulfur and sulfuric acid from acid tars, oil sludge and sulfur-bearing effluents — with no SO₂ emissions, no gypsum, no brine. A 20-foot container; scale comes by adding modules. In the US alone, such sulfur in waste amounts to 1.5 to 3 million tonnes a year — about a third of consumption.
⛏️ By the way, the US closed its last sulfur mines when a tonne cost $80: unprofitable. Today it costs almost 9 times more. The mines are gone, and the sulfur lies in oil lagoons and effluents.
How do we loosen the second?
🧬 ARBOK works with the solvent, not the solute: it removes the water and leaves everything else. A cubic metre costs the same at 0.3 µg/L and at 9,900 µg/L. Iron, aluminium and sulfate, which in other methods eat sorbent and reagent, go into ballast dry fractions. The sludge is not “cheaper to dispose of” — it is not created at all. The output is a rare earth concentrate led by yttrium, with a heavy fraction of dysprosium and terbium, of a quality a separation plant accepts.
🧮 The value of the basket depends on dysprosium and terbium no less than on yttrium: heavy elements pull revenue up. The concentrate goes to a separation plant under contract, and the hydrometallurgical plant gets a line of income where a line of expense used to be.
🔋 While the solution passes through the same stage, it also holds cobalt. Cobalt has no mines of its own: it is a by-product of copper and nickel. Mining — the Congo, which accounts for 96,600 tonnes of about 220,000 tonnes of world output in 2026; refining — China. The price rose from $56 to $60/kg. And the same cobalt is already dissolved in effluents — on top of world mining and outside Chinese refining. Co²⁺ concentrates, a second pass in the same stage brings it to commercial grade, nickel and copper follow.
What does a closed loop look like?
🔁 Leaching hands over a solution with metal. The metal is taken, as before. The spent acid goes to ARBOK-ACID: acid and water return to leaching, salts and metals fall out as dry concentrates. Water with hydrogen sulfide, your own or a neighbour’s, goes to ARBOK-HS: the sulfur stays in sulfates instead of leaving as a fine. If a refinery is nearby, ARBOK-SULPHUR supplies the missing sulfur and acid. The effluents pass through the vacuum stage, and rare earths with yttrium go into a concentrate instead of sludge.
💵 One module — a 20-foot container, 200 m³ a day, 73,000 m³ a year. On mine effluent, where the law requires the water to be treated, it brings in up to $270,000 a year: lime no longer bought, plus metal. The metal is less than a quarter. At a hydrometallurgical plant that line gains what a mine does not have: acid that is not bought, and sulfur that is not shipped across the ocean.
📜 No permit condition is relaxed, and the water leaving is cleaner than after lime. The lime plant stays in place, switched off: the day-one fallback is the old scheme. On acid, the BOOM model applies: ARBOK takes the financing on itself, the plant owner needs no capital expenditure, and pays for volume.
What is missing?
🤝 There is no shortage of technology. All 3 run on one vacuum platform, which means they combine into one installation. What is missing is the customer’s strategic project for developing the technology in industrial form: a site that will open up its solution and its effluents. Such a site can be a nickel or cobalt plant, a battery recycler, the operator of an ash pond being closed, or a mine reclamation fund. One stream or a combination of technologies is enough. After that the path is short: stream analysis, calculation of the number of modules, installation in parallel with the existing treatment, start-up within the limits of the plant’s own permit, the rare earth concentrate — to a separation partner. No “pilots” — with mass use, all system parameters improve and costs fall. For us at the institute the word “pilot” is a curse word. It has no meaning. The regimes can be worked out in the first stage of a large contract.
🔌 The connection points are familiar to any process engineer: the leaching line and heap-leach collection, the copper extraction raffinate, the tailings water circuit, the effluents of a battery recycling plant, mine discharge. Every one of these streams already exists and is already paid for. What changes is what happens to it next.
📦 What the customer gets: acid not dragged halfway around the world but bought on its own site, the same way as sulfur that it does not ship, sludge that it does not create, metals that it does not send to the dump, and independence from two foreign permits. What it pays: for volume, not for an installation. ARBOK takes on the rest. All this under the BOOM business model, in which Arbok itself invests.
🌐 I am tired of reading that America or Europe are “looking for an alternative to Chinese rare earths”. There is no trace of such a search. The solution exists, yet I keep watching the concentrate go into lime next to their own plants, while the raw material is bought 12,000 km away. The alternative flows through the pipe. It is enough not to neutralize it, and to know how to handle what is in it.
🎯 A plant with a closed loop does not depend on a tonne of sulfur in Tampa, on a licence for yttrium that takes 45–90 days, or on a landfill for sludge. The others keep paying 3 times — each time for what they already hold in their hands.
⏳ The acid goes round in a circle. The sulfur stays at home. The yttrium lies in a container, not in a sludge pond. One thing is missing — the customer’s signature.