Overview
Sludge from mine water and landfill leachate is normally paid for twice: once to generate it through neutralization or filtration, and again to haul it to landfill. Inside that same sludge sits germanium at $8,597/kg, along with gallium, vanadium and other critical and rare-earth metals — the same substances that make the waste hazardous also make it valuable, and the reason they are not recovered is not chemistry but the absence of a technology that produces a usable concentrate rather than more waterlogged waste.
TEGFIL is a bed of thermally expanded graphite that sits directly on that stream and delivers a dry concentrate by gravity, with no electricity in its base configuration. The carrier is a depth filter, not a surface filter: capture is distributed through the full thickness of the bed, so the mechanism keeps working long after a surface-type medium would have blinded. It is chemically inert across the entire acidity range including nitric acid, is not wetted by water, and does not burn — properties that let it sit on streams that destroy membranes, sand and activated carbon in the same service.
Once loaded, the bed becomes the product rather than the waste. Two recovery routes follow from the same carrier: calcination burns away the graphite and concentrates whatever it captured into a dry residue, appropriate for streams rich enough that the carrier's one-time cost is immaterial; acid or alkali leaching strips the captured metal in solution while the carrier survives and returns to service, which divides the carrier's cost by the number of cycles and brings ordinary, low-grade, high-volume streams — ordinary mine water, ordinary leachate — into a positive economic case.
Applications
Tailings ponds and acid mine drainage. On the discharge downstream of neutralization and precipitation, in a working band of 10–1,000 mg/l suspended solids, replacing the thickener-plus-filter-press pairing with a vessel and a charge of graphite.
Landfill leachate — guard stage ahead of the expensive equipment. Installed directly ahead of reverse osmosis, an evaporator, or a zero-discharge system, replacing the polymer pre-filter that fails within weeks on oil, biofouling and abrasives, and protecting the service life of the membrane or evaporator behind it.
Flue gas cleaning and mercury capture. On moderate-temperature gas streams downstream of the primary stage, replacing the pairing of a temperature-limited fabric baghouse (which forces deliberate cooling of the gas stream) and a carbon adsorber (which is a recognized fire risk).
Oily waters. Stormwater from industrial sites, produced water, ship bilge water, and effluent from wash bays and depots, replacing energy-consuming coalescing and flotation units with a passive, unattended point on the perimeter of a site.
Users: operating mining and processing plants with problematic water circuits; operators of closed and orphaned sites with no power and no staffing; publicly funded remediation programs; municipal landfill operators with a polishing stage installed; coal-fired power, non-ferrous metallurgy, cement and waste-to-energy operators with mercury written into their permit; ports, transport depots and refineries with monitored stormwater outfalls.
Operating Principle
Thermally expanded graphite is a carbon structure of high porosity that works as a depth filter: capture is distributed through the full thickness of the bed rather than concentrated at a surface, so the bed does not blind the way a membrane or a cloth does. It is chemically inert across the entire acidity range, including nitric acid; it is not wetted by water, so it separates hydrocarbons from water on the wetting differential alone, with no reagents and no moving parts; and it does not burn, which is why it survives hot flue-gas duty where a fabric baghouse or a carbon adsorber cannot. On calcination the carrier burns away completely, concentrating whatever it captured into the residue that remains — the mass ratio of captured solids to carrier is high, so there is almost no carrier left in the final concentrate. Because the graphite itself is not destroyed by acid or alkali and loses no mass over a leaching cycle, a loaded cartridge has a second route besides the furnace: the captured metal is stripped from the carrier in solution, and the carrier goes back to work. Calcination into concentrate is the route suited to a valuable stream; leaching with return is the route suited to a large one.
Three deployment forms follow from the same material: as a fixed bed inside a vessel, sized to the flow it is treating; as a guard cartridge ahead of an expensive downstream stage, swapped rather than washed when spent; and as loose powder, scattered directly into a flow or onto a pond, where it is far lighter than water, floats, collects suspended matter and oil film onto itself, and is skimmed off with a net, a screen or a boom — the only deployable option on an orphaned, unpowered site with no engineering budget.
Key Parameters
Bed porosity: high, engineered for depth filtration. Capture capacity: a high ratio of captured solids to carrier mass. Working band, tailings and acid mine drainage: 10–1,000 mg/l suspended solids. Flue-gas duty: moderate temperature range, downstream of the primary stage. Acidity tolerance: pH 2–4 tolerated on mine water; chemically inert across the full acidity range including nitric acid. Bed format: a gravity-fed vessel sized to flow; a pump is required only where gravity flow is geometrically impossible. Electrical supply: none required in the base configuration. Waste-volume reduction after incineration as fuel: up to 20×. Enrichment relative to the incoming stream: tens of times. Radioactive-waste volume reduction on calcination: 10–20×. Germanium market price cited as context for the recoverable value: $8,597/kg.
Comparison with what is installed today:
| Property | Membrane | Sand | Carbon | TEG |
|—|—|—|—|—|
| Acidic stream | degrades | holds | loses properties | holds |
| Oil in the flow | blinds | breakthrough | clogs | captures |
| Hot gas | no | no | burns | works |
| Energy | pressure | pressure | pressure | gravity |
| Fate of spent media | landfill | no enrichment | furnace regeneration | concentrate |
| What comes out | a cost | a cost | a cost | a feedstock |
Architecture and Components
A vessel holding a charge of thermally expanded graphite, sized to the flow, with gravity-driven inlet and outlet and a pump fitted only where gravity flow is geometrically impossible. Throughput scales with bed area, not with pressure, because the bed is compressible and raising the head adds no flow. Three deployment configurations on the same material: a fixed-bed vessel for continuous duty on tailings, leachate or oily-water streams; a guard cartridge installed ahead of a membrane, evaporator or zero-discharge stage, changed rather than washed; and loose powder for no-hardware deployment on unpowered or orphaned sites, recovered by net, screen or boom. Downstream of the bed: a calcination stage for valuable, low-volume streams, or an acid/alkali leaching stage that recovers the captured metal while returning the carrier to service.
Advantages
Chemically inert where the alternatives fail. Holds across the full acidity range including nitric acid, where membranes degrade and carbon loses its properties.
Handles oil where the alternatives blind or clog. Captures hydrocarbons on the wetting differential instead of blinding like a membrane or clogging like a carbon bed.
Works on hot gas where the alternatives cannot. Does not burn, removing both the fabric-temperature limit that forces gas pre-cooling ahead of a baghouse and the fire risk inherent to a carbon adsorber.
Runs on gravity, not pressure. No electrical supply required in the base configuration — the only scheme that functions unattended on a site with no grid connection.
Output is a feedstock, not a cost. The other three technologies are optimized to meet a discharge limit at minimum extra spend; TEGFIL reverses the sign — the more it captures, the more concentrate accumulates.
The carrier can outlive a single use. Where leaching with return applies, the carrier's cost divides by the number of cycles, extending the economic case from rich streams to ordinary, high-volume ones.
Integrations
Base material supplied by Thermally Expanded Graphite (TEG). Installed as a guard stage ahead of reverse osmosis, evaporation or zero-discharge treatment trains, complementing ARBOK-EFFLUENT. Shares its hydrophobic, oil-affinity separation mechanism with OILTRAP, which uses the same material for marine and land oil-spill recovery. Concentrate output feeds the same class of downstream metals-recovery step addressed by ARBOK Critical-Materials Recovery and, for streams carrying germanium and gallium specifically, ARBOK-Germanium-Gallium. The underlying economics — an obligated treatment cost that also yields a saleable concentrate — parallel the case built for ARBOK-Yttrium on acid mine drainage.
Deployment & Operation
A vessel is sized to the site's flow and charged with graphite; where the application is a guard stage, the cartridge is installed ahead of the membrane, evaporator or zero-discharge unit it is protecting. Operation requires no chemical dosing and, in the base configuration, no electrical supply. Maintenance consists of changing a cartridge once it is loaded; spent cartridges accumulate and are processed in batches, either by calcination for streams rich enough that the carrier's cost is immaterial, or by acid/alkali leaching where the carrier is returned to service and the recovered metal is taken off in solution. On an unpowered or orphaned site with no vessel and no engineering budget, the same material is deployed as loose powder directly onto the flow or the pond surface and recovered by net, screen or boom — the value captured there is the enforcement notice cleared, not the metal.
TRL
The base material, thermally expanded graphite, is produced in-house at ARBOK today and is relied upon by shipped products, placing the material itself at TRL 8–9 (see Thermally Expanded Graphite (TEG)). TEGFIL is a specific filtration application of that material; a TEGFIL-specific TRL figure and field-deployment record, independent of the base-material analogy, [требует уточнения из базы].
Market Potential
Four streams, each already generating an obligated or regulated cost that TEGFIL displaces or monetizes: acid mine drainage and tailings-pond discharge at operating and orphaned mine sites, where treatment is mandated by permit or reclamation obligation; landfill leachate ahead of membrane or evaporator trains at municipal and industrial sites, where the guard-stage market is set by the service life of the equipment it protects; flue gas cleaning at coal-fired power, non-ferrous metallurgy, cement and waste-to-energy plants, wherever mercury is written into the operating permit and gas temperature exceeds what fabric filtration tolerates; and oily-water and stormwater treatment at ports, refineries and transport depots with monitored discharge points. A distinct, higher-value segment sits in rich, low-volume streams — electroplating rinse waters, refinery slimes, catalyst solutions, electronics-etching effluent — carrying gold, silver, palladium, platinum, indium and rhenium, where the value travels as particles and colloids that a depth filter is suited to collect.
Typical Project Economics
Germanium, cited directly against a mine-water and leachate stream, trades at $8,597/kg — one indicator of the value sitting inside sludge streams that are currently paid for as waste.
Disposal-cost economics dominate for low-level radioactive and other high-disposal-cost residues. Disposal of low-level radioactive waste runs into thousands of dollars per cubic metre, and a 10–20× volume reduction from calcination repays the carrier many times over even where the concentrate contains nothing separately saleable; the same logic applies to mercury under an emissions permit, where the payment is for compliance rather than for metal.
Waste-volume reduction translates directly into hauling and landfill savings. Incineration of the loaded carrier as fuel reduces waste volume by up to 20×, a saving calculable directly from a site's existing sludge-disposal invoices.
Enrichment sets the value of the concentrate. Relative to the incoming stream, enrichment in the captured residue runs into tens of times, moving metals such as germanium, gallium, vanadium and rare earths — present in mine water at concentrations where sorption schemes do not pay back — into a grade worth handling.
The carrier-return route changes which streams qualify. Where the carrier is single-use, the case depends on the captured metal being worth more than the carrier — a narrow band of genuinely rich streams. Once the carrier is returned by leaching, its cost divides by the number of cycles, the payback threshold drops by an order of magnitude, and ordinary mine water and ordinary leachate — low grade, large volume — come into scope.
No vendor CAPEX figure is given in the source material for a standard TEGFIL installation; the qualitative cost position is a single vessel and a charge of graphite, against a thickener-and-filter-press train, a coalescing/flotation unit, or a cooled baghouse for the displaced alternative.
Risk Factors
Concentrate value is stream-specific and requires assay. The metals basket and its grade at a given discharge determine whether calcination or leach-and-return applies, and neither route is validated by the source material against a site's own sampling data.
Disposal and hauling savings are site-specific. They are stated as calculable from a site's own invoices, not as a general figure that transfers across sites.
Carrier-return durability across leaching cycles is asserted, not quantified. The source material states that the carrier loses no mass over a leaching cycle but does not report a cycle count or a service-life figure for the carrier under repeated leaching [требует уточнения из базы].
Flue-gas application depends on upstream primary-stage performance. TEGFIL is positioned downstream of a primary gas-cleaning stage, not as a standalone solution for raw flue gas.
Loose-powder deployment recovers a fraction of what a vessel captures. It is presented as the only option for unpowered, orphaned sites, not as equivalent in yield to a fixed-bed installation.
Related Technologies
Thermally Expanded Graphite (TEG) · OILTRAP · ARBOK Critical-Materials Recovery · ARBOK-Yttrium · ARBOK-Germanium-Gallium · ARBOK-EFFLUENT