Uranium mining and milling involves extracting uranium ore, grinding, acid leaching (usually H₂SO₄), solvent extraction or ion exchange, and precipitating yellowcake (U₃O₈). Pumps handle acidic leach slurry, radioactive materials, and corrosive chemicals. This guide covers pump selection for uranium mining and milling operations.
Uranium Process and Pump Services
| Service | Fluid | Temp | Key Characteristic | Pump Type |
|---|---|---|---|---|
| Ore slurry (ground ore + water) | Uranium ore slurry (50–70% solids, ground to ＜75 μm) | Ambient–50°C | Very abrasive (silica, ore), corrosive (acid if pre-acidified), viscous, large flow, settling | Heavy-duty slurry pump (high-chrome/rubber-lined, large passage, expeller seal) |
| Acid leaching (H₂SO₄) | Ore slurry + H₂SO₄ (5–15% acid, pH 1–2) | 40–80°C | Very corrosive (hot acid), very abrasive (ore), radioactive, large flow, scaling (gypsum) | Rubber-lined slurry (acid + abrasion, hot, large passage, expeller seal) or high-chrome |
| Leach slurry transfer | Acid leach slurry (U dissolved, 30–50% solids) | 40–80°C | Corrosive (acid), abrasive, radioactive, large flow, scaling | Rubber-lined slurry (acid + abrasion, large passage, hot) |
| Counter-current decantation (CCD) | Leach slurry (thickening, washing) | 40–70°C | Corrosive (acid), abrasive, radioactive, large flow, settling, precise underflow | Slurry pump (large passage, acid-resistant, underflow control) |
| Solvent extraction (SX) feed | Clarified leach solution (acidic, U-bearing, low solids) | 30–50°C | Corrosive (acid + organic), radioactive, moderate flow, clean (after filtration), emulsification | 316L/duplex centrifugal or fluoroplastic (acid + organic, clean, large passage) |
| SX organic (extractant + diluent) | Organic phase (amine/phosphate extractant in kerosene/diluent) | 30–50°C | Flammable (kerosene), corrosive (organic), viscous, precise, hazardous | Gear pump or screw pump (positive displacement, flammable-rated, organic-compatible) |
| SX stripping (acid strip) | Loaded organic + H₂SO₄ (stripping solution) | 30–50°C | Corrosive (acid), flammable (organic), radioactive, precise, emulsification | Magnetic drive fluoroplastic or 316L (zero leakage, acid + organic) |
| Ion exchange (IX) feed | Clarified leach solution (acidic, U-bearing) | 30–50°C | Corrosive (acid), radioactive, moderate flow, clean, fouling (resin) | 316L/duplex centrifugal (acid-resistant, clean, large passage) |
| IX eluent (HCl/H₂SO₄) | Acid eluent (1–3 M HCl or H₂SO₄) | Ambient–50°C | Highly corrosive, precise, radioactive, hazardous | PTFE diaphragm metering or magnetic drive fluoroplastic (zero leakage, acid) |
| Uranium precipitation (yellowcake) | U-rich solution + NaOH/ammonia/MgO (pH 6–8) | 50–80°C | Corrosive (alkaline transition), radioactive, precipitating (U₃O₈), scaling, hot | Slurry pump or 316L/duplex (precipitation, hot, radioactive, large passage) |
| Yellowcake slurry (product) | U₃O₈ slurry (20–50% solids) | 50–80°C | Radioactive, abrasive, hot, viscous, corrosive (alkaline), hazardous | Slurry pump or peristaltic (radioactive, abrasive, hot, gentle, sealed) |
| Acid dosing (H₂SO₄) | Concentrated sulfuric acid (93–98%) | Ambient | Highly corrosive, precise dosing, hazardous, exothermic, large quantity | Magnetic drive fluoroplastic or PTFE metering (zero leakage, acid, large flow option) |
| Oxidant dosing (MnO₂/H₂O₂/NaClO₃) | Oxidant solution (MnO₂ slurry, H₂O₂, NaClO₃) | Ambient | Corrosive (oxidizing), abrasive (MnO₂), precise, hazardous | Diaphragm metering (MnO₂ = slurry pump) (oxidizing, precise, zero leakage) |
| Neutralization (limestone/lime) | Limestone slurry (CaCO₃, 10–30% solids) or lime | Ambient–50°C | Abrasive (limestone), scaling (gypsum), alkaline, viscous, large flow | Slurry pump or peristaltic (abrasive, scaling, alkaline, large passage) |
| Tailings slurry (waste) | Leached ore tailings (30–60% solids, acid, radioactive) | 30–60°C | Very abrasive, corrosive (acid), radioactive, large flow, settling, environmental | Heavy-duty slurry pump (high-chrome/rubber-lined, large flow, acid-resistant, expeller seal) |
| Tailings pond water (recirculation) | Acidic water (pH 2–4, heavy metals, radioactive) | Ambient–40°C | Corrosive (acid + heavy metals), radioactive, scaling, large flow, environmental | 316L/duplex or fluoroplastic (acid-resistant, large flow, radioactive) |
| Wastewater treatment | Acidic wastewater + radium/heavy metals | Ambient–50°C | Corrosive, radioactive, scaling, toxic (Ra, heavy metals), environmental | 316L/duplex or slurry (corrosion, radioactive, solids) |
Critical: Acid Leach Slurry (Hot Acid + Abrasive + Radioactive)
Acid leaching is the most demanding pump service in uranium milling:
- Hot acid + abrasive: 5–15% H₂SO₄ at 40–80°C + ground ore (silica, ＜75 μm). Use rubber-lined slurry pump (natural/butyl rubber resists acid + abrasion, ＜80°C). Or high-chrome iron (A532 III) for higher temp/abrasion. NO 316L (abrasion removes passive layer → acid corrosion). NO carbon steel (rapid acid attack). Large passage open impeller. Expeller seal (no mechanical seal to wear out in slurry). Plan 32 clean water flush (acid-free).
- Radioactive: Uranium ore and leach slurry are radioactive (U-238, Ra-226, Rn-222 gas). Use sealed pump (containment). Remote operation. Shielding (concrete, lead). Radiation monitoring. PPE. Secondary containment. Closed system. Gas detection (radon). Maintenance procedures (ALARA). Our slurry pumps can be supplied with sealed configurations.
- Scaling (gypsum): H₂SO₄ + limestone (gangue) → CaSO₄·2H₂O (gypsum) scale. Large passage. Velocity ＞2 m/s. Flush with water on shutdown. Periodic acid wash (but pump is already in acid — use water flush). Open impeller. Rubber-lined (smooth rubber resists scale adhesion).
- Large flow + settling: Leach circuits are large (100–1000 m³/h slurry). Flooded suction. Large suction lines. Velocity ＞3 m/s (prevent settling). Continuous operation. Multiple parallel pumps. N+1 redundancy. Wear life 3–12 months (monitor vibration/performance).
Critical: Solvent Extraction (Acid + Flammable Organic + Radioactive)
- Acid + organic: SX handles acidic aqueous (pH 1–2) and flammable organic (kerosene + extractant). Use magnetic drive fluoroplastic pump (zero leakage, acid + organic). Or 316L centrifugal for aqueous (clean, low solids). PTFE/FFKM seals (NO NBR — kerosene swells NBR; NO EPDM — acid). Explosion-proof motor (kerosene vapor). Gas detection.
- Emulsification: Mixing aqueous + organic creates emulsion — pump must handle two-phase flow. Large passage. Low shear impeller (avoid stable emulsion). Settling time. Coalescer. Velocity control.
- Precise flow: SX requires precise organic:aqueous ratio (O:A = 1:1 to 1:3). Use VFD + flow meter. Multiple mixer-settler stages. Feedback control. Our magnetic drive/metering range provides precise flow.
Critical: Yellowcake Precipitation (Radioactive + Hot + Alkaline + Abrasive)
- Radioactive + hazardous: U₃O₈ (yellowcake) is radioactive and chemically toxic. Use sealed slurry pump or peristaltic pump (zero leakage, gentle, no valves to clog). Remote operation. Shielding. Radiation monitoring. Secondary containment. Closed system. PPE. ALARA procedures.
- Hot + alkaline: Precipitation at 50–80°C with NaOH/ammonia (pH 6–8). Use 316L/duplex (alkaline less corrosive than acid) or rubber-lined (abrasion). Jacketed pump (maintain temp). High-temp seals (PTFE/FFKM, carbon/SiC).
- Abrasive + precipitating: U₃O₈ crystals are abrasive. Use rubber-lined/high-chrome slurry. Large passage. Flush with water. Velocity ＞2 m/s. Peristaltic for small flows (gentle, no abrasion to pump internals — only hose wears).
Material Compatibility
| Material | Acid leach slurry (60°C, 10% H₂SO₄ + ore) | SX organic (kerosene + extractant, 40°C) | Yellowcake slurry (70°C, alkaline, U₃O₈) | Concentrated H₂SO₄ (ambient) |
|---|---|---|---|---|
| Rubber-lined (natural/butyl) | Excellent (standard, ＜80°C) | NOT (kerosene attacks rubber) | Good (abrasion + alkaline) | NOT (concentrated acid) |
| High-chrome iron (A532 III) | Good (abrasion + acid) | Fair | Good (abrasion) | Fair (concentrated acid) |
| 316L SS | NOT (abrasion + acid) | Good (clean aqueous) | Good (alkaline) | NOT (concentrated acid) |
| Duplex 2205 | Fair (abrasion) | Good | Good | Fair |
| PTFE/PFA lined | Fair (abrasion) | Excellent (acid + organic) | Fair (abrasion) | Excellent (standard for acid) |
| Hastelloy C-276 | Good (acid, but abrasion) | Excellent | Good | Good |
| NBR (nitrile) seals | NOT (acid) | NOT (kerosene swells NBR) | Good | NOT |
| FKM (Viton) seals | Good (acid) | Good (kerosene) | Good | Good (concentrated acid) |
| PTFE/FFKM seals | Excellent | Excellent | Excellent (high temp) | Excellent |
| EPDM seals | Good (acid) | NOT (kerosene) | Good (alkaline) | NOT (concentrated acid) |
Critical: Acid leach slurry = rubber-lined/high-chrome slurry (NO 316L for abrasion+acid). SX organic = PTFE lined/magnetic drive + FKM/PTFE seals (NO rubber, NO NBR/EPDM for kerosene). Yellowcake = sealed slurry/peristaltic (radioactive, zero leakage). Concentrated acid = PTFE lined/magnetic drive. All radioactive = sealed + remote + shielding + ALARA.
Common Problems and Solutions
Problem 1: Leach pump wears/corrodes (acid + ore). 316L pump fails in 3 months with hot acid + abrasive ore. Solution: use rubber-lined slurry pump (natural rubber, 60+ Shore A). Expeller seal. Plan 32 clean water flush. Large passage. Reduce tip speed. Monitor wear. Our rubber-lined slurry range handles acid leach slurry.
Problem 2: SX pump leaks (kerosene + acid). Mechanical seal fails — flammable kerosene + acid released. Solution: use magnetic drive fluoroplastic pump (zero leakage). FKM/PTFE seals (NO NBR/EPDM for kerosene). Explosion-proof motor. Gas detection. Secondary containment. Our magnetic drive range handles SX safely.
Problem 3: Yellowcake pump leaks (radioactive). Seal failure releases radioactive U₃O₈ slurry. Solution: use peristaltic hose pump (zero leakage, only hose contacts fluid) or sealed slurry pump. Remote operation. Shielding. Radiation monitoring. Secondary containment. ALARA maintenance. Our peristaltic/sealed slurry range handles radioactive product.
Problem 4: Acid dosing pump fails (H₂SO₄). Concentrated H₂SO₄ attacks 304SS/NBR seal. Solution: use magnetic drive fluoroplastic pump (zero leakage, PTFE wetted). FKM/PTFE seals. Secondary containment. Dilution injection (exothermic). Flush with water. Our magnetic drive range handles concentrated H₂SO₄.
Problem 5: Tailings pump settles/clogs (large flow). Tailings slurry settles in pump/piping — clogs. Solution: use heavy-duty slurry pump with large passage open impeller. Flooded suction. Velocity ＞3 m/s. Continuous operation. Flush with water on shutdown. Strainer (remove large debris). Our heavy-duty slurry range handles tailings.
Selection Summary
- Ore slurry: Heavy-duty slurry (high-chrome/rubber-lined, very abrasive, large flow, expeller seal)
- Acid leaching: Rubber-lined slurry (hot acid 40–80°C + abrasive ore, NO 316L, expeller seal, Plan 32 flush)
- Leach slurry transfer: Rubber-lined slurry (acid + abrasion, radioactive, large flow, scaling)
- CCD thickener underflow: Slurry pump (large passage, acid, underflow control, settling)
- SX feed (aqueous): 316L/duplex centrifugal or fluoroplastic (acid, clean, low solids)
- SX organic: Gear pump or screw pump (flammable kerosene, FKM/PTFE seals, NO rubber/NBR/EPDM, explosion-proof)
- SX stripping: Magnetic drive fluoroplastic (zero leakage, acid + organic, precise)
- IX feed: 316L/duplex centrifugal (acid, clean, fouling-resistant)
- IX eluent (HCl/H₂SO₄): PTFE diaphragm metering or magnetic drive (zero leakage, acid, precise)
- Yellowcake precipitation: Slurry pump or 316L/duplex (hot 50–80°C, alkaline, U₃O₈ precipitation, radioactive, sealed)
- Yellowcake product: Peristaltic or sealed slurry (radioactive, zero leakage, abrasive, hot, gentle)
- Acid (H₂SO₄): Magnetic drive fluoroplastic or PTFE metering (zero leakage, concentrated acid, hazardous)
- Oxidant (MnO₂/H₂O₂): Metering or slurry (MnO₂ = abrasive, oxidizing, precise)
- Neutralization (limestone/lime): Slurry or peristaltic (abrasive, scaling, alkaline, large passage)
- Tailings: Heavy-duty slurry (very abrasive, acid, radioactive, large flow, settling, expeller seal)
- Critical: acid leach = rubber-lined slurry (NO 316L for abrasion+acid), SX organic = PTFE/magnetic drive + FKM (NO rubber/NBR/EPDM for kerosene), radioactive = sealed + remote + shielding + ALARA, yellowcake = peristaltic/sealed slurry (zero leakage), acid = PTFE/magnetic drive, all = flush + scaling control + radiation safety
- Our rubber-lined slurry covers leach/tailings; magnetic drive covers SX/acid; peristaltic covers yellowcake; metering covers chemicals. For uranium pump selection, talk to our mining engineers with your ore grade, leach conditions, and process flow.