Anfield Energy Inc. plans to restart the Shootaring Canyon Mill in Ticaboo, Utah, with a refurbished uranium circuit and a new vanadium recovery facility, drawing on the original flowsheet design while replacing key equipment.
Critical Data
| Parameter | Value | Unit | Notes |
|---|---|---|---|
| Facility type | Existing conventional mill | Not applicable | Constructed circa 1980-1981; operated sporadically until 1982 |
| Target commodities | Uranium, vanadium | Not applicable | Vanadium recovery is a new addition to the original plant design |
| Ownership | Anfield Energy Inc. | Not applicable | Property located in Henry Mountain District |
| Development status | Preliminary Economic Assessment | Not applicable | PEA dated May 4, 2026 |
| Initial design capacity | 750 | tons per 24-hour day | Expandable to 1,000 tpd or higher |
| Grinding equipment | SAG mill, 12 ft diameter x 6.5 ft long | Not applicable | Driven by 250 Hp motor; 4-inch cast steel ball charge |
| Leach circuit stages | 2 | Not applicable | First stage: 3 tanks, 2 hours retention; Second stage: 4 tanks, 16 hours retention |
| Design circulating load | 200 | percent | Grinding/classification circuit |
| CCD washing efficiency target | Over 99 | percent | Less than 1 percent soluble loss |
| Final CCD underflow density | 65-70 | percent solids | Pumped to tailings impoundment |
| Yellowcake precipitation pH range | 6.5-8.0 | Not applicable | Direct neutralization with ammonia gas |
| Ammonia consumption design | 0.18 | lb NH3 per lb U3O8 | Not applicable |
| Product drum fill weight | Approximately 800 | pounds | Includes tare weight |
| Vanadium product grade options | Minimum 98.0 to 99.9 | % V2O5 | Black flake specification range |
| Personnel estimate, uranium | 100 | employees | Includes management, hourly, and administrative staff |
| Personnel estimate, vanadium | 73 | employees | Additional staff for concurrent production |
Overview
The Shootaring Canyon Mill sits in the Henry Mountain District near Ticaboo, Utah. Constructed around 1980-1981, the mill operated intermittently until 1982. Anfield Energy Inc. holds the property and has maintained a radioactive materials license through amendments while the facility remained on care and maintenance. Some components, including the Counter Current Decantation thickeners and pumps, were salvaged and sold. The diesel generators are outdated and unusable. However, the main process building and ancillary structures remain in very good condition.
The mill was among the last conventional uranium mills built before the industry downturn. Its design drew on two decades of advances in solvent extraction and operational experience from dozens of earlier mills. The Preliminary Economic Assessment prepared for Anfield Energy and dated May 4, 2026, includes capital and operating cost estimates for restarting the mill. A 2008 internal report by Lyntek, Inc. provided an initial outline for restart evaluation, and Precision Systems Engineering completed an update and preliminary design in 2023.
Key Process Stages
Feed Preparation. Run-of-mine material arrives by truck and is dumped onto a graded, paved storage area. A front-end wheel loader reclaims the ore and feeds it to a grizzly with 14-inch square openings. Oversize material goes to secondary breaking. Undersize enters a surge bin. Coarse material at minus 3 inches is withdrawn by a variable-speed apron feeder and discharged onto a steeply inclined stationary grizzly with 3-inch openings. Undersize falls onto a 42-inch wide by 316-foot mill feed conveyor. Dust from ore handling is captured by a wet scrubber; the scrubber slurry goes to the grinding and classification circuits.
A sizer replaces a conventional crusher ahead of the SAG mill feed hopper. Crusher product passes under a metal detector and over a belt scale before entering a 12-foot diameter by 6.5-foot long semi-autogenous grinding mill. The SAG mill is driven by a 250 Hp motor. About 8 to 10 percent of the mill volume is charged with 4-inch diameter cast steel balls. Slurry at roughly 60 to 70 percent solids overflows through the SAG discharge trunnion into a pump sump and is pumped to hydrocyclone classifiers. Cyclone oversize returns by gravity to the SAG feed spout. The design circulating load is 200 percent. Cyclone overflow flows by gravity to a sump and is pumped to two agitated leach feed holding tanks.
Leaching. The leach circuit uses two stages, a configuration historically chosen for ores with relatively high acid consumption. Current laboratory testing has confirmed this approach. Tetravalent uranium is oxidized to the soluble hexavalent state with sodium chlorate and complexed with sulfuric acid.
The first stage has three agitated tanks, each 14 feet in diameter by 18 feet high, with an effective volume of 16,120 gallons apiece. Total retention time is 2 hours at 29 percent solids. Slurry mixes with overflow from the number 1 CCD thickener, with sulfuric acid and sodium chlorate added to maintain optimum pH and EMF. Flocculent solution is added as needed. Partially leached slurry is pumped to a thickener with a 19.5-foot diameter and 8.75-foot side-wall height. Underflow at about 50 percent solids goes to the second stage.
The second stage consists of four agitated tanks, 20 feet in diameter by 24 feet high, with an effective volume of 46,400 gallons each. Retention time is 16 hours at a design density of 50 percent solids. Additional acid and sodium chlorate are added. Up to 99 percent of the uranium and over 90 percent of the vanadium are expected to dissolve.
Countercurrent Decantation Washing. New CCD thickeners will be installed. A study is underway to evaluate thickener types, including High-Rate, High-Density, and Deep-Cone paste thickeners. The design will be finalized after settling tests on leach residues from fresh core samples. The objective is over 99 percent washing efficiency, equivalent to less than 1 percent soluble loss. Leached residue slurry is pumped to the number 1 CCD thickener mix box and combined with overflow from the number 2 thickener. Recycled solvent extraction raffinate enters the final CCD thickener mix box. Washing solution advances countercurrent to solids flow. Final underflow at roughly 65 to 70 percent solids is pumped to the tailings impoundment pond, where supernatant water is reclaimed for process water supply.
Overflow from the first-stage leach discharge thickener may go to a clarifier. Modern thickeners with improved flocculation may eliminate the need for additional solids removal, requiring only polishing in sand filters. Three sand-type filters operate in parallel with automatic back-washing. Design hydraulic capacity is 5 gpm per square foot, giving each filter about 38 square feet of effective area. Backwashed solids return to the second-stage leach circuit. Filtrate, containing no more than 10 ppm solids, is pumped to two pregnant leach solution storage tanks, each with 23,000 gallons capacity.
Solvent Extraction. Uranium concentration and purification use liquid ion exchange. Aqueous uranyl sulfate ions contact an organic liquid containing a tertiary amine extractant, a modifier, and a diluent. The extractant is Alamine 336. The modifier is a long-chain alcohol like isodecanol. The diluent is a type of kerosene with a high flash point. Amine concentration in the organic phase is expected at 1.0 volume percent per gram per liter of U3O8 in the PLS. Isodecanol concentration is about 5.0 volumetric percent. Mixer retention time is about 2.0 minutes. Settler area is designed for a specific flow of about 1.25 gpm per square foot. Organic flows countercurrent to the aqueous phase through four stages.
The loaded organic stripping circuit uses controlled pH stripping with ammonium sulfate solution. pH is regulated between 4.0 and 4.3 using ammonium hydroxide or anhydrous ammonia. Below pH 4.0, stripping efficiency is inadequate. Above pH 4.3, phase separation slows and stable emulsions form from uranium hydrolysis. Stripping uses four mixer/settler stages in countercurrent fashion.
A single scrub mixer/settler unit treats stripped organic with aqueous sodium carbonate to remove co-extracted metals such as molybdenum. The scrubbed organic is pumped to a surge tank for reuse. Most of the aqueous phase is recycled to maintain a low organic-to-aqueous ratio, with a bleed stream going to tailings or evaporation ponds.
Yellowcake Precipitation and Drying. Pregnant ammonium sulfate strip solution passes through two carbon columns in parallel to remove residual entrained organics. The solution is heated to about 80 degrees Celsius through a steam-fed tube and shell heat exchanger. Three agitated precipitation tanks arranged in series provide about 9 hours total residence time. Each tank has temperature control valves with hot water. Direct neutralization with anhydrous ammonia gas achieves a final pH of 6.5 to 8.0. Design ammonia consumption is 0.18 pounds per pound of U3O8.
The precipitate slurry is pumped to a 12-foot diameter thickener with 4-foot side-wall height. Overflow returns to a small surge tank ahead of precipitation. Underflow goes to two vacuum drum filters in series with a repulping tank between stages. A centrifuge is being considered as an alternative. Filter cake or centrifuge paste is extruded by a Moyno progressive cavity pump into a vacuum rotary dryer or a multiple-hearth calciner. The existing calciner has a maximum operating temperature of 870 degrees Celsius. Drying occurs on the top hearth. Calcining up to about 650 to 700 degrees Celsius yields a very dry yellowcake product. The calciner enclosure operates under negative pressure. A wet scrubber on exhaust gases captures fine dust, and slurry returns to the yellowcake thickener.
Dry yellowcake passes through a pulverizer and goes to a new automatic drum filling and weighing machine with lid attachment. Drums filled to about 800 pounds move by roller conveyor to the product loading dock.
Vanadium Recovery. A new vanadium recovery facility will be built near the existing process building. Construction of the vanadium section begins after uranium section start-up. The depleted uranium raffinate from solvent extraction provides the feed. The vanadium concentration process begins with pH and EMF adjustment tanks, followed by sludge thickening. A flotation column aids oil and aqueous disengagement. A new solvent extraction circuit concentrates vanadium into a vanadium product liquor.
The VPL flows to a conversion tank. Anhydrous ammonia is added, and steam heats the solution to above 180 degrees Fahrenheit, precipitating ammonium metavanadate. The AMV cake is dried in a fuel-fired rotary dryer. Three product options exist. The AMV may be packaged and sold directly. It may be fed to a multiple-hearth calcining furnace, melted in a fusion furnace, tapped into a water-cooled casting wheel, and packaged as black flake containing a minimum of 98.0 percent V2O5. Or it may be dissolved with dilute sulfuric acid in an acidulation tank, neutralized with ammonium hydroxide, cooled through a heat exchanger, and crystallized. The re-crystallized AMV goes to a washing belt filter, then to the deammoniator, fusion furnace, and casting wheel. This product can contain up to 99.9 percent V2O5 and is also called black flake.
Tailings Management. Leached and washed residues are pumped to an impoundment cell located about 200 yards from the plant. The impoundment will be upgraded and re-lined with an appropriate membrane and leak detection system.
Additional Interesting Data and Summary
The original wood-stave leach tanks will be replaced with steel tanks lined with acid- and abrasion-resistant elastomer. Most equipment, including the SAG mill, leach tank agitators, and most pumps, will be fitted with variable-frequency adjustable-speed drives to handle varying flowrates and solids loadings. The Waukesha diesel generators cannot meet current particulate emission standards and will be replaced by new Volvo equipment. All new instrumentation and process control apparatus will be installed, with local manual control stations provided.
The uranium section initial capacity is 750 tons per 24-hour day, expandable to 1,000 tpd or higher depending on mine production. The plant was originally designed without vanadium recovery capability. The vanadium recovery and refining section is entirely new.
Personnel estimates show 100 employees for uranium production and 73 additional for vanadium production. The operation will run 24 hours daily, 7 days weekly. Actual hourly personnel numbers may change depending on shift length decisions, such as 8-hour versus 12-hour shifts. A single weekly dayshift shutdown for planned maintenance is possible.
Key Processes
- SAG milling with hydrocyclone classification at 200 percent circulating load
- Two-stage agitated acid leach with sodium chlorate oxidant
- Multi-stage countercurrent decantation washing targeting over 99 percent efficiency
- Uranium solvent extraction using tertiary amine, isodecanol modifier, and kerosene diluent
- Controlled pH ammonium sulfate stripping at pH 4.0-4.3
- Yellowcake precipitation by direct ammonia neutralization at pH 6.5-8.0
- Vacuum drum filtration or centrifuge dewatering with rotary dryer or calciner option
- Vanadium recovery from uranium raffinate via new solvent extraction circuit
- Ammonium metavanadate precipitation with three product options including black flake
- Tailings impoundment with membrane lining and leak detection system
Source: THE SHOOTARING CANYON MILL AND TRIBUTARY MINES, UTAH AND COLORADO, USA PRELIMINARY ECONOMIC ASSESSMENT NATIONAL INSTRUMENT 43-101, May 4, 2026. Project website: Shootaring Canyon Mill and Tributary Mines
