This section describes the proposed processing methods for potash and magnesium products recovery at the Wynyard Carnallite Project, based on a prefeasibility study completed in 2012.
Report context
The recovery methods presented in this article are drawn from Section 17 of the amended and restated Technical Report titled "KCl and MgCl2 Reserve and Resource Estimate for the Wynyard Carnallite Project, Subsurface Mineral Permit KP 360A and Subsurface Mineral Lease KLSA 010, Saskatchewan, Canada," dated 27 June 2012. The report was prepared on behalf of Karnalyte Resources Inc. for the Magnesium Products Prefeasibility Study. The recovery methods section outlines the proposed processing route for potash production and describes the magnesium products recovery method, supported by testwork data from dissolution, evaporation, crystallization, and milling test programs.
Processing route
Potash Processing Plant Design
The Potash Processing Plant design is based on a production capacity of approximately 630,000 tonnes per year of KCl. The processing plant is designed to treat brine produced from solution mining of the Patience Lake, Belle Plaine, and Esterhazy members. The plant incorporates a conventional crystallization circuit for KCl recovery. The processing route was developed from testwork including dissolution testwork, evaporation and crystallization test work, and milling and grinding tests.
Insolubles Removal
The processing flowsheet includes an insolubles removal stage as the first step in brine treatment. The brine from solution mining is expected to contain insoluble materials that must be removed prior to evaporation and crystallization. The design basis for insolubles removal is drawn from industry standard practice for potash processing operations in Saskatchewan.
Evaporation and Crystallization
The evaporation and crystallization circuit is designed to concentrate the brine and selectively crystallize KCl. The process is based on the solubility characteristics of the carnalitic brine system. Evaporation is performed using mechanical vapour recompression evaporators. Crystallization is controlled to produce KCl product crystals of specified size and purity. The design of this section incorporates results from dedicated evaporation and crystallization test work that was completed as part of the metallurgical testing program.
Sodium Chloride and Potassium Chloride Debrining
After crystallization, the KCl crystals are separated from the mother liquor and subjected to debrining to remove residual brine. Sodium chloride debrining is also incorporated in the flowsheet to manage salt content in the process stream. The debrining step uses centrifuges and washing stages to achieve product purity specifications.
Drying and Formulation
The debrined KCl crystals are dried in rotary dryers to produce a finished product with a moisture content suitable for storage and handling. The formulation stage includes screening and compaction equipment to produce granular product as required by the market. The design incorporates standard potash drying and formulation technology.
Product Storage and Load-out
The finished KCl product is conveyed to product storage facilities with capacity for seasonal production and shipping schedules. Load-out facilities are designed for rail and truck transport.
Magnesium Products Recovery Method
The Magnesium Products recovery method is described as a separate processing route. Two process options are identified in the report. The first option is a Magnesium Chloride Brine Process that produces a concentrated magnesium chloride brine product. The second option is a Hydromagnesite Process that produces hydromagnesite (magnesium carbonate) as the final product.
Magnesium Chloride Brine Process
The Magnesium Chloride Brine Process is designed to process the magnesium-rich brine that remains as a by-product stream from the potash recovery circuit. The process involves further evaporation and purification steps to produce a concentrated magnesium chloride brine product. The mass balance for this process was developed by the qualified person responsible for the Magnesium Products Prefeasibility Study beginning in August 2011.
Hydromagnesite Process
The Hydromagnesite Process uses the magnesium chloride brine as feed and precipitates hydromagnesite through a carbonation reaction. The process is described as producing a solid magnesium carbonate product. The report notes that testwork results were used to support the development of the mass balance for this process option.
Key reported parameters
| Parameter | Unit | Design Basis | Notes |
|---|---|---|---|
| Potash production capacity | tonnes per year KCl | 630,000 | Proposed design |
| Potash resource | KCl equivalent | Various | From resource estimate sections |
| Evaporation technology | , | Mechanical vapour recompression | Proposed design |
| Drying technology | , | Rotary dryers | Proposed design |
| Magnesium product process 1 | , | Magnesium chloride brine | Proposed design |
| Magnesium product process 2 | , | Hydromagnesite | Proposed design |
| Testwork: dissolution | , | Completed | Metallurgical testing |
| Testwork: evaporation and crystallization | , | Completed | Metallurgical testing |
| Testwork: milling and grinding | , | Completed | Metallurgical testing |
| Mass balance development | , | August 2011 to May 2012 | Prefeasibility study period |
Project website: https://www.mindat.org/locentries.php?p=289456&m=234
Project website: http://karnalyte.com/news/press-releases/karnalyte-resources-inc-announces-2024-year-end-results-and-provides-corporate-update/
Technical qualifications
The recovery methods section of the report is based on a prefeasibility study level of design. The processing plant design has not been finalized with detailed engineering; the report notes that the flow sheet and mass balance were reviewed and updated several times between August 2011 and the report date. The design assumptions rely on testwork results from dissolution, evaporation, crystallization, and milling test programs. The report does not include detailed equipment specifications, operating performance data, or operational history for the proposed plant, as the project has not proceeded to construction or operation. The recovery methods are presented as conceptual designs that would require additional testwork and engineering for final process definition. No pilot plant or commercial operating data from the Wynyard Carnallite Project were available at the time of the report.
Source: Section 17 of the Technical Report "KCl and MgCl2 Reserve and Resource Estimate for the Wynyard Carnallite Project, Subsurface Mineral Permit KP 360A and Subsurface Mineral Lease KLSA 010, Saskatchewan, Canada," dated 27 June 2012. Recovery Methods sections 17.1–17.3.
Consolidated report summaries
The following former standalone pages about this operation were consolidated here on October 25, 2026. They are retained for source traceability; dates and figures reflect each report’s own effective date and may be superseded by the current information above.
Optimizing Potash Recovery: Evaporation & Crystallization at Wynyard
Optimizing Potash Recovery: Evaporation & Crystallization at Wynyard
Source: Karnalyte Resources Inc (2026)
Website: https://karnalyte.com/our-project/wynyard-carnallite-project/
Critical Data
| Parameter | Value | Unit | Notes |
|---|---|---|---|
| Throughput | 2,025 | tpd | Phase 1 KCl product (675,000 t/a ÷ 333 operating days) |
| Mill Power | N/A | kW | No grinding equipment in solution mining process |
| Target Grind Size | N/A | μm | No grinding; product is granular after compaction |
| Head Grade | 9.29 | % | KCl concentration in feed brine (114.5 g/L) |
| Recovery % | 69.20 | % | MgCl₂ brine conversion in hydromagnesite precipitation (potash recovery not stated) |
| Processing Capacity | 2,027 | tpd | Phase 1 KCl product (675,000 t/a at 333 days) |
| Energy Consumption | 320 | kWh/t | Electrical power per tonne finished product (0.32 MWh/t); natural gas 15.5–16.5 GJ/t |
| Water Consumption | 18 | m³/t | Total water per tonne finished potash product |
| Operating Hours | 24 | hours/day | Continuous operation, 8,000 hours per year for potash plant |
Overview
Karnalyte Resources Inc. is advancing the Wynyard Project in Wynyard, Saskatchewan, a fully integrated potash and magnesium recovery operation based on a comprehensive 2025 NI 43-101 feasibility study. The facility is designed to produce 675,000 tonnes per annum (Phase 1) of high-grade potassium chloride (KCl) at 97% purity using solution mining brine as feed. The recovery methods leverage a proven multiple-effect evaporation (MEE) and draft tube baffle (DTB) crystallization circuit to selectively precipitate KCl and NaCl from the brine, achieving efficient separation and high product quality. The brine, sourced from underground caverns at approximately 50°C with a density of 1.265 g/cm³, contains 9.29% KCl and 9.86% MgCl₂. After removing insolubles and blanketing oil, the clean brine is evaporated in two trains of three-stage evaporators, followed by flash cooling to precipitate carnallite. KCl is further purified in a three-stage DTB crystallization train, dried in a rotary drum dryer, compacted into granular form, and stored for rail loadout. An integrated magnesium products plant processes the MgCl₂-rich end brine to produce 104,000 t/a of hydromagnesite at 99% purity via a carbonation and ammonia regeneration process. The combined potash and magnesium recovery methods maximize resource utilization, reduce waste, and deliver significant economic and environmental benefits. With annual operating hours of 8,000 for potash and 7,500 for magnesium, the Wynyard Project represents a modern, efficient solution for sustainable mineral production in Canada.
Key Process Stages
- Stage 1: Insolubles and Blanketing Fluid Removal – Feed brine is treated with flocculants in an inclined plate thickener to separate fine particulates and residual blanketing oil. Oil is recycled to the well field, and clean brine is stored in the evaporation feed tank.
- Stage 2: Evaporation and Carnallite Precipitation – Two trains of three-effect forced-circulation evaporators heat brine to precipitate NaCl and KCl crystals. Crystals settle in elutriation legs and are dewatered via 1,400 mm x 2,100 mm screen bowl centrifuges. Mother liquor is flash cooled in two stages to precipitate carnallite, which is converted in a DTB crystallizer to KCl and NaCl.
- Stage 3: Crystallization and KCl Purification – The KCl-rich overflow from the low-magnesium thickener is fed to a single train of three DTB crystallizers. The liquor cools from 99.0°C to 44.1°C under vacuum, producing KCl crystals. Water addition dissolves residual NaCl, and the KCl slurry is centrifuged to produce a 95% solid cake.
- Stage 4: Drying and Particulate Control – The KCl cake (95% solids) is dried in a 3.3 m diameter by 18 m long rotary drum dryer to 0.1% moisture. Natural gas burners provide heat. Vent gases pass through a cyclone and a three-section electrostatic precipitator to meet Saskatchewan emissions limits of 0.57 g/dry reference m³.
- Stage 5: Compaction and Product Handling – Dried fines are compacted into 14 mm sheets using two parallel compaction loops (120 t/h each). Sheets are broken, screened, and oversize crushed. On-size material is coated with a compaction additive, redried in a fluid bed dryer, and stored in a granular storage building before rail loadout.
Additional Interesting Data and Summary
The Wynyard Project’s recovery methods are supported by detailed equipment specifications and utility consumption data. The Phase 1 potash plant uses 0.32 MWh of electrical energy per tonne of finished product, supplied by Saskpower, and 15.5–16.5 GJ of natural gas per tonne for steam generation, dryer fuel, and building heating. Water consumption is approximately 18 m³ per finished tonne, used primarily for cavern development, process makeup, and NaCl dissolution. Reagents include flocculent for insoluble removal, lime for dryer exhaust neutralization, and compaction additives to improve granular hardness. The magnesium products plant, designed to treat 1,604 t/d of MgCl₂-rich brine (35% MgCl₂) from the potash process, produces 307 t/d of hydromagnesite at 99% purity via a six-step carbonation process. The process recycles ammonia with 98% efficiency using slaked lime from limestone calcination, minimizing makeup requirements (1.6 t/d). Environmental considerations include compliance with Saskatchewan air emission regulations (0.57 g/dry reference m³ for particulates) and deep-well disposal of waste brines into the Deadwood Formation. The combined potash and magnesium operations improve overall resource efficiency, converting a waste stream into a valuable product. Economic impact is significant: the Phase 1 capital cost for potash is estimated at CAD 1.4 billion, with magnesium facility costs additional. Future expansion to Phase 2 (1,425,000 t/a KCl) and Phase 3 (2,175,000 t/a) is planned, leveraging the same recovery methods. Opportunities exist to optimize ammonia capture further and reduce operational costs. Risks include variability in brine chemistry and potential scaling in evaporators, mitigated by robust design margins and continuous testing. The Wynyard Project positions Karnalyte Resources as a leading low-cost potash producer with a unique magnesium co-product, supporting sustainable mineral development in Saskatchewan.
Key Processes: Ball Mill, Crushing
Target Commodities: N/A
