The K.Hill Manganese Project in Botswana, owned by Giyani Metals Corp., is designed to process 220 kt/a of run-of-mine ore through a flowsheet that combines crushing, grinding, reductive acid leaching, and purification steps to produce High Purity Manganese Sulphate Monohydrate and High Purity Manganese Oxide, along with a saleable ammonium sulphate by-product.
Critical Data
| Parameter | Value | Unit | Notes |
|---|---|---|---|
| Plant capacity (dry) | 220,000 | t/a | Run-of-mine ore, as per design |
| Crusher plant availability | 80 | % | Design value |
| Crusher plant utilisation | 80 | % | Design value |
| Crusher plant throughput | 39.24 | t/h (dry) | Design value |
| Milling and hydromet circuit availability | 94.25 | % | Design value |
| Milling and hydromet circuit utilisation | 93.9 | % | Design value |
| Milling and hydromet circuit throughput | 28.38 | t/h (dry) | Design value |
| Mn grade (design basis, SYSCAD model) | 16.08 | % | Average grade over LOM as per mine plan |
| Mn grade (Years 1–6) | 16.84 | % | |
| Mn grade (Years 6–8) | 11.88 | % | |
| Mn grade (Years 8–25) | 9.90 | % | |
| Total Mn recovery | 87.00 | % | |
| HPMSM, % Mn in product | 32.43 | % | |
| HPMSM, % of recovered Mn to product (design) | 75.97 | % | |
| HPMO, % Mn in product | 71.91 | % | |
| HPMO, % of recovered Mn to product (design) | 11.04 | % | |
| Crusher plant product size | 13 | mm | Design value |
| Milling circuit product size | 150 | µm | Design value |
| Average 24 h load | 25,985 | kW | Energy requirement |
| Maximum demand load | 30,700 | kW | Energy requirement |
| Raw water demand | 50 | m³/h | |
| Neutralising reagent | Not finalised | Not applicable | Ammonium hydroxide tested; sodium hydroxide under evaluation |
Overview
The K.Hill Manganese Project, located in Botswana and owned by Giyani Metals Corp., is planned as an open pit operation feeding a processing plant designed for 220 kt/a of dry run-of-mine ore. The plant targets two main products: High Purity Manganese Sulphate Monohydrate, commonly abbreviated as HPMSM, and High Purity Manganese Oxide, or HPMO. The process also generates ammonium sulphate as a saleable by-product. The mineralised resource consists of manganese and iron shales classified as soft ore, and it responds well to reductive acid leaching.
The flowsheet starts with crushing and milling to reach a target particle size. The milled ore then moves into an acid reductive leach at elevated temperature. The leach circuit discharges a solution containing manganese sulphate with impurities such as iron, aluminium, and base metals. A Fe/Al precipitation circuit removes iron and aluminium, followed by ion exchange to strip base metal impurities. The purified solution goes through a precipitation stage, and the filtered precipitate undergoes redissolution with acid. That manganese sulphate solution feeds the HPMSM crystallizer to produce the primary final product. An impurity purge stream from the crystallizer still carries a high manganese loading, so this manganese gets precipitated and converted to HPMO. The HPMO is filtered, dried, and bagged as a secondary product. The filtrate from the HPMO conversion step is mostly ammonium sulphate, which advances to water recovery for calcium removal, then concentrates by reverse osmosis. Crystallisation of that concentrated solution yields the saleable ammonium sulphate by-product.
One note from the feasibility study deserves attention. The neutralising reagent has not been finalised. The DFS process design, reagent operating cost, and the sulphate by-product revenue all assume ammonium hydroxide, the reagent tested during development. Sodium hydroxide remains under evaluation. The final selection could shift based on reagent operating cost and the type and value of the by-product.
Key Process Stages
The plant is organised into distinct areas, each handling a specific part of the flowsheet. Area 2100 covers primary and secondary crushing. A dump truck tips ROM ore into a stockpile, and a front-end loader transfers material to the ROM bin through a static grizzly screen. A hydraulic rock breaker handles oversized material on the grizzly. A vibrating grizzly feeder extracts material from the ROM bin and feeds the primary jaw crusher. Primary crusher discharge and grizzly undersize travel by conveyor to the secondary vibrating screen. That conveyor carries a weightometer for tonnage control, an XRF online analyser for manganese grade indication, and a belt magnet for tramp iron removal. Oversize from the secondary screen goes to the secondary crusher bin, with a tramp metal belt magnet protecting the secondary cone crusher. A belt feeder delivers crushed ore to the cone crusher, and the circuit runs in closed loop back to the screen. Screen undersize reaches a transfer tower where it either diverts to an emergency surface stockpile or moves to the ball mill feed bin. Mobile equipment reclaims ore from the emergency stockpile when needed. Dust suppression water is applied at both crushers and all transfer points.
Area 2200 is the grinding circuit. Its purpose is to reduce material to a size suitable for leaching and to get the slurry to the required density for extraction. A wet scrubber and a ball mill operate in closed circuit with a cyclone cluster. The ore first goes through the scrubber to remove fines and prevent overgrinding. Scrubber fines are pumped to the mill discharge sump, and oversize moves by conveyor to the ball mill. The scrubber can be bypassed by switching the direction of the reversible ball mill belt feeder. Mill discharge gets pumped to the cyclone cluster, where overflow feeds the mill thickener and underflow returns to the mill inlet. The cyclone underflow recycles to the ball mill for regrinding. Flocculant is added to the thickener feed tank. Thickener overflow feeds the process water tank in the milling area. Return water from the tailings dam solution pond also reports to this tank, with raw water available for top-up if needed. Lime can be added for pH control. Thickener underflow pumps to the reductive acid leaching section.
Area 2300 is the extraction circuit. Manganese in higher oxides such as cryptomelane, hollandite, and bixbyite occurs as Mn(III) or Mn(IV), and these forms must be reduced to Mn²⁺ to become soluble sulphate. The reduction happens in a sulphuric acid medium. Mill thickener underflow goes to the agitated leach feed tank, where process condensate dilutes the feed to correct density. A de-sanding pump serves the feed tank. Slurry advances through four agitated leach tanks in series, with acid added to each tank to dissolve the manganese minerals. Overflow between tanks moves the slurry down the train, and a de-sanding pump on each tank continuously pushes settling solids to the next tank. Each tank can be bypassed so the circuit keeps running if one tank goes offline. The last leach tank discharges into a sump, and pumps send the slurry to iron and aluminium precipitation.
Area 2350 removes iron and aluminium. A recirculating slurry stream of Fe/Al precipitate is recovered from the thickener underflow into a conditioning tank, then pumped to the leached slurry neutralisation tank for pH adjustment and precipitate seeding. This high-density sludge process creates larger particles that filter more easily. The neutralisation tank overflows to four precipitation tanks in series. Limestone and hydrated lime are added to the precipitate tanks. Slurry from the final precipitation tank goes to the Fe/Al thickener feed tank, which also receives coagulant, flocculant, Fe/Al filtrate, and polishing filter backwash from the ion exchange circuit. The thickener underflow pumps to the Fe/Al filter press feed tank. A constant bleed stream of underflow feeds the HDS process. Thickener overflow reports to the overflow tank. Filter presses arranged in parallel handle the slurry, and each press discharges onto its own cake belt feeder. A common transfer conveyor feeds the Fe/Al repulp tank. The filter cake gets repulped with process condensate and pumped to tailings handling. Filtrate collects in the filtrate sump and returns to the thickener overflow tank. Solution from that tank passes through polishing filters to reach very low total suspended solids, then discharges into the filtrate tank before pumping to the PLS storage tank, which provides surge capacity for the ion exchange circuit.
Area 2360 is the base metal ion exchange section. The feed is filtrate from the Fe/Al polishing filters. The system uses a microporous, weak basic resin to adsorb base metal ions from the aqueous phase. The tank farm holds five tanks: resin holding, wash water, eluant, eluate, and conditioning. Fresh resin prepares in the holding tank for transfer to any of the three IX columns. Wash water is prepared with reverse osmosis water as make-up, and it serves as pre-elution wash, post-elution wash, and backwash. Concentrated sulphuric acid mixes with post-elution wash water in the eluant tank to reach the required strength. Adsorbed base metal ions strip from the resin by the eluant, and that solution goes to the eluate tank for elimination from the process via the by-product. In the conditioning tank, neutralising reagent dilutes with RO water and circulates through the eluted column to activate the resin for reuse. Off-gas from the conditioning tank goes to a scrubber. Each of the three columns operates with stay-in-place resin in a lead-lag-elution sequence. The lead column captures the bulk of target metals, the lag column polishes to maximise removal of base metals and iron, and the third column sits offline or in elution or conditioning. Resin arrives in bulk bags and transfers by hoist to the holding tank, with RO water easing the transfer and limiting breakage. When filling an empty column, the column first fills to 30 percent with water to protect the resin.
Area 2400 covers manganese precipitation and HPMO conversion. The purified PLS from the IX circuit gets neutralised to raise pH and precipitate manganese while impurities stay in solution. The filtered cake redissolves, and the manganese sulphate solution crystallises as HPMSM crystals. An unfiltered solution from the HPMSM crystallizer purges, and a second phase of manganese precipitation recovers that manganese, converting it to HPMO precipitate.
Area 2450 is the HPMSM crystallisation plant. It consists of a pre-concentrator stage and two-stage crystallisation. The MnSO₄ solution feeds the pre-concentrator, where boiling brings the solution near its saturation point without precipitating manganese sulphate. A trash filter removes solids or dirt from the discharge stream before crystallisation. The clean saturated solution feeds the crystallisation stage, where water boils off to form manganese sulphate monohydrate crystals. Vapour from the crystallizer compresses into super-heated liquid used to heat other processes. The crystallizer includes a fines destruction step to build larger particle size and minimise fine crystals in the product. Part of the mother liquor purges to a manganese recovery step to prevent impurity build-up. Centrifuges separate the crystals, and washing with RO water or clean saturated liquor removes trapped impurities. The washed crystals advance to drying.
Area 2480 is by-product crystallisation. Brine from manganese recovery pumps to the by-product brine tank, which provides surge capacity. Two parallel falling film evaporators using mechanical vapour recompression pre-concentrate the dilute feed liquor. Multi-stage designs handle the high boiling point elevation, optimising surface area and allowing a single stage of MVR compression. Feed liquor preheats in counter-current exchange with hot process condensate to maximise energy recovery. A small make-up steam flow balances the energy equation. The crystallizer is a draft tube baffle type designed to grow large crystals, with a fines destruction heater. A bottom entry agitator provides high recirculation rates through the draft tube to manage supersaturation and ensure good mixing and boiling patterns. An annular baffle extracts fine crystals, which get destroyed in the fines-destruction heater. Two-stage MVR fans compress vapours to the heater shell for energy input. Process vapour condenses and discharges to the condensate tank, and non-condensable gases vent. Wet by-product crystals move to product handling for drying and bagging.
Area 2500 handles products. Three drying and packaging units serve HPMSM, HPMO, and the by-product. For HPMSM, wet crystals feed from a belt feeder to the wet crystals bin, then a vane feeder moves them to the rotary dryer. Medium-pressure steam and hot air from the air pre-heater evaporate entrained water. Dry product discharges onto a conveyor. Dryer vent flows to a cyclone to recover entrained particles, and cyclone overflow goes to a baghouse for fine particle recovery. Cyclone underflow joins the dry product on the discharge conveyor. Everything transfers to the HPMSM product silo, which provides buffer capacity. The dried crystals bag in 1-tonne bulk bags through a filling plant that includes filling, weighing, sampling, bag sealing, tagging, and palletising. Forklifts collect palletised bags and transfer them to the HPMSM product store for shipping. The HPMO handling plant mirrors the HPMSM plant, with the filter cake fed to a wet precipitate bin, dried in a rotary dryer, and bagged in 1-tonne bulk bags stored separately in the HPMO product store. The by-product plant also follows the same pattern, with wet crystals fed to a bin, dried, and bagged in 1-tonne bulk bags stored in the by-product store.
Area 2800 covers reagents. Bulk bags deliver reagents to site, where hoists lift them and bins store the contents. Dust collectors above the bins handle dust from emptying. Screw feeders deliver reagent to the mixing tank, which receives process condensate for dilution, and the solutions transfer to dosing tanks. Flocculant arrives in bulk bags or 25 kg bags and feeds through a hopper to a hydration tank. Hydrated flocculant transfers to a mixing and dosing tank, with process condensate making up a dilute solution. Flocculant doses to the thickener feed tanks and dilutes tenfold through in-line mixers at point of use. Spillage pumps to tailings handling. Coagulant arrives as a liquid, mixes with process condensate, and doses to the Fe/Al precipitate thickener feed tank with the same tenfold dilution. Bulk sulphur arrives by road and transfers to a stockpile. A front-end loader moves sulphur to a feed conveyor, and hydrated lime blends in before the sulphur melter. The sulphuric acid plant produces strong acid and liquid SO₂ from molten sulphur. The plant recovers energy as high-pressure superheated steam for power generation. A VPSA oxygen plant supplies high purity oxygen for the acid plant. H₂SO₄ from the plant or bulk tanker stores in the acid storage tank and pumps out for distribution.
Area 2700 covers water services. Raw water comes from the Water Utilities Company through an expanded network of wells at the Dilokwane well field, pipelines, and a new dedicated reservoir. Untreated raw water feeds the fire water tank, which overflows to the raw water tank that also receives process condensate. Raw water pumps to dust suppression and to RO Plant 2. That treatment plant has three stages: ultrafiltration, reverse osmosis, and ion exchange. RO permeate stores in the RO water storage tank, which also receives water from the manganese water recovery unit, RO Plant 1. RO water serves as reagent make-up, dust suppression feed in the comminution circuit, gland seal water, and flushing and hosing water. Brine flows to a storage tank and pumps to the evaporation pond or the brine tank feeding the by-product crystallizer and ammonia off-gas scrubber. Potable water comes from the ultrafiltration stage into a storage tank, then pumps into the safety shower ring main and take-off points for drinking water and ablution. The process water tank near the milling circuit receives mill thickener overflow, tailings return dam solution, and storm water pond water. Process condensate supplements during start-up. Hot condensate from crystallizer circuits and excess steam condensate from the boiler system collects in a hot process condensate tank, then pumps through a heat exchanger heating the acid leach feed to recover excess heat. Acidified process water prevents manganese precipitation in the Fe/Al filter wash stages. Dust suppression water uses grey water from ablution facilities, raw water, and storm water, stored in a haul road dust suppression tank and pumped to an elevated bowser fill tank. Tailings from various plant sources feed the tailings repulping tank, with process condensate for make-up and dilution, then pump to the tailings storage facility. Gland seal water fills from process condensate and pumps to all users.
Area 2900 covers utilities. A steam boiler produces medium-pressure steam for acid plant start-up. The acid plant's waste heat boiler generates high-pressure superheated steam in excess of plant heating needs, so it directs to a steam turbine for electricity generation. Medium-pressure steam extracts from a turbine port, passes through a desuperheater, and supplies plant heating requirements. The turbine exhaust condenses in an air-cooled condenser, and condensate returns to the steam condensate tank. Steam condensate from users returns to the same tank, pumps to the acid plant deaerator, and serves as boiler feed water. RO water tops up steam condensate as needed. Cooling water comes from forced ventilation, closed circuit cooling towers, pumped from the return sump to users including HPMSM crystallisation, by-product crystallisation, the sulphuric acid plant, redissolution tanks, and process condensate heat exchangers. RO water makes up evaporation and blowdown losses. Plant and instrument air produces as dry instrument air through dryers and filters, distributed through receivers and utility stations.
Area 4000 is the tailings storage facility. Tailings slurry flows to the TSF, and tailings solution pumps or siphons from the dam to the return dam solution settlement pond. From there it pumps to the process water tank at the comminution circuit.
Additional Interesting Data and Summary
The design accommodates feed grade variability. The plant capacity sits at 220 kt/a, but the feed rate can vary by plus or minus 10 percent of design, providing operating flexibility when feed grade changes. The crushing circuit is scheduled for 365 operational days per year, with availability and utilisation both at 80 percent. The milling and hydromet circuit also runs 365 days, with availability at 94.25 percent and utilisation at 93.9 percent.
Product output depends heavily on feed grade. At the design basis of 16.08 percent Mn, HPMSM production is 82,922 t/a. At 16.84 percent Mn in years one through six, that number rises to 87,600 t/a. At 11.88 percent Mn in years six through eight, production drops to 61,908 t/a. At 9.90 percent Mn in years eight through twenty-five, HPMSM output is 51,588 t/a. HPMO follows a similar pattern: 5,433 t/a at design grade, 5,736 t/a at the highest grade, 4,056 t/a in the middle period, and 3,384 t/a in the later years. The by-product ranges more widely, from 56,640 t/a at design grade up to 100,332 t/a at the highest feed grade, then 70,908 t/a and 59,076 t/a as grade declines.
Reagent selection remains an open item. The DFS uses ammonium hydroxide for the neutralising reagent, and the by-product revenue assumes that reagent. Sodium hydroxide is still under evaluation, and the final choice may change based on operating cost and by-product value.
Major equipment shows a standard hydrometallurgical train. A Metso Nordberg C80 jaw crusher handles primary crushing, and a Metso HP100 cone crusher does secondary duty. The ball mill includes all ancillaries, and a thickener serves the milling circuit. Leach tanks are cylindrical flat bottom agitated vessels. Filter presses are plate and frame type with power packs. Ion exchange columns are SS316L with SS316L header laterals distributors. Redissolution filters are Scheibler type.
The demonstration plant work informed the flowsheet development, covering mineralogy, comminution, solid-liquid separation, leach development, solution purification, HPMO development, crystallisation, and manganese hydroxide process development. The reference process flow diagrams cover every area from primary crushing through tailings storage.
Key Processes
- Primary jaw crushing followed by secondary cone crushing with interstage screening, including an emergency surface stockpile for feed flexibility
- Wet scrubbing and ball mill grinding in closed circuit with a cyclone cluster, with thickener producing feed slurry for leaching
- Reductive acid leaching in four agitated tanks in series using sulphuric acid to dissolve manganese minerals
- Iron and aluminium removal through high-density sludge precipitation with limestone and hydrated lime, followed by thickening and filter pressing
- Base metal removal by ion exchange using a microporous weak basic resin in a three-column lead-lag-elution configuration
- Manganese precipitation, filtration, and redissolution to produce a purified manganese sulphate solution
- HPMSM crystallisation with pre-concentration, fines destruction, and centrifuge separation
- HPMO conversion from the crystallizer purge stream
- By-product ammonium sulphate crystallisation using falling film evaporators with mechanical vapour recompression
- Rotary drying and 1-tonne bulk bag packaging for HPMSM, HPMO, and by-product
- On-site sulphuric acid production from molten sulphur with energy recovery through a steam turbine
- Water treatment including ultrafiltration, reverse osmosis, and ion exchange, with potable water, process water, and dust suppression systems
Source: K.Hill Manganese Project NI 43-101 Technical Report Feasibility Study, July 10, 2026. Project website: K.Hill Manganese Project
Technical report and processing history
The following archived source profiles have been consolidated here to preserve the project’s processing history and study context.
K-Hill Manganese — 2021 Pre-Feasibility Study
K-Hill Manganese — 2021 Pre-Feasibility Study
| Company | K-Hill |
| Mine | K-Hill Manganese |
| Date | 2021 |
| Region | Not Specified |
| Commodities | Manganese |
| Status | Development (PEA) |
Executive Summary
This 2021 Pre-Feasibility Study outlines the conceptual process design for the K-Hill Manganese project. The plant is designed to treat 200,000 tonnes per annum of run-of-mine material from the K-Hill open pit to produce High Purity Manganese Sulphate Monohydrate (HPMSM). The ore consists of manganese and iron shales, which are moderately hard and amenable to reductive acid leaching.
The process flowsheet involves a three-stage crushing circuit followed by grinding in a ball mill to a P80 of 200 microns. The ground slurry undergoes reductive acid leaching using sulphur dioxide gas and sulphuric acid. Subsequent purification steps include precipitation of iron and aluminium using lime and limestone, followed by base metal precipitation using sodium hydrosulphide. The manganese is then recovered via solvent extraction and finalised through vacuum crystallisation.
Processing Overview
- Crushing: Primary Jaw, Secondary Cone, Tertiary Cone
- Milling: Ball Mill (Closed Circuit)
- Leaching: Agitated Tank (Reductive Acid)
- Purification: Precipitation, CCD Washing
- Solvent Extraction: Mixer-Settlers
- Crystallisation: Vacuum Crystallisation
Website: https://giyanimetals.com/projects
Report Date: 2021
Region: Not Specified
Project Status: Development (PEA)
Commodity: Manganese
Throughput:
Mine Life:
Mine Type:
Ore type:
K-Hill Manganese MRE Update — 2021 Technical Report
K-Hill Manganese MRE Update — 2021 Technical Report
| Company | [To be determined from report header] |
| Mine | K-Hill Manganese |
| Date | October 2021 |
| Region | [To be determined] |
| Commodities | Manganese (Mn) |
| Status | Development/PEA |
Executive Summary
This NI 43-101 Technical Report presents the Mineral Resource Estimate (MRE) Update for the K-Hill Manganese Project. The process plant is designed to treat 200,000 tonnes per year of run-of-mine (ROM) material from the K-Hill Manganese open pit to produce High Purity Manganese Sulphate Monohydrate (HPMSM) suitable for the battery market. The mineralised material comprises manganese and iron shales, is moderately hard and amenable to reductive acid leaching at a characteristic grind size (P80) of 200 microns. The process flowsheet is a conceptual design based on historical metallurgical test work and established manganese extraction chemistry. The project demonstrates strong economic potential with a manganese recovery of 90.7% and annual manganese production of 41,151 tonnes at 99.9% purity.
The processing circuit employs a conventional three-stage crushing operation followed by single-stage ball mill grinding. The ground slurry undergoes reductive acid leaching using sulphur dioxide (SO2) as the reductant, followed by solution purification through iron and aluminium hydroxide precipitation and base metal sulphide precipitation. The purified solution is processed through solvent extraction using D2EPHA extractant in kerosene to produce a concentrated manganese sulphate solution, which is then crystallised using vacuum crystallisation to yield the final HPMSM product.
Process Design Criteria Summary
| Parameter | Value | Unit |
|---|---|---|
| Annual Processing Rate | 200,000 | t/a |
| Daily Processing Rate (Crushing) | 599 | t/d |
| Daily Processing Rate (Milling) | 505 | t/d |
| Head Grade – Mn | 25.9 | % |
| Mn Recovery | 90.7 | % |
| Mn Production | 41,151 | t/a |
| Mn Product Purity | 99.9 | % |
| Product | HPMSM | – |
Processing Methods
- Crushing: Three-stage crushing (Primary Jaw → Secondary Cone → Tertiary Cone), P80 = 13 mm
- Grinding: Ball Mill (3m X 3.7m), closed circuit with cyclones, P80 = 200 µm
- Leaching: Reductive Acid Leach (SO2), Agitated Tanks, 2 hours retention time
- Washing: CCD (Counter Current Decantation), 3 stages
- Purification: Fe & Al precipitation (limestone/lime), Base Metal precipitation (NaHS)
- Solvent Extraction: D2EPHA in kerosene, 3 extraction stages, 2 stripping stages
- Crystallisation: Vacuum crystallisation
Reports
Website: https://www.juniorminingnetwork.com/junior-miner-news/press-releases/1007-tsx-venture/emm/76193-giyani-files-updated-and-amended-technical-report-for-k-hill-manganese-project-botswana.html
Report Date: October 2021
Region: [To be determined]
Project Status: Development/PEA
Commodity: Manganese (Mn)
Throughput:
Mine Life:
Mine Type:
Ore type:
K-Hill Manganese Technical Report 2020
K-Hill Manganese Technical Report 2020
| Company | K-Hill |
| Mine | K-Hill Mine |
| Date | February 2020 |
| Region | Nova Scotia, Canada |
| Commodities | Manganese, Electrolytic Manganese Metal |
| Mine Type | Not Specified |
| Throughput | 175 ktpa RoM |
| Mine Life | Not Specified |
| Annual Production | 42 ktpa HPEMM |
| Status | Development |
Executive Summary
This NI 43-101 Technical Report details the proposed hydrometallurgical processing route for the K-Hill Manganese project. The report outlines a comprehensive recovery method starting with comminution to achieve a target grind size of P80 200 µm. The process involves acid leaching using sulphuric acid and sucrose as a reductant at 90°C, followed by solid/liquid separation using vacuum belt filters.
The leach solution undergoes solvent extraction to remove impurities before entering the electrowinning stage. Electrowinning utilizes membrane cells to separate anodic and cathodic zones, producing manganese metal. A second stage of electrorefining is proposed to achieve high purity (>99.9%) Electrolytic Manganese Metal (HPEMM). The design plant production rate is 175 ktpa of Run of Mine (RoM) ore, expected to yield 42 ktpa of final product.
Processing Profile
Website: https://giyanimetals.com/projects
Report Date: February 2020
Region: Nova Scotia, Canada
Project Status: Development
Commodity: Manganese, Electrolytic Manganese Metal
Throughput: 175 ktpa RoM
Mine Life: Not Specified
Mine Type: Not Specified
Ore type:
K.Hill Battery-Grade Manganese Project — NI 43-101 PEA
K.Hill Battery-Grade Manganese Project — NI 43-101 PEA
| Company | K.Hill |
| Commodities | Manganese |
| Mine Type | Open Pit |
| Throughput | 200 kt/a |
| Status | Development |
Executive Summary
The Pre-Feasibility Study outlines the processing plant design for the K.Hill Battery-Grade Manganese Project. The plant is designed to treat 200,000 tonnes per annum of Run-of-Mine (ROM) material sourced from an open pit. The ore, comprising manganese and iron shales, undergoes a complex hydrometallurgical process to produce High Purity Manganese Sulphate Manganese (HPMSM). The process involves crushing, grinding, acid reductive leaching using sulphur dioxide, sequential purification, fluoride polishing, and evaporative crystallisation.
The mineralised material is moderately hard and amenable to reductive acid leaching in sulphate media. The process achieves an overall plant recovery of manganese at 88.5%. Key operational parameters include a grind size (P80) of 150 µm and leaching at an elevated temperature of 90°C. The purification stages remove impurities such as iron, aluminium, and base metals through precipitation and polishing steps.
The final product is produced via evaporative crystallisation, followed by filtration and drying. The plant infrastructure includes reagent preparation, water treatment, and fully automated control systems. Waste streams are managed through tailings storage facilities and dust suppression reuse, ensuring environmental compliance and resource efficiency.
Reports
Website: https://giyanimetals.com/projects
Report Date:
Region:
Project Status: Development
Commodity: Manganese
Throughput: 200 kt/a
Mine Life:
Mine Type: Open Pit
Ore type:
K.Hill Battery-Grade Manganese Project — NI 43-101 Feasibility Study
K.Hill Battery-Grade Manganese Project — NI 43-101 Feasibility Study
| Company | Not Specified |
| Date | Not Specified |
| Region | Not Specified |
| Commodities | Manganese |
Executive Summary
The K.Hill Battery-Grade Manganese Project is a feasibility study outlining the processing of manganese ore from an open pit mine. The plant is designed to treat 200,000 tonnes per annum of ROM ore with an average head grade of 18.9% manganese oxide. The objective is to produce High Purity Manganese Sulphate Monohydrate (HPMSM) with a grade greater than 31.5% manganese.
The processing circuit involves a three-stage crushing circuit followed by ball mill grinding to a P80 of 150 µm. The ore undergoes acid reductive leaching in sulphate media at 90°C using sulphur dioxide as a reductant to extract manganese as a soluble sulphate. This is followed by a sequential purification process to remove impurities such as iron, aluminium, and base metals.
Final purification includes fluoride polishing and evaporative crystallisation to produce the HPMSM product. The plant operates on a 365-day basis with 16 hours of operation for the crusher and 24 hours for the mill. Water management includes reuse of liquors and dust suppression on haul roads.
Website: https://giyanimetals.com/projects
Report Date: Not Specified
Region: Not Specified
Project Status:
Commodity: Manganese
Throughput:
Mine Life:
Mine Type:
Ore type:
K-Hill MRE Update — 2021 Technical Report
This report presents an updated Mineral Resource estimate and preliminary metallurgical testwork results for the K-Hill manganese project, supported by drilling data collected from April 2018 to July 2021.
Report context
SRK Consulting completed an update of the Mineral Resource Estimate for the Kgwakgwe Hill Manganese Project, based on drilling data collected by Giyani from 16th April 2018 to 19th July 2021 inclusive. The Mineral Resource is classified according to the CIM Best Practice Guidelines and reported in accordance with the 2014 CIM Definition Standards. The estimate incorporates an updated block model constrained by an updated optimised pit shell, with domain modelling undertaken in Leapfrog Geo and estimation in Leapfrog Edge. The Qualified Person responsible for the Mineral Resource Statement is Dr Lucy Roberts, MAusIMM(CP), a Principal Consultant (Resource Geology) with SRK.
Processing route
Proposed flowsheet and product
The metallurgical studies, based on testwork completed by Lab 4 Inc. and Dalhousie University, indicate that the mineralised material is amenable to reductive acid leaching and can be processed using a flowsheet that consists of an acid leach followed by solution purification, solvent extraction and vacuum crystallisation for the production of a high purity manganese sulphate monohydrate product (HPMSM) suitable for sale into the battery market. The ongoing metallurgical testwork and updated plant design will focus on a slight modification to the planned flowsheet in order to produce HPMSM, building on earlier work that targeted High Purity Electrolytic Manganese Metal (HPEMM).
Mineralogical testwork
Dalhousie University undertook mineralogical analysis on a selection of manganese oxide bearing rocks taken as grab samples from K-Hill mineralisation. Four samples were tested to determine the mineralogical composition. Identified mineral species included cryptomelane, hausmannite, hollandite, psilomelane, pyrolusite, jacobsite, and coronadite. The manganese minerals occurred in three forms: as staining on silicates, iron oxides and as themselves; as small veins where manganese oxides have been deposited on each other particularly within well fissured zones; and as nodules where the Mn has built up into botryoidal masses that may contain other minerals within them.
Head assays reported for the mineralogical samples showed MnO grades ranging from 4.3% to 60.8%. Samples tested included dump material (48.7% MnO), altered shale (48.8% MnO), silicified shale (4.3% MnO), and shale with kaolin (60.8% MnO).
Leach testwork
Dalhousie University conducted run of mine acid leach tests with sucrose added as a reductant on three samples from a single drill hole, plus baseline leach tests without reductant addition. Test conditions included a grind size P80 of 200 µm, sample mass of 25 g, acid concentration of 260 g/l H2SO4, temperature of 90°C, and retention time of 3 hours.
Results showed that the reductant significantly improved Mn extraction and leach kinetics. For sample MT10, Mn extraction with reductant ranged from 87.7% to 91.7% compared to 2.9% to 3.2% without. For sample MT11, extraction with reductant ranged from 83.1% to 93.9% versus 0.4% to 2.3% without. For sample MT12, extraction with reductant ranged from 94.6% to 100.5% versus 1.8% to 2.3% without. The testwork programme did not evaluate other possible reductants such as SO2, which is used in acidic sulphite reduction processes at several operating plants.
Solution assays from the leach tests indicated co-extraction of metals including Fe (6,589 mg/l), Al (938 mg/l), Cu, Zn, Ni and Co as sulphates. The report notes that the solution can be purified by removing Fe and Al sulphates as hydroxides via precipitation with lime, with further purification by removal of base metals as sulphides via precipitation with sodium hydrosulphide.
Solvent extraction testwork
Solvent extraction tests were conducted by Dalhousie University on pregnant leach solution using the organic extractant D2EPHA. Results indicated that approximately 96% of Mn could be extracted by D2EPHA into the organic phase. The report notes that these tests were not optimised but conducted as a standard scoping test, and that 98.5% Mn extraction is assumed for this study, to be verified during future test work. The loaded organic solvent can be stripped with concentrated H2SO4 to produce a concentrated manganese sulphate solution, with the sulphate recovered by vacuum crystallisation to produce HPMSM product.
Comminution testwork
The report states that comminution test work was not completed. This means important design parameters such as Bond Ball Mill work index must be assumed for process development and estimation work.
Key reported parameters
| Parameter | Value | Units | Basis |
|---|---|---|---|
| Overall Mn metallurgical recovery | 90.7 | % | Calculation from testwork and assumptions |
| Leach extraction (with sucrose reductant) | 93.3 | % | Testwork |
| Mn recovery – Fe & Al precipitation | 99.9 | % | Assumption |
| Mn recovery – base metal precipitation | 99.8 | % | Assumption |
| Mn recovery – solvent extraction | 98.5 | % | Assumption |
| Crystallisation efficiency | 99.0 | % | Assumption |
| Leach test – grind size P80 | 200 | µm | Testwork condition |
| Leach test – acid concentration | 260 | g/l H2SO4 | Testwork condition |
| Leach test – temperature | 90 | °C | Testwork condition |
| Leach test – retention time | 3 | hr | Testwork condition |
| Indicated Mineral Resource | 1.6 | million tonnes | Within optimised pit shell, >7.3% MnO |
| Indicated MnO grade | 22.0 | % | Block model estimate |
| Inferred Mineral Resource | 1.4 | million tonnes | Within optimised pit shell, >7.3% MnO |
| Inferred MnO grade | 13.9 | % | Block model estimate |
| Pit optimisation – HPMSM price | 1,588 | USD/t CFR Japan/Korea | 2020 market data |
| Pit optimisation – marginal cut-off | 7.3 | % MnO | Calculated from parameters |
| Pit optimisation – total process recovery | 90.7 | % MnO | Applied for pit optimisation |
| Pit optimisation – mining recovery | 98 | % | Applied for pit optimisation |
| Pit optimisation – dilution | 3 | % | Applied for pit optimisation |
| Pit optimisation – overall slope angle | 41 | degrees | Applied for pit optimisation |
| Pit optimisation – mining cost | 3.46 | USD/t rock | Applied for pit optimisation |
| Pit optimisation – processing cost | 213.0 | USD/t RoM | Applied for pit optimisation |
| Pit optimisation – G&A | 20.0 | USD/t RoM | Applied for pit optimisation |
| Core recovery – Upper Mn Shale (DD program) | 41 | % | Measured average |
| Density – A2 domain (SET 2, wax coated) | 2.14 | g/cm³ | Average of 14 samples |
| Density – B domain (SET 2, wax coated) | 2.32 | g/cm³ | Average of 4 samples |
| Block model cell dimensions | 25 x 25 x 1 | m | Parent cells |
| Minimum composites per block estimate | 4 | , | Estimation parameter |
| Maximum composites per block estimate | 12 | , | Estimation parameter |
Project website: https://ca.finance.yahoo.com/news/giyani-metals-advances-k-hill-123900034.html
Technical qualifications
The report identifies several specific limitations and data quality considerations:
- Core recovery from the diamond drilling program within the Upper Mn Shale unit averages 41%, and confidence in the accuracy of individual assay grades is reduced as a result. No clear relationship has been identified between core recovery and grade.
- Density data is limited. The most reliable dataset (SET 2, wax coated dry samples) contains only 49 samples, and no corresponding MnO assays exist to establish a correlation between MnO grade and density. SRK considers the limited quantity of appropriate dry density data a potential risk to the reported Mineral Resource.
- Comminution test work was not completed, meaning important design parameters such as Bond Ball Mill work index must be assumed for process development.
- The metallurgical testwork programme did not evaluate other possible reductants such as SO2.
- Direct metallurgical testwork has not been undertaken on material from the B and C horizons. Initial geological observations suggest the material is lithologically similar to the A horizons, but processing characteristics remain unknown until detailed testwork is completed.
- The solvent extraction tests were not optimised but conducted as a standard scoping test.
- A portion of the mineralised domains at the margins have not been classified where poor geological and drilling support exists.
- Artisanal mining depletion has been applied based on GPR and laser rangefinder surveys, but it is possible that unidentified workings with obscured accesses exist and have not yet been captured.
*Source: SRK Consulting K-Hill MRE Update – Main Report, October 2021, Sections 13 and 14.*
K.Hill MRE Update 2022 — Recovery Methods
This section details the proposed processing flowsheet, historical operating data, and metallurgical testwork results for the K.Hill manganese project.
Report context
This report, dated March 2022, was prepared for Giyani Metals Corporation by SRK Consulting (KZ) Limited under project number KZ0647. Section 17 of the report presents the recovery methods proposed for the K.Hill project, drawing on historical plant data, process design criteria, and metallurgical testwork conducted by Mintek and Lab 4.
Processing route
Process Flowsheet Development
The proposed process flowsheet was developed based on metallurgical testwork and historical operating data. The flowsheet comprises crushing, grinding, acid leach, solution purification, solvent extraction, crystallisation, and product handling stages.
Crushing
Run-of-mine ore is fed to a primary crushing circuit. The design basis for the crushing stage is derived from the process design criteria established during the preliminary economic assessment (PEA) mining study.
Grinding
The crushed ore is milled in a grinding circuit to achieve the required particle size distribution for downstream leaching. The grinding circuit design parameters are consistent with the overall process design criteria.
Acid Leach
The ground ore reports to an acid leach circuit where manganese is dissolved using sulphuric acid. This stage represents the primary extraction step in the flowsheet. Metallurgical testwork by Mintek on K.Hill Main and B-Horizon samples investigated manganese variability leach extractions.
Solution Purification
Following leaching, the pregnant leach solution undergoes purification to remove impurities. This step prepares the solution for subsequent solvent extraction.
Solvent Extraction
The purified solution is processed through a solvent extraction circuit to concentrate and further purify the manganese-bearing solution prior to crystallisation.
Crystallisation
Manganese is recovered from the purified solution via crystallisation, producing a final manganese product.
Product Handling
The crystalline product is dewatered, dried, and packaged for shipment. The product handling section includes equipment for storage and loading.
Key reported parameters
| Parameter | Design Basis | Historical Operating Data | Testwork Basis |
|---|---|---|---|
| Crushing circuit configuration | From PEA process design criteria | Not reported | Not reported |
| Grinding circuit design | From PEA process design criteria | Not reported | Not reported |
| Acid leach conditions | Not reported | Not reported | Mintek variability leach extractions on K.Hill Main and B-Horizon samples |
| Solution purification steps | From PEA process design criteria | Not reported | Not reported |
| Solvent extraction stages | From PEA process design criteria | Not reported | Not reported |
| Crystallisation method | From PEA process design criteria | Not reported | Not reported |
| Metallurgical recovery | Not reported | Not reported | Lab 4 metallurgical testwork and Mintek testwork |
Technical qualifications
The report contains specific limitations regarding the recovery methods information presented. No detailed flowsheet diagrams, equipment specifications, or operating conditions beyond those listed in the process design criteria are provided. The metallurgical testwork results from Lab 4 and Mintek are referenced but not presented with full extraction data in this section. No economic parameters, capital or operating cost estimates, or project ownership details are included. The report does not specify whether the process design criteria represent final engineering or preliminary study level design.
Source: SRK Consulting (KZ) Limited, K.Hill MRE Update, March 2022, Section 17 Recovery Methods, Sections 13.4 Lab 4 Metallurgical Testwork and 13.5 Mintek Metallurgical Testwork.
